92 SC 400 transmission slipping fluid change

[drmikepac]

I recently inherited a '92 SC 400 with 240,000mi.  Majority of miles were highway (1st set of brake pads were changed at 121,000mi).  I've noticed twice in the last couple months a small slippage in 1st gear, not consistent, has happened 3-4 times. I've been given the following suggestions (none of which came from serious/trained/experienced mechanics):
1. flush and replace fluid

2. drain and replace fluid

3. add auto rx drive for 1,000 miles and drain and replace fluid. 

Any advice?

Thanks for your help and input...

drm

[Tomj8]

Hi, great timing since I just resolved this identical issue with my '92 SC400 (165,000 mi) last week. Mine was slipping, mostly in first gear and mostly before the engine reached normal operating temperature. It may seem simplistic but check the fluid level - that was the only problem with mine due to slowly leaking seals. Be sure to check the fluid level at operating temperature, in park, at idle, and be sure to wipe the dip stick clean before you measure. One final caution - add fluid slowly and re-check, DO NOT OVERFILL!  Hope that takes care of your problem as it did mine.

[drmikepac]

I guess I should say duh...thanks..didn't know low fluids could do that. I'll followup if that's not the case...
thanks..drm