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junebug
02-15-2011, 08:02 PM
do you change length of drive shaft when switching from a 9 inch to a quickchange....my driveshaft is close to botoming out now and didnt want to make the problem worse

HEAVY DUTY
02-15-2011, 08:38 PM
the driveshaft lengths are the same when everything is right. The quickchange pinion is lower which makes it push the driveshaft in farther as the pinion rotates, so you will get more movement with the quick change,so you might need to shorten the driveshaft or counterbore the yoke.Check and make sure you have at least 2" of yoke inside the tailshaft seal at rideheight to keep the driveshaft from puuling out under decell.

junebug
02-15-2011, 11:46 PM
at ride height how much yoke should be visible to keep it from bottoming out on the tail shaft? 2-3 inches? or whats bout right with a quickchange

HEAVY DUTY
02-16-2011, 06:16 PM
I think about 3" is enough for most unless you are getting extremely hiked up with a lot of LR rod angle, just make sure you still have 2" inside the seal at ride height

Darkstar15
02-17-2011, 07:35 AM
We went from a 9 inch in our Shaw to a QC. Kept the 29 1/2 in driveshaft with long yoke. Pay attention to what Heavyduty said. Had one pull out once. man that was not pretty, tore up lots of stuff.

John

PIERCE3J
02-17-2011, 11:24 AM
I am also switching from a 9" to a Q.C. and have a 29.5" driveshaft. It appears to roughly 1.5" shorter when I held it up to the rear. Was that the case with your car Darkstar 15? How long of yoke did you get and how far does it stick out the tailshaft? I'd like to stick with my same driveshaft and stick a long yoke on, but I don't know how far sticking out the tailshaft is too far.

HEAVY DUTY
02-17-2011, 12:25 PM
If you had the long pinion yoke on the 9" rear end your drive shaft will be too short.If you had the short pinion yoke then the drive shaft legth should be alright.When you put a long yoke on the front you must make sure that it doesnt bottom out on the splines inside the tranny(make sure the yoke will slide all the way into the seal)

racin6mod
02-17-2011, 05:18 PM
I undercut the tailshaft to allow the longer yokes on older bert trany's.it only takes about 2 hours from start to finish.

Darkstar15
02-18-2011, 07:58 AM
PIERCE3J
We had the same pinion length on both rears so everything stayed the same. What Heavyduty said about yoke length inside the transmission and outside is what we were told by the Shaw guys when we changed over.

John