Castrol 10W-60 synthetic motor oil for transmission?

[Vette73]

Just to clarify, because I want to change next week,Castrol 10W-60 synthetic motor oil for the transmission fluid? 91Z...

Thanks....

[BigJohn]

I would not use motor oil!

[Scrrem]

Originally Posted by BigJohn

I would not use motor oil!

Yes, that is correct, although Castrol has reformulated that oil. Not sure if it is the same.

Just to clarify, the Castrol 10W-60 is what ZF and Bill B. recommend for our transmissions.
http://www.zfdoc.com/techinfo.htm

Rich

[Dynomite]

LT5/ZR-1 Fluids

[Mystic ZR-1]

Believe it or not, the last time I bought it, 2 years ago, the BMW stealership
was the least expensive! Including on line.
BMW uses it as motor oil for various M series cars.

[George Maz]

John, there four choices; Amsoil, Castrol, Redline, or ZF oil from Rockland Gear...they now own ZF. After my transmission was replaced due to "rare reverse spline lubrication failure" these were the recommended motor oils that must be used in our ZF transmissions, level checked, and changed at regular intervals.

I chose the Amsoil Manual Syncromesh 5w-30.
A thicker viscosity would dampen gear chatter noise for a lightweight flywheel, but I just wanted a thinner faster moving oil for guaranteed lubrication.

When filling, snake a hose from the top of the engine down to the fill hole, allow the excess to drip out from the fill plug hole till it settles, making sure car is level then insert plug. Trying to squeeze that extra love in there...winds up leaking out of the tailstock seal. 17mm stubby Allen impact socket if you need to borrow it.

[Paul Workman]

When I had my base 95 car, I too had that "rare reverse spline lubrication failure". Bill Boudreau reams the oil galleries out to a bit larger to (he said) assist w/ lubrication - as part of his "blue-printing" procedure on the ZF. But, he went on to say that if I opted not to have my replacement trans undergo his procedure, to be sure to use a synthetic oil.

The Castrol 10W-60 synthetic is no longer available (been re-formulated, as I understand it). But, as an alternative, Marc Haibeck recommended the Red Line High-Shock, synthetic gear oil as a substitute.

My transmission is in need of a Boudreau "laying of hands". However, the crunching I sometimes get when shifting into 5th (especially when cold) is noticeably less since the switch to the RL product.

This thread provides some new product info (to me). But, FWIW, I've driven 2 full seasons ≈ 7000 miles, and many WOT runs with the RL w/o problems.

[Dynomite]

Originally Posted by Paul Workman

The Castrol 10W-60 synthetic is no longer available (been re-formulated, as I understand it).

Castrol 10W-60

Zf S6-40 Oil TIPS
Castrol Edge Comparisons TIPS