I was wondering if anyone might have some advice for a problem I have recently been noticing. I have a 2002 2500HD 8.1L Crew CAb 2WD , and I have been getting a vibration/ shake at speeds around 45-55mph. To me it seems to be coming from the back half of the truck. Steering wheel does not seem to shake and truck tracks straight. Had new tires put on about 250 miles ago. The rear tires are feathering in the middle of the tread. I was running 80psi in them now dropped down to 72psi to see if it helps. The feathering has lessened but vibration/shake is still there. Had tire balance rechecked on rears one tire was out .75oz total. Not really enuff to cause shake I wouldnt think. Also at speeds greater than 60mph shake goes away, but I still seem to feel a slight, constant road noise almost like a dull vibration. Any help would be greatly appreciated thanks, Marc

When the vibration occurs, see if it happens when accelerating throught the speed, decelerating throught the speed and put it in neutral while at the speed of vibration. If it goes away in neutral it is most likely a drivetrain issue (ujoints,driveshafts, axles). If it is still there in neutral it's a tire, wheel issue. If it only happens on accel or decel it could indicate a differential problem also. First thing to check is the drive shaft and ujoints.

Join the vibration party ... below is an email i just sent to a few relatives explaining my problem ...your problem sounds almost exactly what I am experiencing. I am currently running Weld Outback 16x8's and Toyo Open Country A/T's ... 295-75R16's. Never vibrated with BF KO's 315-70R17's and Weld Evo Renegades. You would think it would be tire/wheel related but read on ...
<DIV class=Section1>
Took truck back to Les Schwab today. They drove it and said it vibrates from 40-63 mph as I told them it did. I told them I was done with the Toyo’s and wanted the BF Goodrich tires again. They said ok …and left the truck. Mike, the senior guy there who has worked on it all along worked on it the entire day. After multiple test drives, tire/rim combos it still has the vibration. He tried stock wheels, smaller tires, larger tires, etc. with no luck. At first he thought the factory wheels (hub centric) solved the problem but later testing showed the vibration with the OEM wheels. So the truck is still down there, parked inside for the night. He’s getting the BF Goodrich tires in the morning, will mount them and go from there however he’s confident the new tires won’t solve the problem and he is thinking it’s something else …just not sure what. Truck just turned 15K miles. We discussed trying a hub-centric adapter but didn’t think it would help as the vibration is always in the rear. They also inspected everything related to the lift kit …didn’t find anything wrong. They also inspected u-joints and appear fine.

Symptoms:

<UL style="MARGIN-TOP: 0in" ="disc">
<LI class=MsoNormal style="mso-list: l0 level1 lfo1">Always drove perfect with Weld Evo wheels (17”) and 315-75R17 tires
<LI class=MsoNormal style="mso-list: l0 level1 lfo1">First noticed when Toyo tires were rotated …. However I may not have really paid attention until the rotation …but think I would have noticed it.
<LI class=MsoNormal style="mso-list: l0 level1 lfo1">Vibration is ALWAYS in the rear. Mike says right rear. Rotating tires/wheels does nothing.
<LI class=MsoNormal style="mso-list: l0 level1 lfo1">Vibration noticeable under power, coasting and in neutral coasting … most noticeable from 40-50 …less noticeable above 50 but still feel it. I notice it the most going downhill off the throttle at 40-45 mph and also under steady throttle (not accelerating or coasting) </LI>[/list]

Other possible causes:
<UL style="MARGIN-TOP: 0in" ="disc">
<LI class=MsoNormal style="mso-list: l1 level1 lfo2">Driveline out of balance? Seems it would cause a resonating vibration. Doesn’t make sense I noticed it first when tires were rotated

My guess would be rear drveshaft angles causing it.

Would the rear drive shaft angles on stock trucks be the same? If so, wouldn't all trucks vibrate? I know what your saying and have others say the same thing ...just doesn't make sense why, after 10K miles the truck decides to vibrate ...drive shaft angle change after 10K?

You said you had a lift, so it would not be the same as a stock truck! Do you have shims or angled blocks in the rear?

Check the brake rotors for discoloration. The calipers on these GM trucks are very rough. They aren't machined smoothly where they are supposed to slide, and they can bind up causing them to drag and overheat. This can warp a rotor. Is there any pulsation through the brake pedal? Check the rotors and pads for uneven wear. Also, is the rubber donut damper thingy on the driveshaft still in good shape?

