Help me choose a gear oil for my transaxle/lsd

[92dx]

I have a 1992 mazda protege. It is turbo and makes ~250whp. I use the stock transaxle with an mfactory helical type lsd in place of the stock open unit.

The spec for the trans is 75-90 gl4. mfactory recommends torco mtf for the lsd. I cannot get that locally and want to run what I have available to me.

I was thinking amsoil, mobil-1, pennzoil syncromesh or something along those lines. Should I use amsoil 75-90 gl4 or the severe gear gl-5 EP?

I do daily drive the car and occasional drag strip sessions. Thanks!

 

[dparm]

Motul Gear 300 is a good bet. It's a 75w90 with a very high viscosity index (222) and is GL-4 and GL-5 rated. I've run it in my Audis' transmissions and rear differentials, and it stood up to track and autocross days without breaking a sweat.

There is a version for LSD-equipped cars. I think it's called Gear 300 LS.

 

[Donald]

I would go with Amsoil, severe gear if its speced for the diff. You order, they deliver. What could be easier.

 

[92dx]

Thanks for the input. Ive read many good things on motul as well. Unfortunately I cant get it locally. I can get amsoil, m1, pennzoil sm, and redline around here.

 

[92dx]

Originally Posted By: Donald
I would go with Amsoil, severe gear if its speced for the diff. You order, they deliver. What could be easier.


The only lube recommended by the manufacturer of the lsd is torco. I assume the sever gear is "equivalent" because of the ep rating. I can pick it up. I hate waiting for parts/stuff to be delivered.. Thanks.

 

[dparm]

Originally Posted By: 92dx
Thanks for the input. Ive read many good things on motul as well. Unfortunately I cant get it locally. I can get amsoil, m1, pennzoil sm, and redline around here.



Most local speed shops can get it for you, or call Motul USA and find out who the local distributor is. If you order a case online, it's not too bad.

 

[mechtech2]

Who knows why they specify the kinda rare Torco ffluid?
Somebody is somebody's cousin? Payolla? Who knows?
I'm sure a similarly spec'd lube is going to be easy to find.
Amsoil or Redline will surely have one.

BTW, the geared limited slip is great.

 

[WMSmotorhead]

Synthetic 75-90's are easy to find. Is there some magic with one brand over the other?

 

[dailydriver]

Originally Posted By: dparm
There is a version for LSD-equipped cars. I think it's called Gear 300 LS.


But sadly enough, the V.I. for the L.S. version drops WAY down.

 

[dailydriver]

Originally Posted By: mechtech2
Who knows why they specify the kinda rare Torco ffluid?
Somebody is somebody's cousin? Payolla? Who knows?
I'm sure a similarly spec'd lube is going to be easy to find.
Amsoil or Redline will surely have one.


I agree with you, but, Torco's mineral gear oils ARE some of the best on the market, whereas their synthetic gear oils are only about even with all of the other boutique brands, while costing MUCH more (in some cases).

 

[artificialist]

Originally Posted By: dailydriver
Originally Posted By: dparm
There is a version for LSD-equipped cars. I think it's called Gear 300 LS.


But sadly enough, the V.I. for the L.S. version drops WAY down.

What would happen if you bought Torco's non-ls fluid, and then mixed in ls additive?

 

[jake88]

So... this is a helical transaxle with no hypoid gearing? I think the GL-5 is a little excessive and may cause yellow-metal issues. It sounds to me like what you really want is an API MT-1 or SAE J2360 rated gear oil.

 

[mechtech2]

Torco is good - I am not against it.

The worm/helical geared limited slip devices like the MFactory ones [Gleason Torsen] don't need a limited slip type, just fluid biased for it.

BTW, I think you have a G5M transmission that Ford used .

 

[dailydriver]

Originally Posted By: artificialist
Originally Posted By: dailydriver
Originally Posted By: dparm
There is a version for LSD-equipped cars. I think it's called Gear 300 LS.


But sadly enough, the V.I. for the L.S. version drops WAY down.

What would happen if you bought Torco's non-ls fluid, and then mixed in ls additive?


Did you mean to say Motul's Gear 300 we were speaking of??

If so, that is EXACTLY what I would do if I wanted the HIGHEST V.I. gear oil on the market (and could use THAT weight), in a limited slip app.

With Torco, you have NO choice but to add the friction modifier (if needed for the diff), since Torco adds NO limited slip adds to their gear oils.

I am not sure if the aftermarket, added by the customer, L.S. additives decrease the actual V.I. at all, or by how much if that's the case. (Maybe Jim, or Mola, or one of the other tribologists on here knows the answer to this?)