Anyone have any "Yeas" or "Nays" regarding the use of Lucas 85-140W Heavy Duty gear oil? I found some at Pep Boys to use in my T-10 that is having difficulty finding 2nd gear most of the time. I had some Pennzy 75W-90 GL-5 in it until I read that it was harmful to brass synchronizers. I think I got it out in time, I hope. Only 3 weeks. I tried to find the 80W-90 GL-4 gear oil at several retail stores, but everyone gave me the deer in the headlights look. Something I'm getting used to seeing.
-
-
Re: 85W-140W Lucas gear oil usage?
recently having gotten some myself, don't know where you live but I had no problem finding some at Autozone. If you are able to buy Pennzoil products, that supplier should have this:
65 MM Convertible, L76 (365 hp) -
Re: 85W-140W Lucas gear oil usage?
Jack, that is exactly what I had in the tranny before I read that the GL-5 rated gear oils have additive packages that are harmful to the brass synchronizers in the early BW T-10's. I know I have brass synchronizers, as I installed them. Apparently, the additives are very corrosive to the brass synchros. I went out at lunch and did find some Lucas 80-90W Plus gear oil that I am going to try this weekend. The 85-140W stuff I put in last night was very thick and I'm afraid it may be TOO thick for proper usage in the gearbox.Comment
-
Re: 85W-140W Lucas gear oil usage?
Sorry, grabbed the wrong pic. Pennzoil makes the 80w-90 in both GL-4 and GL-5 additive package variants. see this link, you should be able to locate this stuff:
65 MM Convertible, L76 (365 hp)Comment
-
Re: 85W-140W Lucas gear oil usage?
The "corrosive to the brass synchros" has become an overblown myth - much like unleaded fuel will rapidly erode integral cast iron valve seats myth.
There is some evidence that the suphur based additive required to achieve GL-5 status is mildly corrosive to brass AT VERY HIGH TEMPERATURES, but 80W-90 GL-5 is the commercial equivalent to the original MIL-L-2105D that GM called for.
Millions of these transmissions have survived 40-50 years with the recommended lubricant without dissolving the synchos, so replace the 85W-140 (which, if a GL-5 as it probably is has the same additive) with 80W-90 GL-5 and quit worrying.
You select gear oil by SAE viscosity and GL-spec, and 80W-90 GL-5 is the spec for all vintage B-W and Muncie four-speeds. Do not use a "modern" manual transmission lubricants. Most are lower viscosity - 70W-75, like ATF, and most only meet the GL-4 spec.
DukeComment
-
Re: 85W-140W Lucas gear oil usage?
Duke----
YUP!In Appreciation of John HinckleyComment
-
Re: 85W-140W Lucas gear oil usage?
Duke and Joe....thanks for the input. Having been a "blue oval" guru for 25 some odd years, I was only aware of adding Dexron III to Tremec T-5's and the like. Actually, I bled off about 2/3 of the Lucas 85W-140 and refilled with Lucas 80W-90 Gear Plus to see if I can't improve the 1-2 shifts. The synchros are giving me some trouble. The "corrosion" myth is akin to the "synthetic oils cause more engine leaks" myth. I ran two 5.0L Ford engines from 0 to well over 100,000 miles using only Mobil 1 every 3,000 miles + filter and never experienced any unusual leaks. In fact, the engines upon tear down, looked like new inside. The crosshatches were still in the cylinder bores with no ridges after 115,000 miles of daily driving!! I'm a BIG believer in synthetics.
Thanks again.Comment
Comment