You said you had a lift, so it would not be the same as a stock truck! Do you have shims or angled blocks in the rear?


I should have been more clear ... yes my truck has a lift, however there are several other people with "stock" trucks with the exact same symptoms. To my knowledge the lift is suppose to retain near-stock geometric angles of the drivetrain components. One of the guys working on the truck has a new 04 LLY with 12K miles, all stock, experiencing the same problem.


Precision37, I'll have to look ...not exactly sure what you are referrring to as the "big rubber donut" thing on the drive shaft. I don't have the truck here so I can't look but from memory I don't recall anything on the drive shaft that would resemble this ...I have the single drive shaft ... no, I don't have any pulsation in brake pedal ...or any vibration in steering wheel. It's definately coming from the rear.


Edited by: tophog

The rubber thing I'm refering to is on the driveshaft, right where it goes into the rear end.

I took my truck back in last night and dropped it off since the dealer had called the other day and told me they had gotten the left rear hub assembly in that they said was the cause of the vibration. Was supposed to be done today but i called dealer in afternoon and he told me that the tech was having a heck of a time getting the rear hub assembly off, and that after working on it for 5 hours he had just finally gotten it off so it would not be done today. I'm not very confident that this will solve my vibration problem either. The 3rd time in they said that a leaking rear axle seal was the cause of my vibration and that it had gotten on the left rear pads and when it heated up was causing the rotor to grab to the pads. They replaced it and turned the rotor and put new pads on but it didnt make any difference. The next time they put a different set of wheels and tires on the truck off a new truck and drove it and still no difference. Then that was when they said it was the hub assembly that was bent causing the vibration. I think they are grasping for anything. My truck has the 2 piece driveshaft, and someone had told me to have them check the carrier bearing. Also someone told me GM has a shim kit that they can install under the tranny mounts to take care of the vibration also. Has anyone heard of this. My suspension is all stock with standard size tires. I just dont get why out of the blue it started at like 30k miles. Very frustrating at the least. Take care, Marc

I took my truck back in last night and dropped it off since the dealer had called the other day and told me they had gotten the left rear hub assembly in that they said was the cause of the vibration. Was supposed to be done today but i called dealer in afternoon and he told me that the tech was having a heck of a time getting the rear hub assembly off, and that after working on it for 5 hours he had just finally gotten it off so it would not be done today. I'm not very confident that this will solve my vibration problem either. The 3rd time in they said that a leaking rear axle seal was the cause of my vibration and that it had gotten on the left rear pads and when it heated up was causing the rotor to grab to the pads. They replaced it and turned the rotor and put new pads on but it didnt make any difference. The next time they put a different set of wheels and tires on the truck off a new truck and drove it and still no difference. Then that was when they said it was the hub assembly that was bent causing the vibration. I think they are grasping for anything. My truck has the 2 piece driveshaft, and someone had told me to have them check the carrier bearing. Also someone told me GM has a shim kit that they can install under the tranny mounts to take care of the vibration also. Has anyone heard of this. My suspension is all stock with standard size tires. I just dont get why out of the blue it started at like 30k miles. Very frustrating at the least. Take care, Marc


What I found just a few minutes ago could be very much related to what the dealer is doing. I'm waiting for new tires to arrive tomorrow but found something that doesn't seem right.


Since the tire shop told me they are 95% confident my vibration is localized to the passenger-side rear I grabbed ahold of the tire and push in/out with quite a bit of force. When I do this I can hear a very noticable "clunk" that is either coming from the hub/axle or the rear end. I do not get the "clunk" when doing the same thing to the driver-side rear.

Bearings shot? I think tripping had his front bearings replaced already. He was also running aftermarket wheels. Interesting if nothing else.

Bearings shot? I think tripping had his front bearings replaced already. He was also running aftermarket wheels. Interesting if nothing else.


