January 15, 2009Ok, so.. I was driving my blazer, and me and a friend (yes i know stupid idea) decided to go drive over a little pile of gravel rocks. well, the truck has a 6 inch lift, and 38" super swamper boggers, so it was no problem. so we got over the rocks, then my back driveshaft broke off the u joint connected to the transfer case. it broke off at the u joint and snapped an ear off the yoke. why did this happen? too much torque on the shaft at the angle, *or* partly because the previous owner never greased it? it wasn''t that big of an angle either, i''d taken it at bigger angles before. i know it sounds stupid, and i can fix it, just curious as to why it does it now, and not at times when i''d had it at bigger angles.
January 15, 2009Sounds like axle wrap with all that weight sitting on the rear end when you gassed it to get over, that''s what usually breaks when it binds up.
January 15, 2009ooh, that sounds like it could be it. any idea of how to prevent it?
January 15, 2009
then my back driveshaft broke off the u joint connected to the transfer case.
The diff yoke/u-joint breaks with axle wrap, not the t-case one.
Something must have bound up. Suspect would be too much angle. I''m guessing this is a fairly short wheel base vehicle, with a steep angled driveshaft and then you just happened to flex it out the wrong way.
Setting things up to run a higher angle joint at the t-case would likely solve your problem. Give any driveshaft a shop and talk (I recommend Jesse at High Angle Driveline). My truck runs a CV joint off the t-case to solve my angle problems.
January 15, 2009so, your saying the yoke and u-joint breaks cause of axle wrap at the gearbox, and not the transfer case? and yes, the shaft is angled kind of steep to the tcase. and, use a cv joint off the tcase instead of a u-joint **or** what? i''''m lost on that part lol. can i angle the gearbox **or** something, to make it less steep **or** what?
February 12, 2009go to a driveline shop and have a driveshaft made for high angle. they will know what you need.
February 12, 2009yeah, we got this part fixed. its still got the angle, but i''ll have to live with it for now.
February 21, 2009shim the rear axle to have the correct angles
February 21, 2009Lower the cross member by putting it on the bottom side of your frame, it will help the driveshaft angel. I do it all the time on blazers..
February 22, 2009shim the rear axle, you mean by cutting it where the spring, *or* whatever can''t remember the name, connects to the rear axle, then rotating it so the diff. gears are pointed upwards more? and i will see about lowering the cross member, thanks for the advice.
February 22, 2009You can cut the spring pads loose, move the rearend and reweld it..But they do make shims that go between your pads and springs...Lower your cross member, trust me, it will help your front and rear drive shafts.
February 22, 2009alright, thanks alot. anyone know where to get the cv joint for the back end drive shaft fairly cheap? i have one on the front driveshaft that was on it when i bought it. i priced a new cv joint for back driveshaft and it was somewhere around $400. more than i was willing to spend.