Re: 51 transmission fluid

Posted by Eric Boyle On 2008/7/25 1:43:06

I've found that the best fluid after trying Dexron, and Type F was B&M TrickShift. My trans never shifted so well, and the groan I had dissappeared. The reason why you get the groan is the car sits so long that the direct drive clutch dries out and becomes hard. Changing fluid won't fix it, but the right fluid puts off the inevitable for a while so you can drive the car and get used to it's characteristics.

On the subject of the "groan", I did what PackardV8 advised me to do, when it does it, instead of letting off the throttle, push it down harder every time it does it. Eventually you'll burn off a thin layer of the hardened clutch material, and it'll work a lot better. I'd change the fluid as soon as it starts appearing black when you do this. The best option of course is to just pull the trans and install a new direct drive clutch, then you can replace the gaskets and seals that cause 99% of all Ultramatic leaks.

One other thing, and I know this is a lot more than you asked for, but pull the pan and clean the filter, it's reusable. The gaskets can be found on eBay all the time from Ron's Gaskets and several others. Ron's is the one that comes to mind right now. I can't remember Peter Finch's eBay handle, I think it's UltramaticDynamics, but I'm not certain.