I hope this will be helpful/useful to somebody..........

First my background with 4x4s.<O:p></O:p>

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My first 4WD was a '96 Chevy Ext Cab SB Z-71. It replaced a '92 Chevy Ext cab Short bed 2WD. I loved how my Z-71 handled rough roads and mild off road. I never had a ground clearance problem, and truck could go fast over this type of terrain with a smooth ride. This truck was completely stock.<O:p></O:p>

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When I PCSed to lace>Japan</ST1:place> in '98, I sold the Z-71 and got an '87 4x4 Suburban as my "stateside" rig. I lifted it 2.5", ran 31"x10" tires, and eventually put in 4.10 gears and Warn hubs. I used this rig in <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com /><st1:country-region>Japan</SPAN></st1[img] /><st1:country-region><?xml:namespace prefix = st1 ns = <st1:place>Oregon</ST1:place></st1:State> and <st1:State><ST1:place>Texas</ST1:place></st1:State>. It did not ride as smooth as the Z-71, but it did track through the mud better because of the better tires. The only problem happened when I was in <st1:State><ST1:place>Oregon</ST1:place></st1:State>. I was just turning around on a logging road, and pulled off and drove in some tall grass in the process. I hit a stump hidden in this tall grass, and it bent the tie-rod in and dented the front diff cover. I drove it home 60 miles this way, with about an inch of toe-in, and then replaced the tie rod. However, that incident put me off any 4x4 that has steering linkage out in front of the front axle.<O:p></O:p>

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When I returned from <st1:country-region><ST1:place>Japan</ST1:place></st1:country-region> I ordered an '01 Chevy Ext Cab, SB, Z-71. I kept this truck stock. Once again, I liked it's ride on rough roads very much. The factory highway tires were not very good in the mud. I traded it 11 months later because I needed more room in the cab.<O:p></O:p>

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So I wound up with my current truck, an '02 Chevy Crew Cab SB 2500 HD Duramax/Allison. I immediately went from the factory 245/75R16 to 265s. I took it hunting in my usual environment, which is driving on rough roads with a little bit of very mild off roading thrown in. I filled the skidplate under the front diff with mud and grass. I installed aftermarket t-bar adjusters--though I later learned the stock adjusters would also have worked--and cranked the t-bars about 1.5". I went over the same exact place where I had stuffed my skid plate and had plenty of ground clearance.<O:p></O:p>

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I later added some Bilstein shocks, and the ride was very good, cranked t-bars and all. I also added an HP chip and a less restrictive muffler.<O:p></O:p>

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After having the truck for a year and a half, I realize I had not been sold truck tires when I had the 265s installed. I also discovered that I was maxing the tires out with the truck empty. So I bought some truck tires (General "Trail Tires", and decided to go to 285s. Well, the manufacturer recommends running 285s on an 8" rim, so I also got some 8" rims. Everyone told me that would be fine. <O:p></O:p>

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Well, it wasn't. I immediately had rubbing on the front tires. So I tied back the parking brake cable, tied back and reformed the inner fender liners, and cranked the t-bars to 2" over stock. I would only get rubbing when I went though a dip while turning. The ride was borderline "joucny", so I added a 1" lift block in the rear, but that didn't help the ride. <O:p></O:p>

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I had been told that it was bad I was running my CV axles at a steeper angle than stock. I also didn't like that I would occasionally get rubbing. So I installed a 4" Rancho lift kit. I installed this myself, with an occasional hand form my father-in-law. <O:p></O:p>

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Now these lift kits all drop the torsion bars and the crossmemeber under the frame, about the same amount that the truck is lifted. I didn't like the idea of the t-bars and the crossmember hanging down under the frame--it was something that could get in the way, and if I ever hit a t-bar hard on a rock, it would break, the suspension would settle, and I'd be stranded. So when I installed the lift, I also installed some torsion bar relocaters that allowed the t-bars and the t-bar crossmember to be put back up in the frame.<O:p></O:p>

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I hadn't had the lift and relocaters on three weeks when I hit a 8"ish curb head-on with the left tire at 20 mph as I swerved to avoid a guy that stepped out in front of me. This blow caused the left t-bar to twist in the relocator and settled the suspension about an inch and a half.<O:p></O:p>

