Transmission oil - Anyone using Penzoil Synchromesh?

[sunsetoutpost2]

As a new M37 owner I thought nothing of putting whatever 90W I found in the transmission. Most available now is GL5 rated that I now realize is not good for the brass synchros. Your eariler post recommends Chevron Delo RPM straight weight 50 for the transmission. See Chevron info at:

http://www.chevrondelo.com/en/aboutdelo/default.asp

I don't find Delo RPM on Chevron's web site when I went looking for the spec sheet. Is this still your oil of choice? Have you looked at Penzoil Synchromesh? See Penzoil Synchromesh at:

http://www.stealth316.com/misc/pennzoil ... ummary.pdf

It is not weight rated, but an Penzoil Technical Information lists it as aprox. 80W.

The concern with oil for our transmissions is the extreme pressure (EP) additives that contain sulfur-phosphorus compounds that can be corrosive to "yellow" metals. One post on another forum gave a bad report on Penzoil Synchromesh oil. It seems that after 2500 miles the oil was silver in color indicating a bearing problem. Could have just been it's time to go.