Over Thanksgiving weekend I replaced both of my front wheel bearings. They were so loose that when I'd grab the tire at the top and bottom and try to wiggle it, I'd get 1/2"+ movement. There bearings themselves were fine, but just loose. Of course, there is no way to tighten them back up (thanks GM engineers). The inside tread of both front tires was 1/32" more worn than the rest of the tread.

My truck is an '02 2500 HD D/A, CC, SB, 4x4. The replacement was easy, though the bearing/front hub units are spendy. I am sure the dealer would have warrantied it if I had put stock tires and wheels back on, but I didn't even ask, and I really didn't have time to wait on a dealer anyway.<O:p></O:p>

I spoke to DmaxAlliTech today, and he said he didn't see any reason why my bearings went out with so little mileage on them. He said if you get a defective one it normally fails right away, and it usually is only one side. So let me step you through the "events" of my truck's life and let's see if we can't figure something out. All mileages are approximate.<O:p></O:p>

<O:p</O:p
1. Immediately after buying the truck I had 265/75R16s installed on the stock wheels. <O:p</O:p

2. At 13,000 miles, I installed Bilstein shocks, cranked the t-bars 1.75", and installed a 90 HP Juice. I made several full-stall launches in 4x4 with the chip set at 90 HP. <O:p</O:p

3. At 15,000 miles I installed a 190 lb front bumper.<O:p</O:p

<O:p</O:p
3. At 17,000 miles I was letting a BMW from an adjacent lane into my lane. As soon as he got in front of me the traffic came to a sudden stop. I hit him at about 30 mph. The impact marred the left push bar on my front bumper a little, and it shifted the bumper a bit in it's mounts--I had to loosen to bolts and put it back to where it should go.<O:p</O:p

4. At 19,000 miles I had 8" rims with 4.375" backspacing and 285 75R16s installed<O:p</O:p

5. At 21,000 miles I installed 125 HP juice and stopped making full stall launches

6. At 23,000 I installed a 4" Rancho Lift Kit and Realift T-bar relocators, but used the same tires and wheels I installed in item 4.<O:p</O:p

7. At 24,000 miles I hit a curb head on at 20 mph with my left tire as I swerved to avoid a guy who jumped into the street in front of me. This impact put approx 65,000 PSI of torque on the t-bar and the left t-bar twisted in it's t-bar relocator. It was my fault the reloactor failed--I didn't really have it set right. However, what is most interesting here is that at this point, both front wheel bearings were solid. Before I figured out that the relocator had twisted, I checked everything to include the frame. I could not get any wheel movement at all from the bearings.<O:p</O:p

8. At 24,500 miles I had BFG ATs in 295/75R16 installed<O:p</O:p

9. At 26,000 miles I put on tie rod sleeves<O:p</O:p

10. At 30,000 miles I noticed a squeaking noise from the front left wheel and discovered BOTH front bearings were loose<O:p</O:p

I haven't really been off-road, and have been on rough roads only a little. I have driven through a lot of water though, and I will use 4x4 when driving through standing water (2-4" or so). BTW, the CV axles are in great shape, even though they ran at a steeper than stock angle for 23,000 miles.<O:p</O:p

If I had been running 37" tires off-road, then I might expect bearings to get loose in 70-80,000 miles. However, many guys have run 295s (33's) for a lot of miles with no issues. The lift kit itself has no effect on the front wheel bearing/hub assemblies--the stock hub mounts in the new steering knuckle just like it did in the stock knuckle. On top of that, I also know guys who have run knuckle lifts on these trucks for more miles than I with no front bearing issues.<O:p</O:p

When you see how the CV axle fits in the hub bearing, you can see that the t-bar relocator will have no effect on the bearing. Once again, many guys have run these relocators for lots of miles with no bearing issues.<O:p></O:p>

<O:p</O:p
After the left tire curb impact, the bearings were still tight on BOTH sides.<O:p></O:p>

The only "events" occurring after the last time the bearings were tight are the tie rod sleeves and the BFG 295s, neither of which would likely cause the bearings to come loose. Yes, the sleeves will flex less and potentially transmit more movement to the steering knuckle, but that won't stress the bearing--the CV axle telescopes and would absorb that. <O:p</O:p

I am not sure what caused the increased wear on the inside thread of both front tires. The toe was slightly toed-in, like it's supposed to be. I run the tires at 50 PSI. Perhaps the wobble in the front tires caused by the loose bearings were a factor, though that is not what I would expect from loose bearings.<O:p</O:p

Any ideas or comments? I do know it was not hard to find the hub/bearing assemblies at dealerships, even small dealerships in small towns............

