Leaking Automatic Transmission Cooler - Help Wanted
 

Greetings all,
Thing One's car has a leak in the transmission cooler and has contaminated the tranny fluid with coolant (Pepto-Bismol pink).
We plan to drain and flush the transmission, replace the filter and plumb out the existing cooler and replace it with an aftermarket cooler.

BTW-This car is still shifting OK until the oil gets warm.

Anything else we should be thinking about doing? What else should I be concerned with?

Transmission Update
 

So far, we've installed an aftermarket oil cooler and plumbed the leaking, OE cooler circuit back to itsself so that it will be common with the engine coolant and won't leak.

The cooler installation was a little tricky but, using a 9" x 12" cooler, we could just barely squeeze it in behind the bumper and straddling the left side of the radiator and over onto part of the engine oil cooler. The lines from the transmission were cut with a tubing cutter and suitable rubber tubing was used to connect to the cooler. The lines were routed along the underside of the radiator and through a gap on the right side of the radiator.

Thank goodness for that drain in the torque converter; we were able to drain all the nasty, coolant contaminated trans fluid. Now, that it has been has been drained, we replaced it with new fluid and added a Trans-X treatment.

After the install we had time to put about 25-30 miles on the car last night and, at this point, it is shifting fine (firm shifts when you stand on it and soft when you gently accelerate) and the fluid still looks good (no foaming and no scorching).

After about 100 miles of useage, we'll drain this fluid, drop the pan and replace the filter. New fluid will go in and we'll drive it more. Hopefully, there won't be any troubles with this transmission and Thing One will have a reasonably reliable ride.

During the test run we did discover that the driver's side trailing arm bushings are shot. The car is a handful at 55 mph. 70 is out of the question. I'll cover the bushing replacement in a separate thread.

Good luck!! My past experience with coolant contaminated trans fluid has not been good. Unfortunately the friction material on the clutch plates in the transmission is held on with a water based adhesive which is dissolved with the coolant.

Let me know how it turns out, I may have a transmission available!

Brandon

So far, Thing One's put about 75-100 miles on the suspect transmission and reports some intermittent slipping at start-up.

He's not familiar with Benz tranny's and I've only ridden in the car about 20 of those miles so he might actually be experiencing a 1-2 flared shift. I'll have another chance to drive/ride tonight and will see what happens.

Unfortunately, we can't dog this car until those trailing arm bushings are in....waaaaaay too scary to drive it very fast/hard.

Meanwhile, we've scored another 722.xxx automatic. The boneyard is holding it on the off chance we need it.

I'm not taking any chances. This car has to make it from Texas to New York (and be reliable when it gets there too). $400 for a working tranny is cheap insurance...and they're no big deal to swap out.

To be continued...

Coolent water in transmission - update
 

I drove it at lunch today.

This ride is definitely getting a replacement tranny; it's function has deterioriated since we replaced the fluid the other night. Intermittently, this transmission won't hook up from idle and the 2-3 shift usually has to be coaxed by modulating the throttle.

You have a manual transmission sitting in your garage... if you really loved the boy you would put that one in that wagon and he would never have any problems with it... and you could score the instructions for that swap... which I have not seen documented yet..... :D

I don't think he really loves Thing One that much. Remember, the manny tranny is held in reserve for Marlene.

TO and I discussed all the options. And actually, it's a matter of simple economics.

1) Add a cooler and drive it till it broke
2) Do the manual swap on this car
3) Stick in a boneyard tranny

And, I do love Thing One dearly because here is the other option I offered...

4) Take Marlene's auto transmission out and put it into TO's car.

Even if I gave him the stuff in my garage to do a conversion to manual, it would still cost another $750 to get it on the road.