Okay. If I go to do a fluid and filter change on my e40D tranny, other then draining the transmission and torque converter and changing the filter, is there anything else I should do? By the way, I'm getting my local mechanic to do it so, I'm just wondering what I should tell him to do. Any help is appreciated.

 

Get a can of "TransTune", add to tranny fluid and drive 2-3 days prior to change. Desludges, restores full flow rate to cooling coil, dissolves old baked oilcoating. Will improve function & reduce operating temp. After draining out the muck, the best thing you could do to prolong life of your tranny would be to switch to synthetic trans Fluid (Google "Synthetic transmission fluid").

 

Would the transtune work well in my 91's 4spd manual as well, or should that just be a drain and fill only?

 

Yep, also as Power steering & differential flush. It desolves contaminants and keeps in suspension so they drain instead of just relocating. You'll know how well it works when you see (and smell) what drains out. It also neutralizes the corrosion properties that petrol base fluids produce as a byprobuct of their molecular decmposition that begins as soon as it is heated above room temperature and continues till it returns. The same company also makes "SeaFoam" for decontaminating the engines interrnal wokings,including injectors, air intake, and combustion chamber surfaces.