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Tran and Differential Oil?

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FYI :thumbsup:;From an old(NOS)bugger thats seen ALL the news on the needed oil for Brit cars....First off ordinary 30W NON-DETERGENT oil for the tranny OD or NOT.30W creates the proper hydralic pressure for the syncro o-ring etc.Alot of times this simple remedy will effeciently(for one thing)stop the tranny gears from slipping out of gear.For the OD's its ALL ABOUT PRESSURE.As for the diff GL4 is best.Don't forget NOT TO GREASE THE TRUNNIONS :hammer: @ THE FRONT,(90w oil) greasing the trunnions at the rear is ok.Light graphic grease in the steering box.(replace the plug with a zerk fitting)
HAPPY MOTORING :driving: :savewave:
 
myspitfire said:
Don't forget NOT TO GREASE THE TRUNNIONS :hammer: @ THE FRONT
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Sorry, can't agree with that. Factory recommendation up until the TR4A was for grease, and the early trunnions are frequently not oil-tight. Any slight advantage of oil over grease is obviated by having the oil leak out while grease won't. The later trunnions are a totally different design. And the trunnions on TS39781LO have lasted over 20 years and well over 100,000 miles with just grease (and are still in better condition than the ones I found on TS13571L).

I also disagree about non-detergent oil, but that horse has been pretty well beaten already. Check out John's site where he says the countershaft on the big TRs has be upgraded to roller bearings ... using better oil will make the stock thrust washers last a long, long time (which is exactly why the factory switched to <span style="font-weight: bold">recommending</span> gear oil).

Graphic grease? Assuming you meant graphite grease, I still disagree. It's no wonder everyone wants to convert to R&P; no one understands how to make the original steering box work. Replace the worn out bushing and fill it with full synthetic gear oil, the difference will amaze you. Grease makes it drive like a truck!

And my TR3A diff has had GL5 in it for upwards of 20 years and perhaps 200,000 hard miles. Was well worn when I got it, no worse now ... you can try to tell me that's the wrong oil but I'll never believe it after that kind of experience. The ones I've busted have all had GL4 ... maybe there's a correlation there and maybe not.

That reminds me, I'd better change the diff oil in the project.
 
Theres an awful lot of talk about GM Synchromesh being the best stuff... any thoughts on the use of this stuff in the tranny?
 
pjsmetana said:
Theres an awful lot of talk about GM Synchromesh being the best stuff... any thoughts on the use of this stuff in the tranny?
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Recommended highly for the V8 Wedge trans.
 
Well is it better to use MT-90, 30 weight motor oil, GL-4, or 20W50 in the J-Type over drive?
 
R_Lyle said:
Well is it better to use MT-90, 30 weight motor oil, GL-4, or 20W50 in the J-Type over drive?
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That point has been endlessly debated for a long time; with no clear consensus. My opinion is that the J-type works well with any of the above (also GL-5 and ATF); it just doesn't matter. But since it shares oil with the gearbox, the oil should be chosen for your gearbox.

Note when reading through all the discussions on OD oil; that the J-type is a considerably different beastie than the earlier A, D and LH types. I believe it was a major redesign, with the intention of eliminating all the problem spots discovered with the earlier designs (including the dependence on oil). The result was a very successful, rugged design; that is still being manufactured and sold today. (Unfortunately they haven't gotten any cheaper, or I would have installed one in my motorhome.)
 
this might be a stupid question but if you are suppose to put 30 weight oil in a transmission with an OD and 80/90 weight in a non OD transmission, would there be any benifit(like easier shifting) or damage if you put 30 weight in a Non OD transmission
 
There has been plenty of discussion and I have never seen any agreement on what should go in the OD trans. Plenty of people say don't use GL-4 (90wt) but the Triumph manual stats you should use GL-4. Think I'll read some more documents now.
 
A lot of people don't understand that the way of measuring engine oil and gear oil weights are different. 20W50 motor oil has a very similar viscosity range to 80W90 gear oil.
 
Looks like that Quantum Mechanics article points to using 30 weight non-detergent for the over drive: "Based on these tests we have since and continue to recommend the 30 weight non detergent motor oil as the best oil to use in the overdrives." Apparently the 90 weight oil causes plenty of problems with the overdrive unit which may eventually lead to the unit blowing up due to excessive pressure.
 
R_Lyle said:
Looks like that Quantum Mechanics article points to using 30 weight non-detergent for the over drive:
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Yes, that's what it says. However, the Triumph (Leyland/BL) recommendation from about 1960 onwards was for 90 weight gear oil. Seems hard to believe that the factory would recommend something that would "lead to the unit blowing up". Especially when legend has it that they changed their recommendation specifically to REDUCE warranty returns!

There's also the little detail that prior to about 1960, Standard-Triumph recommended 50 weight motor oil for the TR2-3 A-type in air temperatures over 70F. 50 weight motor oil is actually thicker than 90 weight gear oil.

With respect to John, I think there must be something he's not telling us. Note, for example, that the article totally fails to mention what TYPE of overdrive he was testing. There is a difference!
 
Last time I was there talking with John, I seem to remember it had to do with something in the 90 weight oil that was causing a problem. ( possibly a higher sulfer content and affecting the copper rivets? ) But unfortunately I wasn't paying as much attention as I should have. I was just amazed at the stuff he had in his shop.. I was too much like the kid in the candy shop analogy... Those 5 speed conversion kits he had sure looked sweet.....
Dennis
 
There's very little difference in viscosity between 90 wt gear oil and 30 wt motor oil. I think there was something wrong with his test.

For instanace Esso EP 100 gear oil (couldn't quickly find 90 wt) has a viscosity range of 100 to 12 cSt from 40 to 100 deg C, where as Essolube WD 30 wt has a viscosity range of 100 to 12 cSt from 40 to 108 deg C.

There is no reason for 90 wt gear oil to not work in a OD tranny when 30 wt motor oil does.
 
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