Can I put degreed shims on the front axle to lessen the driveshaft angle? I have broken the double u-joint end twice. Wasn't beating on it that bad.

 

Obviously a leaf spring front suspension but any other specs? year and model lift tires axles?

As of right now the #1 solution is cut and turn the Cs but so many other things come in to play. IE 44" tires a healthy motor and 1310 drive line.

 

cut and turn is the best route....but you may want to think about turning at the diff itself.....just you better have a torch to get them plug welds out....they will laugh at a drill, this way you wont have to make new spring perches......

 

Yes, more info....


You could buy a high angle CV, put a CV at both ends, cut tubes and reweld for better pinion angle, etc....

 

Depending on the year of the front axle, changing the angle by rotating the center section may be close to impossible. If the spring perch is cast into the diff, a wedge will have to be made to make the perch square with the spring again, so turning the "C's" are a better option.
While adding wedges can work, it also changes caster and steering becomes faster. This can cause the "bad shopping cart effect" while on the highway.
Usually the double cardan joint binds when the slip joint is not working properly or binding. If the DL angle was too dramatic, it usually results in a broken single joint at the pinion yoke.
Might be thinking that there are other problems here. How much spline is exposed on the slip joint, and how loose is the spline engagement?
It is not way out at the end allowing the shaft to wobble is it? This vibration and changing angle can kill a DC cage quickly.

 

if thats the case he will have to mod the perches anyways b/c of rotating the axle up.....

 

it would be better to turn your axle. is your front axle at a different angle than your rear? if it is then you keep breaking u-joints because your velocity is different from front to back. the more angle your u joints have the more the pinion is going to spin than your drive shaft, and if your back pinion is spinning less or more than your front it will put stress on the u joint causing it to break. hope this helps

 

I read that, and read that and I do not understand.
I was commenting on the statement that you made regarding the relocation of just the center section (diff). Turning just the diff itself is tough to do with the OP's axle. I believe that the OP has a 79 truck, and that has a spring perch that is cast into the diff. Rotating the center section will no longer allow the spring perch to line up and mate with the spring.
A later axle with two spring perches on the tubes will allow a modification to the center section all day long, but is much more difficult to the axles with a cast perch. Unlike later axles, in this case the front is easier to turn the "C's" if the axle has a cast driver side spring perch.
I have seen some chevy guys perform this by welding a wedge on the perch, but I am thinking that is far too much work. Thats all.

 

how does the angle change speeds??? im not understanding this at all. i could be just reading it wrong but i dont understand how a u joint at 90 degrees spins the yoke any faster then if it was straight. there is no reduction in a u joint only directional change. the reduction in rpms is done at the ring and pinion. a bad pinion angle causes binding and that causes them to break not a change in speed from an angle.

 

by rotating only the center section nothing else along the axle changes except the pinion angle. thus if the tubes are left at the same position the spring perches never have to be moved. and the alingment isnt an issue

 

littleme13:

This would be true if the spring perch is not cast into the diff case itself, but I believe the OP has a 79 truck that has the driver side spring perch cast directly into the differential casting, so rotating just the center section will not permit the spring to bolt up to the leaf any longer (without modification). The perch will roatate along with the center section, and will be at the wrong angle since it will rotate with the differential center section.
This is why rotating the "C's" was recommended for this application.

 

If the spring perch is cast into the center section, not the tube, it will not mate to the spring if the center section AND perch is turned.

 

75350, you beat me. I must not type as fast.

 

that makes sense and i see what your saying now thanks for clearing that up for me. i think the whole post before yours had me way too confused to think clear.

 

Right on guys....