fhu004

Hey all,

I recently bought a 1985 Porsche 944, and the previous owner had taken out the transmission, and sold the car with the transmission in the trunk of the car.
The previous owner of the vehicle is no longer with us so, there's not much history on whether or not he got around to rebuilding it.

That being said, I'm planning on checking if the transmission is good, rebuilding if not, and then reinstalling.
It is a manual transmission.

I was wondering if anyone knew of anything else I should replace while the transmission is off? Since I know that a big pain is taking it out in the first place.
Also, if there are any tips on rebuilding transmissions i'd love to know.

Thank you all,

Winter44

The gas tank. If it is an early model, the tank will be metal (aluminum?) and will likely have a crack in the top corners/seams. If its a later model, it should be made of plastic. Either way, good chance to take it out, flush it, reseal it, and replace gaskets at the inlet and outlet. You won't want to have to do it later.

Van

Do the clutch - you're halfway there.

whiggins

Replace cluctch and torque tube bearings. There will NEVER be an easier time to do these things.

MAGK944

whiggins

We can agree to disagree. If the transaxle is out it is not that much more work to lower the suspension to slide out the torque tube, especially if you are replacing the clutch. These cars are old and I'm a believer in replacing things when they are easy to do. The torque tube bearings don't last forever.

KevinGross

I agree with Van's suggestion to replace the clutch. Change the engine rear seal while you're there. I am not a big fan of redoing the torque tube bearings unless they are definitely an issue. I'd reseal the transmission: input and output shaft seals. Clean, repack the CV joints. Good luck!

Otto Mechanic

You might consider replacing the transmission mount?

Tiger03447

While the transmission is out, drain it, pull the side plate cover, inspect the ring and pinion. Clean the two magnets in that section of the trans, and if you want to, you can pull the rear cover(s) off the trans, and clean the rear magnet as well. You will have to replace the gaskets and the rear rubber plug. (Pelican Parts) Get a WSM (workshop manual) for torque values for reassembly.. It will be invaluable in the future..CD online...cheap...Replace the trans fluid with Redline MT 90. (Amazon).
As far as the fuel tank goes, if it is a metal tank, they do tend to split.(See posts by Elgy). They are steel and are soldered.Drain, remove and rinse it out (water) Mine was damaged and I resealed it using a heat gun and acid core solder. NO TORCH!! .Run a vacuum check with a mightvac and see if it holds..You'll need to cap off the various tube adapters that are soldered into the tank to do this.Change the in-tank and inline filters.. Repaint and re-reinstall. Hope this helps some..

fhu004

Thank you all for the information/advisory!! I really appreciate it as a new 944 owner.

I'll most likely go ahead and replace the clutch, check transmission, check fuel tank, change in-tank and inline filters, and replace the transmission mount while i'm at it since mounts are pretty cheap.

I'll be sure to document any further updates on things I notice that might need to be replaced when I have had a better look at the car.

Otto Mechanic

If you're thinking about ever installing a short shift kit, it's a lot easier to do with the transmission out.

whiggins

Make sure you check the torque tube bearings. You may be surprised. LOL

KevinGross

Nice idea, but I am not sure it's worth the hassle or that you'll learn much from a visual peak at the pinion gear. The ring gear teeth always look a bit dodgy, that is their natural condition. The 4 mm tension pin retaining the magnet in the diff cover can be yanked out using a pair of needle-nose vice grips. Flip it when reinstalling. The 5 mm pin retaining the magnet in the rear cover can be tapped through with a drift, and I heat the cover to make it easier to tap out and in. I think everything you'll touch per Tiger's suggestion is 24 Nm: the diff cover bolts, the output flange center bolts, and the rear cover bolts.

Correction I should add the torque value for the input shaft rear bolt, since it has to come out to get the end cover off. For the M10 bolts used on the eight-valve, normally-aspirated cars, it's 70 Nm. For the hollow bolt used on the S/2/Turbo, it's 150 Nm. Both bolts can usually be cleaned up and reused with a little red thread locker. However, the M10 bolts sometimes get "soft" after a couple of uses, and if it keeps stretching as you try to get it torqued, replace it. (Factory says always replace, and that's a safe conservative thing to do.) BTW, I pull off the end cover using a two-armed puller on the two "ears," rather than whacking the ears with a hammer - quick and clean.

Do not use Redline MT 90. It is a GL-4 grade, you should use a GL-5 grade lubricant, 75W90. It is also not recommended for hypoid pinions, of which you have one. I know at least one soul has called Redline and apparently been told that it's okay, but I would not chance it based on only that conversation given that there are so many good alternatives.

pfarah7

Hey Kevin,

Are you still rebuilding early trannys?

Otto Mechanic

On that note, I suppose a few good alternatives might be appropriate? I'd certainly like your opinion. I've got less than 500 miles on the transmission you helped me with a few years ago and I don't think I ever asked you what you thought? I ended up using the 75W90 Mobile 1 LSD formula a few others recommended for my AOR, but if that was wrong it's not too late to fix. I know everyone has a favorite, I'd just like to know what yours happens to be.

You did jog my memory about trans coolers though. If the OP is considering an LSD or an oil cooler, this would be a good time to do it.