Perhaps ... I know tires/wheels aren't the PROBLEM! I think all the threads on my wheel studs are almost gone from 5 different tire/wheel combos being installed multiple times. I just hope the "clunk" I'm hearing is something relatively simple ...like a bearing/bushing and not the rear-end, axle, etc. You'd think with 15K on the truck the drivetrain wouldn't need fixin ... I'm just waiting for the steering wheel "clunk" to develop.Edited by: tophog

I got my truck back yesterday from the dealer after they replaced the rear hub assembly that they said was bent and causing my vibration. Well guess what it didnt make any difference! They even told me when i went to pick it up that they are pretty much at a loss and that they took the truck down to their other dealership and had them use their "force variation balancing machine " on the tires and now they say that 3 out of the 4 tires are out of range and are causing my vibration. They said using a regular balancing machine wouldnt pick it up and that they would show ok. I told them that on one of the previous times in they told me they switched tires and wheels from another truck and that it hadnt made any difference. They then said that now they dont believe that got done afterall, and that everything else on the drivetrain and suspension checks out. I also told them i had the vibration before i got the new tires. I give up, they told me to go back and get the tires replaced and then they would go from there. They are just trying to push me off on someone else. I guess its time to start looking at another brand of truck. Good luck to everyone else, Marc

Mrkpero, that bites. I just dropped my truck off at tire shop and having new tires installed/road-forced balanced today. I know it's not going to help any however I just wanted the BF's.


The tire shop had already tried 3 or 4 different variations of tires/wheels on my truck, including road-force balancing, etc. which didn't help a thing.


It is very strange this vibration/hop develops over time...based on what I've researched after 10K. I'm at a disadvantage because I have a lift and larger tires so people naturually want to blame the lift and or aftermarket tires/wheels ...HOWEVER there many other people with this exact problem with a 100% stock truck.


I'm beginning to wonder if GM knows something and aren't sharing ...perhaps it's why GM trucks come with donut size tires and GM disclaimers/warnings about changing tire size may result in them not even looking/diagnosing your truck unless you have OEM wheels and stock tire size.


No matter which way you look at it, it doesn't make any sense. If it's not tires/wheels then what? Loose flywheels, bad ujoints, out of balance driveline, bent axle, wheels bearings, ....if the tires/wheels can't be balanced by a normal spin balancer machine then what does that tell you? I haven't seen any GM requirement stating tires/wheels MUST be road-forced balanced even though that's the best balance money can buy ...at least I think it is. Nonetheless tires/wheels are not the problem ...at least in my case.


I'll let you know if anything changes on my end with the new tires. Doubt it though ...

Hey Top i hear ya, my truck is 100% stock suspension and tire size, and it started at about 30k miles. I think they know its a problem and they are just trying to ignore it! I bet they do try and blame it all on your tire and lift combo. Thats got to be a worse run around than the one im getting, good luck to you too, Marc

Hey Top i hear ya, my truck is 100% stock suspension and tire size, and it started at about 30k miles. I think they know its a problem and they are just trying to ignore it! I bet they do try and blame it all on your tire and lift combo. Thats got to be a worse run around than the one im getting, good luck to you too, Marc


I knew what I was doing when I had the lift/larger tires installed as I was well aware a dealer's perspective on aftermarket stuff. That was a choice I was willing to make.


I have a lot of faith in the shop that's working on it and will let them see if they can find/fix the problem before something warrants a dealer visit. As you know a dealer would start from scratch and give me the "it's the lift kit or tire/wheels" story first, etc. etc. I would much rather see your dealer fix your problem so I knew what was wrong. :)


They think my problem is related to the PS hub, rotor or axle. They at least found the hub goes up/down (making it appear out of found) which would make it "hop". Found it way out of spec with a dial indicator on it, etc.


They are going to work on it more tomorrow. I know at least they aren't doing the work based on 'speculation' or throwing parts at it. They want to find/fix the problem as they are more curious/frustrated then I am as they claim they've NEVER seen a problem like this before. I dropped by this afternoon to see if they had made any progress and there were 4 guys working on it ...guess it must have been a slow afternoon, or perhaps the challenge of finding the problem. My fingers are crossed but at this point reading the new rear hub didn't fix your problem my faith is diminished. It if doesn't get fixed perhaps we can get a 2 for 1 discount elsewhere.

Same problem here and worse at 42-43mph. Started at around 35k and getting more noticeable as mileage increases, now at 92k. Bfg 295's on stk. wheels, 2pc. driveshaft changed to single at 15k, and no lift. Tire changes have made no difference. Occasionally it can be so bad I find myself literally bouncing in the seat. Front 50 psi....rear 35.


All other speeds up to 100 smooth as silk. Seems to me if it were tires it would throw me off the road at the higher speeds.


Billy

Well got my truck back today. No miracles, still vibrates. The shop finally had to throw in the towel and admit they baffled. All components on PS rear side (rotor, hub, bearings, etc.) ended up being fine. The only thing they noticed was the entire motor/tranny shakes at the speed the vibration is worse (40-50) and they said they thought something was wrong there but not sure what. Mounts looked fine.


