stswartz

81 c3 Im removing the drive shaft and half shafts for transmission replacement and coil over installation I'm spraying down the bolts on the universal joints but i'm having trouble getting a decent fit with a socket. Is the size 9/32? Any suggestions will be appreciated

suprkoop

iirc you need to use a 12pt socket and I thought they were 1/4

MelWff

dont you want a 6pt socket to prevent rounding the nuts?

Antz81

12pt 1/4" for the diff end of the drive shaft.
I think it was E20 that I used on the half shafts (female torx socket) or 8mm spline sockets give a very nice fit.
That's for a manual anyway. Auto may be different.

stswartz

Still can't find anything to fit E10 to large E8 to small haven't found a E9 locally as yet
1/4 12 pt way to large box end wrenches are 12 point and nothing fits on standard sizes could be a 7mm just need to find one this is the half shaft outboard driver's side

Antz81

5/16 12pt fits nicely (again this is on manual trans)

stswartz

5/16 12 point is too big

Antz81

In that case you must have an auto. Which uses different parts to the 4 speed.
I can save you some time and say that 7mm is bigger than 1/4". 6mm is only slightly smaller. So it could be 5mm.

These cars are a mixture of metric and imperial.

suprkoop

I'll check mine when I get into work tomorrow.

stswartz

yes mine is a 81 automatic. i'm installing coil over shocks in the rear and will be rebuilding the rear end also

CA-Legal-Vette

Make sure that you're on it as straight as possible. I don't remember the size but 12 point is correct. I remember using a long extension and having the ratchet on the far side of the frame member in front of the diff. Turn the driveshaft so the bolt is exposed

For good measure, there should be locktite blue on the threads so even when you start it, the fight continues.

stswartz

heading to harbor freight today to stockup on 12 point std and metric

suprkoop

Ok my 81 auto is 1/4 12 pt...

derekderek

A lot of these bolts corrode smaller. You can see that kind of in that first pic of that 12-point Bolt. May have to go with a slightly smaller size and bang it on there with a hammer. That might be why that quarter feels loose. So then you're going to want 7:32 or 6 or 6.5 mil. Another size is 5.5 mil.

suprkoop

and I will say this, when I removed one of my half shafts the bolt head was rounded off so much that I had to use a small pair of Vise Grip pliers to lock on and start it loose. The remainder of the threads are in the coupling so once it broke loose I was able to spin it out by hand.

His do look rather buggered and crusty.

Street Rat

I decided to replace those fasteners after rounding off a few heads. I went longer hardened Allen heads. I use a socket with an Allen key made in it to remove them.

I HAVE TRASHED A REAR END DUE TO THE ONE OF THE OLD STYLE FASTENERS SHEARING OFF.

My two cents.
Craig

stswartz

Sucess i finally found some 12 point 1/4 in sockets the 1/4 12 pt is correct

thanks for all the direction and help