Transmission disappearing fluid

[CamoCUCV]

M1008 started slipping yesterday. pulled over and checked the trans fluid. It wasn't even on the stick? I looked all over for signs of a leak but I don't see anything??? I had recently changed the filter and fluid a month ago. So it's defiantly going somewhere. Now I had one thought and I'm not sure it's related. But I noticed the other day when I was checking my fluids that my radiator had a orange oily substance. I flushed it and now it's back? Could my trans fluid be going in the radiator through the trans cooler. Isn't the transmission fluid cooler built into this radiator?

 

[blueblaze]

Your rad could be broken that way. I've never seen that but it is all in the same unit so its more than possible I suppose. I'd also check your transfer case aswell. Sometimes the seals go bad between the trans and tcase and the trans empties into the tcase.

 

[welpro222]

I had same thing happen, it was the input shaft seal in between tranny and transfer case. Hard to tell, as it leaked mostly when driving, it did coat my driveshaft and rear end with fluid. Pull transfer case fill plug and see if it seeps out. Its not really a hard job, the transfer case can be pulled out by hand (without fluid weight). I did the job with my truck up on jack stands. Sourcing the trans adapter to transfer case gasket can be a chore, the tranny shop gave me a few different ones and none of them were right so I made one work with alittle RTV sealant. Use very little RTV if you do, you don't want it to end up in transmission.

Also while you have it out and on bench, do an inspection and change all seals.

 

[rustystud]

I would also check your modulator hose. If the modulator diaphragm gets torn it will suck transmission oil into the engine vacuum pump. Also the transfer-case could be the culprit, just remove the fill plug and check. The radiator cooler could also be bad. Since the transmission cooling pressure is greater then the water pressure it will fill the radiator.