u joints randomly breaking

[blazerpro79]

i know there are a thousand threads a dayon here about this...

my situation though is a little difference. i have a 5" lift and had my driveshaft lengthened, retubed, and rebalanced about 6 months ago. i had spicer u joints in it. i drive a 79 k5 and put a 6* shim in at the axle and a tcase drop.

i didnt have u joint problems until about a month ago, i didnt change anyparts, but one day my truck started blowing u joints. i dont know why. i changed my transmission mounts which i was suggested by some people, but what else could be my probem. my angles are not bad at all!

i have a high idle and a very strong shift kit, and when i throw it in reverse, its a very strong jerk, would this be a problem? im guessing yes, but the motor is running very good at the idle... should i drop the idle and sacrifice the reliability? thanks

 

[big83chevy4x4]

it might be that you are putting just enough stress on them while driving that after a while the faitigue and break. a ujoint will only take so much stress so many times before it breaks, the spicer cold forged ujoints can take this stress more times before they break.

a bigger ujoint will take more power before you stress them, so they will last longer.

 

[k20]

are your u-bolts tight? Are your rear shocks worn out? Im thinking something is letting the axle rotate, causing excessive axle wrap, binding the joints, and breakin em.

 

[blazerpro79]

ya one of my rear shocks is shot, my u bolts are tight though


the joints are breaking about every 2 weeks, i will get new rear shocks, and see if that helps, thanks, i brought the idle down, and when i put it in reverse now, it is much smoother. thanks for the responces guys... i will also put a set of spicers in there when i put the shocks on.

 

[k20]

if its the shock on the front side of the axle that is shot, that could possibly be letting it rotate up putting it in a bind, if its the one on the back of the axle tube though, i dont know how much of an effect it would have.

 

[blazerpro79]

if its the shock on the front side of the axle that is shot, that could possibly be letting it rotate up putting it in a bind, if its the one on the back of the axle tube though, i dont know how much of an effect it would have.

it is the shock that mounts behind the axle

 

[short sub]

is it actually breaking the u joint or just throwing the bearing caps off? how hard is it to install the new ones- can you push them in with your fingers? and yes i have seen a driveshaft with the push in u joint option before. your yokes may be messed up now since u have broken a u joint a few times. i have seen that happen alot. well goodluck man

lata ryan

 

[ssls6]

Check your driveshaft angle. If it is greater than 20 degrees then your front yoke may be binding. You'll need to grind on the sides of the yoke to fix it. Jack the rear of your truck up via the bumper or frame (not the axle) which will uncompress your springs. Now try to rotate the driveshaft by hand (tranny in neutral), does it bind?

 

[81jimmyslt]

Make sure you don't tighten the u-joint straps too tight! Will crush cap and mess up bearings. Just a thought.

Jesse