Transmission Fluid Brown and Stinky

[ClownRoyal]

Towed the boat 1250 miles from Spokane to Havasu. Got to Havasu and checked the tranny oil - brown and stinky. I am thinking my fan blew or ?? I just had the trany overhauled about 14 months ago and upgraded it for heavy long-distance hauling (of course the warranty was only good for 12 months). Truck is a 99 Heavy Duty F250 7.3 Turbo Diesle. I have 138K miles on it.
Any ideas and/or suggestions? I love this truck and really don't want to spend money to replace it.
Thanks

[wrenchdaddy]

Im no tranny expert but I have destroyed a few in my past and this is what I've learned. First off brown or stinky tranny fluid is not good, I'm sure you know this. Fluid that is abnormal in color or smell is because of one or both of the following, slippage and excessive heat. Given that your tranny was just rebuilt I would lean towards the heat side, unless ur tranny builder messed up something. Your transmission will generate a lot of heat on take-off and during shifting until you get up to speed. Most automatics have a lockup converter nowadays, once that converter locks (when ur going a steady speed) the transmission should generate little to no heat. I'm guessing you were going mostly highway, your radiator fan does nothing for you at highway speed, your radiator is gettin plenty of air from the ram air effect. BUT most stock tranny coolers are either built into the radiator or are undersized, so they really can't cut it when you need it the most. If you were downshifting a lot or going up hills, it just can't get rid of the heat fast enough which results in breaking down your fluid.
Sorry that was kinda long, off hand I would recommend a good sized tranny cooler, put it in the very front of your intercooler, an auxillary screw on type filter and a temp gauge wouldn't hurt either. Hope this helps

[ClownRoyal]

If you were downshifting a lot or going up hills, it just can't get rid of the heat fast enough which results in breaking down your fluid.
Sorry that was kinda long, off hand I would recommend a good sized tranny cooler, put it in the very front of your intercooler, an auxillary screw on type filter and a temp gauge wouldn't hurt either. Hope this helps
Thanks wd...and you are correct...as I was downshifting and going up several long grades. I will be looking into a bigger cooler. The truck seems to shift fine. I just had tranny flushed and the guy said the oil was cooked.

[Patyacht]

Sure hope they dropped the pan and took a peaky.... You might want to consider a deeper pan. http://www.genosgarage.com/prodinfo.asp?number=MH-5R110 See you in a few days.

[Sotally Tober]

Use to have tranny problems with my Banks Powerstroke. Added a 40k cooler and a Mag-hytek pan which made the tranny hold 6 gallons of ATF. No problems for 90,000 miles so for. Never see over 160 on the guage pulling 12k uphill in 100+ degree weather.
How hot did it get?