Failing Synchro - What Additive(s) worked for you?

[unDummy]

Originally Posted By: FusilliJerry82
Would a high-friction ATF (Type-F) help at all? Perhaps Redline High-Temp ATF (33% thicker)?


From Redline's website:
This product can also be used in manual transmissions which require ATFs, providing better gear wear and better shiftability, but Red Line MTL® will provide even better wear protection and shiftability

If you want to step up in visc, just grab the Redline MTL over their Type-F racing ATF. BG Syncroshift II and Amsoil MTF would be good choices.

Amsoil ART would be a normal 7cst Type-F ATF worth trying. And, original B&M TrickShift is a mineral Type-F ATF. Some worn transmissions shift better with mineral fluids.
Also, RoyalPurple Synchromax is a thin MT fluid similar in visc to ATF with a synchromesh type additive package.

 

[ammolab]

Originally Posted By: Craig in Canada

The negative effects will happen to 2nd first because it is always the most-abused synchro in any MT. Anyone driving an MT looking to move fast winds it out in first and then tries to jam it into second - high revs, large difference between the gear ratios, hamfisted shifting = synchro wear. It's good that your car passes all of the other tests but it was certainly worth checking or you would continue to make things worse.


MTL worked wonders for my 2002 BMW tranny!! And YES on Second gear always the one to show first syncro troubles.. One main factor is that second gear is a big, HEAVY gear, much more inertia there...it needs more work from it's syncro to get up to/down to speed!

 

[[RT] ProjUltraZ]

Originally Posted By: webfors
Redline's Lightweight Shockproof is now marketed as a manual transmission oil. It has been known to 'mask' the symptoms of old synchros in Subaru 5mt's. I've used it, and it was smooth as silk. However, I'm not sure what fluid is spec'd for your tranny.


i see that on their website too, so i had the same idea. i emailed Dave at Redline to see if i could put it in a manual req ATF

"Thank you for contacting Red Line Oil, the LightWeight ShockProof isn’t an ATF and wouldn’t be recommended in your T-56 transmission. We don’t make a Super LightWeight ShockProof gear oil.

In your transmission the D4ATF would be recommended, though if you wanted to try a higher viscosity the MTL would be an option, the next higher viscosity above the D4ATF."

Regards, Dave
Red Line Oil

so i'm considering the oft tried 1-2 qts MTL in 2-3 qts ATF before going to 100% MTL

 

[mechtech2]

Don't put moly or graphite in a manual trans.
It makes the synchros too slick to 'bite'.

 

[dailydriver]

Originally Posted By: [RT
ProjUltraZ]so i'm considering the oft tried 1-2 qts MTL in 2-3 qts ATF before going to 100% MTL


OK, but our T56es only have a 4 quart capacity total.

Dave at RL DID confirm that there is NO PROBLEM WHATSOEVER with mixing his company's D4 and MTL 50/50, which I might just try next change. (Even though this sounds like an incompatible mix to some on here.

)

 

[Matt_N]

UPDATE

I purchased Pennzoil SynchroMax off the shelf at AAP. I drained the tranny yesterday and refilled with the SynchroMax. During my 15mi drive back home, I experienced ZERO grinding in 2nd gear or any other gear. Shifting was somewhat smoother, but I was still characterize it as notchy-er than most shifters I've experienced.

So the verdict -- grinding seems to be gone and shifter feel is slightly improved.

 

[69GTX]

GM T56's of that era came with the cellulose lined blocker rings. I'm assuming BMW's would have as well. Those often don't work great with synthetic fluids, and viscosities higher than the ATF's (ie above 8.0). The abundance of AW/EP chemicals in the GL-4 rated MTL's (like Synchromesh) can make the synchronizers shift poorly. If previous owners were using incompatible products the synchro's could have their surfaces altered which affects grip, even without being too worn. The links below explain that in detail.

See 3 links at the bottom of this RSG lubricant page

Some interesting synchro information from 2002-2003 which would apply to your 1997. Tremec still only recommends DEX 3 ATF's and M1 ATF in their T56's. No synchromeshes. While many users report excellent results with them, there are also far more negative reports than there are with conventional ATF's.

I didn't know there was a 5 speed T56. Sounds more like a T5, which has the same synchro concerns as the T56. If the Synchromesh gives you issues down the road, try plain old conventional DEX 3 or equivalent (such as GM's manual transmission lube for T56's - an upgraded Dex 3 ATF).

 

[MolaKule]

Quote:
Those often don't work great with synthetic fluids, and viscosities higher than the ATF's (ie above 8.0). The abundance of AW/EP chemicals in the GL-4 rated MTL's (like Synchromesh) can make the synchronizers shift poorly. If previous owners were using incompatible products the synchro's could have their surfaces altered which affects grip, even without being too worn.


There are no EP chemicals in MTF's.

