1965 differential front bracket problem

[Timothy B.]

I am trying to remove the differential front bracket on a 1965 because the early design rear has left the front holes egged. The car has a bad clunk like you would expect and the rubber cushions are also in very bad condition and need to be replaced. Are these cushions # 3795333 and 3788637 still available from GM??

The rear bracket through bolt is frozen in the carrier and I can't budge it. I tried heat, six point socket etc. Short of taking the rear out to remove this stuck bolt I would like to know if anyone has any better suggestions. I have not done any damage to the bolt head and I have been careful not to break the bolt.

Today I mixed some acetone and ATF and sprayed in hopes some would get inside and free the bolt from the rear. Brother cringes about removing rear fearing opening pandoras box.

All suggestions are appreciated..

[Rich P.]

Re: 1965 differential front bracket problem

Tim,

don't know if GM has the cushions but LICS and others do.

Which bolt is stuck Bolt with castle nut or regular nut. In either case I would let pennatrant soak in. Then use a 6 point impact socket along with a impact gun and an air hammer with a taper punch. First start to impact the head of the bolt to jar it loose and at the same time try to punch the bolt through with the air hammer. The shock of both tools should be enough to break the rust bnd loose. If you are careful you wil not damage the bolt (All depends on how frozen it is)

Rich

[Timothy B.]

Re: 1965 differential front bracket problem

Rich,

On the early rear the front two bolts go in from each side. That's where the egg shap is in the bracket.

The rear mounting bolt has a regular nut and it's froze inside the rear carrier. I am not sure you can get square with it for a air hammer.

[Jack H.]

Re: 1965 differential front bracket problem

GM Parts Direct (www.gmpartsdirect.com) has both parts showing up as available. 3795333 is $7.42 and 3788637 is $8.78, but their shipping is usually fairly high so keep that in the equation.

[Rich P.]

Re: 1965 differential front bracket problem

Ok si it's 63-64 style...

I would take a 12" or so piece of flat stock (3/8-1/2") run the nut on the end so it's flush with the tip. then as you are impacting the one end (Or turnung with a wrench) place the flat stock on the nut/bolt and use a hand held sledge begin to tap on the flat stock as close to the nut/bolt as you can don't be afraid to hit it. And rember you are not loosening the bolt so you can apply tourque in either direction. You just need to jar it loose a little then the penetrant can get in.

Rich

[Wayne M.]

Re: 1965 differential front bracket problem

Rich,

On the early rear the front two bolts go in from each side. That's where the egg shap is in the bracket. ......

Timothy -- just curious as to your approximate VIN. I too have the early carrier casting 3818753-N on my '65 VIN 014xx. Still got the original front diff-to-frame mount bracket, without any of those temp fixes that are described in the Tech Service Bulletin.

[Timothy B.]

Re: 1965 differential front bracket problem

Rich,

Thanks for your suggestions, that's what I am going to try after soaking for a few days. I really wanted to use this bolt again. There is really no other way to tackle this, I am afraid of breaking the bolt..

Anybody try this acetone and ATF solution before and can report the results, does it really work on rust..

Wayne, This 65 is vin 3xxx, (I can't remember the rest) built November 64. The differential front mount is the second design with the flat washers on the front holes. The mounting cushions are really shot and that's what I contribute to the cause of the up/down action thus loosining the bolts. You know the rest of the story.

I am trying to figure out if this part has been changed in prior life because after I swing the mount down there is a clean rectangular spot that looks like a part# tag could have been there. It's possible the original mount for this car was still the first design. I will post some pics after I get it down.

Are these mounts still out there to buy or is it best to fix this one. The drivers side hole is egged approx 1/4".. I would really like to replace it..

[Edward S.]

Re: 1965 differential front bracket problem

Get yourself a can of Aerokroil penetrating oil from Kano Laboratories,their phone number is 615-833-4101. This stuff will change your frozen part and rusted world forever. This really works. Ed