5 Sp LUBE What's best?

[JJW_ND]

Mikepvg... . I just sampled a 99 trans with 30K on it (lots of hard pulling in those 30K). Oil was very clean and doing well other then it was NOT 75W80 Castol. This was a factory new (12/99 data plate) trans (replacement on my 96). Visually , the oil look good but very thin.

Based on the lab report I believe it as with newer 30wt oil used in the NVG5600.

From the samples I have looked at from my orignial trans and this replacement, not alot of break "stuff" is generated. All my samples were collected when I replaced to fluid.

BTW, this 30wt oil shift terrible. The 75W90 I replaced it with shifts much better. This is why I dumped in the first place.

jjw
ND

 

[mikepvg]

JJW
I changed changed fluid in my NV4500 last w/e. I looks as if the fill plug or PTO bolt was never removed. (Bought truck used so don't know for sure) Fluid was plenty dirty & a greenish color.
Note: It shifted effortlessly before the change @ 126,000 & continues to do so after the change. A lot of unknowns in my case but if it was factory fill that lube did pretty good job for 126,000 miles of towing. Good synchronization etc. . Previous owner was a contractor who pulled digging equipement. I towed horses w/ it over the Divide.
Mike