On a recent 4K mile trip I had the Overdrive "OFF" light flicker from what I think was low transmission fluid level. I think my radiator may be the culprit! Is it possible that my tranny fluid is seeping into my cooling system? Before the trip I did a tranny fluid and filter change and didn't notice any coolant in it. What would tranny fluid in the coolant look like? Thanks!

 

The OD off light won't flicker because of low fluid. Low fluid can cause the transmission to slip and that can set a DTC _that_ would flash the OD off light.

You didn't say if you checked the fluid and it was actually low or not. Or what its condition was.

Coolant in your transmission will make the transmission fluid look like pepto bismol. That is; a pink milky appearance. Same goes for transmission fluid contaminating the coolant in the radiator.

It is possible for transmission fluid to leak into the radiator and/or engine coolant into the transmission fluid. One doesn't necessarily garantee the other. If you have transmission fluid in your engine coolant its as simple as bypassing the radiator and adding an external transmission cooler. Then flush the cooling system and top up the transmission.

If you have engine coolant in the transmission fluid the transmission is ruined and it will have to be overhauled. Flushing the transmission will only waste your money.

Steve
'95 Clubwagon XLT

 

I checked the fluid when the light on the OD stalk started flashing. It looked clean and pinkish. When the light started flashing the cruise control kicked off. I stopped for gas and the tranny shifted hard from 1st to 2nd and alittle less hard from 2nd to 3rd. I added a half quart of Mercon ATF I had left over from changing the fluid/filter and the symptoms stopped. Drove about 500 miles and it started again. Added another half quart and it stopped again. I think there is a leak somewhere as the lines are wet going to the radiator. I need to crawl under it I guess and get a better look. Thanks Steve!

 

The light flashes when the tranny goes into 'limp home mode' or emergency operation. The two items may be connected, and then again, they may not. The 'limp home mode' is a protective device built into the electronics of the transmission. It gives you a chance to get the rig home while protecting the tranny from catastophic damage (maybe). Most of the time when you get the light it's a computer board, not transmission internals. But a scan tool should be able to give you some codes that you could decipher. Hope this helps, Ken