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The guy who makes the relocators said that shouldn't have happened and sent me some new ones. I also replaced the torsion bar, though it was okay--more on that later. After the curb incident, the left side of the truck has needed about 1/2" more adjustment of the t-bar than the right to make the truck level. Before the blow, the left side was within a turn of the right side. However, a 1/2" difference left to right is not uncommon, though I think a new t-bar crossmember would fix that. In all fairness here, that was a severe blow and some folks have told me such a blow could have broken a leaf spring, though I am not so sure…………….<O:p></O:p>

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After I sorted all that out I switched to BFG 295/75 R16 ATs, and installed some tie-rod sleeves. I also installed an additional one-inch lift block in the rear, raising the rear lift to 3.5". I did this so the truck would not squat when towing/hauling heavy. Most of these lift kits raise the front, but only level the rear. The stock truck is about 2" nose down.<O:p></O:p>

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Everything was great for several months, until I noticed a funny squeak coming form the left side during this past Thanksgiving. It turned out both front wheel bearings had come loose. The didn't fail, they were just loose, but there is no way to retighten the pressed-in sealed bearings. The new Fords have the same problem with their front wheel bearings. <O:p></O:p>

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After I installed the bearing/hub assemblies--easy to do but spendy--I had the alignment checked Friday 3 Dec. My front tires were toed-out 5/8". This was my fault for not being careful enough when I checked the toe after installing the tie rod sleeves. The front bearings were tight at 24,000 miles after I twisted the relocator, and the were probably tight when I installed the tie-rod sleeves, but they were loose at 30,000 miles. Without going into the details, I think this excessive toed-out condition accelerated the loosening of the front bearings. I know many guys who have run lots of miles with no bearing issues on these trucks<O:p></O:p>

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Dec 4th and 5th, I took a friend's 21 yr old son hunting. We went to the range Sat AM, then drove 170 miles to the hunting place and hunted that afternoon and the next morning. On the way out I went through a pretty steep dip on a dirt road.<O:p></O:p>

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Now I had been through this dip three times before. The first time was Summer of '03, and I was following my friend to his place. He forgot about this dip and I hit it at about 50 mph. This was before I had the 4" lift and 295s, so all I had was 2" of t-bar crank and 285s. The front skidplate hit the road as I went through the dip. After that, I made sure I slowed down to 15-20 mph for said dip.<O:p></O:p>

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Well, on the trip out last Sunday--with lift kit and relocators--I went through the dip at approx 20 mph. This had worked great the day prior. However, this time I hear a "BANG" as the suspension bounced and the steering wheel needed to be turned 3/4 of the way to the left to go straight. I pulled over and discovered I had broken the right side t-bar relocator. It didn't just let the t-bat twist inside it, it actually broke in two, and settled the right suspension about 6". The a-arm was resting on the little yellow bump stop/auxiliary spring.<O:p></O:p>

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The truck was actually driving okay, so I drove it back home 170 miles. It's not like anywhere along the way could have helped me anyway. With the suspension fully settled on the bump stop, the CV axle was angle upward a gross amount, something like 45 degrees. <O:p></O:p>

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Since I am in the midst of moving from <st1:City><ST1:place>San Antonio</ST1:place></st1:City> and depart 12 Dec, most of my household goods are already shipped an in . This included the pieces I needed to put the lift back to the way Rancho designed it. So on 6 Dec I ordered these pieces overnight express. I got them on the 7th, and then had to go buy a set of stock t-bar adjusters because the high lift adjusters I was using with the relocators don't work too well with the Rancho lift.<O:p></O:p>

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Anyway, I finally got it all sorted out and re-aligned yesterday, 9 Dec. The stock Rancho lift is very stout and the ride is a little better without the relocators. Also, I only lost 1" of ground clearance under the middle of the frame when I took off the relocaters. The clearance under the front skidplate and under the rear diff is the same. Yes, the t-bars are exposed and that is bad for heavy duty off-roading, but then again, a Crew Cab pick-up is just not built for that--you need a much smaller rig if you want to rock crawl or go over really rough stuff. <O:p></O:p>

