Hello all. I'm finishing up a 4.6 stroker and am currently doing the trans filter and installing a cooler. I'm not sure but the fluid seems wrong. It smells very bad, like cat urine and I think that it's gear oil. It's pretty clean, but I wonder if I need to flush and replace with Mercon. What trans cooler do you like for a daily driver that will see light to moderate off road action. Any advice is appreciated.

 

There are a variety of trans coolers out there that would suffice, some that are even dual circuit, (1 section of 4 pass, another separate section of 2 pass), for trans fluid and oil, or ps fluid. I think Derale makes those.

Will it see a lot of off road use, or only occasionally? If its 90% dd, and like 10% off road, a regular cooler should suffice, however if it will see more slow speed off road use, see about having an electric fan so that the cooler will have air pulled through it at slow speeds.

Where did you get this transmission? Is it installed in the vehicle? If it is suspect, I would open it up and take a good look at it. Since you are building a stroker motor, (putting time and effort and $$$ into the truck), I would make damn sure there are no problems with the trans before you reinstall everything. If you do everything the right way the first time, you won't have to do it again.

 

Thanks, I have no reason to believe that the trans is damaged in any way. It drove fine before I garaged it. My issue is identifying the fluid that was in it before I refill it. It has that distinctive pungent smell that I don't associate with Dexron/Mercon III, but I could be misremembering...

 

I'd flush that puppy. Dex/Merc is cheap. Transmissions aren't.

I did a flush on mine when it was slipping badly. By '"badly:", I mean, once it got good and warmed up I was not sure I was going to make it home. I did a flush and got another 50k miles before wrecking that Cherokee. Dunno how long it would have lasted.

Here are the instructions for a complete flush, as provided by a retired Ford transmission engineer, Mark Kovalsky. Yes, it's for a Ford, but the steps are almost the same. The only difference is, the AW4 has no real filter, so there's no real reason to drop the pan,. Just do the flush.

https://www.ford-trucks.com/forums/1...and-video.html