Rusted gears in rear pumpkin - worth saving?

I've had a tri-five Chevy rear (pumpkin only) sitting in my barn for years. Looked at it today and the ring gears has pretty bad surface rust - I can turn it with the pinion but it is not smooth and almost binds at one point.

Junk???

 

I vote no.
Hose it with some oil and use it.

 

Sounds like you will have to take it apart to clean it up at that point you would be better to replace them.

 

???

 

Just curious, what ratio is it?

 

Sounds like the bearings are shot!

 

In all likelyhood.

 

How much trouble or money are you willing to spend to do it right? Or, the second time, if you don't do it right? Here's what I did, and I'm NOT recommending it. First off, DO NOT keep turning it rusted up. Clean it in a kerosene/solvent soak. Then dry it off. Now, soak the whole thing in a molasses solution; see prior threads on molasses if you're not familiar with it. Give it 5 days in the molasses, rinse it off with HOT water, quickly dry it off, then submerge it immediately in the kerosene/solvent soak, but toss some clean oil in with it. Now see how it turns! I did this with a 57-64, 4.88 geared, blocked spider gear, open carrier, Olds/Pont pumpkin I had. Let a friend sell it at the swap meet. He knows the guy that bought it, and it's still apparently working just fine. That was several years ago. I have a 5.13:1, 55-64 Chevrolet, Positraction third member that has several ring gear teeth scale rusted. I'm going to take a wire wheel on a drill to it, and see how it turns out; if it is't satisfactory, I'm doing the molasses soak to it. I was going to use it in my 56 Sedan Delivery when I pulled the broken 3.70 third member out, but because of the rust, I used a 4.88:1 geared, Positraction third member I also had on hand. Good luck with yours. Butch/56sedandelivery.

 

How far away from home is the OP going to drive?
I am not very good at gambling.

 

3.36 - nothing special

 

If it's surface rusted past the depth of the hardening process it could be junk. Gears aren't heat treated all the way down, but frankly I forget how deep the heat treat goes. I spent a couple years at Chevrolet Gear and Axle in Hamtragic, MI and worked both the "hot roll" and "cold roll" sides. I know that each gear set was lapped together in a machine with a wet grit solution that made them a 'set' once that task was done. I recall the job instruction that too long would cut past the heat treat, but don't remember how far too long was. Maybe some who understand heat treat better could chime in on that.

I'd love a 3.36 gear set right now, maybe 2 of em. With a 27" tall tire and typical OD 1st gear ratios, 3.31 to 3.42 are perfect for high speeds and stout 1st gear launches. It's worth cleaning up given the proper heat treat info, and the molasses idea is right on. It really works, and better than one can imagine.

 

A full tear down will answer all doubt. I've run 3rd member in the exact state that you've found your's. In most cases it's a collective amount of dirt and surface rust between the pinion and ring gear that cause's the bind. Tear it down completely and look at the bearings first. If they look good to run, clean gear surface with scotch bright pad and WD-40 or like product. Then reassemble.

 

I'd love a 3.36 gear set right now, maybe 2 of em. With a 27" tall tire and typical OD 1st gear ratios, 3.31 to 3.42 are perfect for high speeds and stout 1st gear launches. It's worth cleaning up given the proper heat treat info, and the molasses idea is right on. It really works, and better than one can imagine.[/QUOTE]


Highlander - I have a 3.36 gear set out of a '56 Chevy wagon rear that you can have for $50 + shipping. PM if you're interested.

Chris

 

wire brush it & soak it in a mixture of 1/2 kerosene & 1/2 atf

 

Thanks. New R&P for these rears are relatively expensive, which is another factor.