TR2/3/3A What weight gear oil to use in TR3 transmission?

[TuffTR250]

I have searched past entries and I could not find a thread discussing what weight gear oil to use in TR3 transmission. The red Service Manual says in countries where the temperature is over 70 degrees (as it is quite often in North Carolina)to use 50 weight motor oil, something like Shell X100-50. That seems strange to me since the original specification for my TR250 calls for 90 weight gear oil. Is there any problem using 90 weight GL4 gear oil in a TR3 transmission? Thanks!
Regards,
Bob

 

[martx-5]

Not that I'm aware of...

The recommendation you have is an earlier one that was changed because of thrust washer problems.

 

[pacotaco]

Just went through trying to find gear oil to buy. Not sure if it's true but to read TRF's description of their Brad Penn GL4 most gear oils don't protect brass or soft metal components like the Castrol Hypoy does/did. Because Castrol is not marketed in qts any more here they (TRF) have it "bottled" in qts. Although I did not want to have to order gear oil, I did because I wasn't sure about anything else I could find locally. Is there something easily found that protects soft metals?

 

[CJD]

I've been using 75W-140 fully synthetic in everything that uses gears. Shifting is smooth and the box is quiet. I used to buy it from dealerships, but lately the local parts house has Royal Purple that I have been using. It comes in a lighter weight too.

John

 

[Marvin Gruber]

The Lucas oil additive works well also. The XKE I have growled a little when I shifted into third gear. Added about a cup of Lucas and no more growl. I use 80/90w oil for all the std. trans. A straight 30w for the o/ds.

Marv

 

[Andrew Mace]

Sta-lube is a GL-4 gear oil commonly found in NAPA stores. I've been using it for many years now without a problem!

 

[3798j]

Here's my strong vote for Redline's MT90. It's a synthetic. It helps the synchros to do their best - even from start up.

 

[FordFiesta]

+1 for Redline.

I was getting ready for an event last weekend and had to do a quick drain-and-refill of my stock TR3A gearbox oil. I was out of my usual 75W-90 NAPA goo, and threw in a quart of Redline MTL (Miata gearbox oil) instead. MTL is, I think, lighter than the MT90, but it performed just great on a 160-mile drive on a day that went from about 60 degrees to 90 degrees. Plus, it's GL-4 rated, rather than GL-5.

The only reason that I wouldn't use it would be in a leaky gearbox, because it's more expensive.

 

[Member 10617]

This subject has come up many times in this Forum, and the consensus seems to be Redline's MT90, although there are many other options.

 

[JKB1957]

I've been using Redline MT90 in my TR3A and straight 30 wt in my 1966 Spitfire. Both cars work well, no issues with shifts, and both have overdrive transmissions.

 

[TR3driver]

+1 on the MT-90. But Valvoline Racing (motor) oil in 20W50 is a good choice too, plus less expensive and easier to find locally. I ran it for many years and it worked well for me. The MT-90 just gives a bit more positive shifts.

Both of them lack the additive that is found in some gear oils, which can over time degrade the brass/bronze components inside the gearbox (and differential).

PS, personal opinion, I would avoid using non-detergent motor oil in a TR2-6 gearbox. The issue is not the detergent, but rather the same ZDDP you hear so much about needing to protect the camshaft and lifters. It also helps protect the thrust washers in the gearbox. There is a well-known vendor who recommends using non-detergent motor oil; but he also recommends doing an expensive upgrade to the thrust washers so they don't need extra protection

 

[TuffTR250]

I'm a bit leery of the Redline since this is an old non-OD transmission that I know little about. I think I will try the Sta-Lube GL4 gear oil from NAPA, since I understand it will not leak as bad as the Redline. Thanks for the responses.
Regards,
Bob

 

[Member 10617]

Thanks Andrew. Has anyone else had experience with Sta-lube and can comment on it vs Redline?

 

[tdskip]

PS, personal opinion, I would avoid using non-detergent motor oil in a TR2-6 gearbox. The issue is not the detergent, but rather the same ZDDP you hear so much about needing to protect the camshaft and lifters. It also helps protect the thrust washers in the gearbox. There is a well-known vendor who recommends using non-detergent motor oil; but he also recommends doing an expensive upgrade to the thrust washers so they don't need extra protection

So would to add a touch of ZDDP?

 

[glemon]

Thanks Andrew. Has anyone else had experience with Sta-lube and can comment on it vs Redline?

I have Sta-lube in my TR250 tranny right now, can't comment on it vs. Redline, but I did have straight 3ow non-detergent in the tranny before, the shifts feel about the same, but in and out of O/D is much smoother with the gear oil.

I haven't tried the Redline because have heard it will find leaks you didn't know you had and it is more expensive and mine leaks a little bit with the GL4 (although less with the GL4 than the 30w now that I think of it).

Have heard enough people say Redline will improve the quality of shift action in both the Triumph and Healey world to believe it, but bottom line you should be fine with either one.

 

[TR3driver]

So would to add a touch of ZDDP?

I wouldn't, no.

In general, I don't like "aftermarket" additives. Blending motor and gear oils is a complicated topic, there is a lot more to it than just ZDDP level. There can be literally dozens of additives and they all interact to some extent, so getting the desired properties is a careful balancing act. Even just too much ZDDP is a Bad Thing, worse than too little from what I've read.

So my preference leans strongly towards buying what I think I need, already formulated by a professional.

Just one anecdote : In a weak moment, I tried a popular motor oil additive in my old Chevy. Two weeks later, the crankshaft broke while just driving down the highway. Now that engine was known to have a weak crankshaft, so maybe it was just "its time"; but after 250,000 miles I have to think the additive had something to do with it. I'm not going to take the chance again.

 

[mallard]

When I had a non OD trans in my TR6 I ran the Sta-Lube for over 20 years without any problems. I still run it in the rear end in both the TR3, and TR6.

 

[tomshobby]

Another + for Redline MT90. I switched to it several years ago when I was having some trouble downshifting into 3rd when the gearbox was thoroughly warmed up. 25,000 miles and years later and I could not be happier and my tranny does not leak.

But I don't recommend it. I am a believer in everyone using what they want. Then many miles and years later they can report on what they have been using. It is the only way we can build a knowledge base.

 

[Member 10617]

I don't mean to drag this thread out unnecessarily, but I have a question.

We've talked here about Redline MT90 and Sta-lube, among others. It appears that some with OD favor Redline MT90, while those without OD choose Sta-lube or other brands. Is there something in the composition of Redline MT90 that is to be preferred for transmissions with OD (other than its tendency to find ways to leak)?

Is the NAPA Sta-lube OK to run with an OD?

Just wondering....

 

[TR3driver]

It appears that some with OD favor Redline MT90, while those without OD choose Sta-lube or other brands.

Just for clarity, I would still be using MT90 without overdrive, if I didn't have overdrive. But the TR3 just seemed so unhappy driving at 75-80 mph with the 4.1 axle and no OD (the way it came to me) that I had to pull it apart and install the OD.

Hopefully someday soon, I'll have the 3.45 axle ready to go in.

IMO the Sta-Lube GL4 should be fine for the overdrive. Sta-Lube makes quality products IMO, and GL4 is what Triumph recommended.