S-10 pinion angle

[wizbang]

Have a 2003 ex-cab 2wd, auto trans. I have done the lower arms and bags w/ outbd mounted shocks up front and the wishbone deal in the rear, no notch in the frame along with short snubbers.

I cannot find a good position for the pinion angle that gives a half way nice "noise/vibration" free ride ?

It is either horrible on acceleration or horrible at 70 mph or noisy all over the range ? Thought maybe it was the driveline, had it gone through, no difference. Even took it to a completely different shop, they said it was in great shape ?

I can adjust the angle from way high ( 1.5 + ) , to way low ( - 2.6 ) and various places inbetween. It just changes the way it acts ?

Anybody got any ideas on where they found a good angle ?

[Tony@AirRide]

Is this a one piece drive shaft or a two piece?

[wizbang]

Sorry, yes it is a 2 piece driveshaft assy, with a double ujoint deal at the rearend, like a cv joint ?

[wizbang]

Nobody has any suggestions ?

[Tony@AirRide]

One thing I would check first would be the slip yoke on the carrier bearing. Those have a tendency to get packed full of dirt and grease causing the drive shaft to prematurely bottom out on the debris.... that could be causing the vibation and the noise.

[wizbang]

I had the complete driveline assy rebuilt at one shop.. Didn't make any difference, so I took it to a completely different shop and had them check it. They agreed it was in great shape.

I can change the angle from =2.8 degrees, to - 1.0 degrees and all it does is change the amount of vibration and the rpm/mph. At - .8 degrees, it makes a little noise on hard acceleration from a standing stop then it is quiet until 75 mph , then it vibrates pretty bad from there on up, really bad if your on the throttle at that point ?

What if I take the rear shaft out and replace it with a non-cv type ujointed shaft ?

[darren@ridetech.com]

Typically if the vibration beocmes worse on acceleration it is too high. If it gets louder on deceleration it is too low. Is it possible that the driveshaft is out of balance?

[Alistair Davidson]

I had a similar problem with my car, which has a one piece driveshaft. Turns out it was a broken trans mount. Probably not the cause of your problem, but worth a look maybe.

[britt@ridetech.com]

I have an 02, ZQ8, extended cab, 4.3L, auto trans that I use for R&D. It has Shockwaves and tubular arms up front and the normal AirBar in the back. Not sure what I set the pinion angle at (I did it 5 years ago) but I had the same vibration problem. I ended up having the entire shaft rebuilt. It was the double u-joint deal on the rear of the shaft.

I know you had yours checked, but I have the exact same truck and it has had zero driveline issues since. I'd check everything else just to make sure.

[wizbang]

Mine is the same truck as yours , just a year newer.

The driveshaft was rebuilt. All new joints , etc. I double checked the phasing of this two piece assy after talking to one of your techs last week, it is correct. BUT, he told me I have the truck to low ? I have the rear bump stops at 5/8" tall and 2.5 inches of air between them and the axle housing. I haven't checked the bag mounts, as he wanted ( the note is at home? ) like 9.0 between the mounts. I'll have to check that.

It doesn't sit too much lower than stock at this point that I drive it at ?

I bought it brand new, so I know it wasn't modified until I did the bags.

To be honest, I'm not happy with the way it is now, I am kinda of thinking about buying all stock stuff and taking the bags out.

[sjutte]

when they "Rebuilt" your drive line did that include replacing the carrier bearing assembly? i have a 99xtreme and had a nasty vibration after i lowered it. took the drive shafts out and removed the carrier assembly and found the rubber was shot. replace the assembly and now just have a nice tire vibration, need to replace them soon.

[ride1216]

i have an 02 s10 ext cab with the cv style double knuckle rear shaft too. its given me nothing but problems. ive had it rebuilt and it only lasted 10 months. i do have 3in blocks in the back but i dont see how that could screw up everything that bad. its sitting right now. i dont have a solution for it. cant find used one in junk yards. why rebuild it if it last 10 months....so i dont know what to do. it was the center ball on the shaft that wore and caused major vibration.

[Madferraristi]

I've been rebuilding and modifying driveshafts for over 40 years and a CV joint, in good condition will run vibration free through a much greater angularity change than a single u-joint, that's why they are used on lifted 4x4's, because they are the ONLY way to connect a driveshaft, even with the front (and sometimes rear also) dif rotated upward substantially. On large luxury cars they are/were used simply to remove ANY vibration.

In many instances, due to the cost of rebuilding a totally destroyed CV on say a seventies Cad or Lincoln, I have removed them entirely and installed a single joint with satisfactory results.

It sounds to me though, that your issues are somehow 100% driveshaft related.

Here is what I would do. First I would double check the timing/alignment of the front shaft to rear shaft. One tooth of misalignment can cause quite a noticeable vibration. Second, I would unbolt the CV from the rear end and rotate it through maximum angularity by hand to feel for any sign of binding which could certainly cause your symptoms. Prior to bolting it back to the dif, I would lightly flat file both mating surfaces, just enough to check for dings or damage that would cause misalignment.

On the assumption that everything checks out OK, then ask the shop that did the rebuild if they rebalanced after doing so. This is not always necessary but occasionally it is an absolute necessity due to mis-positioning of the u-joints by the factory assembly equipment prior to injecting the joints with the nylon rings that is changed when it is reassembled using the steel snap rings.

If this continues to give negative results, then my next suspicion would have to be pinion angle. I typically set pinion angle down 2* in relationship to the transmission or in your case, the front shaft. This is typically sufficient to allow the angle to become neutral under hard acceleration. However, at this point, I have no idea what angle change occurs when you are accelerating. This, of course, may be the crux of the whole issue.

You say you have done "the wishbone deal". Can somebody explain this to me in term of angularity change under hard acceleration?

[Madferraristi]

i have an 02 s10 ext cab with the cv style double knuckle rear shaft too. its given me nothing but problems. ive had it rebuilt and it only lasted 10 months. i do have 3in blocks in the back but i dont see how that could screw up everything that bad. its sitting right now. i dont have a solution for it. cant find used one in junk yards. why rebuild it if it last 10 months....so i dont know what to do. it was the center ball on the shaft that wore and caused major vibration.

Sorry to say, has to be a less than best rebuild. They last 100k in many OE installations.