Synthetic oil in T-case

[gallf1]

Hi:
I am running synthetic oil in my Ashcroft high-ratio t-case. It has developed a slow seeping leak around the intermediate shaft area which I am attributing to the o-ring.
Before I pull it out and replace it, does anyone know if the o-rings are not compatible with synthetics?

Also, should I smear some Hylomar around the shaft and o-ring before I re-install for alittle extra insurance?

Thx!

[TedW]

Synthetics are prone to creepage / seepage to a much greater degree than are dino hypoids. Good seals are key (to state the obvious).

I've used synthetics for almost 20 years; my truck doesn't seem to leak any worse than any others I've seen, and is better than many.

[alaskajosh]

This might open a can of worms but I understand that Ashcroft's warranty doesn't allow use of synthetics.

Kind regards, Josh

[gallf1]

Hi Josh:
Not sure where you got that info....it is not in their warranty statement. They do recommend specific oil types for the automatic transmissions but not for the High Ratio T-case (which is what I have).
Thx

[alaskajosh]

Hi Josh:
Not sure where you got that info....it is not in their warranty statement. They do recommend specific oil types for the automatic transmissions but not for the High Ratio T-case (which is what I have).
Thx

Well I admit that it is hearsay... though it was said by RN (and I don't remember the name I spoke to). It goes along with the whole "yellow metals" debate. I put Amsoil in my T case despite that and other doomsayers. I'm not worried about it but couldn't escape the irony of a RN rep stating that syn where not safe with yellow metals (citing, for one thing, the ashcroft case) but they sell and recommend Amsoil for Series gear boxes.

Kind regards, Josh