IRS Differential Removal

[Elm Zobens]

I am in the process of removing the differential on my 69' coupe for rebuilding.
It looks like I need to remove the 2 bolts that hold the differential crossmember to the frame. Since I don't think these bolts have ever been removed, do I need to worry about these bolts snapping off in the frame? From what I can tell, it doesn't appear that there is a way to access the back of these bolts to spray some WD-40 type lubricant. Are there any special 'tricks' to this? The last thing I want to do is snap these hardened bolts in the frame.
I want to drop the IRS with the spring and crossmember as a unit and remove those items once I have it removed from the car.
Any tops or advice would be greatly appreciated.
Thanks!

[Joe L.]

Re: IRS Differential Removal

Elm-----

Have you tried removing the bolts? These, particular, bolts are not usually a problem. In any event, there's really no way to do it other than putting a socket on them and "wrenching away". If the bolts break, which I doubt, you'll still be able to remove the crossmember. Then, you'll have to remove the bolt stubs from the brackets by drilling and using an extractor.

Once the bolts are out, you'll very likely find that the crossmember will just stay exactly where it is. Getting it out is the biggest problem faced by folks doing this job. You'll need to get a BIG pry-bar (like a 5+ foot long one with a THICK cross section). Wedge it between the removeable crossmember and the welded-in one immediately to the rear and pry away so that you force the crossmember downward. It will take a lot of effort to get it out.

[Joe L.]

Re: IRS Differential Removal

Elm-----

Have you tried removing the bolts? These, particular, bolts are not usually a problem. In any event, there's really no way to do it other than putting a socket on them and "wrenching away". If the bolts break, which I doubt, you'll still be able to remove the crossmember. Then, you'll have to remove the bolt stubs from the brackets by drilling and using an extractor.

Once the bolts are out, you'll very likely find that the crossmember will just stay exactly where it is. Getting it out is the biggest problem faced by folks doing this job. You'll need to get a BIG pry-bar (like a 5+ foot long one with a THICK cross section). Wedge it between the removeable crossmember and the welded-in one immediately to the rear and pry away so that you force the crossmember downward. It will take a lot of effort to get it out.

[Joe L.]

Addendum

One other thing: you can use heat from a torch to heat the bolt heads to help ease their removal if they prove to be difficult. However, keep in mind that you may very well damage the crossmember cushions in the process. Usually, these cushions are fine for re-use but not if you damage them with heat in the bolt removal process. So, I'd try to remove the bolts first without applying any heat.

[Joe L.]

Addendum

One other thing: you can use heat from a torch to heat the bolt heads to help ease their removal if they prove to be difficult. However, keep in mind that you may very well damage the crossmember cushions in the process. Usually, these cushions are fine for re-use but not if you damage them with heat in the bolt removal process. So, I'd try to remove the bolts first without applying any heat.

[Elm Zobens]

Re: Addendum

Joe,
Thanks for the advice.
I haven't tried too hard to remove the bolts yet since they seemed awfully tight when I briefly tried with my 3/8" drive and short breaker bar.

I don't see why the crossmember would need any prying to remove it from the car. It looks like once the 2 bolts are removed, it should just come off- Is there something else holding it in that I can't see?
Thanks again!
Elm.

[Elm Zobens]

Re: Addendum

Joe,
Thanks for the advice.
I haven't tried too hard to remove the bolts yet since they seemed awfully tight when I briefly tried with my 3/8" drive and short breaker bar.

I don't see why the crossmember would need any prying to remove it from the car. It looks like once the 2 bolts are removed, it should just come off- Is there something else holding it in that I can't see?
Thanks again!
Elm.

[Joe L.]

Re: Addendum

Elm-----

As far as fastners go, there's nothing else holding it except for the 2 bolts. However, while it might LOOK like it should just drop out, unless it's 1 in a million, it won't. If it's never been removed before, it will be especially hard to get out.

Keep this in mind: as I mentioned above, there are only the 2 bolts holding the crossmember in. That's for absolute certain (assuming that you've removed the front bracket from the differential as you must to remove the crossmember). When you try to get the crossmember out, though, you'll THINK that there is something else holding it in. But, there is NOT. It will just take a LOT of "coaxing".