I think I remember reading something about torque converter or flywheel bolts coming loose? It seems if the engine/tranny vibrate to the point where they told me I should take to dealer then I'm wondering if I could possibly have loose bolts causing the engine/tranny to vibrate? Grasping at straws at this point but have to cover all the bases.

VIBRATION SOLVED!!!
I found the source of the vibration today J After thinking more about what Les Schwab said yesterday about the motor/tranny vibrating “abnormally” at the speed the vibration occurs I decided to remove the Juice module. Problem solved! Go figure. I would have never thought it could have been the Juice module when the vibration appeared to come from the PS rear side. Everyone, including myself was focusing specifically on the PS rear.

Over the last few weeks (since I had tires rotated, coincidence...) I noticed the motor appeared to be louder, more “clattery”. I didn’t associate this with the vibration problem at all. The motor did not vibrate/shake at idle. The increased noise was not significantly louder but enough that I noticed. I thought it was related to fuel or the lack of running additive, etc. My guess is the Juice module is faulty throwing the motor out of time or whatever causing it to vibrate/run rough at a specific RPM range.

While I don’t know the specifics I do know the vibration is gone with the Juice removed. Also, changing levels, etc. has no effect, vibrates in all levels. BTW, this is a 1-month old Juice ... the 90hp tow version. I had the original replaced after running it 1 year after it started wigging out in the level-confirmation mode. I had been running it on level 3 and level 1 in tow/haul mode.

After this escapade I am done with aftermarket performance tuners, modules, etc. A non-vibrating, stock performance Dmax will do just fine, thank you. I can actually read my GPS now whereas before you had to grab it with your hand to keep it from shaking.

I've learned several things from all this. While the symptoms across trucks may appear identical, the root cause may be very different. Isolating vibration problems is a nightmare and the vibration itself may come from the least "suspect" component. I don't think there are any posts on this forum where the Juice has caused vibration problems such as this. Hopefully the engine isn't hurt from "whate

[QUOTE=tophog]


VIBRATION SOLVED!!!
I found the source of the vibration today J After thinking more about what Les Schwab said yesterday about the motor/tranny vibrating “abnormally” at the speed the vibration occurs I decided to remove the Juice module. Problem solved! Go figure. I would have never thought it could have been the Juice module when the vibration appeared to come from the PS rear side. Everyone, including myself was focusing specifically on the PS rear.

Over the last few weeks (since I had tires rotated, coincidence...) I noticed the motor appeared to be louder, more “clattery”. I didn’t associate this with the vibration problem at all. The motor did not vibrate/shake at idle. The increased noise was not significantly louder but enough that I noticed. I thought it was related to fuel or the lack of running additive, etc. My guess is the Juice module is faulty throwing the motor out of time or whatever causing it to vibrate/run rough at a specific RPM range.

While I don’t know the specifics I do know the vibration is gone with the Juice removed. Also, changing levels, etc. has no effect, vibrates in all levels. BTW, this is a 1-month old Juice ... the 90hp tow version. I had the original replaced after running it 1 year after it started wigging out in the level-confirmation mode. I had been running it on level 3 and level 1 in tow/haul mode.

After this escapade I am done with aftermarket performance tuners, modules, etc. A non-vibrating, stock performance Dmax will do just fine, thank you. I can actually read my GPS now whereas before you had to grab it with your hand to keep it from shaking.

I've learned several things from all this. While the symptoms across trucks may appear identical, the root cause may be very different. Isolating vibration problems is a nightmare and the vibration itself may come from the least "suspect" component. I don't think there are any posts on this forum where the Juice has caused vibration problems such as this. Hopefully the engine isn't

Vibrated home this afternoon. I discovered I can reproduce the shake/vibration sitting in my driveway by simply increasing throttle. At about 1K rpm you can feel the exact same vibration ...up around 1400-1500 you can really feel it ...you can see the seats shake. It's much more pronounced under load going down the road though ...but still very noticable standing still, in park. Thoughts?