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The broken relocator did cause a little damage:<O:p></O:p>

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- The underside of the upper a-arm received a couple of cosmetic dents when it compressed against the top of steering knuckle<O:p></O:p>

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- The metal mounting "box" on the side of the frame the receives the aft part of the upper a-arm was pushed up a 1/4" or so and the weld on the top started to open at the very front. I had this rewelded and it is fine now<O:p></O:p>

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- The lower balljoint boot was pinched and now has a small slit in it. As long as I frequently grease it the ball joint will be okay, but I will soon either replace the boot or if I have to, the whole balljoint.<O:p></O:p>

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After all that, here is the "TRUTH" about the GM HD IFS:<O:p></O:p>

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1. The CV axles are EXTREMELY stout and there is no problem running them with 2" of lift<O:p></O:p>

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2. The torsion bars are stout<O:p></O:p>

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3. The a-arms, balljoints, a-arm bushings, and frame mounts are plenty strong<O:p></O:p>

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4. The front wheel bearings are a weak point<O:p></O:p>

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5. The stock tie rods are a weak point<O:p></O:p>

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6. The Rancho Lift is a very stout kit <O:p></O:p>

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7. The t-bar relocators aren't sturdy enough for HDs with diesel engines and 200 lb front bumpers, though there are some that are in the works<O:p></O:p>

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My Recommendations:<O:p></O:p>

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If you just want to run a 33" tire, then run 285s or even 295s on the stock wheels. Crank the t-bars 1.5-2", install some Bilstein shocks, tie back the parking brake cable, and tie-back and reform the inner fender liners. Then install the tie-rod sleeves to beef them up.<O:p></O:p>

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Yes, I know the stock wheels are supposedly to narrow for 285s and 295s, but I know guys who have run these tires this way with no problems. One friend has 100,000 miles on his truck and is on his second set of BFG AT 295s on the stock wheels. He tows a bull-dozer and spends a lot of time on rough, rocky terrain. He had no rubbing, tire, or stability issues. Also, he has no crossmember sticking down under the frame of the truck and his t-bars are not exposed.<O:p></O:p>

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If you need to haul/tow heavy and don't want the rear to squat lower than the front, then install a 1 or 2" lift block on the rear, depending on how much you crank the t-bars.<O:p></O:p>

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If you want to run 35inch tires, then get a lift kit. I still like the Rancho 4" lift for this, even though you do have to crank the t-bars a little for clearance. The Rancho will raise the front of the truck 4" while keeping the CVs at stock angles. Since I know from personal experience as well as the experience of many others running a HDs CVs at an sane angle is no problem, I have no issue with cranking my t-bars a bit with the Rancho to clear 35s.<O:p></O:p>

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With whatever you do, make sure you keep the front end properly aligned, and use wheels with the least amount of offset that you can.<O:p></O:p>

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I can't speak for the new Dodges or Fords, except to say that many mechanics have told me that the Fords also run a sealed bearing and they get loose as much as the Chevy’s. Also, I have been told that none of these trucks are really engineered for larger tires and the required offset wheels to run those tires. Yes, we all know guys who have run big tires with no problems, but we all also know many guys who have had problems.<O:p></O:p>

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For me personally, I absolutely love the Duramax engine, the Allison tranny, and the GM 14 bolt rear end on my truck. The engine is stout beyond anyone's expectations, and can produce an insane amount of HP. It does all this at what, 300 lbs less than the Cummins? (Though the weight is the ONLY SEMI-negative about the Cummins pickup engine). the Allison is not back stock, and with a tranny kit can handle all a chipped DMax can throw at it. Finally, there is no stronger rear end in a pickup truck.<O:p></O:p>

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This brings us the front IFS suspension. No doubt, the HD IFS is one of the strongest IFS ever made, though it does have a couple of weak areas. I will either convert to a straight axle or go with the new coil over system that is supposed to hit the market soon. I like a t-bar suspension the least of any kind. However, I do like how the IFS rides, I like how it gets the front diff up out of the way, and I really like how the steering linkages aren't in front of the axle to be hit and bent. And yes, I may very well trade my truck in if GM ever offers an HD with a straight axle--as long as the front bearings are stout.<O:p></O:p>

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<st1:City><ST1:pBlaine</st1:City>

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good reading thanks for the info

Very nice info, thanks for posting. I am sure that some people on here will find this very useful in the future...

