Old Transmission. Questions About Fluid Change.

[kinggrimwood]

Take a 1992 SC400 with 200,000 miles. Original tranny fluid.

What can i do to help the rough shifting. I think i read once that if you do a pan drop on transmission oil that is that old, it can destroy the transmission.

Can someone please give me advice on what to do to save this transmission?

[lexus082]

Remove the pan, clean the 4 magnets and you can either clean or replace the transmission filter. I purchased a gasket for the transmission from an auto parts store instead of using the sealant that Lexus uses. Inspect metal material on the magnets, before cleaning them. Its a pretty good indication of the condition of your transmission. Refill when cold to cold line and then add if needed when hot. Then shift slowly from P-R-N-D-2-L and then slowly shift from L-2-D-N-R-P. Use Toyota Type T IV fluid only. Also, to clean up your exisiting fluid I would do a series of drain and refills. What is the condition of your existing fluid? Is it dark brownish/black or smell burnt? Many people believe that transmission flushes can potentially be hazardous to an old transmission that has been neglected. Thats my opinion also and I'd rather be safe than sorry when it comes to servicing the transmission. Others have had it flushed without any problems. As far as removing the pan and replacing the fluid it should improve the shifting. I've drained and refilled my transmission at least 10 times over the last year to improve the fluid quality without having to get it flushed. Also note there is a drain bolt on the transmission pan so you don't have to remove the pan everytime to drain the fluid. Drain and refill capacity is approx 2.0 qts., if you remove the pan and filter it should require more fluid than a simple drain and refill. Just remember SC400 Transmissions require Toyota Type T IV Fluid and the use of other fluid types can or may result in harder shifts.