I am hoping one of you can give me an idea of what is going on with my truck.

It's an '02 that I recently did a swap to a 5.7L and had the transmission upgraded to the 5 speed RFE version.

I get the truck back and I notice it is leaking where the transfer case mounts to the tranny. Most concerning is that it is bright pink fluid! I check the dipstick and it looks like pepto.

Looks like classic coolant in the tranny fluid, but where the heck did it come from? As far as I can tell there is only an air-to-oil cooler on this truck, and there are no lines going to the radiator. They guy who rebuilt the tranny said it was assembly grease, but other mechanics I have talked to had never heard of such a thing.

Is there any other way for coolant or water to get in the transmission? Is there an assy grease that makes it look like pepto? It still seems to shift ok at the moment.

Do I need to flush it? Have it rebuilt again? WTF? I have already spent a ton of cash on this, and it has been one problem after another.

Thanks!

 

If you do not have cooler lines going from the trans to the rad, where is your trans oil coolers?

 

Weed,

It appears that the lines only go to the air-oil cooler on the front of the rad and not to a radiator cooler first, so I don't see anywhere for water to have entered the system. I think that was standard with the 4.7L. I am wondering if I need to upgrade radiators if the 5.7s tend to have water-oil coolers as well.

 

The only reason I can think of is somebody power washed the engine bay with the dipstick off?
5.7 rad is the same design as the 4.7. Just a little more capacity.

 

That's a pretty disturbing issue there-I would personally drain and fill mine-Perhap's have a different Transmission Shop inspect it-

 

Only thing i can think of is, if the box and engine were split before installation water ingress before re assembly.
Al.

 

My coworkers truck (a Nissan however) had this issue. It was common with the Frontiers to have had radiator/trans cooler issues where they would leak into each other. Maybe its the same with this?

 

This can't happen here.
His (the OP) transmission cooler, is a completely different and seperate circuit isolated from the engine coolant circuit.
His tranny cooler has separate lines running into a standalone cooler, mounted on the front of the main engine coolant radiator.

The system you describe is where transmission lines run into a cooler, which is an integral part of the main engine coolant radiator incorporated at the bottom of it.
This type of cooler can rot and corrupt the ATF with engine coolant as its literally part of the main radiator.
I hope that all make sense lol.
Al.

 

Correct. I assumed the same thing, that my radiator was contaminating my tranny fluid. I even took the pressure tester out to check it, when I noticed the cooler lines didn't even go into the radiator.

I am guessing it was contaminated when it was split at some point. I am flushing it and refilling and hoping for the best. Keep your fingers crossed for me.

 

Greg, this is probably one of the only times I would consider doing a power flush.
Water will get everywhere in the transmission and there's just so many galleries and passages in an auto box, that only a power flush would get it out. A simple drain would not I believe suffice.
Good luck on the flush and let us know how it all goes.
Al.
PS, everything crossed for ya bud.