Removing the differential cover

[jeff72]

Greetings -I need to replace my differential cover on my 72. In studying the connections -it appears that the rear crossmember must also drop down??

Has anyone had the fun of replacing their diff cover? -mine is slightly cracked.

Your comments appreciated.

Jeff72

 

[JohnZ]

Yup, the diff crossmember has to come down in order to get to the four bolts that attach the diff cover and diff to the crossmember; your cover is probably cracked because the last guy who had it down tightened up the spring retaining plate bolts before the car was back on wheels (which is almost guaranteed to crack the ears on the diff cover). When you re-install the spring, don't final-torque those four bolts until the car is on wheels with full car weight on the spring.

 

[GTR1999]

John is correct about the spring bolts breaking the cover-very common if someone isn't experrienced working on vettes. Although some of the old manuals say to separate the cover from the housing while still in the car,that is just going to make it a harder task. Drop the crossmember,use a floor jack under it because you're going to catch about 120 lbs!

Check the play in the side yokes at this time. If they are over .050" replace them now while you have the rear end out. Look at the carrier for sign of cracks by the openings and see if you can see any play in the center pin. The center pin is the shaft the spider gears ride on in the carrier. check for oil leaks at the seals too. If you need a pinion seal be sure to mark the nut BEFORE touching it. If you need more info on this,let me know.

 

[jeff72]

Wow -I am glad I asked. Thank you for responding. As I think this out, which piece comes off first? -I see the cover is bolted to the crossmember -seems that has to be unbolted first since the cover-to-crossmember is bolted from the top of the member (no way to get to those bolts).

So, if I unbolt the ends of the cross member -then the cover -this assembly should drop out (all 120 lbs of it) -correct?

When you say "spring bolts, you speaking about the 4 bolts mounting the spring to the cover and these should be tighted when the car if OFF the jacks and full load back ON the rear wheels..correct?

As you can see, I am a mechanic-wana-be and looking forward to getting into this -have always had an interest just no hobby car to tinker with.

thanks for you help.

 

[Bob Chadwick]

Once you get under there you'll see what has to come loose. The strut rods, the half shafts and the spring come to mind. If you have the original strut rod design, you will need to removed the lower shock tower bolts which can be a bear. Soak those things in PB Blaster and get a couple of nuts to put on the ends to hammer them out.

 

[GTR1999]

You're going to have to mark the rear strut rod camber position prior to moving them so you don't loose your alignment, There are special washers in between the strut rod end and bracket,don't lose them.

I'm going to PM you my day time number, I'll be glad to walk you through the job and it will save me form typing!!!

 

[jeff72]

Hey -thanks all. Now I need to go slide under the car and study for awhile. This is a great forum -you guys are fantasitic !

jeff72

 

[Bob Chadwick]

If you have to replace the bushings on the strut rods go ahead and get the VBP replacement. Easier adjustment and looks better also. I got mine at The Last Detail for less than what VBP was selling them for.

 

[GTR1999]

Jeff,

I just PM you again. Feel free to contact me with any questions.

Bob, not that it really matters but I'll disagree on the VBP struts. I'd stay with the stock rods as long as they are not bent and use rubber bushings. I've heard of the camber nut loosening up too many times from several people. Again just my opinion no flame intended. I also heard of vette shops heating up and rebending stock rods, I don't follow this route either.

 

[Bob Chadwick]

Bob, not that it really matters but I'll disagree on the VBP struts. I'd stay with the stock rods as long as they are not bent and use rubber bushings. I've heard of the camber nut loosening up too many times from several people. Again just my opinion no flame intended. I also heard of vette shops heating up and rebending stock rods, I don't follow this route either.

That can be an issue. I had it as well but a little locktite took care of it. They just look so nice, are easy to adjust and make it so easy to remove the strut rods without having to remove the lower shock bolt.

 

[George Black]

When the rear differential plug is replaced after a rebuild or fluid change, is it OK to use teflon tape, or some other sealant, on the plug threads?

I know the plug is tapered and should be self sealing, but mine has been leaking. Small leak, but it has been dripping on the rear exhaust pipe and undercarraige.

 

[froggy47]

I'd like to know re: the teflon tape also. Does it hold up to heat, vibrations? I think you would back off the ft lbs of torque when you tighten if the plug is all slicked up with teflon?

 

[mike weyman]

you can buy pink teflon for oil line use, it is much thicker than the regular teflon and is oil resistant.mike

 

[George Black]

Thanks Mike!

 

[froggy47]

Hi Mike,


Where did you find the pink stuff, I must confess I've never seen it.

you can buy pink teflon for oil line use, it is much thicker than the regular teflon and is oil resistant.mike

 

[George Black]

Froggy47: I got mine (teflon tape for gasoline, oil, etc.) at Lowes in the plumbing supply section. I am sure any hardward store should carry it.

 

[dfw81shark]

Bob, not that it really matters but I'll disagree on the VBP struts. I'd stay with the stock rods as long as they are not bent and use rubber bushings. I've heard of the camber nut loosening up too many times from several people. Again just my opinion no flame intended. I also heard of vette shops heating up and rebending stock rods, I don't follow this route either.

I'm in the "have vb&p rods and they loosen up with no warning" department.

Does the differential/spring installation process cover 81's with the fiberglass spring too? I.e. do I need to put weight on wheels before tightening the spring bolts? If so, hopefully it's not too late and I need to go outside and try to "fix" a few things...

 

[froggy47]

Thanks George

Froggy47: I got mine (teflon tape for gasoline, oil, etc.) at Lowes in the plumbing supply section. I am sure any hardward store should carry it.