Very Hard Shifting Between Gears

[alis888]

I have a 96 LS400 with 158K miles. When the engine is cold (I live in FL, so the engine is never truly "cold" temperature wise, by "cold" I mean when the car hasn't been driven in several hours) the shifts between gears while driving is rough and slightly stalling. Also, putting the car in reverse has the same effect. I recently discovered 2 damaged vacuum lines which I replaced, but this has not fixed the problem. The rough gear shifts only occur when the engine is cold, after driving for 15 minutes the problem disappears.

The oil was changed recently and the transmission fluid is at the correct level. I do drive about 20K miles a year though. Any ideas what the problem is? I've heard talk about the solenoid in the transmission causing this, any opinions?

[landar]

When you say 'The oil was changed recently', do you mean a complete flush or just the two quart drain and refill? What (brand and type) fluid was used in this operation?

[alis888]

When you say 'The oil was changed recently', do you mean a complete flush or just the two quart drain and refill? What (brand and type) fluid was used in this operation?

Just drained and refilled with Castrol GTX 10W-30

[landar]

ok, now I am really wondering...when you said 'oil', I thought you meant transmission fluid but it appears that you are mentioning engine oil. So, you are having shift issues(correct?)...did you have the transmission fluid flushed or drained and refilled? Old, worn tranny fluid can cause harsh shifing. ONLY use Toyota Type IV.