alternative to atf

[sevenznuf]

hey guys I have a 1999 mazda b2500 with the m5od trans that calls for atf. I have tried Pennzoil synchromesh that really didn't help with shifting. I have mercon atf in the trans now. when I first drive the truck in the morning when the fluid is cool it shifts perfectly smooth as silk but as it warms up it gets a lot notchier. my question is is there a lube I can use that will be a little bit thicker? I know I cant use gear oil in this trans but matbe something slightly thicker than atf, or a specific manual trans lube. can I use redline mtl in this trans? I used this in my capri with a t5 and it made a huge difference. how about adding something like lucas trans fix to the fluid that's already in there? im just looking to buy a little time because I know a rebuild is in the near future. thanks for any replies. also I have heard of people running motor oil in these transmissions, does that sound right?

 

[CATERHAM]

I use Royal Purple Syncromax in my BMW gearbox which is spec'd for ATF. The reason I tried it was to improve the subfreezing shift quality which it certainly did vs a dino ATF.

 

[Dufus2]

Amsoil has a 5w30 for a specialized MT application. Not sure if you are interested in trying a 5w30 motor oil to see if it might shift better on a hot fluid. An old mechanic told me to add 1/2 bottle STP (blue bottle) to gear oil and you have fewer problems, something to consider.

I can relate to the gear clash when the fluid gets warm and thins out.

Lucas trans additive is Naphtha oil with a thick base product, it makes your fluid tacky and may give you more trouble than its worth.

 

[sevenznuf]

thanks for the replies, yea I was a little suspect of the lucas/ where is the best place to buy amsoil? don't know of anybody in my area that sells it? would draining about a qt out and adding gear oil to the fluid be too much or would they not mix? I have heard claims that if u put all gear oil in these transmissions the front bearing would fail because of not lubricating good enough?

 

[MolaKule]

The Mercon is about 7.5 cSt@100C kinematic viscosity as well as the Royal Purple.

Pennzoil Synchromesh is thicker at about 9.3 cSt, and Amsoil MTL is almost 10 cSt.

My thinking is if Pennzoil Synchromesh didn't do it for you then neither will Amsoil MTL which is a mite thicker.

I would try the Royal Purple Synchromax first.

 

[Dufus2]

I learned in college that gear oil is a heavy mineral oil and mixed with a synthetic it can make a thick tar mess in your transmission.

If you want to mix fluids, stick with a motor oil as those are a lot cleaner and most ATF products are high detergent.

Gear oil is 40-50 weight, truck transmissions and some CAT equipment use straight 50 weight in their gear boxes.

ATF is around 5w20 if you compare it to motor oil.. My opinion would be to add some 15w40 because of the detergents and better wear chemistry and will put your fluid in the 10w30 range if you go 50% or close to it. *A total drain and fill would be a better option.

 

[simple_gifts]

+1 for RP Synchromax; it is in my B2300 manual right now;

15F mornings and about a 1 minute warmup and it shifts nicely.

 

[sevenznuf]

thanks for the replies guys. dufus2 are u talking about draining the atf out and adding all 15w40 instead of adding some to the atf. around here 15w40 diesel oil is cheap, I guess that would be ok to try? if it don't feel right im gonna drain it out and put mercon back in. thanks again

 

[simple_gifts]

Putting 15w40 motor oil into that transmission is probably the last thing most BITOGrs would do.

 

[dave123]

Originally Posted By: simple_gifts
Putting 15w40 motor oil into that transmission is probably the last thing most BITOGrs would do.






This +1

 

[901Memphis]

Stp blue bottle? Atf high detergent? Some bad advice.

 

[Garak]

Beyond bad advice - dead wrong.

 

[default]

How many miles are on the unit, it might just be worn out. Any bearing/gear noise? Lucas trans fix works quite well for tightening up old gearboxes that don't require EP oil.

 

[Garak]

Originally Posted By: Dufus2
If you want to mix fluids, stick with a motor oil as those are a lot cleaner and most ATF products are high detergent.

This always bugs me. There are dozens of ATF used oil analysis and VOAs on this site. Please find me some with high detergent.

 

[sevenznuf]

hey guys the trans has 165000 miles on it and does not whine. I have been doing a lot of searching this subject and leaning towards either redline mtl or redline d4. I am going to stay away from the motor oil. the redline products are expensive though. thanks for the replies

 

[simple_gifts]

I have also used D4 in this transmission. I had it in there for about 50K miles.

 

[sevenznuf]

Hey simple-gifts did the d4 have any noticeable shift difference than regular atf. The d4 is a little cheaper than the mtl. Could u tell if it was any thicker than regular atf?

 

[dnewton3]

I suspect it was spec'd for Mercon ATF right?

If it shifts well when fresh and cool, and it's the vis drop from shearing and heat that seems to affect the shifting, why not try an ATF that is marketed for the original application?

Consider Mobil 1 ATF, or Amsoil ATF, or even the TES-295 clones like ATD? Schaeffers 204S-AT. Etc ... That way you're sticking to the original intent, and upgrading the lube capability without trying to re-engineer the lube specs.

 

[simple_gifts]

Originally Posted By: sevenznuf
Hey simple-gifts did the d4 have any noticeable shift difference than regular atf. The d4 is a little cheaper than the mtl. Could u tell if it was any thicker than regular atf?


Honestly, I can't remember @ this point. I'm pretty sure the shifting feel did not change over the life of the fill; which is a + for me; I changed it only because "it was in there a long time" not because the shifting degraded.

I would say the RP Synchromax is the best shifting so far; however, one BITOG member indicated it had a very short lifespan in his ranger, bad shifting returned after 20K miles or so.

Price for it is HIGHER than Red Line.

https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1603940

 

[ac_tc]

If HDEO is found dirt cheap i suspecta that
THF, STOU or UTTO oils are found as easy...( and even more dirt cheap )
I have used 10w30 STOU oil in my huyndai transmission
for years and it works good no matter whats the temp is.
In fact i used it in the engine until i siezed because
it overheated badly...lower cooling hose went south and
my brother in law fixed it, filled water in the expansion bottle
and went for a long test ride with a bone dry engine.