Got a 98 T100
3.4 L
Auto Trans
4x4

Been getting a strange shudder out of the truck. Feel it more in the seat or under the truck.

Only happens when accelerating after coming out of a curve. Does it for a bit then goes away. Almost feels like a misfire but I don't think it's engine related.

Put 2 u joints in. One at transfer case and one at rear end. Didn't touch the other 2 because of cardan joint. So they are still old. Also replaced carrier bearing and rear seal (was a bit leaky).

The vibration isn't as bad, but it's still there. Only while coming out of a curve with acceleration though.

Had it hooked up to computer got a lean code back.

4x4 works fine.

Tires are only a few years old.

I don't know what else to do. Replace cardan joint? Bad MAF sensor? Bad O2 sensor? Alignment and balance? Rear diff bad?

Anyone have some opinions?

 

New Carrier Bearing <br ><br >





New u joint at transfer case<br ><br > New u joint at rear end<br ><br > Old double cardan joint (with old u joints) <br/><br/>How do I know if it's bad?<br ><br >

 

If you haven't changed your wires and plugs for awhile, may be a good place to start. They say if any of those are bad...it can cause the driveline vibration/shudder. Did you mark your driveshaft connecting points to make sure you installed it back the way it was? Also, take a look at your rear shaft and see if the balance weight is still on there. How does the truck feel when hard braking?

 

Brought to shop. Will be there until early next week. Diagnosed with a misfire. No CEL though. Cylinder on plug was completely burnt.

Changing plugs, timing belt, serpentine belt, and water pump. $900! Does that sound right?

Hopefully this will solve my issue. Any other suggestions?

 

Ok, just wait and see how your truck is after the work is done. $900? well I have heard that price for doing the timing belt so, I would say that's about right. Probably a $300 charge or more for the complete timing belt kit and other parts. The rest labor. If the work doesn't fix the issue, make sure
you post back to update and we'll go from there.

 

How bad was the carrier bearing replacement? I have a similar shudder that's tied to actual speed vs. engine speed. Chasing driveline now. U-joints seem tight, but there's a bit of wobble in the rubber around the carrier bearing.

 

Abyssdncr, I recently replaced the center bearing on my sons 97. They will have some movement in them in new condition. But if it seems to have a lot of movement up & down and side to side then it's shot. As far as u- joints go, i have seen them appear to be ok and went ahead and replaced them anyway to find they were froze up and did not function like they should in good condition. Another thing to check is the rear brakes/drums. They could be hanging up and check to make sure you emergency brake mechanism is releasing like it should.

 

Thanks John. Got the alignment done yesterday, but it was just barely out and didn't change a thing on the road. U-joints & the center support bearing ordered from RockAuto - hopefully, they get here by the weekend.

 

Ok, Good Luck! Update me then!

 

CSB replaced, and things certainly feel a smidge better, but there's still a slight the vibration that comes on around 55-60. The isolator bushing was pretty trashed. New one has no discernible play at all.

Tried to do the u-joints too, but I couldn't even get one cap off. There was just enough still stuck in the yoke at full press that it was going to take something creative to fix & it was getting dark. Try again another day. Planned to grease everything and check, but still haven't done that yet either. Might have to go for a drive w/o the rear shaft to give it a check-see.

 

Might be a good idea! Drop the rear shaft and run it and see if your still getting the slight vibration 55-60. if you still have it then, make sure your tires are balanced. If you don't, I would start with replacing all u-joints. Or could be rear wheel bearings too. Check it though only running truck with front drive shaft first. My sons is a 1997, I will try and post some pics up then. Got a 4inch lift with 33 inch tires on and 217.000 miles. These truck will run forever! Thanks for updating!

 

Sorry....trucks I mean