[Joe L.]

Re: Addendum

Elm-----

As far as fastners go, there's nothing else holding it except for the 2 bolts. However, while it might LOOK like it should just drop out, unless it's 1 in a million, it won't. If it's never been removed before, it will be especially hard to get out.

Keep this in mind: as I mentioned above, there are only the 2 bolts holding the crossmember in. That's for absolute certain (assuming that you've removed the front bracket from the differential as you must to remove the crossmember). When you try to get the crossmember out, though, you'll THINK that there is something else holding it in. But, there is NOT. It will just take a LOT of "coaxing".

[Bill B.]

Re: IRS Differential Removal

Don't have a lot of experience in this area but just recently removed the IRS and everything else in preparation for frame blasting. I personally did not think it was very difficult. I sprayed a "liquid wrench" on things several days in a row before trying to remove. In some cases a big breaker made the task real easy and I don't remember breaking a single bolt (72 conv). I took everything individually apart rather than dropping as a unit. Pretty heavy affair so be careful! The trailing arms had to be cut out. And, the crossmember dropped very easily on ours with just a couple of blows with a rubber mallet.

[Bill B.]

Re: IRS Differential Removal

Don't have a lot of experience in this area but just recently removed the IRS and everything else in preparation for frame blasting. I personally did not think it was very difficult. I sprayed a "liquid wrench" on things several days in a row before trying to remove. In some cases a big breaker made the task real easy and I don't remember breaking a single bolt (72 conv). I took everything individually apart rather than dropping as a unit. Pretty heavy affair so be careful! The trailing arms had to be cut out. And, the crossmember dropped very easily on ours with just a couple of blows with a rubber mallet.

[Mike Cobine]

Something to help make this easier.

Try this URL and see if it helps you.

http://vettenet.org/sharkrear.html

'63-'82 Rear Suspension Removal

[Mike Cobine]

Something to help make this easier.

Try this URL and see if it helps you.

http://vettenet.org/sharkrear.html

'63-'82 Rear Suspension Removal

[Chuck R.]

Re: No biggie Elm

Those bolts WILL start as they were pretty well protected as Joe eluded to.

If they came free from my frame, they will come free from anyone's frame believe me, just put a breaker bar on them and a nice steady strain slowly increasing until they bust free.

Once they are free, as Joe stated, the crossmember will more than likely stay where it is, but to play it safe, take a wrap around the crossmember on each side near the bolts with a good heavy duty rope or better yet light chain.

When the crossmember pops free, it's going to want to head for the floor real fast so for added protection have a jack about two inches below the differential to catch it. The rope/chain will act as an equalizer to keep it from getting away from you.

As for the sombrero rubbers coming free, just nail then with PB Blaster or the like and put a good steady down pressure between the crossmember and the frame with a three or four foot pinch bar and make sure that your well positioned so when it releases your out of the way and braced.

It really won't take long for it to release.

Just make sure that once the crossmember is free, that you wipe the penetrant off the rubbers ASAP.

The strut rod shock bolts will throw you bigger fits than the crossmember by far

Good luck and be careful,

Chuck

[Chuck R.]

Re: No biggie Elm

Those bolts WILL start as they were pretty well protected as Joe eluded to.

If they came free from my frame, they will come free from anyone's frame believe me, just put a breaker bar on them and a nice steady strain slowly increasing until they bust free.

Once they are free, as Joe stated, the crossmember will more than likely stay where it is, but to play it safe, take a wrap around the crossmember on each side near the bolts with a good heavy duty rope or better yet light chain.

When the crossmember pops free, it's going to want to head for the floor real fast so for added protection have a jack about two inches below the differential to catch it. The rope/chain will act as an equalizer to keep it from getting away from you.

As for the sombrero rubbers coming free, just nail then with PB Blaster or the like and put a good steady down pressure between the crossmember and the frame with a three or four foot pinch bar and make sure that your well positioned so when it releases your out of the way and braced.

It really won't take long for it to release.

Just make sure that once the crossmember is free, that you wipe the penetrant off the rubbers ASAP.

The strut rod shock bolts will throw you bigger fits than the crossmember by far

Good luck and be careful,

Chuck