On edit: I had the hood raised and you can see the motor shake when increasing RPM...goes smooth once you let off the throttle. I had my wife run the truck up to 1400 rpm when I was under the truck and the tranny is shaking pretty good. Also, with the small inspection cover off I was watching the torque converter? go roundy roundy ...and looked like wasn't true ...out of round or wobbly. How can I check this thing to see if it's loose or should I just take it to dealer and let them see what's going on? Could injectors be causinghte shake?Edited by: tophog

tophog,


First of all, I am by no means a dmax or related technician but, from years of experience I think you've narrowed your vibration down to a certain area..........the engine and/or or converter. If this occurs sitting parked in the driveway the engine and it's driven parts and accessories, along with the converter, are the only rotating parts of significant value to create or cause such a vibration you describe (hope I don't get slam dunked on that statement)http://www.dieselplace.com/forum/smileys/Geek.gif.


2nd, I used to aid in designing 4 cyl. aircraft engines. When dynamically balancing the cranks, only a few grams on a 3 inch radius at 4,000 rpm would generate thousands of pounds of centrifugal load. I currently have patented and fabricate machines that utilize a 200 lb rotor that turns at 3,000 rpm. If the rotors are not dynamically balanced within a few grams, the 1800 lb. machine will literally walk across the floor.........point being, if your converter appears to be wobbling, given the large diameter of the converter by comparrison to cranks and my machines, I would bet good money this MAY be your problem. Remember, the larger the diameter the greater the off balance loading will be due to surface feet per minute and leverage from the rotating center line. Like swinging a 10 lb. ball on the end of a 2 ft. rope as opposed to a 10 ft. rope both at the same rpm.


3rd, if your dealer can't pin the vibration down with this latest info you've provided, I think I'd seek another.


Hope this might help...............Billy


On Edit: Being relatively new to diesels, if injector balance were off the charts I would think it would be similar to pulling a plug wire off of a gasser, creating considerable vibration. Maybe, maybe not.


Edited by: bhowell

I appreciate the comments/help. Truck is making it's maiden voyage to dealer Thurs. morning. I'll let them figure it out as I'm frustrated enough. My dad listen to it today and drove it ...he thinks it's the engine (miss (injector related), timing, etc.) Just hope it's not those darn injectors ...then again, perhaps I should be glad for version X (whatever it is this week) as long as I don't have to wait 2 weeks for replacements.


I won't pre-judge the unknown at this point. I've always been leary of the injectors after reading the bibles of posts on them. Have had pre-Racor installed since 2K, ran additives in every tank and get good fuel from the same location ...but I guess none of that can eliminate the possibility of injector problems. Rambling now ...will post more when I know more.

Well, truck made it's "maiden" voyage home from dealer ...the last might I add. Had it for 2 days, no codes set so no problem they claim. Tech did drive and admitted it vibrates from 45+, but vibration in Park reving to 1400-1500 is normal ...said he checked another truck and it did the same thing ...and thinks rear u-joint is bad. NOT! They didn't have one ...I remarked "Must be a popular item in 15K mile trucks" which resulted in a "go to h&amp;%L look". The ticket said they did loosen/retighten motor/tranny mounts, blah blah blah and found nothing out of the norm. I asked about flywheel/torque converter and all I got was "Oh, it's fine ...". So I'm back to driving a $45K vibration truck ...until I get frustrated enough to purchase a $1.00 forsale sign. I guess I'll go ahead and buy some Ground Hawg tires to mask the vibration. I shouldn't be too upset ...it's more or less what I expected before I took it in. Guess I'll drive it with Juice Level 4 until something breaks or falls apart. Edited by: tophog

I think it may be worthwhile posting the other threads on other forums directly related to this problem if anyone wants more informaiton. Everyone apparently still has the vibration. So is everyone running around with the GM recommended 300-500 lbs in the bed when not towing?


http://www.rv.net/forum/Index.cfm/fuseaction/thread/tid/14185986/srt/pa/pging/1/page/1.cfm


http://www.rv.net/forum/Index.cfm/fuseaction/thread/tid/13268401/srt/pa/pging/1/page/1.cfm

Just a thought: I remember hearing someone talking awhile back about
a loose crankshaft reluctor causing a similar vibration/bucking in a truck
they used at work. Have your dealer check that.

The dealer still hasn't called me back about the rear ujoint so I assume it hasn't come in yet. I had the driveline checked today by a driveline shop. They just called and told me it has .025 runout and they considered it bad @ .020. They said the u-joints were fine though. http://www.dieselplace.com/forum/smileys/Confused.gif


What am I suppose to make of all of this? Is there a GM spec on the driveline runout? With the driveline being so long perhaps the driveline would still be considered "good" using a GM or Spicer spec?


