I recently acquired a disc brake rear axle out of a blazer that I wanted to use in my F100. After sandblasting it I was going to cut off the spring pads and and set it up with new pads. A quick check found that the pads were set at the proper location on the axle already for my truck. I have springs and mounts on my truck out of a 78 Mustang II. After setting the axle in and bolting it down I find that my pinion angle is over 10 degrees up. I normally set my pinion at about 3 degrees up. My question.....would it be worth using the the shims to correct the pinion angle or just go ahead and install new spring pads and the set the pinion angle where I want it. Being off by about 10 degrees seems to me a bit much to correct with shims. Being able to grab a rear out of a junk yard mount it directly in my truck sounded too good to be true.
Relocating the pads would probably be best, I do have some 6* shims on my front axle though. Posted from the TJJ App for iPhone & iPad
Just my opinion........but I think that is an excessive angle to correct by shimming. When you tighten the U bolts, mechanically speaking, you are trying to force the axle pad to slide toward the spring. That's what wedges do. I do understand there are 'pegs' or center bolt heads involved, but they are/were not intend to deal with that much shear load. The pads being at the wrong angle is, in effect, the same as if they had been spaced incorrectly, but at the right angle. Either way they need to be compensated for. If you want a professional looking job when you are finished, I would suggest you go with your original plan. Ray
I'd redo the pads myself I did see some substantial factory shims on a mid 90s full size bronco 4x4 not to long ago.
I guess my better judgment had already told me what you guys are suggesting and I agree the amount of correction seems excessive for shims. Thanks guys, I'll be installing new pads to correct the problem.
They make wedge shims, which are much better than just shimming one side. If you can get wedge shims from your local spring shop; then that's what I'd do. Summit also seells them in all sorts of degrees and widths: http://www.summitracing.com/search?keyword=leaf%20spring%20shims&dds=1
Find a friend with a mill and make some full size wedges out of steel. The off road guys do this stuff all the time.
How are you checking the pinion angle?? You need to shoot for around 2* down form the motor center line, trans center the same...Get the motor center angle, set pinion 2* down....easy.....
I use an angle finder with the vehicle on the ground loaded as it would be driven. I figured I would get a disagreements on setup, but I've always set my trans. output 3 degrees down and my pinion 3 degrees up without any vibration problems. This truck is a street driver...........Is there a better setup for leaf spring suspension?
I started to address this issue in an earlier post but decided to pass. However, since you mentioned it again, I will add my $.02. I agree with what you say you usually do. The key is to keep parallel the the centerlines of the engine/trans and that of the pinion. Whatever angle that may be, usually about 3 degrees at normal ride height with weight on the springs, because that has been typical of most OEM installs in the past and the carb mounting pad is about that. Some folks 'recommend' dropping the pinion angle a degree or two below that to compensate for pinion rise on acceleration.......Unless you are settting up a race car, I disagree with that practice. For a street driven vehicle the pinion is not heavily loaded but a tiny fraction of the time. In my opinion it should be set for the majority of it's useage. Ray
You could build some angled blocks that not only take the pinion correction into place, but also give some extra drop if you wanted. I do like the idea of welding some shims to the stock pads and be done with it.
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