My 4runner has been leaking oil since I bought it. Not extremely serious, but enough for me to want to stop it. I replaced the front crankshaft seal, the valve cover gasket, and the oil pump seal. I think it may still have a small leak from the rear main seal, but the other seals have stopped the majority of it. I really don't want to pull the transmission just to replace a seal. A friend of mine mentioned that I could put a little ATF in the oil to expand the rear main seal, and hopefully stop the oil leak. My question: will this hurt anything internally? Do you think this will allow me to wait to pull the transmission until it's time for a new clutch? By the way, it's a 22R-E with a five speed. Thanks in advance for your help.

 

I had a buddy that was advised to drain his oil & put on a new filter, fill it with ATF, run it until it reached operating temperature, shut it down.

Then drain the ATF & replace with cheap oil & run it until it reached operating temperature then shut it down.

Then drain the cheap oil & change the filter to a good one & put in new oil of his choice.

That process did stop his leaking seal (temporarily) & cleaned a lot of the carbon build up out of the old Ford LTD's 351. I'm not sure I'd recommend it though, sort of like putting brake fluid in a transmission to get it to grab; sure it'll work but it's only temporary & doesn't "fix" the problem....you'll find a lot of junk used car lots that do these things to pawn off a car quickly.

 

It's not going to hurt anything. Might even work. But, after a lot of miles, the seal begins to crack and it's all down hill from there. Also, the tail end of the crankshaft wears a groove from constant friction from the seal.....especially after it has gotten harder. So, go ahead and try it. If it doesn't work, don't be terribly disappointed. The leak won't hurt anything either. Unless, your losing a lot of expensive oil.

 

Just fix it. If its not leaking bad enough to make you want to pull the trans to fix the leak, dont do anything. Why not just do it right and be done with it? You will be spending more money and time trying to 'fix' the leak instead of just doing once and for all

 

Hey 88,

ATF, is just 10w oil w/lots of detergents added, and colored for identification reasons.

Thanks Kiwi

 

ive been told that in old engines, let a quart or so of oil out and repalce it with atf for about 20 miles, its sapost to clean out, kinda like a enema for motors, never tried it but i belive the guy that told me.

 

Thanks for your comments. I think for the moment I am going to clean up the bottom of the engine and where the engine and transmission meet. There is alot of oil coating the under side of the truck, so it is apparent the truck has been leaking for a while. Then, I will kind of watch it and see if I see any more oil in that area. I just would hate to have to pull the transmission for something so small. The truck has just had the clutch replaced in the past 15,000 miles, so I am still hoping that the oil all over the place is from before, and that the PO replaced the seal when he replaced the clutch.