Is syncromesh, syncromesh?

I'm going to do slave valve removal + drain, flush & refill tranny (6MT) with syncromesh in the next day or two. Just went to the neighborhood Autozone where they had a few brands...Amsoil, Valvoline, Penzoil and Lucas (iirc). The only one in stock in the proper weight was Penzoil syncromesh. In looking through comments left in a couple of my threads here pretty much everyone specifies "GM syncromesh" by name. I doubt there's more than a couple of manufacturers of the stuff anyway & so the brand/label selling it may largely be academic - but thought I'd ask & expose my own ignorance on the topic. Does it matter?

 

I googled "GM Syncromesh" and lookie what I found!

https://www.google.com/webhp?sourcei...%20synchromesh

You got this kid, google is your best friend. Acurazine has a ton of information so remember to search before asking

 

Not the most conclusive in the world and there are certainly differing/conflicting views. For instance:

Pennzoil Synchromesh not the same as GM version | ATF, Differential, Trans, Brakes, P/S | Bob Is The Oil Guy

and

GM/AC Delco Synchromesh vs. Friction Modified version - difference? | ATF, Differential, Trans, Brakes, P/S | Bob Is The Oil Guy

So I figured I'd ask. I'm simply trying to find out if "GM Syncromesh" is the same as Lucas or another. Reading thru google search results yields somewhat 50/50 results. Do you happen to know, definitively?

 

https://acurazine.com/forums/problem...dified-621176/

But no I don't definitively.

 

tanks, mang

 

 

In the add'l researching I've done here the last few minutes I think syncromesh IS synchromesh. Penziol, AC Delco,...whatever.

 

I'm not 100% sure either, but I don't think they are all created equal. I think the GM friction modified from GM is the only one to go with. But maybe I'll be corrected....

 

From one of the 'oil guy' discussions:

"Pennzoil is the SOLE supplier of Synchromesh fluid. They have the rights and patents to it, nobody else makes it but Pennzoil because of this. There should be absolutly no difference between any brand."

This is also what the guy at Autozone told me + a guy at Advanced Auto Parts said sort of the same thing.

 

Does the Pennzoil brand say Friction Modified? If so, give it a go then I guess..let us know. I bought the GM stuff off ebay for a decent price

 

Yeh, I hate paying dealership prices for anything. GM dealership here in town have the GM-labled (AC Delco) for $16.26/quart. Penzoils around town are $7.99 to $8.99. Ebay of course tops them all, but I want to do it this week this weekend at the latest & it probably wouldn't arrive in time.

 

I ordered from this seller and had it within a few days
http://www.ebay.com/itm/221247966896?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

I would not mess around with trying to go a cheaper or faster route. The fluid all of us are using is the GM friction modified synchromesh. Look at gm parts.com or other GM part sites, I recently bought 3 quarts for $35 shipped.
I personally have over 100k on the GM fluid, changing it every 30k and running boost much of the time.

 

^^^^ This.

 

That stuff about the Penzoil exclusive is news to me, but maybe so.

I forget what the exact evolution is/was, but IIRC, what that ebay site says is correct: GM has re-branded the fluid to AC Delco. The original GM part # was 12377916 and on the back label it says (in part):

"The GM synchromesh transmission fluid is a semi-synthetic lubricant for use in 1500 transmissions...."

However, I don't believe that stuff in the Ebay link is the re-branded 12377916. That link says it replaces 12345349, whatever that is...

 

^^^^
Edit: after further review, I believe the ebay auction incorrectly states that it replaces 12345349. 12345349 is the old GM "non-friction modified" fluid. That AC Delco stuff is indeed "friction modified" and everything I can find says that 88900399 is the correct replacement part # for 12377916.