64Corvette

How tight do I get the front differential bolt that goes through the crossmember and through the front differential bracket? Do I tighten the bolt just enough to start squeezeing the rubber bushing?
Car is a 64.

Thank you.

ILBMF

If I remember correctly it's 65 ft lbs

66jack

Here's a Torque sheet...

http://www.stl-vettes.com/65Vette/co...rque_Specs.pdf

tbarb

The 1963 AIM shows the nut torque at 55-75ft lbs. From memory the upper bushing has a metal inner sleeve that will contact the vulcanized metal washer on the lower rubber bushing which will allow you to get the correct torque.

The killer on these rubber parts is gear oil if the pinion seal or pinion gear spline is not sealed properly so make sure it's dry. Plus, keep in mind the forward side bolts on the differential bracket are grade eight and use a thicker flat washer and are torqued the same.

Frankie the Fink

Its important to get the right torque on those side bolts, the early midyear part was weak and the holes could get wallowed out if the car is driven hard. I have a reinforced part to put in my 63 if I start seeing signs of that... There is a TSB about the issue IIRC.

tbarb

Frank,

I think what you pictured is the third version, the first is like ours where there is just a hole for the forward bolts and the second has a thick flat washer welded then the version you picture.

Frankie the Fink

There are a few versions my friend...the very weak ones (first pic), the ones with the plate and the one with washers welded on; the early ones were flimsy; hence the TSB..

I don't know which of the reinforced ones were done by Bubba or the factory....both work.

tbarb

The TSB was to address the problems with the first design bracket. The two you have pictured together are factory brackets. The bracket with the welded washers is the second design and then the final design with the long welded reinforcement that captures forward and aft bolts.

The casting on the rear housing changed around the date on that TSB to allow the through bolt in the forward position which eliminated the problem.