Hey guys, I am planning on doing some long overdue transmission service. However, before I start taking things apart, I had a few brief questions.

First off, I am dealing with the stock automatic transmission on a 1990 W250 (727 3 spd.) that has 211,000 miles on it, though the previous owner said the odometer had broken for a period of about 1,000 miles before being fixed. Obviously, that could be false.

Now to the question(s). I am planning on simply dropping the pan and doing an oil change. While I'm in there, I figured a band adjustment couldn't hurt. However, some people I've talked to said that doing a band adjustment on a transmission with over 200,000 miles could burn it up a lot quicker. I tend to think otherwise, but what are your guys' thoughts on this?

Secondly, I planned on running a little extra fluid in the system for a minute before dropping the pan in order to try and rid the system of as much existing fluid as possible. Any thoughts on this, or suggestions for a better method?

The goal is to help my transmission out a bit for the winter, as I can't afford a rebuild right now. Any suggestions beyond the basic oil/filter change to ensure longevity would be appreciated.

Thanks in advance,
Jake

 

Doing the band adjustment isn't going to hurt it. As for getting as much fluid out as possible, just loosen the valve body bolts and allow the valve body to separate from the case a little bit and let it drain. This will get at least half of the fluid out of the torque converter.

 

Put a drain plug in the pan while you have it apart.https://www.summitracing.com/parts/bmm-80250/overview/

It will make life easier next time.

 

If you are uncomfortable with loosening the valve body bolts, disconnect the hot transmission line (front) - you can do this before or after dropping the pan.

Use ATF+4 fluid; the cheapest Wally World brand will do, as long as it's ATF+4.
If you have a NAPA handy, add a 10oz bottle of Lubegard Red after your fluid/filter change.

 

You don't need ATF4 in these trucks or lube guard. Won't hurt but not needed, you can use Dextron 3, Some people have used Hyd. Fluid with a quart of Dex. for red coloring.

If you loosen the vb bolts, torque them back to 100 inch pounds.

 

There's a sticky about taking a hose lose to pump the fluid out.

What's the Lubgard?

 

Lube guard is a friction modifier that will make hyd/dextron similar to atf4. I've ran regular dext. In 47res with lube guard because I had the Dextron.