88 burban towing

[mballou]

my tranny is now shifting hard... i need a beefier auto tranny.. i have a 700r4
i haul my trailer 3000 or more lbs and my offroad jeep 4000lbs.. i think i messed up tranny big time i have tranny fluid ever under load smoke really bad coming from breather and hitting exhaust.... i have a little trans cooler maybe stock?? i have replaced the trans filter fuild looked great.... but im still having problems.. so now im looking to upgrade.... i wanna keep an auto tranny i have a 88 burban 350 auto 4x4 im running 33s... any help would be great.. thank in advance

[Crawdaddy]

First and foremost, get a really nice stacked plate transmission cooler, the biggest you can find. They are typically rated by GVWR, but just ignore that, get the biggest you can find. The 700R4 is a strong, resilient transmission when you take care of it. I put the 700R4 in my 91 Suburban through just as much stress with only the factory cooler and 2 dead cylinders and it still rocked for at least a good 200 miles like that, likely more like 400-500 miles. An external filter and temp sender would also be a good idea.

As for your issue, low transmission fluid would cause a hard, late shift and possibly loss of higher gears such as overdrive. Sounds like you're boiling the fluid and it's getting out via the breather. Keep the transmission cool, and you should be fine. What I'd suggest for now is to install the biggest honking transmission cooler you can find, make sure the transmission is full, and drive it like that for a while and see if you have the issue still. Make sure the transmission fluid does not smell of burnt almonds.(don't ask, that's just what I've been told, I don't have a strong enough sense of smell) If so, you may want to drop the pan and take a peek inside. It may be to the point that it needs a rebuild. If so, install a mild shift kit and the upgraded parts that were developed in later years. I think there's a stronger sun gear and a few other things...

The TH700-R4 is an excellent transmission, it just needs some love.

[collinsperformance]

you are not running in overdrive are you? if so ---stop it will over heat the tranny too.....mike

[mballou]

no i am not in overdrive