setting pinion angle

[SuperEx91]

my SAS is in the works at the moment. i was curious how i should choose my pinion angle for both the front and rear. i am making radius arms for the front and have weld-on brackets for the axle, i just dont know where to weld them in regards to pinion angle and caster. Also in the rear i am just doing a SOA and lift shackles. I heard somewhere that i should match the angle of what it is now stock but i am not sure if that is right. Also my ujoints have to be at the same angle to eliminate vibrations i believe.
When i mount my radius arms to the frame, would it be a good idea to mount them close to where the front output of my tcase is? (similar to how the trac bar and drag link have to be parallel) or does this not matter? Thank for the help-Tom

 

[unclemeat]

If you do not know how to set the pinion angle, then have professional do it for you. The pinion angle must be set at the same angle from horizontal as the angle of the transfer case driveshaft angle. If not the u-joints will bind and break. Some will add a degree ot to to account for axle wrap on the rear axle. Consult a professional or do a lot more research, and get angle gage.

 

[IZwack]

A somewhat related thread that came up recently:
http://www.explorerforum.com/forums/showthread.php?p=1636156#post1636156

radius arms to the frame, would it be a good idea to mount them close to where the front output of my tcase is?

Ideally that would be the best location to mount the radius arms as doing so would minimize the amount of length changes the driveshaft undergoes during flex.

 

[SuperEx91]

i was wondering about that cause i swear ive seen axles with the pinions in a straight line with the driveshaft. but doing this would require you to reclock the c's so your caster is correct right? so in my case, just set it so that at ride height, the t-case to dshaft angle and the axle to dshaft angle is the same. and maybe add 1* to the rear to account for axle wrap. i dont think i would have to worry about that tho.

now i am doing a SOA and lift shackles in the rear but does anyone happen to know what they set their rear pinion angle to just as a starting point for me? and for the front also if anyone has a similar setup(waggoneer d44 with 6" lift coils). any info would be a great help.

Im gonna assume the best place to measure pinion angle is on the yoke?

 

[mechanix]

i was wondering about that cause i swear ive seen axles with the pinions in a straight line with the driveshaft. but doing this would require you to reclock the c's so your caster is correct right? so in my case, just set it so that at ride height, the t-case to dshaft angle and the axle to dshaft angle is the same. and maybe add 1* to the rear to account for axle wrap. i dont think i would have to worry about that tho.

now i am doing a SOA and lift shackles in the rear but does anyone happen to know what they set their rear pinion angle to just as a starting point for me? and for the front also if anyone has a similar setup(waggoneer d44 with 6" lift coils). any info would be a great help.

Im gonna assume the best place to measure pinion angle is on the yoke?

Well the best angle would be zero degrees, but that aint going to happen. So I would suggest no more than 7* negative but I would say 2-4* would be the best. I think you will get more than 1* with axle wrap. So 2-4 should get you in the ball park when you are putting the pedal to the metal.

Eric

 

[SuperEx91]

now this is rear i believe. do you mean 7* from horizontal? and when u say negative is that pinion pointing down?

 

[Mud Bug 94]

for the front the caster has to be 7*(magic caster #) for the rear just have the yoke on the axle piont right at the yoke on the t-case....set them with the weight of the vehicle on the springs....

 

[SuperEx91]

ah. ok. misunderstood you yhe first time. the 7* is the caster. So you think i would be alright just welding my r/a mounts so that the caster is 7*? or if i do that will the pinion angle be way off? If 7* is a stock number than by lifting the front end, the pinion angle will change but it will change proportionally to the angle at the t-case. they should change at the same rate as long as the caster does not change. and will i be ok for the rear if i angle the pinion at the t-case and dont have a double cardan dshaft?

 

[IZwack]

i was wondering about that cause i swear ive seen axles with the pinions in a straight line with the driveshaft. but doing this would require you to reclock the c's so your caster is correct right? so in my case, just set it so that at ride height, the t-case to dshaft angle and the axle to dshaft angle is the same. and maybe add 1* to the rear to account for axle wrap. i dont think i would have to worry about that tho.

now i am doing a SOA and lift shackles in the rear but does anyone happen to know what they set their rear pinion angle to just as a starting point for me? and for the front also if anyone has a similar setup(waggoneer d44 with 6" lift coils). any info would be a great help.

Im gonna assume the best place to measure pinion angle is on the yoke?

Man we're getting all confused..

This is the pinion angle for the rear since its a single-cardan driveshaft:

This is the pinion angle for the front driveshaft since its a double-cardan at the transfer-case:

The transfer case and transmission generally do not sit at 0 degrees so don't assume that -- get an angle finder and take a few measurements at the transfer case's rear output flange.

