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Discussion Starter · #1 ·
Can someone actually verify if this Synchromesh is the same stuff between GM and Penzoil. I see alot of people are using GM synchromesh in their t 56 cobras and have also heard that Penzoil is the same, Yet people seem to keep using Synchromesh from GM at a higher cost "I'm sure". Also do you use friction modifier or not "those of you with improved results".
 

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Yes. Penzoil makes both and allows GM to run their label on theirs.
 

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They are virtually the same. I have GM in my Cobra. Installing a 5 spd tranny in my old Corvette. The mfgr recommends GM, however, Keisler, the Vendor, told me Penzoil is the same thing and much cheaper.
 

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Royal Purple here. Felt like the tranny was rebuilt with different better sincros. I was shocked at the enhanced smoothness of the shifts.
 

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Pennzoil is the same. Ran it for years in my T56 and all other T56s I have worked on plus its cheaper then the GM Syncromesh. Dont use friction modifier with the synchromesh
 

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$8 bucks a qt at pep-boys for the Pennzoil. I hope it smooths out my gearbox.
 

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Yup as far as I know it's the same, works very well for improving WOT shifting smoothness. And no friction modifier here.
 

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I use Penzoil in mine. Works great. From everything that I heard, its all the same, but from my own experience, I would only use the Penzoil or Royal Purple. Thats just me I guess.....
 

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Discussion Starter · #10 ·
Thanks everyone, I just changed to the Penzoil synchromesh w/o friction modifier as soon as the snow melts, I'll give you my opinion.
 

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Discussion Starter · #14 ·
Well, I got a chance to test My Cobra today after switching to Penzoil Synchromesh fluid w/o friction modifier, and kind of like I thought, "no difference", should I add friction modifier and see if it helps, althogh I've heard of it screwing up the blocker rings somehow???
 

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Well, I got a chance to test My Cobra today after switching to Penzoil Synchromesh fluid w/o friction modifier, and kind of like I thought, "no difference", should I add friction modifier and see if it helps, althogh I've heard of it screwing up the blocker rings somehow???
Have you tried adjusting the clutch for deeper dis-engagement? Basically make the TOB just slightly ride the pressure plate (temporarily of course, don't leave it that way) and see if that makes a difference.
 

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Discussion Starter · #16 ·
Yeah this morning I adjusted it so it would disengage very far with my Fiore adjuster and the clutch actually bottomed out on the cable instead of the floor like usual, and it still fought very hard under acceleration. I encourage you to test drive a GTO with a six speed and powershifting and speedshifting are 5 times easier in these cars.
 

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Well, I got a chance to test My Cobra today after switching to Penzoil Synchromesh fluid w/o friction modifier, and kind of like I thought, "no difference", should I add friction modifier and see if it helps, althogh I've heard of it screwing up the blocker rings somehow???
Tremec says no on the modifier but some are running it. I don't think it makes much difference.

I love my car but have just come to the conclusion that the shifting sucks.
 

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Discussion Starter · #18 ·
I'm going to upgrade to the triple cone synchros or find a trans that has been upgraded alreadt, and I'll report back, unless I buy a GTO with a good, easy shifting transmission.
 

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I've had the best luck out of Mobil 1 ATF. My car had some synchromesh stuff in it when I got it (not sure which brand) I recently swapped it out to Mobil 1 which is what I ran in my T/A and it was definately improved. Still not great by any stretch of the imagination though. Just do some arm work outs and cog that damn thing I guess. :dunno2:
 
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