mikegarrison

Yes you can. You will ruin your transmission, but there is nothing but good sense keeping you from doing it.

oknessad

I'm always shocked when I read these posts how many people start talking about mobil 1 (referrring to their gear oil for rear diffs). It shocks me and I wonder if the people putting this stuff in their tranny are having some major problems? It seems to come up just about any time either a transmission or rear diff is mentioned. Either someone will be putting a diff fluid in the transmission or the other way around. Anyone actually done this and want to fess up? What were the results? Huge damage? caught it in 10 miles and changed it? I wonder if Honda is unknowingly having to do warranty work on peoples transmissions that are blown due to improper fluid put in...

jimknapp

Okay, Guys,

Now I know I am supposed to be a big time racer and all, but I learn new stuff every day (sometimes twice a day). Since I run pretty much stock, I have never even bothered to change the oil in my tranny, so the question of what lube has never come up. Are you guys saying that rear diff lube will ruin a Honda tranny? Seems hard to believe since they are both basically similar high shear pressure applications.

What exactly gets ruined? And what other than some Honda part number is allowed into the gearboxes?

Enquiring minds want to know.

Thanks,

Jim

Ludedude

Jim, the tranny is supposed to use a GL-4 oil. Rear diff fluid is typically a GL-5 oil.

The issue is that a GL-5 fluid will eat the brass syncros in the tranny and that's a bad thing.

GL-4 tranny, GL-5 diff.

I personally use Redline MT-90 in the tranny (a GL-4 fluid).

J.P.

ol' dood

Geez, this topic went askew quickly. Thanks to Xviper and other for getting it back on track. At any rate, I'll chip my $.02 about the GMFM TRANNY fluid. My "S" is an '03 with 41,176 miles. Transmission fluid has been changed twice with the Honda fluid and then I decided to try Torco's racing fluid to see if I could get an improvement in notchiness(especially when cold). The Honda fluid worked pretty well when fresh but the notchiness quickly returned after about 2000 miles into each change. The Torco made no difference at all, didn't get worse either. So, about 4200 miles ago, I decided to try the GMFM. At first, I noticed no difference, but after about 2500 miles or so, I've noticed a dramatic improvement in shifting. It's especially noticeable when the transmission is still cold. I'll be changing it again shortly and am curious to see if I can detect any further improvement with the GM. It appears to me that there's no consistentcy here with with the various types of tranny fluids. Some experience good results. . .others bad. . . and others report no discernable difference. Go figure.

STMike79

Bought my '00 S w/ 36k on the clock, with alot of notichyness in the 1>2 & 2>3 shifts. After putting GM Synchromesh in, the notchyness is down about 75-90%. We'll see how many miles before it returns though

i77ac_10

Man thats so odd. If anything my GM SM FM seems to be feeling more and more notchy....

So is there a Mobil 1 transmission fluid that we can use?

xviper

I don't believe so. The only transmission fluid that Mobil markets is for automatics.

SC_Highlander

I switched to Synchromesh tonight and noticed an immediate improvement in 1-2 shifts. I was running redline MT-90 prior to the change.

ol' dood

From my own personal test, I'm very impressed with GMFM. My transmission seems to like it. I'm one of those guys who looks for faults.