1985 Oldsmobile 442 transmission; is it the modulator valve??

Question

My dad let's me drive his '85 Olds 442 every now and then... when you get off the freeway after runnin it for about 10 minutes, or even in town when it's very hot out, the transmission will shift funny... like, it will go into second a little early and kinda smooth, but not normal... then third kicks in not long after and it jolts the car... and finally 4th is not far after and it really gives the car a jolt and the RPM goes down... at this time, i'm at 25 or 30mph... in 4th and possibly overdrive too...

Does this sound like it could be the modulator valve? also, the fluid and the filter?

Answer 1

when was the last time you checked your radiator? the trans is cooled in that thing...and if its plugged up--being an 85, it could effect the trans .  especially when its hot.. sounds like it could be time to go thru the trans too. usually rough or intermittent shifting is caused by loose seals , weak pumps and the clutches being worn.. one minute its fine and the next its wierd... when its cold its fine--right?  this is could be the "morning sickness" too. once the seals get warmed up it will slip and the opposite in some cases, the trans is cold and it wont build pressure till it heats up, then it slips while shifting --off and on.. after awhile it will quit all together. check the pan for metal or burnt fluid too.  you will not se metal on the dip stick till its too late. good luck with it..

Answer 2

there is a governor that spins and the innertia makes weights pull outward the faster it spins.  Heavier springs will hold tighter for more rpm's before letting fluid pass.  Hence, higher rpm's before shifting.