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View Full Version : TR2/3/3A What weight transmission oil in a tr3 with OD?



sp53
07-20-2019, 07:56 PM
What weight transmission oil in a tr3 with OD? I have been spoking around the internet for ˝ hour and I am still not sure if it is 30 non detergent or GL4. I have always run 30 weight non detergents in my tr3s for more than 40 years—but I will say they have leaked and made noise. Now with this OD I am concerned. It sounds like both would be fine, but 30w is conservative way to go. I just see a huge difference between 90w+ and 30 weights.

TFB
07-20-2019, 08:24 PM
I have been running Redline MT-90 based on recommendations from this site and am happy with it.
12.5k mile and no problems.
tom

TR3driver
07-20-2019, 08:25 PM
Triumph changed their specification around 1958-59, from motor oil to gear oil. Supposedly to make the countershaft bearings in the main gearbox live longer.

If your car is earlier than that, then I can see some justification to using motor oil; otherwise it makes no sense to me.
https://i.imgur.com/fswNtRG.jpg

BTW, 90 weight and 30 weight aren't as far apart as you might think. Motor oil and gear oil are deliberately graded on different scales, so the number tells you what oil you're talking about. 90 weight gear oil is actually about the same as 50 weight motor oil (which is what Triumph recommended in warm climates, before they started recommending gear oil).

FWIW, I really like Redline's MT-90 in the gearbox. Rated GL4 (so meets that spec), but produces noticeably better shifting in the main box, both hot and cold, compared to ordinary GL4. Kind of expensive, but worth it IMO.

https://i.imgur.com/tWDPs6M.jpg

Andrew Mace
07-20-2019, 09:22 PM
FWIW, I really like Redline's MT-90 in the gearbox. Rated GL4 (so meets that spec), but produces noticeably better shifting in the main box, both hot and cold, compared to ordinary GL4. Kind of expensive, but worth it IMO.

Yeah, it is "kind of expensive"; on the other hand, I'll second Randall's comments about noticeably better shifting (in a Herald/Spitfire box, in my case). Also, if your car is anything beyond a $700 "beater," "expensive" is very much a relative term, right? :D

CJD
07-21-2019, 09:47 AM
Hey Steve...I went with the factory recommended straight 30w initially, but had issues with the OD drum sticking. The Redline MT90 fixed that immediately, so that's what I have been using since.

sp53
07-21-2019, 07:26 PM
Does the gear box with OD take I quart or a little more of the red line MT 90?

ckeithjordan
07-21-2019, 08:01 PM
Does the gear box with OD take I quart or a little more of the red line MT 90?

The specs page of the owners manual says a gearbox with OD takes 3.3 pints (52.8 ounces) or a little over a quart and a half. That's for a drain and refill. If dry, the amount is 4.2 pints/67.2 ounces/2.1 quarts.

sp53
07-22-2019, 09:31 AM
Thanks for accurate answer Keith. Those manuals confuse me because there are/maybe was imperial pints and stuff like that. Well at least that is how I remember translating some of the stuff.

ckeithjordan
07-22-2019, 10:52 AM
You're welcome. There are two columns on the page, one for Imperial measurements, and one for us. You just have to make sure you're reading the right one. I copied the info down and posted it on my garage wall above my workbench so I wouldn't get confused (also, because I can't remember the quantities to begin with!).

sp53
07-22-2019, 01:11 PM
Ok it looks like the MT redline 90 is a 75 to 90W synthetic. I did find one quart in town for 17.00 and they are ordering more. Plus I have some 75- 90w Valvoline, but is says limited slip on the bottle. I read how limited slip will effect the operation for the OD in negative way. Is that true?

TR3driver
07-22-2019, 01:52 PM
If you're looking at the synthetic stuff, it's too slick for good synchro operation.
Works good in rear axles, though.

sp53
07-22-2019, 04:04 PM
I am thinking to put the Valvoline 75- 90 w limited slip gear oil in because heck I might be pulling the gearbox if will not go in and out OD well, but did not want to create a problem. I was about to put the Valvoline in and then read some posts from 2012 that said do not use poly weight and non-splip because something in the OD did not like it. Paying for these educations in life requires advice and hands on. My gut tells me put the Valvoline in; it is not that big of deal?

Herk
07-22-2019, 10:35 PM
Ok it looks like the MT redline 90 is a 75 to 90W synthetic. I did find one quart in town for 17.00 and they are ordering more. Plus I have some 75- 90w Valvoline, but is says limited slip on the bottle. I read how limited slip will effect the operation for the OD in negative way. Is that true?
So read the back label, if it says "yellow metal safe" it won't erode the synchros and bushings. But if it's a synthetic you want, you'll be much happier with "synchromesh" or "MTL" or "MTF" labeled fluids. They have a friction modifier package formulated for synchronizers. I made the error of filling my TR6 with 75-90 synthetic gear oil once. The overdrive worked just fine, but it shifted like a cold truck. I filled with Valvoline MTF and never looked back. In fact my dad, who's racked up over 200K with motor oil in his TR3A overdrive box (changed annually) noticed an improvement with the MTF.

Tybalt
07-23-2019, 12:27 PM
I am thinking to put the Valvoline 75- 90 w limited slip gear oil in because heck I might be pulling the gearbox if will not go in and out OD well, but did not want to create a problem. I was about to put the Valvoline in and then read some posts from 2012 that said do not use poly weight and non-splip because something in the OD did not like it. Paying for these educations in life requires advice and hands on. My gut tells me put the Valvoline in; it is not that big of deal?

Herk has pretty much called it when it comes to making sure that you use something that is aimed at transmissions and not differentials. The fact that it says limited slip tells me that it is primarily intended for differentials and not transmissions. The additive package in the extreme pressure gear oils has a tendency to play havoc with synchronizers. Even Valvoline on the product information sheet for the 75w-90 gear oil to use their transmission specific oils in synchronized manual transmissions.

Here are links to the Valvoline Product Information Sheet for their GL-4/GL-5 EP Gear Oil:

https://sharena21.springcm.com/Public/Document/18452/3e467451-fe75-e711-9c10-ac162d889bd3/cf662252-0bbd-e711-9c12-ac162d889bd1

speaking of "not creating a problem," here's a nice little primer on GL-4 vs GL-5, some gear oil history and the havoc that GL-5 can play with synchronizers, it was aimed at the Corviar world but it applies to others as well:

https://www.widman.biz/uploads/Transaxle_oil.pdf

Transmission lubricants have been a big topic of discussion in the Miata and S2000 world as well as in the British Car universe so you can get some reasonable information related to the topic from those types of forums plus there's always Bob is the Oil Guy ( https://www.bobistheoilguy.com/ ).