C2 Rear End Cover Problem

[Joel T.]

Hi Guys;

I just finished installing the original rear end into my 1963. I had it rebuilt over the summer and figured that it would be a good winter project to reinstall... Since I used the original rear cover in the unit which was in the car, I bought a second "heavy duty" rear end cover from Muskeegon Brake. I put the whole assembly together a couple of months back, including a new front bracket and spindles, basically so I could just replace the whole assembly in one shot.

Well, it is all back together but I have one problem, and am looking for some guidance from you guys regarding what I should do about it.

Evidently whoever machines rear end covers for Muskeegon does not like to finish tapping the holes for mounting the rear spring. The front holes were not deep enough to accommodate repro bolts (LI Corvette) and one of the rear holes was not fully tapped. I managed to get the front squared away by using my original bolts which were a tad shorter but wound up working the one rear bolt back and forth, with penetrating oil, until I could get it to actually seat fully (the other rear bolt had no problem at all).

The problem is that the casting has developed a (vertical) hairline crack just behind the problem bolt. I can get the bolt to torque with no problem (70 Lbs) but am wondering if this hairline crack will cause a problem going forward.

I would hate to have to take the whole thing apart again (at least right now). Checking it out, I think I might be able to just remove the cross member and the rear cover but don't want to tackle this unless I really need to.

As always, I appreciate your thoughts!

Joel

[John D.]

Re: C2 Rear End Cover Problem

Joel, I feel for you friend. If it were my 63 I could not live with the crack. It would always bother me. Seems to me we discussed the length of those bolts some time ago. But I can't remember for sure.
Your one sentence is confusing though. "Since I used the original rear cover..... I bought a 2nd heavy duty cover"????

[Joel T.]

Re: C2 Rear End Cover Problem

Hi John;

Thanks for the note. I was afraid you would say what you did!

One of my last posts had to do with the cross member bushings... which turned out fine.

Here's the skinny on the covers...

My car has its original carrier... good casting date, assembly date, ratio code etc... was originally a 3.70. Some years ago Bubba swapped the gear ratio making it a 3.36 which was not too cool with the close ratio T10 I installed. When I figured this out, I picked up an Ikerd's rebuilt unit and installed it using my original 1963 rear cover.. This summer I had the ratio replaced in my original carrier bringing it back to 3.70. To make it a complete, ready to install unit, I picked up a set of side spindles and a new rear cover from Muskegon Brake. The whole thing has been sitting on my bench for months now waiting to be one of my winter projects.

Right nowthe origional rear cover is on the Ikerds unit and the Muskegon cover is on my original carrier.

Hope this makes sense.

Regards,

Joel

[Gary R.]

Re: C2 Rear End Cover Problem

Joel,
I would call Muskegon and speak to one of the Cutlers, they handle the vette parts. Those are very good covers but I've had to fit them to the cross members a lot of times because the radius is off, I always run a tap through them but never found one partially tapped,could be a newer problem? I use them on the 12 bolt vette diff conversions as well and they a good unit. I wouldn't use it if there's a crack in it. Keep in mind too that many old vettes are and have been driven with cracked covers and broken ears. Guys use longer bolts and blow out the inside of the cover and then use RTV to plug it up. I don't do or recommend any of this but it's not too uncommon.

[Michael G.]

Re: C2 Rear End Cover Problem

Joel,
I too have just erplaced my refurbished differential and tried to use a set of new bolts. These bolts are actually longer. I had to take about three eighths of an inch off of the front bolts to avoid bottoming out in the differential. When tightening, start at 50 pounds on all. Then start to increase at either 5 or 10 pound increments but always do the rear bolts first. Mike

[Wayne W.]

Re: C2 Rear End Cover Problem

Cracking off the rear boss is usually caused by trying to tighten the bolts before getting the spring fully mounted . This puts undue stress on the cover bolts. Get it all hooked up and then finish tightening the bolts. That said, once the thing is back together and the car on the ground, that spring would stay there with no bolts in it. So, I wouldnt be too concerned.

[Timothy B.]

Re: C2 Rear End Cover Problem

Joel,

Take that rear down and install the correct 303 cover that is with the Ikerds rear. What's the point of installing the correct #'s rear and the incorrect cover.

I could not live with the crack either so make sure you use the correct length bolts and like Wayne said finish by tightening the spring bolts after the weight is on the car.

[John D.]

Re: C2 Rear End Cover Problem

We all have been there with problems like this. But it's better to bite the bullet and grit your teeth and do the project over again. Besides it's snowing big time Joel. Holler if you need anything. John

[Joel T.]

Re: C2 Rear End Cover Problem

Guys;

I'm convinced! Anyway, my wife predicted that I would not be content knowing that the blasted thing was cracked. Tim made a great point too... why go through all the trouble of putting the correct rear back in and install the wrong cover! I've gone to considerable lengths over the last three and a half years to make this car as correct as I reasonably can... there is no point in deviating now.

Well it is winter, the weather stinks (10 degrees again this morning with predictions of snow) and I could certainly use the exercise. I'll order up some parts from LI Corvette, fire up the torpedo heater and get busy.

Thanks all!!

Joel