Re: Twin Ultramatic Lifespan.

Posted by humanpotatohybrid On 2022/10/12 9:45:14

Thanks Ross. While we're talking transmissions, when I put my 400 in R after starting it, the transmission will stall out the engine unless I rev it up significantly. However once it's past that and in R it idles fine, shifts to D fine, basically is fine the rest of the drive.

In the troubleshooting section, looks like it might be Condition 15, "Chatter when starting in reverse" and it suggests adjusting the reverse brake band. How much of a problem would it be to keep driving the car like this? Obviously I can start backing it into my driveway so I can start it in Drive and hopefully avoid this problem. I won't be able to drop the transmission on this anytime soon.

On Hydramatics:
It's true the Hydramatics had their own annoyances. The most significant in comparison to the Ultras is that the Hydras had only a fluid coupling, not a torque converter. For this reason, they needed to have 4 speeds (3.82, 2.63, 1.45, direct) to provide sufficient torque. Whereas the TC in the Ultras needed only a 1.82 low gear, optional at that. So whereas the Cadillac owners manuals could brag about having the most used automatic in the world, in getting up to cruising speed you'd feel 3 gearshifts each time, compared to only 1 or 2 in the Ultra (including the feel of the TC locking up).

5540:
Yeah if it was over 1/4 million miles I'm not concerned then. I doubt even my 2010 Traverse will make it that far without major service.