Transmission

[David12345]

On my '73 GT, the tranmission leaks in a couple spots and the 1st gear syncro doesn't sync .. my question is, being only a fair mechanic, how difficult is it to overhaul and how many special tools does one need for this? Or what will it cost me approx. to have a mechanic do this?
David
St. Augustine, Fl. (any good shops in this area?)

[Paul]

If you have a Factory Service manual. Its not real. real hard, but you'll need a fair number is tools in your tool box, for example: a 1/8 punch and snap ring pliers.To disassemble the main shaft, you'll need a small hydraulic press and some type of bearing plate to get in behind each of the items that need to be pressed of the shaft. Take pictures and notes as you go. I had another tranny to look back at to make sure everything was correctly oriented.

You can find many sets of rebuild kits on ebay.uk to get the bearings and syncros. OGTS has all the paper gaskets and rubber seals.

If its just leaking I'd just replace the shifter shaft seals, Ft and Rear and pan gasket. Then you can run Redline MTL or MT-90. I've found it helps worn syncros to work better.

[Tru-Craft]

See "removing tranny" thread. Not the same tranny but very close.
Like Paul said, the seals on the selector shaft are probably leaking, at least.
But if you remove the tranny, replace all seals and gaskets, OGTS has them.
Not an easy job, just find a local tranny shop to help you with some of it.
Lyle

[Paul]

For seal replacements, here's my recommendation. Buy/Replace the following:
Front Tranny seal, rear seal and two shifter shaft seals. Also get the Pan gasket and tranny to bell housing gasket.

The front and rear seals are straight forward as are the two gaskets. Now there is a trick/short cut to replacing side seals with out removing the counter shaft.

Remove the two exterior linkages. Make a note of how many threads it takes to remove the nut. Drain the oil and filp it over on its back, on a bench. Use a couple of blocks of wood to stabilize. Using a big flat blade screw driver, remove the pan screws, keeping in mind theres a spring and a steel ball hinding in there just waiting to pop out on the floor.

The following descriptions are assuming the tranny is on its back and with output shaft closest to the person and the input shaft is away. With the cover off, use a punch and hammer and drive, from outside in, the reverse intermediate lever, its on the left. Next, rotate the selector shaft until you get the roll pins up verticle, you may have to move the reverse gear back to accomplish this. Now using a 1/8 inch dia punch, drive out the roll pin for the 3/4 gear intermediate lever. Its on the left side of the shifter shaft. Its okay dirve it on thru, you can get it later, just don't forget. Now you can rotate the shaft to expose the roll pin that secures 1/2 intermediate lever to the shaft. Its on the right side. Now you can drive this pin out.

Added Note Its best to support the shaft ends when driving out the roll pin. A block of wood works for this again. Once the 3/4 lever is free and floating on the shaft, to expose the 1/2 roll pin rotate the shaft 90 degrees and slide the shaft to the left. This will bring the 1/2 roll pin toward the interior of the casing and easier to get the punch on it.

During re-assembly use the shaft support blocks again so that the seal is not damaged from driving the pips back in. Best not the use the seal to support the shaft while hammering away.

As you begin to slide the shaft out, note the position of the forks on the shaft. The shaft will pull right out and you can collect the forks. Now the side seals will come out and you can install new ones. Check the shaft for any burrs. De-burr with a file and emory cloth, you dont want the cut your new seals, right?

Once the seals have been replaced, reinstall everything in the REVERSE order. Clean the magnet that is mounted in the pan.

Did I leave anything out?

Oh yea the roll pins... If there are burrs from driving them out, youcan clean them up on a bench grinder.

[Tru-Craft]

Paul, good short cut!
I pulled mine completely apart, to look for syncro and bearing problems, but didn't have to, everything was OK. Just a few burrs.
Replacing the rear gasket requires removing the output shaft and housing. If it's not leaking this will save a lot of work!

Good idea! You should have posted this a week ago!
But, now I know how to do it, and how it works.
Lyle

[Paul]

Sorry Lyle, I just did this a week ago. Didn't have time to go thru all the steps such as remove the counter shaft, but I had to replace the side seals... Then it just came to me like a vision in the night...

[Tru-Craft]

Paul that's why this site is so great!
If you ask for help you can get it.
The Factory manual leaves a lot out, so a couple "tricks" from the members can save a lot of time and stress!
Oh, my GT is now leak free! The first time in 15 years or so!
Lyle