3" lift/drive shaft angle

Hello all:
Restored a 74 with t-14 3spd. have 3" lift and the u joints did not last long. The angle is pretty harsh. Any input on re indexing the dana 44. How to and how many degrees can I get away with.
THX
Dave

 

What are your ujoint angles at the diff pinion and at the transfer case now?


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I have a 7-9 inch lift on my cj5, i didn't have other choice than put a cv-joint dans a 1 inch drop t-case. I have less vibration than my previous set-up (33" wit 4 inch lift single joint d-shaft). Another thing you can do is to buy some degree shim that goes between the axle and leaf so drive shaft angle will be reduce.

 

How does your rig drive? You have tons of neg caster so should be wandering all over the place.

rocmoc n AZ/Mexico

 

I believe that is the rear in the pic.

 

yes it's the rear in the pic, i can run 60 mhp's no vibration at all.

If you want to go this way you will need to order the yoke for a cv-joint that goes onto the transfert case. You can use whatever chevy 1/2 tons cv joint from 1970 to 1987. Wagonneer cv joint suppose to be the same as the chevy one. If you other question i will be more than happy to help you!!

Also for those who whant to know, the front is pointing up too, but i cut the knukkle to give them a 6 degree positive caster so the wheel are keeping strait forward.

 

Duh! Just assumed wrongly and didn't read OP completely.

rocmoc n AZ/Mexico

 

Hello All:
My apology for not getting back on this sooner. Had to patch my boy up this weekend he is first phase BUDs and full of holes. Specially the boil on his *** LOL. Then sent the other off on deployment, (long week). Any way the U joint angles are severe. I did not calculate them out but the knuckles dam near touch on the closed side. And yes the dam thing does wander all over the highway. Where do I obtain these diff shims, and what is the max degree I can tilt the rears (44). And is the front (30) the same concept to obtain positive caster.
Thx for the help
Dave

 

Pro comp have them, for the rear it depend the way you like to go, single or double (cv joint). With a single u-joint set-up you must have the same pignon angle as the rear output of the t-case. With a 6 degree shim you may get a better angle with a 3 inch lift but you will only know it when everything installed. Other way is to go with a cj joint (double-joint) but you will need to put the drive-shaft strait with the pignon if you don’t want any vibration (look at my picture above). You will need the right end yoke on the t-case for the cv-joint application. For the front end it’s another story, pignon and caster move together unless you unweld the knuckle like a did over my project. Normaly a good running jeep is having a 6-8 degree positive caster on the front so the wheel will get back strait by themselves after a turn. You can run an angle finder on a socket nut over the upper ball joint nut, it will give you a good idea of you’re caster at the moment….i was running 6 degree shim with a 4 inch lift front and the jeep was running fine.

 

Roger that:
My concern is that the shims on the rear will absorb the shackle pin space and therefore the pad on the axle will not seat on the pin, or very little of it. Is it better to reindex the pads on the axle rather than install the shims? As for the front. If I shim the front for 6deg positive then will that throw the pinion down ward and aggravating the pinion angle even further? Not sure what you mean by re welding the knuckle?

THX
Dave

 

For the rear you can cut the spring perch no problem just be sure to realign them corectly. For the front you’re right….the more shim degree you put the more the pignion will go down. Knuckle and tube on a front axle are welded together to set Oem caster. To change that you must grind off the weld and rotate the knuckle on the tube and weld everything back. I did it on mine because I was having more than 3 inch lift and dana 44 from scout came with zero degree of caster Oem. After grinding the weld and rotate the knuckle I bring to whole jeep at the alignment shop and ask them to put the right amount of caster (I asked for 6) and they did with a difference of 0.2 degree between right and left. But you don’t need to do that unless you really want to have more than a 3 inch lift. First with a angle detector check you’re caster at the this moment.

 

Before you do anything get a cheap angle finder and check your u-joint angles front and rear. Report what you have here and we can probably help. Without knowing where you are at you don't know where to go.....


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KK roger that I will get an angle finer and get the numbers.

THX
Dave