Trans Fluid, Lucas SAE 75W-90?

[Chriscote]

A friend is looking to sell me 4 32 oz bottles of Lucas Synthetic SAI 75w-90 Gear Oil / trans and diff lube for extremely cheap that he has laying around. I am just curious as if this will work for my transmission flush. Not very knowledgeable on the subject so i come to MSF.





thanks

[Constantin]

Personally, I would not be cheap with any fluids in the car. Especially trany oil!

Last weekend I put in

MOTUL MOTUL GEAR 300 SYN HYPOID - 317811

MOTUL MOTUL GEAR 300 SYN HYPOID - 317811
MOTUL MOTUL GEAR 300 SYN HYPOID - 317811

[captain slow]

Most people use redline mt90 or the motorcraft stuff.

Go with one of those.

[silvapain]

IIRC, the transmission uses 75w90 GL-4 fluid, so that should work.

I highly recommend the Motorcraft XT-M5-QS fluid with 1/3 bottle of the Ford XL3 friction modifier though. I've run four or five different types of oil in my transmission, and that setup is BY FAR the best I've used.

[qweedqwag]

What makes it better ??? I call bullshit.

[Mizzle]

The cst values are retarded-high on that stuff. It will be like shifting in molasses in winter.

[silvapain]

Originally Posted by Mizzle The cst values are retarded-high on that stuff. It will be like shifting in molasses in winter.

I had that issue with the Royal Purple fluid I ran. I've always thought that the OE fluid viscosity spec was way too high.

[Chriscote]

Originally Posted by silvapain IIRC, the transmission uses 75w90 GL-4 fluid, so that should work. I highly recommend the Motorcraft XT-M5-QS fluid with 1/3 bottle of the Ford XL3 friction modifier though. I've run four or five different types of oil in my transmission, and that setup is BY FAR the best I've used.

add the modifier before or between motorcraft bottles?

[btstarcher]

When I drained/filled I didn't use any friction modifier...is this bad?

[Constantin]

Originally Posted by silvapain IIRC, the transmission uses 75w90 GL-4 fluid, so that should work. I highly recommend the Motorcraft XT-M5-QS fluid with 1/3 bottle of the Ford XL3 friction modifier though. I've run four or five different types of oil in my transmission, and that setup is BY FAR the best I've used.

Did you have a chance to run MOTUL oil? And how do check which oil is better?

After I put MOTUL, I do feel smother shifting, especially during lower speeds, but that is about it. Difference is there, but nothing dramatic. If you can tell me what I should be looking for, it will be great!

[silvapain]

You don't have to use the friction modifier, but it does make a noticeable difference if you do. You can add it after filling the transmission completely with fluid; the bottle is only 4 fl.oz. and you only use 1/3 of it. We're not talking a lot here.


Tapadatass

[silvapain]

Originally Posted by Constantin Did you have a chance to run MOTUL oil? And how do check which oil is better? After I put MOTUL, I do feel smother shifting, especially during lower speeds, but that is about it. Difference is there, but nothing dramatic. If you can tell me what I should be looking for, it will be great!

The friction modifier especially helps the synchros function much more smoothly. I use a stock shift knob with a short shift plate and NO weight, and before using the friction modifier I could feel an initial resistance putting the transmission into gear when moving, even with the Motorcraft transmission fluid. That resistance is the synchros matching gear speed before letting the gears mesh. With the modifier, it's super smooth.


Tapadatass

[Constantin]

Originally Posted by silvapain The friction modifier especially helps the synchros function much more smoothly. I use a stock shift knob with a short shift plate and NO weight, and before using the friction modifier I could feel an initial resistance putting the transmission into gear when moving, even with the Motorcraft transmission fluid. That resistance is the synchros matching gear speed before letting the gears mesh. With the modifier, it's super smooth.

Thx. I'll try to find out if the friction modifier is a good idea with MOTUL oil I have now. If it is, I'll definitely add it.

So, all your really are looking for is how smooth the gear change is? Are there any other things you can be on a lookout for to see difference in fluids?

[guitarzan134]

This is something I've been looking into recently, so I greatly appreciate the info, too.

My shifter mods/mm are in my sig, and I have a weighed knob on it's way... I still get some grind when doing hard shifts. My transmission was rebuilt by Mazda @~59k, so i'm assuming they used new gear oil afterwards, but since then I've noticed more resistance than it had pre-rebuild. I'm at 81k now and am serious about getting this to perform smoothly. It's a bummer to time my 0-60, only to miss 1-2 or 2-3 and have to start over.

~$20/qt, @ 3 qts, for the MC? And ~1.5oz FM... Right?

Thanks to the OG's.

[silvapain]

Originally Posted by Constantin Thx. I'll try to find out if the friction modifier is a good idea with MOTUL oil I have now. If it is, I'll definitely add it. So, all your really are looking for is how smooth the gear change is? Are there any other things you can be on a lookout for to see difference in fluids?

Viscosity and API ratings are important. Too thin an oil will shear and won't protect the transmission components. Too thick and it won't flow well and you'll have a hard time changing gears. The API GL-4 rating identifies what additives are included for detergents and to prevent shear (see above).

Motorcraft XT-M5-QS is 75w-90 GL-4 as specified by Mazda. I have also ran Pennzoil Synchromesh fluid, which is 75w-80 GL-5 without problem.


Tapadatass

[phate]

I'm using the Lucas stuff in the trans of the other 6 right now. Seems to work fine Shifts better than my 6, but who knows what's in it, lol.

I'll likely use the Motorcraft fluid in mine, but the Lucas seems to be a good contender so far. I liked it in my 3, with a bit of friction modifier.

[silvapain]

I will add that I ran the Motorcraft stuff without friction modifier for a while, and even then it was still the best I've used.

I haven't tried the Lucas fluid, though.


Tapadatass