Coolant in transmission, W124
 

My '87 300E has fallen on hard times! The 2-3 upshift has been rough after warm up (but smooth when cold). Brought it to the local trans expert, who promptly found coolant in the trans! I installed a new Behr radiator approx. 2 years ago, and thought i would never worry about that again- didn't think the *&#@! trans cooler would ever be a problem. My game plan is to replace the radiator with one that is pressure tested, and pump out the trans fluid, while pumping in fresh. I'm concerned that the coolant may have damaged the friction plates, or their bond integrity- also that my rough shift may be do to corrosion in valve bodies. Any thoughts as to what I might expect? Car has 150K, and trans works fine other than the 2-3 shift. Thanks!

Art

I'm not so sure I would "pump" anything out. This is a technique used on systems that provide no way to drain the converter.

Your converter has a 5mm allen head drain plug. Same deal on you transmission pan. Simpy drain both and change the filter. You may even wish to do so a couple of times just for piece of mind.

Harsh 2-3 shift isn't an indication of worn frictions, a sloppy slipping 2-3 shift is.

The key is the fact that you have a soft 2-3 shift cold -- check the vac lines on modulator, I'd bet one is leaking. This lowers the vac at the modulator, and low vac = hard shift.

There is usually a low temp effect -- new fluid will help.

Late shifts, or un-inteneded 4-3 downshift is an indication of valve body trouble.

Peter