Consensus wanted:MTX trans fluids/friction modifiers?

[Huntervf]

Since getting the 89 back from the trans shop I've had some real trouble shifting...it's very notchy and at times I just plan can't get it into gear. Everything in the trans is new/replaced save for gears 1&2, 4&5, the output shaft and the clutch (OEM, with approx. 7k). I'm running Royal Purple ATF.

I've been doing a little checking around about different fluids and friction modifiers. I would really like some thoughts/opinions on different fluids & modifiers...this isn't my strong suit and I'm desperately wanting my trans back to shifting decently. When I had trans work done back in April I was using the IPT stage IV clutch and regular trans fluid, and after a short break in period (that's when I had new synchros/rings etc. installed) the trans shifted good.

As always, any and all advice is appreciated!

 

[Gloffer]

It may be sacrilege, but some guys in the Honda S2000 forum are using GM Synchromesh transmission fluid. S2000's have close ratio 6 speed transmissions that are a dream to shift when everything is working right. Several different MTF's have been used by S2000 forum members including:

Honda MTF basically a 90 wt gear oil with additives for the synchros. S2000s have double cone synchros on most of the gears and a triple cone synchro for second gear.

Redline MTL
Redline MT-90

GM Synchromesh

Most members have settled on the Honda MTF, but the few members that have tried it, have given the GM Syncromesh rave reviews.

See S2Ki.com and do a search on synchomesh.
There are a lot of threads over there on tranny issues. Here's one link http://www.s2ki.com/forums/showthread.php?threadid=70383

When you think about it, it's really not all that sacrilegious since a some Honda and GM guys are using Ford heavy duty brake fluid for beyond street driving applications.

Hey whatever it takes, right??

<small>[ August 16, 2002, 04:48 PM: Message edited by: Gloffer ]</small>

 

[DeaconBlue]

The '89 MTX has the old material syncos. Try some standard Mercon F fluid and see if it works any better. Vadim and Eric at Rickety, both of whom have rebuilt a few MTX's, have told me sometimes you just have to try a few different types of fliuds before you find the one that works right with your MTX. Several people have tried any number of ATF fluids, some have even tried 10W-30 motor oil and even standard heavy weight gear ****.

 

[SHODUDE]

You need to find out what synchros they replaced them with. Paper or brass?

Redline MTL for the Brass and Redline D4 for the paper.

I have fixed a number of notchy shifting SHOs with these two fluids.

This could also be a pressure plate problem. Does it grind in reverse after trying to put in one of the forward gears?

<small>[ August 16, 2002, 05:45 PM: Message edited by: SHODUDE ]</small>

 

[shojuan]

Does the stock 89 transmission use brass or paper? After replacing a wheel bearing and CV joint this last winter I sucked out the factory fill and replaced it with Redline D4 per the shotimes recommendation ("Gary Morrell has tried each extensively and recommends the D4 rather than the MTL.") Although it slides into gear quicker, ever since there is a big grinding problem shifting into 3rd gear. Basically, I have to shift *very* slowly to prevent grind going into third. If sucking out the D4 and swapping with MTL would fix this I'd do it in a second. Sheesh, I've always used MTL in other cars but the "Gary Morrell sez" got to me.

Rick

 

[SHODUDE]

The 89 used Brass Synchros. I would change to MTL and see if your problem is reduced.

 

[Huntervf]

I have brass synchros in there now...I believe the PP is fine as there is absolutely no problem shifting into reverse. In fact it's probably the easiest gear to get into, just throw it into 5th and reverse slides right in

I'll shop around for Redline...what about using the Ford friction modifier with Redline, or ther RP I just put in? At $7/qt I'd really like to keep the fluid I have but if it comes down to notchy shifting or a few wasted $$$ then it's no contest.

<small>[ August 16, 2002, 11:04 PM: Message edited by: Huntervf ]</small>

 

[olympic]

I had my 89 tranny refreshed by SHOnut. New 1-2 synchro, new blocking rings, etc. I filled it with Mobil 1 synthetic ATF and it was terribly notchy. There was like a 2 second delay before it would let me into the next gear. I tried a bottle of Ford friction modifier for a few hundred miles and it didn't seem to help much. So in a last ditch effort to improve things before the convention, I drained the Mobil 1 and filled it with GM synchromesh. Now it shift perfectly and I ran a 14.6 at the convention!

Anyways, Ford recommended Type F ATF for the 89-91 MTX's and DEX-MERC ATF for 92-95. Maybe you should start with TYPE F and see what happens.

 

[fredhurderjr]

Redline D4 ATF in both of mine - Quaife (95)& Stock (89), FWIW.

 

[AutoXSHO]

I agree w/Fred. I drained the fluid out of my trans and put in Redline D4 ATF. The car shifts VERY nicely now.

John V

 

[sdpatt]

The Gen I MTX does not respond favorably to MTL. The synchros were designed for the characteristics of Type F ATF. I have used ATF, Redline MTL, Redline D4 ATF and ATF with the Ford friction modifier. The D4 ATF and ATF with friction modifier were indistiguishable in their results: both allowed as smooth a shifting action as the SHO box can produce. The MTL was very notchy and difficult to engage gears. The ATF and friction modifier combination is cheap and effective.

 

[Huntervf]

Well, I went ahead and bought 4 qts of GM Synchromesh...$7.50/QT my cost, about the same as RP so I thought I'd give it a try. The car will go to the shop this afternoon for the fluid change, I'll keep everyone informed on how it works out. Thanks for all the advice!