Synthetic or dino atf for better trans life?

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6
Location
GA
I have a spec racer ford that uses a ford escort engine-tranny package. It calls for ATF and one of the supposed "top" tranny builders suggested I use non-synthetic atf because synthetic is too slippery and it makes it harder for the synchros to engage and wears out the transmission faster. Is there any truth to this?
 
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25,046
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ON, Canada eh?
 Originally Posted By: adambrouillard
I have a spec racer ford that uses a ford escort engine-tranny package. It calls for ATF and one of the supposed "top" tranny builders suggested I use non-synthetic atf because synthetic is too slippery and it makes it harder for the synchros to engage and wears out the transmission faster. Is there any truth to this?
Use Syn... My cousin races a Mustang and Syn is the only thing that keeps him from destroying his tranny!
 
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19,479
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Chicago Area
Use a Synchromesh fluid like Pennzoil Synchromesh. Or Redline MTL,or MTL/MT90 mix. Amsoil also offers superb manual trans light gear oils. ATF is weak in every respect compared to a proper manual trans lubricant. Lose the ATF as soon as possible for better shifting and wear. It seems you have the G5M tranny, or a version of it?
 

adambrouillard

Thread starter
Messages
6
Location
GA
I'm not sure the technical term for the tranny. It is 5 speed manual and it is the one from the 1.9 escort engine. Why would ATF be specified by ford for a manual? Even the amsoil website recommends their atf for it.
 
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19,479
Location
Chicago Area
"'Even' Amsoil recommends it." Well, of course. They have to go by Mfr. specs. But ask a dealer his personalt opinion, and you'll get a better perspective. You trans in some service manuals was also spec'd for gear oil, originally. ATF is used by Ford in power steering, auto trannys, and manual trannys. Cheap and only one thing to stock in a dealership. Plus it's thin for good cold weather operation. But it's weak for shifting and wear protection in a manual trans/transaxle.
 
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463
Location
California
I smell Bee-S. My old "World Class" T5 calls for ATF. Why? because of the low viscosity compared to gear oil. Some of the passages through which the oil must flow are small and the gear oil will flow too slowly. Works just fine, I run a mix of M1 ATF and RP Synchromax in it. If I do it again I'll go 100% fill with the Synchromax. My wife used to have one of those Escorts with the POS 1.9 engine and the 5-speed. We always ran ATF in it and never had any trouble. Do yourself a favor and throw the 1.9 in the trash and get the later 2.0, which is a much better engine. The 1.9 is gutless and tends to suck in valve seats which wrecks the engine. Tremec now makes the manual trannys for GM and Ford which go behind the V8s. What do they recommend? ATF. FYI, Royal Purple Synchromax is specifically for manual trannys that call for ATF.
 
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1,611
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Pennsylvania
I use Mobil 1 ATF in my Camaro's T-56 tranny. I wanted to use a synchromesh but people on a LSX forum said that these fluids ate up seals or something... I just stuck with the ATF. No problems but if I knew I would have no problems running a Manual trans fluid I would.
 
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962
Location
San Antonio, Texas
 Originally Posted By: jigen
I use Mobil 1 ATF in my Camaro's T-56 tranny. I wanted to use a synchromesh but people on a LSX forum said that these fluids ate up seals or something... I just stuck with the ATF. No problems but if I knew I would have no problems running a Manual trans fluid I would.
The Synchromesh screws up the synchonizers in the Tremecs. SynchroMAX is ok to use. This info came from Tremec engineers that came into a thread about the TR3650's on StangNet.
 
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2,406
Location
Chicago IL USA
 Originally Posted By: adambrouillard
It calls for ATF and one of the supposed "top" tranny builders suggested I use non-synthetic atf because synthetic is too slippery and it makes it harder for the synchros to engage and wears out the transmission faster. Is there any truth to this?
I love how synthetic fluids are "too slippery" according to the Top XYZ Builder. Lies like that are rooted in ignorance and not fact. I would use whichever synthetic ATF you like - synthetic transmission fluids (and oils, greases, &c. for that matter) almost always keep their frictional properties over a wider range of temperatures than dino fluids, exactly the thing you want & need in your spec racer Ford.
 
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8,756
Location
RI
I would definitely use a synthetic ATF or any mtl/mtf type fluid. But, I would avoid universal or multivehicle ATFs in a manual transmission. Certain friction modifiers might affect synchro action and cause shift issues. You can still get synthetic dex/merc and typeF fluids which should work fine.
 
Messages
463
Location
California
If your manual box calls for ATF, you better listen to the people who built it. All the Tremec boxes want ATF. Royal Purple Synchromax is a gear oil designed specifically for trannys that call for ATF. Like I said, I run 50/50 M1 and RP, and my old T5 shifts very smoothly.
 
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8,756
Location
RI
Not all. When you put a real engine behind a Tremec, it suddenly needs 75w85 Syntorque! TR-3550/TKO - GM Synchromesh or Dexron III TR-3650/T-45/T-5 - Dexron III T-56 (Ford and GM) - Dexron III T-56 (Viper only) - Castrol Syntorque
 
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