My understanding is that in 79, Fiat changed the transmission tunnel slightly to allow for more room, and I can confirm after working on my 77, that the 79-85 transmission tunnels has a bit more critical space for taking out the transmission. That being said, I found that I could clear what I though was not possible by tilting the rear of the transmission down when removing or installing and gradually pushing it forward, then re-leveling it.
One of the most important tools of the job was a transmission jack with rollers (Harbor Freight).
In order to be able to work under the car and eventually roll the transmission out from under the car, I used wooden cribs I made with some 3" 1/2' square logs, I used a high lift jack from HF to get them under the car. In retrospect, it was perfect for the job, and gave me plenty of space to work with a creeper. Also I bought a copy of the factory manual from Midwest Bayless a few years ago, and using it for the transmission section was critical to getting the job done right.
First I removed the driveshaft, only remove the 3 bolts on the yoke in the rear of the trans. Leave the pillow block on the trans. You will also have to disconnect the hand brake cable to remove the driveshaft.
Next I disconnected the starter, I used about 3 feet of 3/8 extensions with a u-joint with a piece of tape wrapped around the joint to allow me to get the socket on the bolt without it flopping around. Not that bad, use shorter extensions closer to the bolt. Since the starter was working perfectly, instead of fully disconnecting the starter wires, I wedged a paint stirr between the lower part of the motor and the motor mount and pushed the starter onto that so it wasn't touching the bellhousing.
Disconnecting the bellhousing-to-motor bolts are the same procedure as the starter.
Make sure the flywheel inspection plate is removed before trying to remove the trans.
I degreased my transmission mostly with 70% rubbing alcohol, shopline general solvent, paper towels and q-tips, there are many ways to do it and do it faster.
I used a battery terminal puller I bought off Amazon to pull the output shaft alignment washer behind the snap ring. It is press fit onto the shaft.
To my surprise the 27mm output shaft nut was finger tight.
Carefully following the factory manual's guide for the transmission rebuild will be critical to doing it properly.
I did at one point take the mainshaft to my local machine shop car parts place and they helped me compress the spring washer with a press to push the snap ring fully into its seat.
I found a guy on youtube who made a 20 part series on him rebuilding a 79 spider transmission, which was helpful to watch before getting started.
After splitting case
Shift fork rods
Mainshaft dissasbled
Re-assembling mainshaft
Worn syncro vs. new syncro
Old 3rd gear & New 3rd gear
Input shaft with 4th gear and new syncro
Steel cage needle roller bearing
Pivot fork bolt
NOS Anti-rattle clip vs. rattle clip from autoricambi which seemed to add to the rattling.
Flywheel locked in place
Flywheel resurfaced
The 2-step was maintained on the flywheel, Guy Croft says the step should be .02 thou, which it is. Machinist took .015 from friction and mounting surface. The flywheel was also sent to be rebalanced with the new pressure plate I am installing.
I removed the pilot bearing with a slide hammer puller set from Harbor Freight. The old bearing was right at the end of its life.
I pressed in the new SKF pilot bearing with a gear puller from, of course, Harbor Freight. I used a bearing and race set that I rented from Pepboys to help press it in. Pressed in really smooth, much better than trying to bang on it with anything.
Input shaft seal holder was pretty worn from throw out bearing moving across it, so it was replaced.
Transmission complete before installing
I ended up replacing 3/4 shift fork, both slider sleeves, one slider hub, needle roller bearing, 3 syncros, 3rd gear, and a small detent pin in 3/4 gear, and I flipped 5th gear syncro. I sourced NOS parts from Italy, including original bronze syncros. All the bearings where in really great shape so none were replaced.
There was no hammering or banging throughout the whole build, everything slid together smoothly, I used a couple different rubber hammers when needed, but all the bearings in the case slid in and out with little effort.
Key to the build process is to stay organized, take LOTS of photos, keep parts in bins and in relative order. Make careful note of all spacers, I found that in my diagram they said there is spacer (15) behind reverse gear, but in my gearbox it was a large bellenville washer. I also did not find ball (23) which secures the speedometer drive gear to the mainshaft when disassembling. I ended up using a small ball bearing from the steering column bearing on my 79 parts car. Fit perfectly. Everything has been reinstalled, and the engine seems to be running smoother than ever. I can't tell if it is the new trans mount or the rebalance, but it sounds great and is barely vibrating. After a couple test drives, all is great. Shifts like it did in 1983! Very happy with the result and hope this inspires others to take on this task. Questions and feedback are welcomed.
