How often do you change the MTF in your gearbox and what do you use?

I see on the Bob is the Oil Guy all sorts of different opinions, including one Honda owner who changed his fluid every 6000 miles (which seems excessive,) except he said it improved the quality of his shifts.
I know when I owned my old Saab 9-5 having the manual tranny fluid changed really improved the driveability of the car.

Also, do you think I should stick with genuine Honda mtf while the car is under warranty?

 

a lot of Honda owners complain about the 3rd gear pop out or grind.
its not proven scientifically; but we believe its a fluid problem.

we change the HONDA MTF with a GM syncromesh modified friction fluid.
after, i switched I no longer had the 3rd gear grind/pop out. and I had more confidence in shifting.

I change my fluid every 30k miles.

 

I really don't have any problems, just a maintenance freak. Want to keep the car a long time.
And I enjoy driving an old car that still drives like it is showroom new by constantly changing the fluids a lot more than factory recs.

 

^right, every 30k is sufficient

try out the GM stuff tho. I bet it will improve your already great transmission!

 

Didn't Honda/Acura change the formulation of their MT fluid within the last year or so?

 

^^

they changed it a few years ago. i must be one of the lucky ones, i rarely have the grind and pop out of the 3rd gear in my TL. i've been waiting for my MID to tell me to change the fluid.

 

the GM synchromesh fluid is now - AC Delco brand.

But is the same fluid as the GM, just a different name and label. Even the part # is the same. FWIW.

 

I have noticed my manual trans. has gotten a little bit rough (14,000 miles). But it also seems to become smoother after about 10 miles. Does it really need to get "warned-up" to shift properly? I have driven many manual trans. cars and never noticed this behavior in them.

 

Changed mine at 20K. Put in Amsoil Manual Synchromesh. Before the oil change I have an occasional issue with 3rd gear popping out; I have put on about 1,000 miles since and have not had any problems with the shifts.

 

That is when I plan to use it but I may switch earlier. No issues but the GM juice is just that good. Suspect the whole issue is physical tolerance stack up inside the transmission and GM or other alternate juices let the syncro come up to speed easier. Have the GM juice in the 04 and the 08. The 08 was marginal for third gear pop out and now it is smooth as silk as is the 04. Even a good transmission will perform better with the GM (Delco) juice IMHO

 

I have been reading all kinds of comments about AC-Delco/GM Synchromesh FM manual transmission fluid as a great replacement choice for cars with shifting problems.
I have also read comments like this:

"I personally have never used Syncromesh. About 3-4 years ago EVERYONE in the 3000GT/Stealth community swore by it, saying that it 'solved' a lot of syncro issues that some people were having. Now years later those same people are draining their syncromesh and discovering that it has basically liquefied some of the metal parts in the trans. There are pics of it in the drain pan where it clearly has metal suspended in the oil. As such the Synchromesh has fallen out of favor with pretty much everyone in the 3/S community."

Now I don't know if this prior comment was made about Synchromesh FM or the regular Synchromesh, or if it matters which, but as all this commenting, pro & con, is just posting with no substantiations, I am not ready to jump on this bandwagon yet.

 

It is very common for the brass synchro rings to wear in any (manual) transmission and this causes visible small "grains" of brass to accumulate in the fluid. It does not necessarily cause any problems. It is of course a good idea to remove them by changing the fluid. Any oil (lube) you choose to use will be a compromise because smooth shifting is one requirement, but protecting the synchros and the bearings is an opposing requirement. A lube that performs best at one of these needs will not perform best at the other. The bearings in these transmissions are rather small and are under constant load.

 

I'm at 40k miles and want to change mine soon. I was going to do it last weekend with my oil / rear diff fluid changes but I didn't want to add another task to the list...especially since I hadn't changed the rear diff fluid before and I didn't know how long it would take.

Though I want to go the syncromesh route I will probably wait until I'm out of warranty just in case there are any issues. Until then it's Acura MTF for me. Fortunately I don't have any issues, other than the (very occasional) 3rd gear popout.

 

The manual transmission on mine has been solid so far, no issues. At last service dealer mentioned a MT service, but I declined since the maintenance minder hadn't popped up with this code yet. But, may do so at 50k just to be on the safe side.