Blaine<O:p</O:p<ST1:p</ST1:p

Unless something is different on the unit bearing assemblies on these trucks from the previous generation, you can tighten the bearing assembly with the nut that holds the stub shaft in. The bearing assemblies are pressed together, and they are precision machined to keep the bearings from getting overtightened. If the nut on the end of the stub shaft is loose, the bearing assembly will separate as you drive. If the bearings are not damaged, you can correct this by attaining the proper torque on the nut (200+ lb-ft IIRC). Had anyone ever removed the nuts on your truck?

I have replaced probably 20 hub assys on 03 and newer K2500HD's this year. 95% of them were wider offset wheels/lifted trucks. They were complete bearing failures, tightening would not help here.

Both of my front hub assemblies have been replaced for the exact same thing. Censored
45,000 miles on the truck. 285's for 40,000 miles.

What kinda cost are you looking at to have hub assemblies done..I just put 285's on with 16x10 wheels and turned my bars up some....kinda wanna prepare myself for the heartbreak....

Jared

Dealer cost is around 220 each IIRC. Customer pay is around 380 each IIRC.

Hmmm, I replaced both of my front hub assemblies last weekend as well. I wanted to replace the o-ring in the steering knuckle as well, but the dealer did not have the o-ring.

Eric better start selling those at his store too.

Did some research today. I called the shop where I bought the lift kit, and Rancho. They both said the same thing. It is not unusual for these bearings to need replaced once a year when running 285s and up. I wish they would have said that before I bought the bigger tires. It is just a poorly designed bearing. They get loose, and once they are loose they cannot be tightened and must be replaced. Evidently, the Ford Superduty's--which also use a sealed bearing--are worse than the GMs. I was told there are aftermarket bearings for the C/K trucks that last much longer, but no one makes an aftermarket bearing for the HDs.

I was out of town and had to buy hub/bearing assemblies at the dealership for $317 a piece. Eric has them for about $225 each.

This is a major flaw in the design of our trucks. GM should have put in a straight axle in the HDs. Until they do, the only choice for a 3/4 ton truck for serious rough road work is the Dodge. How embarrassing.

Black Dog,

The nut on the HD 4x4 CV axle shaft is 36mm and needs to be torqued to 155 ft lbs. I have now done this twice, once when I installed the lift and then again last Friday. This nut puts no pre-load at all on the bearings. All it does is hold the CV axle in place. Now in the CV axle was fixed in place, then perhaps the nut could keep the bearing from loosening. However, the CV axle telescopes in and out 1/2" or more, which is required when turning the steering wheel.

36000 miles so far on 35's, no bearing problems...yet. On all of the trucks I've lifted over the years,Ifs units as far back as 88,yet to have one back with bad bearings. Only one I've seen was on a truck with 40's on it(K1500!!!), actual reason bearing separated was because outer(splined) part of CV sheared off. As for SD's, replaced many on trucks with low mileage and stock tires and wheels.
Look closely at the emblem on the grille of any Super Duty, do you see it?, look again..., figured it out yet? They circled the problem.

I wonder if the diesel engine being heavier than the gassers has some impact. Also, maybe the aftermerket front bumpers hurt as well.

just had mine replaced on right side under warranty 2004 hd duramax with edge , 315/75/16 wheels and a 6" tuff country lift. The dealer did it for free as a one time courtesy fix due to the lift and tires. It feels like the left side is on its way out also. .....Who is this eric person selling the hubs for $225.00 I would like to get his number to buy the left hub

Black Dog,

The nut on the HD 4x4 CV axle shaft is 36mm and needs to be torqued to 155 ft lbs. I have now done this twice, once when I installed the lift and then again last Friday. This nut puts no pre-load at all on the bearings. All it does is hold the CV axle in place. Now in the CV axle was fixed in place, then perhaps the nut could keep the bearing from loosening. However, the CV axle telescopes in and out 1/2" or more, which is required when turning the steering wheel.
The axle shaft telescopes at the tripod joint at the differential end of the shaft assembly. The stub shaft and nut do keep the pressed together unit bearing assembly from separating. It is pretty hard to call this a "design flaw" when they last indefinitely with stock size tires and wheels.

