GM Synchromesh friction modified vs regular

[Drew99GT]

I've been searching for half an hour and have not found a definitive answer as to the difference between the friction modified version of GM Synchromesh, and the regular Synchromesh. Does anyone know??? Does anyone have the viscosity/product data sheet information for the 2? Has anyone tried both and noticed a performance difference between the 2? Thanks for any info!

 

[90crvtec]

I haven't researched this for probably close to 10 years now but, this is what I remember back when I was also digging for details on this particular fluild:

GM Friction Modified has an additive for LSD clutch packs found in some GM FWD applications that require a GL4 fluid.

The regular non-friction modified fluid lacks the friction additive for the clutch packs. You'll read many stories about people that swear that the friction modified version is better but, I can never tell any noticeable difference after a few thousand miles between the friction modified and regular Pennzoil Synchromesh. Pennzoil Synchromesh is/was supposed to be a clone of the GM non-friction modified stuff.

Unless you have a high-heat application that requires a full synthetic MTF, I'd give Pennzoil Synchromesh a try, it's available almost everywhere for a reasonable cost. If it doesn't have a good shifting "feel" it isn't a big expense to drain it and try something else.

 

[MolaKule]

They are both friction modified and have the same viscosity.

The so-called Friction-modified fluid had about a bit more FM.

 

[Garak]

Originally Posted By: MolaKule
...had about a bit more FM.

Is that an official SI measure of volume, Mola?

 

[MolaKule]

Originally Posted By: Garak
Originally Posted By: MolaKule
...had about a bit more FM.

Is that an official SI measure of volume, Mola?

Sorry, the official unit of measurement is, "tad."

 

[Garak]

There, that's better. Now, show the layman how to convert this to CGS, so we have no embarrassing questions.

 

[HTSS_TR]

I tried GM Synchromesh Friction Modified in my S2000 some years ago. It was okay the first 4-5k miles became notchy after that, I switched back to Honda MTF-2 and stay with it since.

I may try either Amsoil or Redline MTF next.

 

[BobsArmory]

Originally Posted By: MolaKule
Originally Posted By: Garak
Originally Posted By: MolaKule
...had about a bit more FM.

Is that an official SI measure of volume, Mola?

Sorry, the official unit of measurement is, "tad."

I thought it was "smidgen"

 

[ryanschillinger]

What kind of vehicle are you putting it in?

 

[Ramblejam]

Originally Posted By: Drew99GT
Has anyone tried both and noticed a performance difference between the 2?


I have, and certainly noticed a difference.

This was in a NV1500 that called for the friction modified product. With brand new "traditional" synchromesh, shifting became very notchy going into each gear. Once replaced with the proper fluid (extra FM), smooth engagement returned.

Long story short -- use the right product.

 

[RustyH]

This does not answer the original question, but I have used the GM syncho friction-modified in 2 BMWs with great results! I'm very pleased with this product and continue to use it.

 

[MolaKule]

One "Smidgen" = 0.1 "Tad" .

 

[Drew99GT]

Originally Posted By: ryanschillinger
What kind of vehicle are you putting it in?


1994 Toyota Corolla. The 3rd gear synchro is close to being shot. It's practically inoperable in cold weather and I'm close to scrapping the car since rebuilding the trans would be 3 times what the cars worth, so I figured I'd give the Synchromesh FM a shot since so many people have had miracle cures using it in problem transmissions. If it blows up the trans in the Corolla, it won't be a big deal, and if it helps shifting this winter for the $40 bucks it will cost to buy the fluid, I'll take it.

 

[IndyIan]

Maybe try just regular motor oil? We had a 92 Sentra that started to shift poorly and our mechanic at the time, put in 10W30. I didn't "know better" at the time and it shifted fine for the 60k miles we ran it after.

 

[Drew99GT]

I'm gonna try the Synchromesh FM first. If that doesn't work, I'll either get a junkyard trans or scrap the car.

 

[Greasymechtech]

FM-Synchromesh was labelled synthetic blend. Regular Synchromesh isn't. Suppose to help with cold weather shifting.

Also, I believe the FM dosage was 5%. From what I remember, it supposedly helped this "binding" transmission mechanicals slip and slide better. Wasn't an FM specifically for the synchros. Notchiness was caused by metal/linkage/component binding expansion/contraction from cooler temperature. At normal temps, you were at the mercy at the tolerances of the required clearances. Didn't help too much since it still was easy to 'bend' stuff in the transmission with a forceful shift.

SOPUS and Texaco Synchromesh fluids were 9.2cst at temp. There are full synthetic STF/MTL/MTF/Synchro type fluids that are in the 7.5-10cst range that will work well. Since the OP is Cawhlowrahdoe Springs, I'd start with a thinner full synthetic.

Besides the Pennzoil and Valvoline Synchromesh products, here are some more:
http://www.ravenol.de/en/products/usage/...sion-fluid.html
http://www.ravenol.de/en/products/usage/d/Product/show/p/ravenol-mtf-2-sae-75w-80.html
http://www.amsoil.com/shop/by-product/tr.../?code=MTFQT-EA
http://www.redlineoil.com/product.aspx?pid=146&pcid=9
http://www.drivenracingoil.com/dro/syncromesh-transmission-fluid-stf-15874html/
https://www.bgprod.com/catalog/drive-line/bg-syncro-shift-ii/
http://www.synmaxperformancelubricants.com/Super_70_MTL.html
http://www.pentosin.net/specsheets/Pentosin_MTF-2.pdf
http://www.royalpurpleconsumer.com/products/synchromax-manual-transmission-fluid/

 

[MolaKule]

Quote:
FM-Synchromesh was labelled synthetic blend. Regular Synchromesh isn't.


Both the original GM Synchromesh and FM-modified Synchromesh are blends of Group II, Group IV, and Group V alkyl benzenes, regardless of labeling.

 

[dfarr67]

Searching for the 'lost' smooth shift- IO know this is relative, on a 2015 Honda Accord 6mt, went from factory fill to GM synchro FM, seems almost the same perhaps a tad

better. When new the shift was literally effortless and entered the 'gates' like a light switch- looking for that feeling again....Redline MTL ? Only 8000kms on this car.

 

[dailydriver]

Originally Posted By: MolaKule
Quote:
FM-Synchromesh was labelled synthetic blend. Regular Synchromesh isn't.


Both the original GM Synchromesh and FM-modified Synchromesh are blends of Group II, Group IV, and Group V alkyl benzenes, regardless of labeling.


Thanks for that info Mola.

Did/does Texaco-Chevron make this for GM/AC Delco to package with their labels??

 

[ryanschillinger]

I tried the friction modified synchromesh in my 96 Civic. Didn't make much of an improvement over the Honda fluid from the dealer, if anything. My trans is a bit worn, occasionally makes noise. I run rotella t6 5w40 in it now and it's definitely quieter and smoother shifting. I guess at this age and miles, what works for most people doesn't necessarily work for my car. All the Honda forums swear by the friction modified synchromesh, but it wasn't what I was hoping for in mine. Ran it for 1000 miles and dumped it. T6 is cheap, like $20/ gallon. Next time I might even skip the T6 and use the regular triple protection 15w40 but for now I'm happier with T6 than the other stuff I've tried in here. Might be worth asking on a corolla specific group to see if anyone has experience with that particular model and trans.