Yes, very helpful info, THANKS :cool: :ro)

Excellent writeup, very well explained.
The coilover kit you are talking about would be the rockkrawler kit? http://www.rockkrawler.com/pages/chevy_gmc_1500.html
They have had one out for the 1/2 ton for a while but don't have an HD kit yet. I think it would be easily possible to adapt the coilover springs skyjacker makes for the superduty conversion kits to fit your truck. Or maybe not, just need to call them and see what size around and what length they are. Someone must make some that would fit. I imagine soon someone like rancho or skyjacker will start offering replacement coilover springs as an option instead of dropping the TBs.

Where did you get the T-bar relocaters? Iv been looking for a set up like that for awile.

Sorry about all the junk in the post.....I can't seem to paste in a document from Word, even in "plain text"

Here is a link to Realift: http://realiftsusp.com/

Realift has been able to sort out the problem with the relocators. They were getting a lower grade of steel than they had ordered, and have has now changed suppliers.

Also, I have been told that none of these trucks are really engineered for larger tires and the required offset wheels to run those tires.



this is the same setup as the new hummer h2's, even the same tie-rods with their 315's so GM must have engineered the suspension to run at least this size tire, makes you wonder why they try to deny warranties on their 3/4 ton pick ups when someone puts oversized tires on, when they basically put huge tires on a 3/4 ton tahoe, also I am currently running 305/70/16's on 16x8 ultra wheels with no lift. I had to trim inner fender and trim air dam. I don't have my bars cranked very high (in case someone wants to race) cv's are just over parrallel from the ground, get very little rubbing but I don't go off road. good info though, thanks

It sounds to me that the problem with the T bar relocators stemmed form the fact that you already had a Rancho lift. If the the kit was designed with the T bars lowered then I assume raising the rears would put them at an angle that would cause them to bind. You are the first person I've heard worry about the T bars hanging too low, but like you said , these trucks are not for rock crawling.

Well that is what they are designed for though, is to raise the bars back up from where a lift puts them, it should work with any type of lift. They won't be at an angle because they raise the front part and the back is stock height. As he said though he didn't lose that much clearance without the relocaters. I wouldn't worry much about it...

I guess I should clarify a bit about losing the lift without the relocators. Yes, I only lost an inch, but without the relocators the stock t-bar crossmember is put underneath the frame in the middle of the truck. On a long wheelbase truck, clearance in the middle of the frame is important, and having the t-bar crossmember hanging down some 3-4" under the frame puts it in harm's way. The relocators solve that.

This is a great thread for anyone considering moving up a few tire sizes. I'm considering goung to either 285's with about 1.5" of trosion bar crank, or 315's with a Rancho 4" kit. If I go with the Rancho setup I want to avoid any torsion bar cranking. Do you guys have any opinions about which set up would give the best ride quality.

I drove a truck over the weekend with an RCD 6" kit and 325's I was very impressed with the ride, at least as good and maybe a little better than stock, but 6" is more than I want to go.

I do not believe the Rancho lift will clear 315 tires without cranking the torsion bars. I just had mine done and put on 285 tires that fit quite well. Although quite a few guys running the 4 inch Rancho have put on 315 tires, so hopefully they will add there experiences.

Eric

After seeing the pics you posted of the relocators, although they did look good, there was just something about them that bothered me. It didnt seem like they would work as well as having your t bars in the lower a-arm, guess now we know.

1SAST, I know you're right, at least as far as most people I have talked to, but I have seen a few trucks on this site with 315's and either cranking or leveling kits kits. How they ride compared to stock I don't know, but d**n they look good.

The Rancho will easily clear 295s with stock Cv angles, and with a little crank 315s are not a problem. Realize there is absolutely no problem running HD CVs at 1.5".........

