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Mudderoy
08-12-2011, 12:37 PM
Recently I was replacing a rear transfer case seal, so with the rear drive shaft removed I decided to break out (of the package) my angle finder with magnetic base!

I checked the NP242 transfer case with 1" RC drop and it was 5 degrees. I measured this from the end of the shaft, you know where the slip yoke slides on to.

Then I measured the Chrysler 8.25 axle angle. 15 degrees! So it is pointing at the transfer case. I was really puzzled by this because that would be the drive line angle difference at 10 degrees!

I double checked my measurements and thought about how I was doing it a little, and I couldn't see how I was doing it wrong.

Later 4.3lxj (also puzzled as to how I could still have all my teeth driving with a 10 degree difference in the two drive shaft connection points) asked me to measure the angle from the filler plug on the NP242. I did and I measured, checked, and re-check, 7 to 8 degrees. It's about midway between the two.

So that means the difference is ONLY 7 degrees!!!! :timeout:

I really would like to have a smoother ride, even if my teeth aren't cracking and falling out. Also no telling what damage I am doing to u-joints. I should have checked this much sooner. I just assumed the angle must be fine because it wasn't vibrating like driving over a washboard.

After contacting RC I found that the leaf springs came with 3 degree shims. So if I get a set of 6 degree shims that should put me at 9 degrees and 8 degrees.

Mudderoy
08-12-2011, 12:38 PM
Hmmm can you stack shims? I hope so...

4.3LXJ
08-12-2011, 12:39 PM
Tony, did you measure the face of the pinion yoke when you had the driveline removed?

Mudderoy
08-12-2011, 12:45 PM
Tony, did you measure the face of the pinion yoke when you had the driveline removed?

I measured both transfer case (end of shaft) and axle with drive shaft removed.

5 degrees and 15 degrees.

I re-measured the transfer case (filler plug) with drive shaft in 2 days later.

8 degrees and 15 degrees.

4.3LXJ
08-12-2011, 03:38 PM
Tony

I have used the 5° limit on here and other forums due to personal experience. At 6° I have noticed a little vibration, although not very noticeable on a driveline I used to have in a diesel pickup I had with 450 u joints in it. Big stuff. However the official number from Six States Distributing, a driveline specialist is 6°. So in theory you are only off by 1°. So your pinion is tipped up to high? You could probably just remove a shim you have in and fix that easily.

Mudderoy
08-12-2011, 03:48 PM
Tony

I have used the 5° limit on here and other forums due to personal experience. At 6° I have noticed a little vibration, although not very noticeable on a driveline I used to have in a diesel pickup I had with 450 u joints in it. Big stuff. However the official number from Six States Distributing, a driveline specialist is 6°. So in theory you are only off by 1°. So your pinion is tipped up to high? You could probably just remove a shim you have in and fix that easily.

Removing the shim is what I thought first too, but then I thought about it and actually the 3 degree shim is rotating the pumpkin down. So I would increase the angle from 15 degrees to 18 without it! I'm just really surprised it is angled so far up.

The fat end of the shim is on the rear end side of the axle.

4.3LXJ
08-12-2011, 04:37 PM
Tony, send me some pics. I am having trouble visualizing this.