 

[CDW6212R]

The first picure above is a good example, the orange lines. The main goal is to have those lines parallel, they should never cross. The angle being measured is from the driveshaft to the pinion shaft, or the trans shaft, or the transfer case shaft. The goal is to make those angles at each end of a driveshaft the same, thus the u-joints work smoothly etc. Good luck,

 

[SuperEx91]

ok thats better. i knew there was a reason i liked you izwack. will you be my babys daddy too? just kidding
anyways, now for the front does anyone know if i will have to reclock the c's since the jeep this was in probably didnt use a double cardan shaft and the pinion was not originally pointed at the tcase.

in my situation, i am making radius arms and mounts. i also have new springs and upper buckets. i am not sure where to mount those yet. also where to mount the frame mounts for the R/A's. i have a general area but not exact. what order do you think i should start in in order to make the least work and reworking of the mount positions?
i figured i first need to get the rear done because the front height will be determined by the height of the rear. i just dont know where to start.

 

[SuperEx91]

i just ordered an angle finder so thats a start:

 

[SuperEx91]

I was looking at my axle tonight and realized, like i figured, if i point the diff at the tcase, my caster will be way negative. What are my choices excluding reclocking the c's? Can i get/have made a driveshaft with single ujoints and just run equal angles at each end? What problems might i run into with negative caster? wouldn't i still get the same return-to-center effect since my caster would be around -7*? i dont think caster is a tire wearing angle is it? I just dont want to have to deal with cutting and rewelding the axles. I helped a buddy do it once, all we had was a hack-saw.

 

[IZwack]

As long as you've got a decent grinder (a Dewalt for example), cutting and re-welding the "C"s takes no more than a day.

 

[SuperEx91]

Are you supposed to cut the tube or grind the old weld and try to beat the C off the tube? i can use a band saw if i need to cut it. my only issue is that i am not sure how high the front end will sit yet, so trying this before it is put together will be very difficult without knowing the pinion angle. would it be possible to just get the axle situated and set the pinion angle and then remove it and set the caster based off of the pinion? thats about the only way i can think of doing it.

 

[IZwack]

Yeah you're supposed to grind/cut the old weld off far enough into the C so you cut/grind behind the weld penetration. You dont have to cut far into the C, maybe 3 millimeters. Here's what mine looked like with the C partially knocked "outwards" of the tube 1/4" of an inch or so.

Basically you start from the front of the weld and you keep cutting around the C until you free it from the tube. Its difficult at first but you will see a faint line which is the separation between the tube and the knuckle. I didnt use it but some graphite powder or some mashed up charcoal would probably help reveal this separation line . You need to ensure that this line goes all the way around 360 degrees -- which means there are no more welds between the tube and the C. Dont cut too deep into the tube, remember your cutting into the C and not too much into the tube.

Yeah you have to get the pinion angle set first before you weld the final angle of the C since the C's angle is dependant on the pinion angle. But its a lot easier to free the C now and just get it ready.

What you want to do is remove the old weld now and knock the C either out or rotate it a little bit to ensure that its free and all of the welds are gone. Then you can get the pinion angle set with jackstands or whatever, and then use a large hammer to knock the C to the proper caster angle. Then tack weld them (3 tacks will do). Then remove the axle and do the final welds.

Also, one more thing to take into consideration is the camber. Put the knuckles on so that the knuckles point straight forward as if the vhicle is driving straight, and use an angle finder on the knuckle's face to check for proper camber (knuckle's face = where the spindle bolts to). The knuckle's face must be perpendicular to the axle tube vertically.

 

[SuperEx91]

sorry for all the questions, i just want to get this right the first time. so just grind the weld from the center of the axle to the C and once i see that line, just use a hammer to pound it off the tube. now when putting it back on, how hard is it to beat back on there and is there a stop or something so you dont pound it on too far?

 

[IZwack]

Getting it back on is easy. Getting it off (grindin/cutting) is a LOT harder and time consuming -- you want to go slow cauz you dont want to cut too much.

As for pushing it in too far, You'll have your old gind marks to help you get an idea of how far the C should sit -- as you C pulls out, you'll see a nice clean tube w/o any grind marks. Also, you can look at outside-center of the C where you can see the tube (where the axle shaft pulled out from). The tube is typically about 1/8" of an inch from the edge of the "C" -- dont take that 1/8" for truth, measure it


Be careful where you hammer on the C, try not to pound around the area where the ball-joints would go. You can deform it with enough force (its cast, cast sux0rs in life :thumbdwn: )

 

[Mud Bug 94]

this is your goal pinion angle

 

[IZwack]

LOL mudBog -- you've exceeded the U-joint angle But thats getting close to a top-loader setup.