Manual transmission oil and carbon-coated synchros

[rmcdaniels]

I was using Mobil1 10W-30 in my Civic, then switched to Amsoil 5W-30 manual transmission oil, but my synchros still don't work very quickly. It's like having a mandatory waiting period between gears. Do carbon synchros require thicker oil? I'm thinking of trying something heavier like Redline MT-90. What is anybody else using with their carbon synchros?

[doctorstupid]

Typically speaking, not being overly well versed in the finer points fo carbon-faced friction rings, the thicker oils will slow synchronization a hair, since as the friction ring approaches the cone it needs to wipe oil off before it can start to grab; of course thinner oils are easier to wipe away. The problem with this is the light gear oil is not exactly ideal in terms a splash luybe system in the gearsets and bearings.

I've been very happy using Royal Purple MaxGear 75W90 in not only my own car, but many customer cars (brass synchros). It's nice and thick, and contains a small friction modifier to improve fast shifting. IN my opinion, it combines the best of all gear lubes on the market; friction modifier like BG Synchroshift, high shock-loading ability like Redline, and nice and thick as any good gear oil should be.

But I kind of digressed, the first place to look is the manual for what weight it calls for. If you're still dissatisfied with how it shifts, bearing in mind that thinner usually makes for faster shifting, try adding some friction modifier, or picking up a thin gear lube with it already in.

[rmcdaniels]

Here's the stuff that I'm currently using:

http://www.amsoil.com/StoreFront/mtf.aspx

It's a light transmission oil with friction modifiers. Honda doesn't say what their oil is, but rumour has it that it's about a 30 weight oil with some additives, which would be consistent with it's appearance (looks/feels like motor oil, definitely not like 90 weight gear oil. I'll see if I can find some of the Royal Purple oil locally.

[doctorstupid]

NAPA has it behind the counter for about $11/quart.

I wonder how well it would work in that tranny if it comes filled with lighter oil. In Mitsu and Getrag trannies, I swear by the purple shit :)

[Weston]

I've been really happy with Redline MTL (just the plain "MTL")... that's their recommened weight for Honda/Acura. I have brass synchros, but I'd think that using what works for that would be a good starting point.

[HONDA GHANDI]

Hmm, I havent had any problems with the carbon synchros and jsut regular ol MTL or Honda MTF. Are you sure everything else is in order? Is the problem all the time or does it tend to start happening when the trans temps are high?

[rmcdaniels]

Hmm, I havent had any problems with the carbon synchros and jsut regular ol MTL or Honda MTF. Are you sure everything else is in order? Is the problem all the time or does it tend to start happening when the trans temps are high?

The transmission was just put together with a new final drive set and new carbon-faced synchros. It works great until I start winding it up, then at high RPM's it doesn't want to go into the next gear, I have to wait a bit for it to synchronize, then it slides into gear smoothly. It's not a big deal for daily driving, but I will be taking it to VIR in a few weeks and it will be a big deal there.

[HONDA GHANDI]

Hmm. New clutch too I assume?

[M@]

What kinda tranny fluid should I run in my stock B16 tranny with a 6 puck unsprung? Not that the clutch matters on what tranny fluid to run, but.. just throwing out the fact that I should probably be running synthetic since I'm going to be abusing it. :D

[rmcdaniels]

Hmm. New clutch too I assume?

Competition Clutch Stage 5, I love it so far. 4-puck sprung-hub disk, and very easy pedal effort, my humongous ACT clutch muscle is atrophying.

[M@]

Competition Clutch Stage 5, I love it so far. 4-puck sprung-hub disk, and very easy pedal effort, my humongous ACT clutch muscle is atrophying.
How much did that bad boy set you back?

[HONDA GHANDI]

Hmm, I dont know then. I would try a couple of different oils and see if anything helps. maybe try synchromesh?

[rmcdaniels]

How much did that bad boy set you back?

I found a guy with a shop that ordered one for a customer that flaked, so he sold it to me for $250.

[rmcdaniels]

Hmm, I dont know then. I would try a couple of different oils and see if anything helps. maybe try synchromesh?

I'll give it a shot. I found a few bottles of Royal Purple Synchromax today when I was out shopping for new plugs (COP eats $15 plugs like they are candy). I think I'll give that a shot, then maybe some Synchromesh or Redline MTL.

[oldskoolracer]

i've heard of people using GM synkromesh fluid

[servion]

Hmm, I dont know then. I would try a couple of different oils and see if anything helps. maybe try synchromesh?

Definitely try the GM synchromesh. That took care of all my issues.

[rmcdaniels]

All fixed, it was the Amsoil transmission oil. I put some Royal Purple Syncromax manual transmission oil in it and it works like normal again.

[2genCRX]

i have heard alot of people on H-T. com using gm syncromesh with friction modifier but im curently using honda mtf

[HONDA GHANDI]

Good to know. I was going to suggest BG Synchromesh II.

[doctorstupid]

Royal Purple FTW!

What weight is the Synchromax? I've only used MaxGear.

[rmcdaniels]

Royal Purple FTW!

What weight is the Synchromax? I've only used MaxGear.

It's pretty light, the stuff poured like water. After tearing around for a while today, it still gets just a little sticky if I wind up around 9K, but it's a million times better than it was with the Amsoil stuff. I may try some heavier oil in it like the Redline because I'm running it at VIR on the 11th-12th, but it's not bad now and with the supercharger I really don't need to rev it that high, I was just doing it to check my belts for slippage.

[doctorstupid]

Yeah, figures, most synchro-fix oils are light as hell. Not to my taste, but if it works there's no arguing that :)