vavtx

About 800 miles ago I replaced my clutch with a LUK Pro Gold. Everything seemed fine. I installed add a leaf springs on the front and back the other day. Thay gave me about 1 3/4 inches of lift. I really like the look and the ride was not hurt that bad either. Now I have a slight vibration that seems to be coming from the driveline. I only get it starting out in 2nd gear. I feel it after the clutch is fully released and then only for a few seconds while accelerating. The truck seems to shutter, not violently, but enough to feel. Any suggestions or ideas?

edwinsmith

How are your U-Joints?

spunbearing

That sounds like a clutch chatter. Mine does that sometimes too. It varies by how you let out the clutch.

torquefan

That is a launch shudder caused by driveline angles, which changed when you raised the truck. I think there is an old bulletin on that for your year of truck. You may try lowering the driveshaft steady-bearing (if equipped) or I think the bulletin mentions shimming up the rear axle under the lift blocks, to raise the pinion angle.

rebal

you might keep an eye on your u joints lifting the truck changes driveline angle and can cause u joint failure real fast if the ujoints have been in for a long time "the wear pattern on the needle bearings changes from the drive line angle change" and try to chim the rear axle to get the pinon angle in as close as possable

Hemi Cat

put an inclinometer on the drive shafts and pinions and trans and get your u joint angle. most std u joints are supposed to be 5 deg or less and be 1/2 the combined angle. When you lift the truck you generally compromise that angle. Shimmint the rear axle to get the pinion angle back is good, dropping the trans down will help the rear shaft but compromise the front shaft, but a cv joint will allow more angle, then the front axle becomes a problem, you can't shim it for pinion angle because of the caster angle for the front wheels. So it is a juggeling act to balance out the variables and get it to run right without vibration and short u joint life. hope this helps

jiMMyCTD

i vote for this. my friends power stroke did it BAD after the lift. he shimed the rear and shimmed the pilot bearing as well. jiMMy

Bushy

Yup, I'm gonna throw my hat in on the driveline angle solution too...
You can try adding about 1/4" thickness to the steady bearing mount. Just get a piece of plate steel 1/4" thick, cut it and drill out the 4 holes needed for the mounting bolts and tighten it up.
Try that...it's cheap and easy to do. You may find it's worse or better but you'll know if you're on the right track with this.
Some of the 1st gen trucks had no spacer on them and had to be brought in to a dealer to install the current spacer. Later, the new 1st gens came already equipped with the spacer in place.

pb....

vavtx

Thanks for the quick responses. I don't think it is clutch chatter because it doesn't happen until the clutch is fuuly released and the truck is in motion. I will try the a spacer under the steady bearing mount. That makes sense. The drive shaft angle is the only thing that really changed after the add a leafs. I will let everybody know what happens.

vavtx

OK, I put a 1 inch block of wood under the steady bearing mount. The shutter went away but my clutch chatter dramatically increased. Is there a relationship between driveshaft anlge and clutch chatter? Tomorrow I willl remove the wood and mount something more permanent under the 4 bolts on the bearing mount. I just put the wood under the two bolts or the carrier for the bearing mount. Any more ideas?

vavtx

OK, false alarm on the clutch chatter. Evidently it was damp or cold or both. After driving up to operating temperatures, the chatter went away. The truck had been sitting for about a week and it has been below freezing and damp here. It looks the spacer under the steady bearing mount fixed the problem. Thanks again!