Transmission seal questions...

Chunk · Post by **Chunk** » Wed Aug 19, 2009 12:00 pm

I know that there is a seal in the rear bearing retaining plate where the companion flange is,but where is the seal that seals the front of the transmission where the main shaft comes out of the case? Or in other words,where is the seal that keeps the gear oil from coming out of the case and getting all over the clutch,flywheel,etc?

powerwagontim · Post by **powerwagontim** » Wed Aug 19, 2009 3:28 pm

There isnt a seal in the front. I think the oil gets slung off the turning shaft before it makes it out.
Tim

W_A_Watson_II · Post by **W_A_Watson_II** » Wed Aug 19, 2009 5:36 pm

Not on the NP435's, one of mine had a spiral grove to channel the oil back into the tranny. I've heard others that when they have had the truck towed backwards talk about oil running out and soaking the clutch as a result of no seals in the design.

Chunk · Post by **Chunk** » Thu Aug 20, 2009 8:17 pm

Charles,could you explain? Thanks.

Chunk · Post by **Chunk** » Thu Aug 20, 2009 8:19 pm

It doesn't make sense to me why there isn't one there. Looks like oil would leak all over the clutch on a "steep down hill". Makes no sense.

Lifer · Post by **Lifer** » Fri Aug 21, 2009 2:56 am

The spiral groove collects excess oil from the shaft and "pumps" it back into the housing as long as the shaft is turning. The principle has been around for a very, very long time (see Archimedes screw).