Those with rpm T56 rebuilds?
 

In the process of getting my car back together and with the rebuild trans from rpm. Have all you installed the recommend royal purple syncromax fluid or gone with the standard dex III. If it makes a difference mines is a borg warner t56, 1998 t56. The difference in cost is what I'm looking at. Thanks

I have one by RPM. I used their recommended fluid. I'm not about to go chintzy on oil when I spent $2xxx on a transmission

Imo had I just spent a wad of cash on a rebuild I'd use whatever they recommend. There's a reason they like the Royal Purple

I like Mobil 1 ATF personally.

RPM recommends RP synchromax in their T56 rebuilds. Are there any alternatives?

Some of those transmission speciality shops doing these rebuilds actually do recommend the "chintzy" ATF and not the Synchromax/synchromeshes. From what I've read of the pros and cons on the subject, I would not use RP Synchromax, though a lot of people seem to have good luck with it. Tremec only formally recommends M1 ATF / DEX III for the T56, even with the upgraded carbon blockers. That's not to say a sychromesh won't work ok with carbon synchronizer friction/blocker rings. Personally, I'm leery of synthetics and potential negative effects on the synchronizer friction rings, even with carbon blockers, and particularly at higher rpms.

M1 ATF, Redline D4, Amsoil ATF Torque Drive are all quality synthetic Dex III packages. RP has their own Dex III Max ATF for manual transmissions. The Honda DW-1 ATF (formerly Z1) is pretty good too. If I had a choice with a rebuilt T56 I'd probably choose the Amsoil TD. Cellulose lined blocker rings (pre-2001 T56's) are a different topic and those shouldn't be showing up in current rebuilds.

thanks for the the replies. Yea spending that much 3k for the rebuild I wouldn't want to go cheap on fluid and would want to go with the RP syncromax but like firebrian stated theirs been pro/cons to using it and others stated from what I've read that it it's bad for the carbon rings etc. not sure how long those that use syncromax been running it thier t56's. Maybe with more miles it can become an issue. Maybe those with known mileage can chime in. i wouldn't mind using the honda stuff since I can get it at a discount.

We recommend Royal Purple because we see its benefits when we tear down higher mileage transmissions. If the Royal Purple was bad for the synchronizer rings do you really think we would recommend using it in our new rebuilds? We have a customer with a CTSV that has close to 400,000 mile (300,000 on our rebuild T56) and we periodically tear his transmission down for inspection when he is in the area and it always looks fantastic. ATF isn't thick enough for higher horsepower applications. The fluid film strength between the gears isn't strong enough to prevent fluid sheer and metal to metal contact under heavy loads. The Royal Purple is thicker and resists sheering the fluid film and handles the load better.

I can only go buy what T56 RP users have stated over the past 15 years or so. As I stated above, the majority seem to have no issue with it (90%?). I'm concerned with the minority that do have issues and end up rebuilding their transmissions. I've yet to read of anyone with a basically stock engine/trans set up stating that conventional DEX III killed their transmissions. And there are transmission builders out there that won't recommend using RP. Texas Drivetrain recommends the GM MTL/ATF for their built T56's as of Feb 2016.

https://ls1tech.com/forums/manual-tr...l-support.html

The above thread summarizes a lot of the concerns and benefits of all the various lubricants in T56's. While over 8 years old, it's still applicable from what I can see. Early in that thread SixSpeeds Transmissions and Liberty Gear had concerns about the RP. SixSpeeds is no longer around. While there are less rebuilt T56's out there today than in 2008, there are still a lot of them out there. For a performance rebuild on a high hp car I can definitely see using a stouter lubricant such as RP synchromax. You can always find an example of someone having outstanding success with any particular lubricant....just as you can find someone who had poor experiences with the same lubricant.

For those of us still running stock or only slightly modified set ups, how to get the maximum life from our synchronizers, bearings, and gears, the choice is still not 100% clear. T56 synchronizers, moving shift parts, and bearings seem to be the weakest link in the chain, not so much the gears....unless you're high rpm/high load "pounder." One question I'd ask is if the carbon blocker material being made by Tremec today is identical to those made in 2008?

Synchromax having an operating visc of 7.7 cSt (100c) is negligibly different than the 7.0-7.6 visc of most of the Dex III ATF's. GM's 8861800 MTL is 7.4. Synchromax has a good dose of Boron (252 ppm), Phos (620), and Calcium (116-240). Those numbers are pretty similar to RedLine D4 (visc of 7.6), Amsoil TD, M1 ATF (7.4), Honda ATF, etc. Plain old Pennzoil Multi-Vehicle ATF has a 7.6 visc. In essence, those are all ATF-like lubricants. If someone were really worried about providing more viscosity protection to the transmission gears under high hp, a dedicated Manual Trans Lubricant like the synchromeshes should probably be used (visc 8.9.2-9.6). For stronger applications there are higher levels in the 10-15 range.

https://ls1tech.com/forums/manual-tr...56-others.html

Molakule's listing of lubricants for manual transmissions.

https://shiftsst.com/articles/transmission-fluid/

http://www.flaglercountycorvetteclub...%20Article.pdf