Should I contact the dealer again and tell them about the driveline check or would I get my hands slapped for that? I just want my truck to quit vibrating.


thoughts?Edited by: tophog

At first I thought my vibrations in the same speed range were because of the aggressive tread of my Cooper Discoverer S/T's. They have some moderate cupping, but I have had regular rotate/balances and the vibes are only through the speed ranges, even after rotate/balance. My T-bars are cranked all the way, so I'm going to try taking 3 turns out, alignment, and rotate/balance.


Hopefully your persistance will payoff and we'll all have the cure soon (getting close to the end of my 3/36 warranty).


Good luck and keep us posted.

In my case repeated tire/wheel balancing is a process I am "wishing" would solve the vibration problem when I know it's not tires and wheels. In my case, endless testing with "different" tires/wheels did nothing to change the vibration ...which rules out a tire/wheel problem. Sure, it feels like a tire/wheel problem ... but in my case it's not, can't be based on the testing.


Between the local tires shop (Les Schwab) who had my truck for 3 days and 2 days at the dealer and 1 day at the driveline shop there isn't much else to check...but the truck still vibrates. In my case I'm not talking about a minor vibration that can be ignored if one tries ... it's hard for me to drive the truck 40 miles to work without wondering if something is going to vibrate/fall off of the truck.


I posted more info in another thread I found that was already started hoping I might get more feedback.


http://www.dieselplace.com/forum/forum_posts.asp?TID=8899&amp;TPN=1

Update on my vibration situation..lol. I am heading back to the dealer again for another test drive with the asst service manager. I contacted the place that installed my tires and they in turn contacted the distributor who said that they will replace the tires only if the place(dealership) that is calling them bad will sign the return papers saying that they are sure it is the tires that are causing the vibration, and that if it isnt then someone will have to pay for the new tires that are put on. The distributor told the installer that it is highly unlikely to find 3 tires that are out of round on one vehicle. The dealership is afraid to get stuck with having to pay for the tires so they wont sign the paper if it means they might have to pay up. They said unless Michelin has the same machine to test the tires on rims with, then they might not call them bad. I'm sure not going to be paying for them, so i had my installer cal lthe dealership and tell the sefvice guy that he wants him to go for a ride and see exactly what the vibration feels like. Since he has never driven my truck yet, and then maybe he will change his mind about thinking its the tires and start looking again at the engine or drivetrain. What a mess! My rear tires are still feathering in the center, adn i was out camping this past weekend and i swear the vibration is getting worse. Good luck to everyone, Marc

Here is a link to the GM PIT3009 bulletin addressing Suspension Vibration or Frame Beaming at 40-60mph. No fix. Wonderful. It's a fax copy so the quality isn't great. I would try saving to your disk then opening ...as IE will shrink it down.


.JPG format


http://home.comcast.net/~tophog/duramax/PIT3009.jpg


.TIF format


http://home.comcast.net/~tophog/duramax/PIT3009.tif

I've had the same type of vibration problem on my truck since probrably 1,000 miles. One time it got so bad I had to stop the truck.


It seems to get worse on hard cornering -


I attributed it to the Firestone tires the truck was delivered with. At 58,000 miles I replaced the Firestones with Toyo's one size bigger. I really hoped it would solve the vibration , but it has not, although it does seem more defined speed wise to 42 to 47 mph.


My nieces's boyfriend who is a GM tech at GMC dealer drove it while visiting. He felt it was coming from rear of truck since nothing was felt in steering wheel, but had no answers as to what it could be.


Does this vibration only occur on D max with Allison ? Does i occur on ext cab short beds, ext cab long beds, crews etc ?


I never had any vibration like this with my 6.2 ext cab , even with 500,000 miles !


Perhaps GM does know there is an issue, but hasn't a fix . Or perhaps its a really deep problem in frame design or torgue converter or ?





www.dieselgettogether.com

Hey there ctgmc, I have an 8.1 in my truck and it has a crew cab and short bed, and is also a 2wd so I think the vibration issue is quite diverse. Mine starts around 40-45 and continues until 55. Even at speeds above 65 I still think I can feel it although not as pronounced. It does get very frustrating having to put up with it. Went back for the 6th time yesterday and still no solution. Hopefully one of these days someone will figure it out.

My vibration was solved today. Long story short, put on my brothers OEM wheels/tires and truck drove like glass. Went back to tire shop and took mgr for a ride ...he agreed but couldn't understand it as he said they tried OEM wheels. Come to find out they never tried them on the front as they didn't think they would fit.


