Putting the transmission in the car
Always be aware of the shift rod sticking down in the way of the tranny as you maneuver. I have accidentally shoved that rod up into the car a few times because I jacked up the tranny without realizing it was caught up. I’ve had to hammer the dang thing back down… : ( Go slowly and check all around.
Get the tranny lines routed around the engine (but not hooked up yet) before putting the tranny in.
Don’t forget the torque converter when putting the tranny in.
Some people put it in place and hold it with something (?) across the bell housing. I slipped it into place under the car…
The engine will be sagging with the tail end down. Line up the tranny guide posts and get those bottom bolts in place to help keep things together. Make use of the tranny jack’s adjustment knobs and get the rest of the bolts in place.
Once the bell housing bolts are in place, ignore the torque converter bolts for now… you want to be sure the tranny is going to fit and might need to pull it again… those torque converter bolts are a pain and take a lot of time to deal with. Just don’t forget to connect them when you are happy with the placement of the tranny!!!
Linkages and tranny lines are the last thing to worry about. You don’t want to be hooking these up before you are sure everything (engine, tranny, drive shaft, rear end) lines up correctly.
Before I had my cross member built I relied on the tranny jack to hold the tranny in place. I found that overnight the tranny would sag. My regular floor jack would too. For this reason don’t hook up any linkage, lines, etc. and leave them connected over night. Don’t want to pull/bend things and cause problems.
The tranny should raise up into the tunnel pretty far but should not touch the tunnel. The closest spot to the tunnel I could see was the lug (?) on the upper passenger side. I clear it with about a ¼ inch to spare.
Connect the GM style rubber mount to the bottom of the tranny. The bolt holes need to be lengthened toward the center of the mount to fit the spacing of the tranny bolt holes.
Put the speedometer line on now… it just barely clears and you’ll need to jimmy the transmission a little to get the cross member on but it should squeeze in.
Get the cross member in place and determine how many shims you might need (this assumes you use the cross member I did). I used three 1/8th shim plates. The bolts I used to mount the tranny came from donors at the junk yard.
It’s time to measure for the drive shaft shortening… Drive shaft modification
I measured a 2.5 inch difference in the length of the two transmissions. I didn’t trust my measurement and had the drive shaft cut 3” because I had read somewhere else they had shortened their even more. This turned out to be just fine, though 2.5 would have been better.
I learned that you don’t want the yoke to be too short when sticking into the transmission. The further out the shaft is the less there is to grip and drive angle issues magnify against the rear bearings in the tranny causing them to wear/fail.
For those local to Los Angeles I took my drive shaft to Wenco in Van Nuys CA. Very reasonable and quick turn around.Drive-line angle
This was a crap shoot for me and I think I lucked out.
I learned that you can measure the angle of the valve cover fore and aft and keep it up to about 3 degrees. Mine ended up at 4 degrees but it’s working.
I also measured the angle of the yoke and of the drive shaft and anything else I could figure out…
Get the cross member in place and start to work out the drive-line angle, shimming as needed. Linkages, lines, shifter
I used all of the linkages I previously had on my 727. I had to swap the two shifter levers on the 518 with the ones I had on my 727 to make this possible.
The levers on the left side of each pair is from the 727. Very similar but the A518 levers didn't fit the linkages.
There was not a lot of room for the back cooler line and the shifter linkage (from the shift rod to the arm on the tranny). I got the cooler line figured out first and had it bend up as close as possible to the floor pan so the linkage will work underneath it. Be really careful not to cross thread the cooler fitting. It’s easy to do and I had to replace one. Sigh.
I secured the shift rod with the bracket I designed and start working on the linkage to ensure clearance. My son sat in the car and worked the shifter for me so I could ensure full throw in the linkage from Park to 1st. Misc:
I learned a lot from Rory when getting things up and running again. I never understood what the kick-down linkage really did. I thought it had something to do with flooring the motor and having the gear kick down to handle it… well it’s more important than I thought.
To get the most out of your transmission and to save it from premature wear you need to be sure the kick-down linkage is correctly configured. It’s really a pressure valve which works against the throttle pressure (?) to determine the correct time to shift. When correctly setup you get the maximum out of each gear before the shift (there are other factors too) but if it’s not setup (or missing) you will foul things up in the tranny and can burn a your band and lose a gear. A friend of mine didn’t have this connected and lost shifts to second gear.
It’s a good idea to prop up the motor (block of wood and a jack) on the back half of the oil pan if the tranny is going to be out for a while.
If you still have the old fashioned boat anchor starter, now may be the time to replace it with a smaller high torque version. I found mine at (you guessed it) the junk yard for $11 and it works great!
It’s just nuts & bolts (you can do this)The swap in a nutshell
Two notches are made in the transmission case.
These are simple modifications and do not effect structural integrity.
This notch allows the transmission to fit up into the tunnel.
Looking up from below note the clearance.
Notch here to make room for the shift rod
I should have smoothed this out closer to the case. That lip has been a pain.
The steel bracket holds the rod in place. You need to fabricate this piece unless you can find something.
The cross member holds the transmission in place.
This is the key to making the whole project work.
It’s designed to provide adjustment for fit.