2nd Gen Non-Engine/Transmission High speed vibration

[THess]

I went on a long trip yesterday and noticed a vibration at speeds of 55 and above. I didn't notice the shake until I was loaded on the way home. Only about 2500 lbs in the bed. The steering wheel doesn't shake but the shifter does. It only does it when accelerating up or down hills. When I coast the truck rides real smooth. Someone suggested a u-joint in the driveshaft. How do I check this and does this sound like it could be the culprit?

 

[snappy]

Inspect the u-joints for rust or a trail of rust from an end cap. This happens mostly on sealed u-joints. Grab the driveshaft close to the u-joints and move it side to side and up and down. Look for play/movement. There should not be any.

You could put jackstands under the differential and run it up too. Also check the rear yoke for play. This yoke can wear and spread open which will allow a u-joint to move. Grab the driveshaft and look for play in this yoke.

 

[Missouri Mule]

You mite have to take the driveshaft off. I have read that the sealed u-joint can freeze when they dry out and need to taken appart for inspection.

 

[THess]

Thanks for the ideas. I haven't had a chance to get under the truck and wiggle anything but I did remember one more symptom. When taking off from a dead stop I can hear a little pop from underneath.

 

[JMcCoy]

Make sure you are not parked on a hill with the transmission in park. This will put tension on the joint and make it feel tight. You want to be on flat grownd and in neutral. Give the carrage bearing a juggle as well Also look to see if you threw a weight or broke a belt within the tire. Check each tire for roundness. Good luck

 

[THess]

It turned out to be the u-joint at the back of the drive shaft. It came apart and went together really easy but I broke one of the little bolts that hold the cup straps(?) on. I can't find one to match anywhere and the closest dealer is in the next county. Can anybody tell me what the correct name is for those little bolts or where to order some?

 

[snappy]

I call 'em u-joint strap bolts, but it would not surprise me if the dealer called them propeller shaft bolts for the rear differential. I have bought them at the dealer.

 

[WilsonF]

I got mine @ NAPA IIRC about $12 for the kit bolts and straps.

Floyd

 

[PC12Driver]

The u-joint straps shouldn't be reused. They're intended to deform slightly around the u-joint cups for a snug fit as you tighten them down. Along those lines, the strap bolts only get about 14 ft/lbs (and blue Locktite), so don't overdo it.



Quad 4x4 can hook you up with whatever you need. They have a kit (QU40709) with two straps and four bolts for about $10. Good folks and great service.

 

[THess]

I ordered from quad4x4. I've dealt with them before and they are great to work with. Thanks everybody.