I need pg 27 in TDR Issue#24

[mikepvg]

Can anyone fax or email me a copy of this page? Its supposed to have lubricant specification info for the NV4500. Just curious to see if it says anything in more detail than what I already know. Always searching for more info on the NV4500.
Thanks to anyone that can help! #ad

 

[Joseph Donnelly]

My comments are in []

"Other members will ask about the GL-4 rated Castrol Synthetic gear lubricant (75W-90)[sic--it's actually 75-85]. If the GL-4 classification is good... shouldn't a GL-5 rated lubricant be better? In the case of the NV4500 gearbox, not necessarily so. The GL-5 oil uses twice the amount of sulfur/phosphorous [sic--phosphorus] additive package as GL-4. At high temperatures, the phosphorous [sic] plates out and reduces the coefficient of friction of the synchronizer rings (New Venture Gear has seen this on shift stand tests). Since there's twice as much of it, there's more of a detrimental effect compared to GL-4.

Although it does not affect the NV4500, the additional sulphur content of GL-5 attacks brass. [the synchro rings appear to be a brass or bronze-containing metal, with a clutch lining inside, to me. ]"

 

[mikepvg]

Joe, thanks for your insight as to what you think the syncro rings might be made of. Are you aware of any other specific performance criteria that the Castrol Syntorq meets other than the standard GL-4 categories? Something NVG might have had originally requested to solve their problems on the shift stand tests? #ad

 

[Joseph Donnelly]

Castrol Syntorq LT where LT=low temperature. That was one other criterion. If you run another oil, be sure it keeps the transmission temp as low as Castrol did. The NV engineers worked closely with Castrol in the development of the lube. I hope to talk with them soon and learn more about it.