My left front went at 49k if I remember correctly and the right went at 54k. The bearings are underdesigned. I also heard that water can get in them if you drive in water deep enough.

Black Dog,

I see your point and agree that the axle nut washer and the CV axle could hold the bearing together if they were designed differently. However, the outside diameter of the back portion of the bearing is held in place by the knuckle. The CV axle only presses against the inner small diameter of the backside of the bearing. The axle nut/washer also only presses against the inner diameter of the bearing. So while the inner diameter of the bearing is held together, the outer diameter is only supported at the knuckle. The wheel-side outer diameter of the bearing remains unsupported, and this is why the get loose so often. A sealed wheel bearing that cannot be tightened has no place on a truck.

They don't really last indefinitely with stock tires and wheels. I was concerned about finding the bearing/hub assemblies when I discovered what my problem was. I needn't have been concerned--EVERY little dealership in the three little towns I called carried these items in stock. They fail quite commonly.

Further, any supposed "heavy duty" truck that cannot accept bigger tires and wheels so you can really use it as a heavy duty truck has a serious flaw. What good is a 4x4 if every time to try to turn around on an old logging road you high-center on something? GM should have put a straight axle with real bearings on the HDs.

I also heard that water can get in them if you drive in water deep enough.Yep, This is why I wanted to replace the O-ring in the knuckle. I drove through some really deep water to get home. (I-10 in Houston). I think it washed the grease out of the bearing.:(

Yup, I just did one on a Super Duty yesterday... TOAST! 35K, 315's.

They definately don't last indefinately on stock trucks.
1/2 ton trucks all with 245s:
93- replaced both at around 90000 miles
dad's 95-replaced both at around 40000 miles, along with idler and pitman
dad's 2000 replaced passenger side at around 55000
These trucks didn't have big tires and were used on the farm but I wouldn't say beat on. First thing I did on this truck was slap 285s on it, and if I end up buying wheel bearings sooner then I will consider it worth it because these tires are so much better than the 245s.

I talked to another forum member on the phone today. He has run BFG 295s on stock rims for 100,000 miles now. He hauls heavy and spends a lot of time on rough and rocky terrain. His bearings are still tight. He also has the Hot Juice, and he has an even heavier front bumper than I.

Maybe these bearings are just susceptible to being improperly pressed in, and the one that aren't right don't last?

Max,

What part of Southern Oregon are you from? I am a native Oregonian and graduated form Grants Pass High School in 1978. I usually make it home once a year to elk hunt the SW Cascades in October. I am currently active duty USAF. This past Oct I saw a dk blue CC DMax flying up HWY 62 between the dam and Shady Cove. He must have been chipped. It would have all been good except it was a rainy day and the road was wet.

Blaine

EPHS in 1996, Live in C.P. right now. We do all the service on that truck you saw, if it was the one with 4 huge hoop-steps. It's chipped. Next time you are in, get it touch, we could BS over a beer or six.

Max,

Small world. I went grades 2 - 9 in Central Point, then we moved to GP in 1975. I sent you a PM with my e-mail.

Saw an H2 today and it go me to thinking. I called Rancho tech. They told me the H2 front hub/bearing assemblies are virtually identical to the HDs. The H2s run what, 34" tires? I wonder how many bearing "loosenings" they see form H2s?

Blaine, you have put your truck throught the mill since I responded to a post of yours. I am sure you will get to the bottom of it.

Michael,

Any ideas?

No, but ask me in 20K miles. Sounds like another GM weakness maybe. OTH, you did mention tire wear issues. if the tire isn't sitting square, then there is lateral stress on the bearing full time...not designed for it. A thought.

