1st installment of the Tranny Rebuild Tech Article

[red-beard]

It's still rough around the edges, but take a look! It's complete to removing the gear stacks from the transmission.

James

Full on Synchro change!

So yer gears are a grinding…I feel your pain. You too can rebuild the 901. It’s not that hard. Really! If all of the oil seals are in decent shape (no leaks!!!), then you can change the synchro’s while leaving the tranny in the car.

Tools – You’ll need a few tools. Most of them ya got, but there 2 special ones which really help

Synchro hub removal tool - This puppy helps you remove the dog teeth from the actual gear. There are ways to get around buying this one. I’ll address those later.

http://www.pelicanparts.com/catalog/shopcart/9144/POR_9144_tranny_pg1.htm#item5

Shift fork alignment tool – There is no substitute for this. If you want to rebuild the tranny, ya need it!

http://www.pelicanparts.com/catalog/shopcart/9144/POR_9144_tranny_pg2.htm#item17

30 mm deep socket (I found one at Autozone for $6.99)
2 mm pin punch
13 mm socket wrench with extension
17 mm socket
17 mm allen for the drain plugs
19 mm deep socket (you can substitute a ¾ inch)
"Big Ass" Crescent wrench
Plastic and brass hammers
A thin file
Gasket scraper (or a single edged razor blade)
Some sort of cleaning fluid (I like to use diesel fuel)
Lint free rags
A couple of brass brushes
3 jack stands
2 drive up ramps (optional, but nice!)
A big plastic box.
A plastic in sink wash tub.
Some clean containers for parts (Coffee cans, etc)

Parts:

4 gaskets – Intermediate plate to transmission housing, End cover to intermediate plate, the fork gasket and rear cover plate gasket. The factory manuals don’t show the 3rd or 4th gaskets for side shifters, which use an o-ring with the side shifter and no rear cover plate on the rear cover.

Up to 5 synchro bands.

http://www.pelicanparts.com/catalog/shopcart/9144/POR_9144_tranny_pg1.htm#item3

Up to 5 sets of dog teeth

http://www.pelicanparts.com/catalog/shopcart/9144/POR_9144_tranny_pg1.htm#item4

Up to 3 sliders

2nd/3rd and 4th/5th are one type and Rev/1st is different.

http://www.pelicanparts.com/catalog/shopcart/9144/POR_9144_tranny_pg1.htm#item6

What will you need? It depends on what is actually wrong and how many gears grind. If it only grinds in 1st or 2nd, you may only need parts for those areas. I’ll show you good and bad parts. If the grinding just started, you may be able to get away with just a few synchro-bands. As a bare minimum, you need to get 2 brand new synchro-bands, for 1st and 2nd. These get the most wear and you might as well replace them while you’re in here!

2 Muffler gaskets

http://www.pelicanparts.com/catalog/shopcart/9144/POR_9144_exhaus_pg2.htm#item9

Back the car up onto the ramps. For safety sake, disconnect the battery. You don’t want someone accidentally starting the car while this is all going on. Support the heat exchangers with wire or jack stands. Remove the muffler and the muffler hanger from the transmission. Disconnect the transmission ground strap from the end cover.

Clean – Clean – Clean

Youze about to get into the inner workings of the transmission. You do not want to get dirt inside. We all get oil leaks and some of this oil ends up on the transmission. Clean the dirt and grime off the transmission. You might try one of those pressure washer engine degreasers at the u-spray it car wash places before starting this job. Besides, no one likes working on a greasy mess. Clean at least the end cover and the intermediate plate on the outside.

While you’re under there, take a look at the CV joints and check the boots. Squeeze them while holding a strong light on them. Cracks? Dry rot? Replace them! And don’t forget to repack them with grease!

While you’re cleaning, pay special attention to the nuts which hold the transmission cover on. Clean the threads as best as you can. Then spray them liberally with penetrating oil. While they’re soaking in it, remove both drain plugs and drain the tranny oil. Remove the shiftrod cover. Clean the shift rod area and soak it’s nuts with penetrating oil.

Remove the shift rod:

Tail shift: You disconnect the two 13mm nuts which hold the shift rod support bracket. Then push it back on the shift rod. You may want to go ahead and completely remove the shift rod from the car and renew all of the shift bushing (See the tech article on shifting improvements).

Side Shifter. Using an allen wrench, remove the shift rod set screw and separate the shiftrod from the shifter arm. Remove the 2 nuts which hold the shifter arm to the transmission. Pull the shifter assembly out of the transmission. Disconnect from the shift rod. Soak it in your cleaning fluid.

Remove the speedo cable.

Place a jack stand underneath the transmission and support it. Remove the bolts transmission support bolts. These are through bolts and you’ll need to place a wrench on top as well as the ratchet on the nut.

Remove the Tail cover. All of the tail cover nuts should be 13 mm. Don’t worry if the nut is rusted on and the stud backs out. We’ll take care of that later. Remove the nuts and the washers. Put them into a jar with some cleaning solution. On a tail shifter, remove the rear cover nuts washers and cover. Put something underneath the transmission, because you are about to have reverse drop out on the ground!!! Using a plastic and/or brass hammer, tap the cover off. Tap lightly on the “ears”, the rear transmission supports. Collect all of the pieces that fell on the ground and remove any loose pieces from the inside of the end cover. Put them in a clean plastic box labeled reverse. Make sure all loose pieces are there.

Tail shifter: remove the fork. It is in the same spot the side shifter uses for the shift selector. Use a screw driver to pry it out, but only at the “pointy” ends, not in the middle. Note which way the “toes” are pointing.

Before we remove the intermediate plate, we need to loosen/remove a couple of things.
There is a rod on the left side which is connected to a brass ½ moon thing. This is you 1st/rev gear selector. The ½ moon thing is the shift fork. It is attached to the 1st/rev slider. Push the rod and the slider into the transmission (Towards the front of the car) and engage it to 1st gear. Now look at the same level as the first shift rod on the intermediate plate. You’ll see the protrusions of the other 2 shift rods. Using a ratchet extension and a hammer, tap both of these rods into the intermediate plate. This engages all gears, locking up the entire transmission so it can’t turn. Use the 30mm socket and a breaker bar and loosen the rear bolt with the speedo worm drive (Yeah! THE BIG BOLT). Just make sure you can turn it by hand, but don’t remove it yet.

Using a 13mm ratchet, remove the little bolt from the shift fork. Slide the shift fork and the slider off the transmission. You may need to use a large screw drive to pry the slider out of engagement with first gear, depending on the condition of first gear.

Take the pin punch and remove the roll pin from the castle nut on the right side of the transmission. Use a 19mm wrench and a breaker bar to loosen (but not remove) the castle nut.

Remove the intermediate plate and the gears: Using a brass hammer, lightly tap the intermediate plate towards yourself. Once it’s loose, hold tightly (It’s heavy!) and pull the intermediate plate and gear stacks out of the transmission.

Now the fun begins!

[JayDarden]

Thanks for the post - this really helps!