Contour Enthusiasts Group Archives Forums Modifications Transaxle Clutch Overhaul & MTX75 Upgrade

INTRO:
Before I start ordering a bunch of parts, I thought I'd run my plans by the MTX75 gurus on CEG. My 96SE MTX now has 112K on it, the majority of which are city miles. The MTX still shifts great (I've run the cocktail in it for many years, changing it regularly, and never abusing the tranny), so I don't feel any internal work is necessary, with the exception of a Torsen install (I told the wife it was necessary when I had the transmission out ).

TORSEN STUFF:
- Torsen (M-4204-F20)
- Carrier Bearings (F7RZ-4221-AC x 2)
- Speedo Gear (F5RZ-17285-AA)

Q1=Is there a "Differential Seal" that I should purchase?
Q2=What sealant do I use to reseal the MTX casing?

CLUTCH STUFF:
- Spec Stage I Kit (Disk/Plate/Throwout/Alignment Tool)
- SVT Flywheel (F8RZ-6375-AA)

OTHER STUFF:
- Rear Main Seal (F4AZ-6701-A)

Q3=Can the Input/Output Oil Seals (F5RZ-7048-AA and F5RZ-1S177-AA) be replaced during the overhaul I'm doing? Without digging through my foot-thick Ford Service Manual, I not 100% sure which seals these really are.
Q4=Are there seals between the CV driveshafts and the transmission? If so, what are the part numbers?

I had hoped that my clutch would hold out until the weather was cooler. Maybe this project will give me an excuse to Air Condition my garage! (I doubt the wife will go for that "upgrade").

Thanks for any feedback/comments you can provide!

1. No differential seal
2. Use the quality Permatex RTV black in the really small tube, available at Autozone or similar in a cardboard and plastic package ~$4.50 a tube, one tube is sufficient for the whole transmission; or use the Ford required sealant. Don't use standard RTV Silcone (like blue or orange) with the trans, especially if running ATF dino or synthetic.

3. There are only three seals, one input and two output. One is the input shaft seal that is integral with the clutch slave cylinder. When you replace the slave you replace this seal automatically. Make sure to use a bead of the same RTV sealant when installing the slave, or use an o-ring. (Ford manual cites a bead of sealant)
Output seals are the axle shaft seals. They are the same part number. Don't remember the part number but just get two replacement axle shaft seals.

4. See answer to number three.

Recommendation. Don't use the cocktail anymore with a torsen. Use Redline MTL if in moderate to cold climates. Penzoil synchromesh fluid seems to do OK with DemonSVT. Royal purple MAXGEAR works great in the south in the summer, NOT good for cold morings anywhere else though. Pretty much can't go wrong with the redline MTL or similar GL-4 gear oil. YOU NEED at least a GL-4 gear oil, or a GL-5 listed as not harming bronze synchros i.e. "yellow metals" by the manufacturer in order to provide the best protection for your torsen under heavy torque loads and to keep it quiet.

hey guys terry told me "RTV clumps up and will
lodge in the seals and cause leaks.Ford DO NOT advise
it...The corrct sealer is Permatex 'Anerobic Gasket
Maker' which is a RED GEL...that is the ONLY sealer
that should be used on an MTX...NEVER EVER RTV!"

just passing along some info.

Thanks for the informed feedback guys.

I ordered the Torsen this morning (<$550).

I'll pick up a tube of this:


With the information you guys provided, I've also updated the MTX75 Components spreadsheet: Updated Spreadsheet

I will be using some RedLine MTL.

When I get back from vacation, the overhaul will begin...

Doh! That is the one I meant! The little tube in the cardboard containrer...oh well.

unless you are doing serious power mods, I'd skip the spec clutch and get a stock SVT clutch. the gear rollover noise on the spec is quite loud at idle after it's warm. I wish I'd known this when I overhauled my transmission (fidanza, quaife, the works)

I won't be surprised if I have some rollover noise, but that's part of the reason I am going with an SVT flywheel instead of a super-lightweight flywheel (which would REALLY magnify the rollover noise). Besides, anything has got to be quieter than the noises my clutch is making now.

When I have a good enough excuse, I'd like to drop in a 3L, so I might as well start upgrading the other components now (that's why I'm putting in a Torsen as part of this project). I've also ordered the latest/greatest shift forks, as I hear they're easy to drop in with the MTX opened up.

the forks are definitely easy cause you have to take them out to take the diff out...well actually you would not HAVE to take the forks out cause the diff is on top...but it would be very easy to take them out once apart.

Any upgrade combination is possible. The reason I leaned towards the SPEC 1 kit (over SVT components) was the fact that the SPEC kit came with the alignment tool -- a small, but critical piece!

The price of the SVT flywheel is very attractive ($95) -- the slight weight reduction over a standard Duratec MTX flywheel is minimal (a bonus is the slightly faster throttle response). I didn't want to go to the 'extreme' and pay a bunch for a super-lightweight flywheel; besides, I've heard that a little bit of rotational mass ain't that bad (in a way, I think this ties into the whole DMD modification -- a little rotating mass helps smooth things out a bit; i.e. potentially less rollover noise).

To answer your question, a super-lightweight flywheel isn't going to bring about astronomical engine power gains, so any clutch (SVT, SPEC 1, or others) would be able to handle the 'extra power' brought about by the flywheel.