Jerked the Weld Outbacks off the truck and installed a set of 16x8 GM hub centric aftermarket wheels and you can ride down the road with a glass of wine on the dash http://www.dieselplace.com/forum/smileys/Big Smile.gif


I think I made the tire shop look silly ...they spent ALOT of time trying to find a vibration somewhere else based on the false assumption the tires/wheels weren't the problem.


I'm happy again and will be able to sleep at night.

Congradulations TOPHOG ! Glad your's is corrected ! After reading most of these posts , I don't think thats the answer, going back to oem tires / wheels. Because my 2002 Chevy Dmax did it with 1,000 miles on it, factory tires and wheels. I switched tires and it still does it ( at 60,000 miles I bought new tires)


Perhaps it has something to do with the new thinner walled frames and a harmonic setting up at certain speeds.


Perhaps we should set up a poling post to track this problem and send it to GM and NHTSA.


I'm wondering if quad shocks on the back , like the used to offer as an option on the fronts of the old straight axle k series might help solve it. Anybody know if any company makes a kit to add 2 extra shocks in back ?


At almost 70,000 miles I must say this problem is the only major aggrevation this truck has given me.





Terry








Edited by: ctgmcduramax

I read somewhere (maybe on this forum) about someone who had an engine vibration that turned out to be a sheared key in the harmonic balancer. Apparently the Dmax doesn't have a very heavy key and they can shear.

Another source of wheel vibration comes from aftermarket aluminum wheels that have the center hole cast, not machined in. The tire guy mounts the wheel on the balancer through the hole. He balances the wheel off center. When it is installed, the wheel is centered on the lugs, which will be the true center. This is why the wheels keep coming up balanced on the balancer, but hop down the road. It is crucial to have a device called a lug adapter on the balancer. You bolt the wheel to the balancer just as you would to the truck. It centers on the lugs. Most tire shops don't want to mess with an adapter, because you have to bolt it on the machine, and set it to the wheel bolt pattern. Plus, the adapter costs alot, like $700. Typically steel wheels have the center hole actually centered, and they mount up okay on the balancer. Off center wheel balancing is called mounting error. It takes very little to make a big shake.

i have a 02 2500 4x4 long bed st.cab sle gmc dmax allison.i have stock tire wheel combo and all stock truck.i have a 45 to 65mph vibration.i've had the truck for 3000miles and it now has 42000 on it.i've rebalanced and rotated the tires with no change.its at the dealer now(over a week) for a transfercase leak and the vibration but the tech said he cant feel anything!when i get it back i'm going to run it on jack stands with and without tires.then move on to rebalancing the drive shaft.

i have a 02 2500 4x4 long bed st.cab sle gmc dmax allison.i have stock tire wheel combo and all stock truck.i have a 45 to 65mph vibration.i've had the truck for 3000miles and it now has 42000 on it.i've rebalanced and rotated the tires with no change.its at the dealer now(over a week) for a transfercase leak and the vibration but the tech said he cant feel anything!when i get it back i'm going to run it on jack stands with and without tires.then move on to rebalancing the drive shaft.





I think you are going to get very aggravated in chasing the vibration. Been there done that. I had a BAD vibration due to bad aftermarket wheels and while it first appeared my truck was "smooth" after getting different wheels I still notice the infamous "45mph vibration" but it is minor compared to the vibration I used to have...not to say it's "normal" by any means. You probably have found there is an actual TSB issued by GM regarding the "45MPH +" vibration that says it's normal (Yeah, right). This tells me there is most likely nothing that will fix it as the vibration is more or less built into the truck via the engineering specs.


I went full circle ...tires/wheels, greased driveline splines (helped), had driveline checked (was perfect), had motor/tranny mounts checked, etc. The thing that made the most difference was placing about 400 lbs of weight in the ass end. BTW, this is the fix GM spells out in the TSB http://www.dieselplace.com/forum/smileys/smiley21.gif

ben97532,


Do you have a one or two piece driveshaft? Either way, check the U-joints both for freedom of movement in both planes and smoothness of movement. Even though the truck doesn't have very many miles, it could have a bad joint. I just replaced a joint in my '91, it only had 20K on it, and has had synthetic grease also. If it is a two piece, make sure that the two are phased properly. Someone may have had it apart previously and reassembled it wrong.