2nd Gen Non-Engine/Transmission Shudder when braking. Wheel bearing?

[KWentling]

My truck has developed a shudder when braking. It feels like what I would expect from warped rotors with shot pads. Can't hear anything unusual. It still stops in a straight line, but feels terrible. Truck is 4x4 with 76,000 miles. I had just rotated the tires a couple of hundred miles prior to the problem showing up. That was on a trip of 1100 miles. Lug nuts were torqued in the crisscross pattern to 140 ft/lbs. I pulled the wheels back off today and the brake rotors and pads look great and there is no decernable run out that I can eyeball. I'll pick up an indicator from work next time in town and check them. Rotating the driver side wheel there is a clicking sound when rolling the wheel forward, but not backward. It clicks about 15 to 20 times per rotation, so I'm not hearing a bad U-joint. Axle shaft and wheel bearing seem to have no play in them. I can't tell exactly where the noise is coming from. I tried the screwdriver to the ear and a piece of garden hose to try to locate the source with no luck. Sound is the same no matter how the steering is turned. Is this likely a wheel bearing noise or a noise from the differential? Would a wheel bearing cause the shudder? Anybody have any experience here?

I'd appreciate any suggestions.



Kim

 

[Motorhead]

It really sounds like a warped rotor to me. I also have tried to "look" to see the run-out. I'm sure if you put a dial indicator on the front rotors, you would find one with run-out.

 

[KWentling]

I drove it town last night and it was considerably better than before but not gone. I stopped at the shop and grabbed one of my indicators so I'll pull the fronts again and check the run out. Also got the stethescope from the horse trailer so I'll try to locate the source of the clicking. I'm about convinced that I was hearing the spider gears in the diff. Not sure if that's a good thing or not though. Thanks for the reply.



Kim

 

[QRTRHRS]

Do you manually adjust your rear brakes? The so called auto adjusters just don't do it. Get in the habit of doing them yourself. If the front brakes are doing more than their share of providing the stopping power, even a little warpage will be amplified. Rotating the tires will immediately change the feeling if you have some irregularities. I would think that the back tires would be smoother though when you move them to the front. That is if your front wears the tires even a bit funny as they often do. Do you run different pressures front/back? Can't help with the tick.

 

[KWentling]

Checked the run out on the rotors. Both are less than . 001 on both sides of the rotors. The ticking noise is the spider gears. Can really tell with the stethoscope. I replaced shoes on the rears about 7,000 miles ago due to a leaking seal on the drivers side and have not touched them since. I'll definately check that they are adjusted up. I looked the wheels over real good and made sure the stud holes were OK and the mating surfaces were clean. Taking the wheels of and then putting them back on seemed to change the severity of it yesterday. Wheels and tires seem to run true enough. I guess if adjusting the rears don't cure it I'll try rotating the tires back the way they were before and see if that does anything for it.

Thanks for the replys guys. Anyone else?



Kim

 

[Extreme1]

I've heard of rotors getting warped by over torquing a lug nut. Do you get to the 140 ft-lbs in 2 steps? It would be unusual if you were able to do it this way but that's the only thing that comes to mind since they have such little run-out with the wheels off.

 

[KWentling]

I just checked the run out on the inside of the rotors with the wheels mounted and torqued. Still about . 001 run out. I adjusted the rears also but haven't driven it yet. I use the impact to just bring the lug nut up to touch, making sure the conical lug is centered in the hole in the wheel, then go around it in the criss cross to snug them up good. Then I get the torque wrench out and take them to 140. I'm probably getting 80 to 100 with the impact the second time around. I think that's pretty much the standard way tire shops do it and it's the way I've done it since they first started putting disc brakes on vehicles here. My dad had a Standard gas station back when you didn't pump you're own gas. I got lots of practice late '60s to mid '70's. Not much for disc brakes untill the '70's though.



Kim

 

[Devildog]

Do the 98's have Anti lock brakes?

 

[Bugman]

Originally posted by KWentling

I'm about convinced that I was hearing the spider gears in the diff. Not sure if that's a good thing or not though. Thanks for the reply.



Kim [/B]

Kim, I have had similar problems. I could hear a front axle u-joint ticking when close to concrete median dividers. No spider gears in front diff are there? LSD in the rear has spiders gears, more like grinding, crunching and popping at first, till you wear em down to nubs and won't move. I was given a price of between $1,800 to $2,800 dollars to fix (depending what they find, yeah right!). Replaced spider gears and clutches myself, $200 for parts and the help of the TDR.



Was getting heck of a wobble braking, changed pads which helped a lot. Also found rears like brand new (causing excessive work from the front) manually adjusted rears... . BIG difference! Will take TDR advice: go with the bigger rear brake cylinders and adjust manually every oil change.



I still have a bit of a shimmy when braking but my rotors must be (are) shot. Without rears working the front must get too hot and warp etc. Can't do the bearing much good either. New front rotors for me next. The better the rears work the less time I have to spend on the poxy front brakes.



My 2 cents worth,



Bugman.

 

[KWentling]

I thought all diffs had spider gears. But I've been known to be wrong before. I drove the truck to work and back, and the shudder is still there. Now I'm wondering if the rear drums have gone out of round on it. I thought for sure it was in the front end, but? I could probably stand to replace the front pads too. They are the originals but still have about a quarter inch left in them. I'll mess with it more this coming weekend.

Thanks for the reply.



Kim

 

[Cooker]

Rear drums out of round will cause the shudder. I cannot believe you have 76k on the original front pads you must drive with a very light foot and brake very easily.



I would bet the front clicking is the u-joints.

 

[KWentling]

My truck has rear wheel antilocks.

The clicking noise is definately coming from the differential.

10-4 on the light foot. I think it mostly has to do with the type of driving though. My commute to work/town is 10 miles of hiway with one stop sign. Then another 3 miles in town with a maximum of six lights and one more stop sign. Gotta love Wyoming.