Differential Alignment
Thread Starter
Instructor
Joined: Dec 2015
Posts: 167
Likes: 10
From: Woodway, Texas
Differential Alignment
Fellow Vetters:
I’ve just finished rebuilding the entire rear end suspension on my ‘91. In the process, I removed the batwing and replaced those bushings with polys, then reinstalled it along with the differential. So, the question is: should I torque the batwing bolts before or after connecting the driveshaft/C-beam between the differential and the transmission? I’m worried that doing it beforehand will result in a driveshaft alignment problem due to the front of the differential not being supported, and therefore, pointing slightly downward rather than forward. Any suggestions will be greatly appreciated!
SnorT91Man
I’ve just finished rebuilding the entire rear end suspension on my ‘91. In the process, I removed the batwing and replaced those bushings with polys, then reinstalled it along with the differential. So, the question is: should I torque the batwing bolts before or after connecting the driveshaft/C-beam between the differential and the transmission? I’m worried that doing it beforehand will result in a driveshaft alignment problem due to the front of the differential not being supported, and therefore, pointing slightly downward rather than forward. Any suggestions will be greatly appreciated!
SnorT91Man
Melting Slicks
Joined: Mar 2001
Posts: 2,149
Likes: 302
From: Timra, Sweden
It is a good practice to get all the bolts in before torquing them down.
I have had the driveline down and up more times than I remember.
I allways disconnect the outer bolts on the spring and remove the batwing to frame bolts with a jack supporting the pumkin.
By adjusting the jack the bolts come out easy.
Then lower the jack a bit. That makes it easy to get the C-beam in place.
Then I raise the jack and install the batwing outer bolts again. Then torque everything down and reinstall outer spring bolts.
I have had the driveline down and up more times than I remember.
I allways disconnect the outer bolts on the spring and remove the batwing to frame bolts with a jack supporting the pumkin.
By adjusting the jack the bolts come out easy.
Then lower the jack a bit. That makes it easy to get the C-beam in place.
Then I raise the jack and install the batwing outer bolts again. Then torque everything down and reinstall outer spring bolts.
Last edited by JoBy; Jan 31, 2020 at 05:10 AM.
Le Mans Master
Joined: Sep 2013
Posts: 6,192
Likes: 750
From: near the thumb in the mitten
Most of the time it's better to have bolts a little loose during assembly. Then tighten everything thing up after all the bolts are started. With the c beam there's no driveshaft misalignment. The nose of the differential will droup a little without the c beam with bolts torqued. To me a bolt(s) in c beam on the differential end the lift and swing in on transmission and install the other 2.
