1939 Gearbox Removal

[Guest Grant Magrath]

Well, that was an interesting morning! Removing the coupe's gearbox! Thanks to Owen C. for his tips, it went seamlessly. Now to tear down and inspect. Seemed like a good time to do it since the steering box is out getting a new worm gear made. Here's what we did after jacking the car up on axle stands under the frame so the rear wheels didn't have much weight on them....

1. Remove front mat and center floor cover.

2. Remove speedo cable and gear linkages from gearbox.

3. Undo 4 bolts holding torque tube to rear of gearbox.

4. Undo nuts on rear shock links and push shock arms up to clear trailing arms.

5. Undo handbrake cable adjusting nut by diff and let it hang.

6. Remove handbrake outer cable retaining clip (looks like a brake hose clip)

7. Undo brake hose from brake line in center of car, removing retaining clip as well.

8. Undo nuts holding torque ball to frame. The nuts are on the inside of the frame facing the torque ball. Don't undo the outer ones with the locknuts!

9. Remove 4 nuts and bolts that hold the rubber insulated frame mountings of the torque ball, and remove mountings, marking them left and right. These can affect rear axle alignment, and should go back as they came out.

10. Undo rear axle torsion bar from axle, and push up.

11. Pull diff and axles back so torque tube moves far enough back for gearbox to clear. For this step, I used 2 light ratchet tie downs around each side of the diff, and looped up around the bumper irons. I slowly ratcheted each side at the same time, noting how the wheels were moving back, and taking care not to put too much pressure on the roll pan under the trunk.

12. Remove 4 bolts that hold gearbox to bell housing, and pull gearbox back, and lower down.

13. Enjoy a St Patrick's Day beer!

Needless to say, chock the front wheels, and take all the usual safety precautions while under your car. It's possible I may have left something out, so feel free to point anything out!

Cheers

Grant

[danhar1960]

G'day Grant,

What was wrong with the box to warrant removing it ??

Danny

[Guest Grant Magrath]

Danny, a bit of a noise changing from 2nd to 3rd. And a whine in 1st. I wouldn't have a clue when it comes to gearboxes, so our friend, Owen, is checking it over. Found a worn shaft so far. The gears themselves don't look too bad.

Cheers

Grant

[danhar1960]

I think the whine in 1st is pretty normal as long as it's not a bearing grinding whine. Every car I've had with non syncro 1st had an annoying whine. Were you running the correct weight oil ?? Running a heavier grade oil can stuff up the syncros and stop them from working properly. Got to see all that when I did a lot of prototyping work way back when. At least there are always parts available on ebay for the '39. I managed years ago to score NOS nearly all the internals for my box. It was a bit weird how I came across them.

Danny

[1939_Buick]

I,,, I managed years ago to score NOS nearly all the internals for my box. It was a bit weird how I came across them

OK:- what is the weird story ?

Over many years have been buying 39 internals. Still need the synchros

[danhar1960]

Ok, seeing that you asked. :)

When I first got my '39, I took the top cover off the box only to find that water had got into it and the bottom of the cluster and reverse idler had rusted. No internet back then and I had never heard on Hemmings. No real help for parts around here so the search was on. Talking with a friend one day he told me of his father's farm that had a neighbour that he thought had an old Buick sitting way down in his back paddock. I rang the neighbour that confirmed it was a Buick but he thought it was a '40s. He wasn't sure of the year but said he was happy for me to have what ever I could use for a few bucks. He said the car was partially buried and would need to be dug out as it had sat there so long that it was sinking into the ground. We drove the few hours to get there with a trailer load of tools all psyched up that the box was going to be good and that we'd be spending the day digging to get the old girl out. When we got there it was obvious he was right about needing to dig it out. It was a '46 and was totally complete but was also totally rusted. The farmer went off and left me and my mate with the car. We got into it and decided to have a look through it before we took the top of the box off to see if the internals we OK. On the back seat was a box full of NOS parts still in there original boxes and covered in the protective coatings. It was all the bearings and gears, syncros, etc to rebuild the box. The only thing not there was the input and output shafts. There was also all the bearings for the diff and axles, along with a heap of various other new parts. Carby kits, ignition parts........ The guy had said we could have the whole car for $100 bucks so we didn't even bother with the gearbox in the car although we did strip a lot of other parts from the car to be resold.

We went up to his house to pay him where he had just finished reloading a couple of hundred rounds for his 357 magnum. He invited us down to the paddock and let us blast away on some old drums. I'm normally an old rifle bloke but hand guns are quite fun.

All in all, it was a good day's outing.

Danny

[Guest Grant Magrath]

That is a pretty cool story Danny!

Tried different weight oil. No go. And the whine is quite loud in 1st compared to Ross Woodbury's 39 sedan. It's ok from 1st to 2nd, but will graunch from 2nd to 3rd. 3rd to 2nd is smooth. Reverse is slightly noisy as well. And it jumped out of gear on hills as well. Forgot to mention that before.

Cheers

Grant