Originally Posted by spidey3479
So this is not hurting anything for it to have the high revs until I rebuild the OEM tranny?
Not really, so long as you are not exceeding the rev limit on the 3800. The motor should be able to run at the rev limit for an indefinate amount of time without doing any harm to the motor (That'* the whole purpose of a rev limit.)
Now, joining back to your problem from a few days ago: Because the Cutlass transmission was set up for a motor with a higher rev limit, it probably is still trying to use the 3.1L Cutlass setup to do it'* shifts. This is where it get'* sticky, since you have jumped off the normal diagnostic charts into a whole new realm. (Ain't part swappin fun!!!)
I would venture a guess at this point that the governor in the transmission is what is causing the higher than normal rpm up-shifts. The governor uses the vehicle speed (it'* gear driven off the output shaft) vs. line pressure modulated by the Thottle Valve and vac operated modulator. Problem is, it doesn't "know" the rev limits on the motor driving the input shaft. It was calibrated for the 3.1L motor and the Cutlass weight. What you might need is a governor calibrated for the Bonneville'* weight and the 3800 motor.
Good news is the governor is easy to get to. It'* on the top of the transmission right where the passenger side axle exits the case. You don't have to dissassemble the transmission to make a change to it'* springs and weights.
Bill: Thanks for posting the link to the drive ratios. Made lights go off...I'm not used to having *all* the gears inside the transmission case. Just takes some getting used to. At least I dug up the build sheet for the '90 and looked at the codes for mine: F17 - 2.84 final with a 1:1 chain...so I keep my eyes peeled for an FW2 code in the junkyards (for the 3.06 final)