365/65-16'2 on 16x10 rims. NO suspension mods. A little trimming.

http://dieselplace.com/forum/attachment.php?attachmentid=17&stc=1

Blaine, what do you think about the ride quality Rancho 4" lift versus just turning up the keys. I've read a lot of your posts here and on 24 hour campfire, you've definitely been there done that.

By the way very nice truck I've had a lot of people say that a 33" tire is too small for a 4" lift but I think yours looks right.

I have had the Rancho 4" lift for over 1 1/2 years and love it. IMO 295's are the perfect size tire for the 4" lift. I did run 315/70R17's initially but had to trim, rubbed occasionally, etc. If people want to run 315's then I would say definately go with a 6" lift ...if you want to be happy that is. And also note the 315's I ran were the H2 size (70 profile) which is actully shorter then a 315/75R16 tire.

I also run 16x8 5.25" backspaced wheels against what most lift companies recommend (due to clearance problems between tire/top a-arm) but I am able to do this by running a 295 tire ...I only have about 1/8 - 1/4" clearance between the inside bulge of the tire and the upper a-arm however I have not had any rubbing/clearance issues since I went with this setup over 6 months ago. The 5.25" rims basically put the front tires/wheels back inside the fenderwells so the view from the front is near stock vice the tires sticking way out and looking stupid. See front end view picture in the link in my sig.

Jeff,

Given my recent bearing failure, I have been wondering if the 5.25" backspacing would be a problem if the bearings get loose?

9W3-HD,

I got a set of relocators made from bad steel. The manufacturer dumped his old steel supplier when the supplier admitted to supplying bad steel...........steel that was heat treated to only half the required hardness. The manufacturer has also beefed up the relocators. The US Military has been testing them, and when they say the relocator is good it will be. The manufacturer has had no issues with his current relocators on the HDs and he has sold quite a few.

I just happened to be one of the "early guys" with the HD relocators and suffered through growing pains. This is similar to what Edge went through with the Juice. They had a bunch of problems initially, even though they had been making chips for the Cummins for some time.

Jeff,

Given my recent bearing failure, I have been wondering if the 5.25" backspacing would be a problem if the bearings get loose?
What type of problelm? The tires rubbing on the a-arms? If so, I'd view the 5.25" BS rims as an early bearing warning device :) I am always taking a looksie at the inside of my tires when I wash or change/oil/grease the truck to ensure I don't have any rub problems. To my knowledge they have never rubbed ... I would hope I would feel any sign of bearings going bad in the steering/wheel, etc. as meticulous as I am to vibrations ... (another story a few months ago).

Tophog,


Very nice truck. In white it looks even better. I've got a white 2005 2500HD Dmax shortbed on order. Making myself nuts trying to decide what to do. Looking at your truck I'm 99% sure I'm going with the Rancho 4" kit and either 285/70/17's or the 295/75/16's. The 295's do seem to make a difference, fill out the wheel wells better.

I think you'd be very happy with the Rancho as it's a nice kit and very stout. The biggest gripe most have are the lift (spindles) puts the front tires outward about 1.5" on each side and most guys run 4.5" or 4 5/8" backspaced wheels which doesn't help matters... however a 5" - 5.25 bs'd wheel and 295 tires is the furthest one can put the front tires inward, not have rub problems and fill out the fenderwell without having rubbing issues. Last but not least, I can still park my truck in the garage which was the primary factor I chose a 4" lift. Good luck on the new 2005 ...I'm envious as I like the new hood design and grill much better then my 03! I'm still up in arms as to what to do for a grille. Have been looking at a few complete replacement grills that are all open in the front similar to GMC's ...but are expensive and have to have painted.

I was aslo thinking about it as an early warning indicator. I would hav ebought some already, but Ultra is out of the Magnums in that size. They said they thought they'd have some in Jan...............

BTW, my truck is 6'10" tall with the Racnho, an additional 1" block on the rear, and an ARE cab height shell. It just barely fits in a std size garage, which has a nominal opening size of 7 feet. Often, there is a 1" piece of trim that sticks down across the top part of the garage door header, and the floor is susally raise about an inch form its owest point to keep water out.

Anyway, I am having my new house built here in Tucson with an 8' tall garage door to solve all that..............