I am going to have the alignment checked........

I have had three wheel bearings replaced in 75,000 miles, so the 2" keyways with 35's do not help this situation. One wheel bearing was so worn out that it worped the rotor, caliper and the dust shield. About two week before that wheel bearing started smoking (yes it got that bad) the ABS light came on so I thought it was my brake pads going bad and not the wheel bearing. It was $1000 dollars to fix that F%&K up. The ABS light came on because the wheel hub was getting hot enought that it ruined the ABS sensor on the hub. So be careful if your ABS light comes on, it could be your wheel bearing getting hot.

I had the front end alignment checked today at a shop with guys who know about lifted 4x4 trucks. Caster and Camber were fine. However, I had about 5/8" of toe out. That explains the wear on the inside of the tires. I am not sure how the alignment got so bad. When I installed the tie-rod sleeves, I had toe in. I measured and set it myself. Maybe because of the large amount of sloppiness and movement in our steering system, I didn't really have the toe set like I thought I did. BTW, the front suspension hasn't settled, and of course such settling would cause toe out.

The guy at the shop was good. He checked everything and then set the toe. Next he drove it, and he also had me drive it. Then he put it back an the rack and rechecked the toe. It didn't change from his first setting.

The guy at the shop thinks part of the problem with wheel bearing "loosenings" on these trucks are the yellow bump stop/springs GM has on these rigs. He is not impressed with their "springing" ability. He thinks they bind the suspension and put lateral stress on the wheel bearings. While I don't see how this would put stress on the wheel bearings, I do see how it could stress the a-arm bushings.

I think part of the reason my bearings loosened so fast is because of the excessive toe-out. Here is how. Toe out causes the tires to try and "pull out" away from the truck. This outward pull is "felt" by the wheel, the wheels studs, and the hub. RE my earlier post about how the axle nut and CV joint only hold the inside portion of the bearing together, and how the outer portion of the bearing is not restrained from moving outward. All this works to loosen the bearing by pulling the inside of the bearing out form the outside.

Remember, my wheel bearings were solid 6000 miles before they loosened up. Perhaps all this is just a result on my not being careful enough in setting toe-in?

Regardless, a lifted 4x4 rig does require more maintenance that a stock rig, and I can assure you part of my normal maintenance cycle will include frequent checks of toe-in. I'll know in a year if that solves the problem.

Thoughts anyone?

With new alignment, Get some chalk and make a line across the tire. Drive a hundred yards. Does the chalk wear off evenly? If not, consider readjustment.

I bought an IR gun (pyrometer) like the AC guys use. After a days driving, if the inside of the tire has a different temp than the outside, adjust.

It is also the correct way to set your tire pressure, most of us are overinflated (empty) using placards. My rear 315's run around 28 psi now. Front at 38. And the tires show no signs of wear. BTW 1.5-2" of torsion lift is where the alignment adjustment ended on mine, so I lowered a quarter inch (one turn) to be on the mark.

I reshaped my yellow jouncers, they are part of the progressive front end rate. In the course of messing with lifts etc, they often get displace a quarter inch or more from the a-arm. I believe GM designed the stresses with the a-arm resting (barely) on the jouncer. This would limit travel, .25" jounce spacing is over an inch of wheel travel.

As much as anything, torsion lifting would stress the bearings with each bump, (a close look at the "dipod" geometry might reveal that) so 4 wheeling demands stock ride height IMO for longevity. Obviously, a real lift is in order.

Keep in mind this is just the stress opinion of an engineer, don't know where your torsion settings are, what is important, is making the a-arms close to horizontal, with minimal down angle.

One other thought. When running a down angle on the a-arms, a little extra toe in might unburden the bearings. I'm not an alignment expert or anything, just looking at the stress points. Use what I say lightly. If you have fresh tires, or can rotate an even set to the front, that is a good thing to check wear after a few miles. When I did the torsion lift, the wear problem was apparent within 200 miles. That was with new tires and the little flash parts and nubs wore off quickly on one side. The chalk idea helps make it easy to detect.

