Synchromesh - Advice Needed

[BigBossZ]

Hey Everyone,

First of all I'm sorry for posting a new topic on something discussed so much. However, all the posts regarding Synchromesh are related to Honda/Acura or VW. I drive a 2003 Nissan 350Z 6spd with 53k miles on it. I changed the transmission oil for Redline MT-90 awhile back (15k miles or more) and just recently I've been getting a grind going into 5th gear. I wanted to try GM Synchromesh as I know the Honda crowd has been loving it since it smooths out the shifts on worn synchros. But, I'm not sure if it's safe for my Nissan which asks for API GL-4 75W-85. Any input?

Also, can I mix some of the GM Synchromesh Friction Modified with Redline MT-90? I ask think because I ordered some more MT-90 and wanted to mix it with some GM Synchromesh FRICTION MODIFIED my girlfriend has.

Thanks.

 

[04SpecV]

I'm using a 50/50 mix of Amsoil MTF/MTG right now.
AmsoilMTF/MTG

Maybe try that or a 60/40 Mix of Redline MTL/MT90.

Or you could do a 60/40 mix of Amsoil MTG/MTF.


It Seems odd you have a 5th gear grind tho. I didn't know these transmissions had problems with that gear. \

 

[BigBossZ]

Thanks for the input SpecV!

I didn't really want to go out and buy more oil though. You see I have already ordered 4 qts of Redline MT-90 BUT I have some left over quarts of GM Synchromesh and the more aggressive GM Synchromesh Friction Modified. I have heard nothing butt good things about these oils from Honda/Acura and Vette owners but I'm wondering if it's safe for me Z. So really I have 2 questions.

1) Is GM Synchromesh (and Synchromesh Friction Modified) safe for my 03 Nissan 350Z?

2) Is it safe to mix GM Synchromesh with Redline MT-90?

Best Regards,

Gus

 

[bulwnkl]

If you care about the longevity of the transmission (or if you care about the next owner), don't use straight Synchromesh. It's far too thin. I cannot comment on the suitability of creating an MT-90/Synchromesh mixture.

 

[forcedtalon]

I agree straight syncromesh is too thin. If your only getting a gring in 5th gear its not the fluid you are using just means the the transmission is getting tired just take it easy going into fifth with the clutch down longer.
If you want to try a diffrent fluid redline MTL is a bit thicker. As of now I am using 1.75 qts of syncromesh and 1 qt of redline shock proof heavy.
You may want to try 1 qt of MT 90 and the rest syncromesh.

 

[unDummy]

No mixing needed if you go online and buy the 75w85 fluid from SF. I think its called MTL-P.
Castrol Syntrans/SMS-x are also 75w85, as are various OEM fluids.

Pennzoil has a GL4 90wt gear oil if you want to thicken the Synchromesh.

RoyalPurple also has Maxgear and Syncromax that can be mixed similarly like the above oils too.

There is nothing wrong with mixing fluids. But, I would think that it would be best to stick within a brand for "like" additives/oils.

To test how well the 350z responds to the Pennzoil/Redline mix, just drain 1 quart of your old MT90 and refill with 1 quart of the Synchromesh.

 

[04SpecV]

Maybe try to contact Redline and ask about compatibility.


I would just try and swap 2 bottles of MT90 for 2 bottles of MTL. Thats if you have a Redline dealer.


What about the other gears how do they work?

 

[mechtech]

I could be wrong, but I think that the GM Synchromesh with the friction modifier is for EXTRA SLIP, not extra grab.

 

[Bror Jace]

"No mixing needed if you go online and buy the 75w85 fluid from SF. I think its called MTL-P."

This is the best solution, in my opinion.

I'm running this stuff in a notoriously picky Nissan SpecV 6-speed ... which also calls for 75W-85. Better than factory fluid, better than my mix of Red Line MTL & MT-90.

 

[Jaykim81]

quote:

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"No mixing needed if you go online and buy the 75w85 fluid from SF. I think its called MTL-P."

This is the best solution, in my opinion.

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I too agree with Bror, my 6-speed in my Spec is very, very smooth with the MTL-P. The fluid also seems to get better with age.

Jay