There is no evidence that any chemicals in MTF's formulated for synchronized transmissions will harm any synchro assemblies in trannies with the T56 design.

The main problem with these transmissions is viscosity of the fluid used.

Viscosities at or below 10 cSt@100C seems to work well.

In some cases, the old fluid has sheared to such a low viscosity that crunching happens.

Replace the fluid first and then check for clutch adjustment as others have suggested.

 

[69GTX]

Similarly, there is no evidence that some of the chemicals in MTF's formulated for synchronized transmissions will not harm synchro assemblies in trannies with the T56 design. There are just too many user posts out there where upon using these MTF's synchro grinding soon began.

Dailydriver had such an experience with a RP synchromax (proper viscosity fluid as ATF) that upon dumping it the grinding immediately went away. And DD has tried numerous MTF's/ATF's in their T56. There are plenty of similar posts/threads out there to read. It might be debatable on what the "evidence" is. I've read a thousand or more posts from Tremec users and keep coming back to the mfg recommended ATF's as being the most suitable. RSG says the same thing.

Dailydriver: "I guess it depends on which grade/model year of cellulose Tremec used in the blocker rings, because when I tried the RP Synchromax in MY T56, I had NEVER experienced a lousier shifting/grinding in EVERY gear/balky/hesitant gearbox than that!! I dumped it the very next day and put in a D4/MTL mix and have not looked back since."

RSG recommended fluids

 

[69GTX]

White paper of synchromesh manual trans fluids posted by Molakule

I've read this same white paper a number of times in the past. And it suggests to me that synchromesh fluids have 40-60% of the EP additives of a GL-4/GL-5 type differential lube. In reading it again, I don't see anything that says different. The paper is on manual trans synchromesh fluids. So this statement should apply that some MTL's including synchromeshes, have EP additives.

Most manual transmission "specific" fluids (GL4) contain about 40% to 60% of the EP additive of differential lubes (GL5) with inactive or buffered sulphurs. GL4 has come to infer a gear lube with the above percentages of EP additive. The exception of course is ATF fluid used in some of the newer transmissions.

 

[MolaKule]

I wrote the text that way back in '08 because of two reasons:

1) in the early formulations of MTF's, the only anti-wear chemistry that was available for MTF additive packages were the addition of reduced treatment levels of differential-type EP chemistry's, which is no longer the case.

2) I used the "AW/EP" text because dedicated AW chemistry's were coming onto the scene to replace the sulfur-phosphorous EP package. That was the implication.

I have stated in many other threads (you may have missed those) that current MTF's only contain AW chemistry's because the gearing teeth and bearing loads in MT's do not need the EP chemistry necessary for hypoid differentials.

I will consider rewriting that WP to reflect updated MTF formulations.

 

[69GTX]

Originally Posted By: MolaKule
I wrote the text that way back in '08 because of two reasons:

1) in the early formulations of MTF's, the only anti-wear chemistry that was available for MTF additive packages were the addition of reduced treatment levels of differential-type EP chemistry's, which is no longer the case.

2) I used the "AW/EP" text because dedicated AW chemistry's were coming onto the scene to replace the sulfur-phosphorous EP package. That was the implication.

I have stated in many other threads (you may have missed those) that current MTF's only contain AW chemistry's because the gearing teeth and bearing loads in MT's do not need the EP chemistry necessary for hypoid differentials.

I will consider rewriting that WP to reflect updated MTF formulations.


No need to rewrite imo. I tend to dig and dig to find information to answer questions I have. And often recall what people wrote years ago on topics I am interested in. And if things are inconsistent, the red flags go off. So probably why this topic continues to confuse me at times, just when I think I have it figured out.

 

[Ducked]

Nylon shirt?

 

[MolaKule]

Originally Posted By: 69GTX
Originally Posted By: MolaKule
I wrote the text that way back in '08 because of two reasons:

1) in the early formulations of MTF's, the only anti-wear chemistry that was available for MTF additive packages were the addition of reduced treatment levels of differential-type EP chemistry's, which is no longer the case.

2) I used the "AW/EP" text because dedicated AW chemistry's were coming onto the scene to replace the sulfur-phosphorous EP package. That was the implication.

I have stated in many other threads (you may have missed those) that current MTF's only contain AW chemistry's because the gearing teeth and bearing loads in MT's do not need the EP chemistry necessary for hypoid differentials.

I will consider rewriting that WP to reflect updated MTF formulations.


No need to rewrite imo. I tend to dig and dig to find information to answer questions I have. And often recall what people wrote years ago on topics I am interested in. And if things are inconsistent, the red flags go off. So probably why this topic continues to confuse me at times, just when I think I have it figured out.


It is being rewritten because new fluids, specs, and additives have arisen since I wrote this original white paper, just as the Oil University was rewritten.


There is nothing inconsistent in the original white paper considering the availability of oils, additives, and the current formulations of the day.