Michael,

I already have the Rancho 4" lift which allows me to run the CVs at stock angles, and the jouncer is just resting on the lower a-arm. I ahve had the lift for the last several months.

Interesting idea on the lower tire pressure. Assuming proepr toe, waht temps should the tires be?

Another interesting thing happened to me today. I was driving back from hunting. I had taked a firend's son out on his first trip. On the way back, I went over a sharp dip in the road. I had been over this dip before, so I knew to slow down. I was going 10-15 mph, maybe 20 max. As the suspension bounced I heard a "bang", and then I noticed the steering wheel needed to be 1/2 to the left to make the truck go straight. I knew I hadn't hit any rocks, there were none above road height. When I stopped to check, I discovered I had broken a torsion bar relocator.

I put these on my truck to get the t-bats back up into the frame after I installed the Rancho lift kit. They are a great idea, but this is the second time I have broken one, and I am coming to the conclusion they just aren't stout enough for the diesel engine and a 200 lb front bumper.

The suspension had settled all the way down on the right jounce stop. Of course, this "toes out" the right side a lot, and winds up making the truck run in an excessive toed-out condition--something like an inch or more toe out. I was back in the middle of nowhere, and had to drive out about 170 miles.

It doesn't appear anything other than the relocator is broken. The CVs are fine, my new front wheel bearings are still solid, the a-arms bushings and balljoints seem okay, and there is no uneven wear on the tires. I won't know about the t-bar itself until I get the truck put back together.

WHY Oh Why didn't GM put a straight axle on the HDs?

Michael,


Interesting idea on the lower tire pressure. Assuming proepr toe, waht temps should the tires be?


The idea on measuring temp, is too make any adjustments that "even" the temp across the tread. In the case of alignment, comparing inside and outside temps. If you have inner tire wear, guarantee the inside is getting hotter.

For proper inflation, compare the edges to the middle. Hot center=overinflation, hotter edges=underinflation.

There is a host of benefits, besides a longer lasting front end, optimum braking traction, etc.

Too bad about the relocators, seemed like a good idea, but I can see how they have to handle enormous torque. Is it just coincidental that it broke after alignment work? Be glad it broke, that is telling an important story.

Here is another thought. With that heavy front end, I'll bet you have a whole lot more travel going on than was originally intended by GM (and a plusher ride). I'm just making a guess here. If you want to keep the relocators, take some stress off them. The yellow jouncers. If you can relocate them to just touch the a-arm at rest. I know they are not made to easily accomplish this. Or perhaps even better, you can get timbrens that are more easily shimable. You don't want to break a TB. The timbrens sound like your solution, especially if you have a gap between the a-arm and jouncer, and perhaps even if you don't. Check out AW Direct if interested, plow vehicles use them a lot. During the heavy excursions, bumps, they give the front end more progressive spring rate, and therefore, less uptravel.

I think you can learn to love the IFS if you work with it.

I remember you had some pics of your lift and relocators. What link is that?

The jouncers already touch the lower a-arms when everything is at rest. I don't think the toe adjust was a factor, but not all of of this stuff is intuitive. I think the relocaters need to be beefier for HDs with diesel engines. I think that last bounce through the dip was just the final straw. Maybe if I had happened to look closely at that relocator before it broke I would have seen a stress crack?

The guy who makes them is thinking of making it a two-piece unit instead of a 4-piece unit. I think that would fix it. He told me that the relocators would break a torsion bar, and they had done that in testing. However, he didn't test with the heavy t-bars we run in the HD DMax. I think we run the second stiffest t-bar that GM makes for pickups.

I know eveyone's big concern with IFS are CVs. However, after driving for 170 miles on a CV angled up a gross amount and not hurting it, I think GM did okay on the CVs. I would prefer coil-overs to t-bars, and if there was a way to tighten the front wheel bearings, then the IFS may be fairly trouble free.

I am putting the stock Rancho t-bar drop brackets back in. This is not so simple. I am in the middle of a move from San Antonio to Tucson, and my household goods are already in AZ. We leave this Sunday to make the trip. Of course, the box that has those Rancho T-bar pieces is with my household goods, so I had to buy some new ones and have them overnight expressed--I pick them up tomorrow AM and will get my truck back together. At least I have my tools and guns with me--I always take those myself.

