3 speed gearbox synchroniser problem

[DutchEdwin]

I did the gearbox today, had to remove the rear main shaft seal. Did get that one out without any problem. But when I turned the gearbox over after I let all the oil out I heard KLING-KLONG from the inside NOT GOOD. So I opened the gear box by removing the gearshift housing. Looking closer I could see pins lying at the bottom. It seems all three pins from the synchronizer stop ring inner had snapped off (see picures). So the question is,

1) How do I get to the stop ring.

2) where do I find a replacement. If there is no replacement, I can try to remake it by perhaps press out the old sheared off ones and make new pins.

To explain the pictures,

1) the gearbox, 3 speed from 1955 plymouth.

2) the inside, when the gearshift housing is removed, showing the pin of the outer synchronizer.

3) close up pin of outer synchronizer

4) 3 recovered pins out of the gearbox

5) the drawing from the service manual

6) In the next mail, the exploded view of the 3 speed gearbox

[DutchEdwin]

6) the exploded view of the 3 speed gearbox

In the centre the synchronizer.

[blueskies]

1) How do I get to the stop ring.

2) where do I find a replacement. If there is no replacement, I can try to remake it by perhaps press out the old sheared off ones and make new pins.

Edwin-

My tranny is a '55 also, but is the overdrive version. Mine has the same pin-type synchro. Mine had a broken outer stop ring, the part with the teeth, not the pins. I was able to buy a new one from Idaho Transmission Warehouse, 800-225-6568 Here's a pic of the assembly just before it went back together.

Unfortunately, the only way to get to the synchro is to seperate the tail shaft from the body, and pull the main shaft out of the case. The synchro can not be access from the front of the case.

If you are going to go this far, you might as well buy the small parts kit while you are at it, and replace the bearings and seals... Not sure how the pins came off from the ring, but it would make me suspect that something is amis with the synchro, maybe the outer stop rings are stuck causing it to bind or shear the pins from the ring. There may be bits of metal in there as a result, which you wouldn't want finding a home in the bearings.

Sorry if it's not the answer you wanted:(. T

Pete

[DutchEdwin]

Pete,

Thanks for the info. I'll contact them. Did find them at http://www.westerntransmission.com/exp.htm.

When I'm at it, I wonder, would it be expensive to go over to an overdrive transmission? In the manual I can see the rear end is different.

Any idea what all has to be changed, and to what cost?

Can I stick to the steeringwheel shift?

Last but not least, where do you find an overdrive trans for a 1955 plymouth.

[blueskies]

When I'm at it, I wonder, would it be expensive to go over to an overdrive transmission?

The overdrives are much more expensive, especially if they have already been rebuilt. I think George Asche is selling them, somewhere in the $1200 range. I have about $700 into mine along with the sweat equity.

In the manual I can see the rear end is different.

The trans case is different too, not just the tail shaft. The reverse shift rail extends from the tranny case into the overdrive case, preventing the overdrive from enguaging when in reverse.

Any idea what all has to be changed, and to what cost?

Unfortunately, the entire tranny has to be changed, but it is a direct swap for the three speed on most cars. It's my opinion, that if you are going to rebuild a tranny, it might as well be an overdrive. There is no point in throwing money at a plain three speed when the overdrive will bring your car to life in ways you never thought possible.

Can I stick to the steeringwheel shift?

All of the shift linkages are the same for either tranny, so no changes there. You do have to add the lock out cable and electrics to make the OD function, but that's not difficult.

Last but not least, where do you find an overdrive trans for a 1955 plymouth.

I found mine in a junk yard in Montana using an online junkyard search engine. I paid about $350 for it, shipped to my door. I have another few hundred in it for to replace the damaged parts, small parts kit for the rebuild, the electrics, and cable. There is a step by step of the rebuild on my site if you want to check it out.

If I can help out in any way with your rebuild, let me know...

Pete

[DutchEdwin]

Unfortunately, the entire tranny has to be changed, but it is a direct swap for the three speed on most cars. It's my opinion, that if you are going to rebuild a tranny, it might as well be an overdrive. There is no point in throwing money at a plain three speed when the overdrive will bring your car to life in ways you never thought possible.

If I can help out in any way with your rebuild, let me know...

Pete

Wow, sounds like a new $$$$ project to me.

I'll look into yours and see what you did.

Your right about getting an overdrive when you will have to do the tranny. But for now I would like to get my car up and running. The rebuilding of my engine did and does cost $$$$$$ So if I can just replace the synchronizer ring assy I think I'll just do that. The gears all look good. I did drive the car, and it did shift with no problem at that moment.

I wonder if all could go right if I just clean it all out the get rid of the remaining metal chips inside, place a magnet inside to trap the loose chips I didn't find and just drive 1000-2000 miles and than do the tranny overdrive thing.

I wouldn't want to harm the clutch and crank. The tranny may be hurt. It will be yunk after all when I swap. Sending it to the US for exchange (return core? you call it in english?) is simply to expensive from europe.

[vanbuskirk]

I bought a used overdrive transmission from Jerry Fletcher of Nebraska. I agreed to buy after he assured me that the transmission was good. It was delivered to me at a Plymouth Meet by a third party. When I inspected the transmission at home, I found that the 3-speed part of the transmission was junk, with badly damaged gears. I used my original transmission from the '54 Plymouth to piece together a good transmission from 2 transmissions. It works fine now, but I initially made 2 mistakes: 1. There is a connector tube that feeds lubricant to the overdrive section from the 3-speed section that I left out, and 2. The detent spring for first-reverse is shorter and stronger for the overdrive transmission. I used the wrong spring, and the transmission would not stay in reverse. The 3-speed part of the transmission is the same for both regular and overdrive transmissions. Bob