Rust pitted ring gear

[Crosley.In.AZ]

How bad do these gear teeth look for rust pits?  I know any rust pitting is bad.

The gears would be used in a drag strip car.  Low power.  Not much use any where else.

It is just a money thing (save money)...  these are 3.70 gears for a 9 inch Ford differential

[kb426]

How about you put it a bucket of Evaporust over night and see what's left?

[enjenjo]

In race cars I have run worse. A quarter mile at a time it will last for years.

[papastoyss]

look on the bright side, the pits will hold some lube!

[Crosley.In.AZ]

The bearing cups and cones are rusted too.  I suppose they will hold up a while too?

[enjenjo]

Well, I would probably replace the bearings  

I suggest you assemble it, with the old bearings in it, fill with cheap gear oil and drive it 10 miles or so, lightly loaded. Pull it out, wash it all up, install new bearings and go racing with good gear oil in it. Gears don't really mind rust pits, bearings is another ball of wax.

True story. The red GMC pickup I had years ago I built from the bare frame of a truck I bought from my brother. I bought a rear end and front suspension out of a truck with only 5,000 miles on it, stolen recovery. To be honest I never checked the rear end further than checking the brakes were good. I drove that truck everywhere for 5 years, then sold it to a buddy. He drove it a few thousand miles over the next 12 years, and then sold it back to me. After I got it back, the axle seals started leaking To replace the seals, I had to pull the rear cover, only to find it was full of water, and what came out looked like chocolate milk. I replaced the seals, washed it down with brake clean, and put it back together. I drove it hard for another two years before I scrapped it because of rust, and it still had the same rear end in it, and it wasn't loud enough to hear over the exhaust.

[Crosley.In.AZ]

Well, I would probably replace the bearings  

I suggest you assemble it, with the old bearings in it, fill with cheap gear oil and drive it 10 miles or so, lightly loaded. Pull it out, wash it all up, install new bearings and go racing with good gear oil in it. Gears don't really mind rust pits, bearings is another ball of wax.

I do not have a vehicle with a 9 inch differential in it that actually runs under its own power or 4 wheels on it or steering....   yet.

[GPster]

True story. The red GMC pickup I had years ago I built from the bare frame of a truck I bought from my brother. I bought a rear end and front suspension out of a truck with only 5,000 miles on it, stolen recovery. To be honest I never checked the rear end further than checking the brakes were good. I drove that truck everywhere for 5 years, then sold it to a buddy. He drove it a few thousand miles over the next 12 years, and then sold it back to me. After I got it back, the axle seals started leaking To replace the seals, I had to pull the rear cover, only to find it was full of water, and what came out looked like chocolate milk. I replaced the seals, washed it down with brake clean, and put it back together. I drove it hard for another two years before I scrapped it because of rust, and it still had the same rear end in it, and it wasn't loud enough to hear over the exhaust.

Sounds like an episode of "Road Kill Garage". How many of us would never admit to something like that? GPster

[enjenjo]

True story. The red GMC pickup I had years ago I built from the bare frame of a truck I bought from my brother. I bought a rear end and front suspension out of a truck with only 5,000 miles on it, stolen recovery. To be honest I never checked the rear end further than checking the brakes were good. I drove that truck everywhere for 5 years, then sold it to a buddy. He drove it a few thousand miles over the next 12 years, and then sold it back to me. After I got it back, the axle seals started leaking To replace the seals, I had to pull the rear cover, only to find it was full of water, and what came out looked like chocolate milk. I replaced the seals, washed it down with brake clean, and put it back together. I drove it hard for another two years before I scrapped it because of rust, and it still had the same rear end in it, and it wasn't loud enough to hear over the exhaust.

Sounds like an episode of "Road Kill Garage". How many of us would never admit to something like that? GPster

I guess if you do something stupid, and it works, it wasn't stupid to begin with.