Until Realift builds a beefier t-bar relocator I will just have to put up with the couple inches less ground clearance I get without the relocators.

Attached is the pic from my truck. The website for Realift is: http://realiftsusp.com (http://realiftsusp.com/)

Hope this is the last of your issues front end issues. You have to get it aligned again?

If you can, take a pic of the relocator, when you get it off.

Would be interested to see what the manufacturer says. I'm assuming he sees a lot of this. He better get a remedy, or he is going to kill a car full of people.

I am definitely going to have the alignment checked. The manufacturer has been very good. He said he got a bad batch of steel and says he'll replace my relocaters with new ones. He has also has made them a bit beefier, and he made them beefier exacty where mine broke.

The US Military is working with him. Evidently, they are testing some GM/Chevy HDs (w/lift) and want to use the relocators. I would be very happy with a set of mil spec relocators.....................

I am currently waiting for my parts to come in. They were supposed to be here at noon, but there is some confusion as to whether or not noon is a guarantee for UPS Next Day Service this time of year. I hope they get here soon, as I'd rather not have to do this in the dark with a flashlight........

BTW, since you are in Phoenix, I'll be in Tucson, and Realift is located about 45 miles North of Tucson; we should just go pay Jeremiah a visit and see how he makes these things.

If I could get away from training the new puppy (brat). Sounds like a good field trip.

But holy cow, is there a chance that will happen again?? I would be soul searching.

Here are some pics. Looks like the metal crystalized in a couple places.

You must like living dangerously. What do you think the result would be a 70 mph?

Twice I have had the suspension settle a significant amount when traveling around 20 MPH. Both times were relocator failures. The first settled the suspension about 1.5", the next settled it 6"? Anyway, all that happened both times was the steering wheel turned opposite the failure to recenter the front wheels with toe-out. There was no swerve or pull or anything. It was kind of like taking off in an airplane in a crosswind, when the plane naturally "weather vanes" into the wind.

In fact at 20 mph, the only indication I noticed was the steering needed to be wheel rotated 30 - 45 degrees or to go straight, and it took a hundred feet or so to notice even that.

I do not know what the reaction would be at 70 mph, nor do I have any plans to test this.............:)

BTW, the ride with the stock Rancho set-up is a little smoother than with the relocators.

The final results from my broken relocater.

- A cosmetic dent on the underside of the right upper A-arm
- A small bend in the upper portion of the "box" on the frame that holds the right upper a-arm. It started to open the weld, so I had it re-welded
- A small horizontal "pinch" tear in the right lower balljoint boot
- A very scrunched looking right side jounce stop/auxillary spring

The only "open" issue is the small tear in the lower balljoint boot. It isn't leaking grease, but I will have to replace either the balljoint or the boot eventually.

I only lost an inch of ground clearance but returning the t-bars to under the frame. the ride is noticably smoother. I now have about 10" under the front skidplate, 10.25" under the t-bar crossmember, and 7.5" under the rear diff. This is with 33" tires. It is plenty for driving on rough hunting roads and mild off-roading.

I am looking for wheels with less offset right now to help the life of the front bearings.

I never thought about offset.

Black Dog,

The nut on the HD 4x4 CV axle shaft is 36mm and needs to be torqued to 155 ft lbs. I have now done this twice, once when I installed the lift and then again last Friday. This nut puts no pre-load at all on the bearings. All it does is hold the CV axle in place. Now in the CV axle was fixed in place, then perhaps the nut could keep the bearing from loosening. However, the CV axle telescopes in and out 1/2" or more, which is required when turning the steering wheel.
What is the nut size on the 2500 HD 2 Wheel Drive? What is the torque spec?

Thanks for the help. Replacing the drivers side this weekend.

Brian.

i seen some heavy duty hubs with bearings offroad magazine in march 2005. they are timken parts, i believe the part # was sp580304 when i looked at them. only thing is that they are pricey at more than $600 each. site they listed was http://www.gounitrax.com/main.html

timkens site is http://www.timken.com/