Cross Shaft/Selector Shaft Seal

Posted by Gary On 2011/12/12 12:37:44

Well I felt energetic over the weekend and decided to tackle the seal on the cross shaft AKA gear selector shaft but ran into a little problem of not being able to remove the shaft from the tranny because of frame interference. Looks like a guy could drill a hole in the frame where it needs to pass through to gain clearance but I've just about decided that most of leaking coming from my transmission was due to a very flat, distorted and maybe even reused pan gasket. I didn't go to a whole lot of trouble to pinpoint the leak because I wanted to change the transmission fluid anyway and the Ultramatic Service Manual states that both the cross shaft seal and the throttle shaft seal can be replaced with the tranny in the car but even removing the rear transmission mount does not allow it to drop down far enough for the cross shaft to be removed. So at this point, I've decided to change the fluid and button it back up to see if the leak is as bad as it was or if it leaks at all. Personally, I was thinking that there are a few 51' thru '54 Clippers running around with an extra hole in the frame...or actually, an enlarged hole as it appears to line up almost perfectly with an existing hole located between 2 frame rivets. Now I'm facing the "what transmission fluid do I go back with?" question...the PO said he always used Dexron but I don't know if it was the III or VI. I read somewhere that Dexron VI does not suffer from viscosity breakdown like the III did so maybe it's at least equal to the Ford FA fluid.

Dexron-VI
Dexron-VI was introduced in 2005. All Dexron-III licenses expired permanently at the end of 2006, and GM now supports only Dexron-VI fluids for use in their automatic transmissions.[3] Fluids asserted by their manufacturers to meet Dexron-III standards continue to be sold under abbreviated names such as Dex/Merc and D/M, but since the Dexron-III licensing system no longer exists, these fluids are not regulated by GM.[citation needed] The use of previous fluids can damage transmissions meant to use Dexron-VI.[3]

Decisions Decisions...