G50/20 Transaxle

[steve_d]

I recently had a starter failure which turned out to be 2 teeth missing from the ring gear. Further investigation shows that the starter pinion has been engaging only about half way into the ring gear. The factory believe this may be unique to the G50/20 6 speed ‘box.
There are 2 possible fixes.
1. A spacer behind the ring gear or a thicker gear. A thicker gear is difficult as the current ones are off the shelf items. The spacer is OK but needs to be about 4mm thick which puts the gear almost off the register that keeps it concentric with the clutch body. A secondary issue here is that the G50/20 ‘box has to have the bell housing relieved to clear the ring gear anyway so would have to have even more material removed in this case.
2. Machine 4mm from the face the starter mounts on. This is the method I have used but is not easy to do. You could lay the ‘box on its side on a milling machine and use an extra long series end mill cutter but it would be difficult to clamp down and get the face square so this was rejected.
If you stand the bell housing of the ‘box on the mill table you need a ‘fly cutter’ with a very large radius as the tail of the ‘box is getting friendly with the drive head of the mill.

There is unfortunately nothing that can be done to the starter bar a redesign with a longer pinion or pinion throw.

I have not refitted the ‘box yet but all is looking good so far so I will report if I have any more issues.

As an aside I had a splendid last evening.
After work I went to a machinist with the ‘box but it would not fit on his machine. He directed me to Jim Stokes Workshops Ltd. in my hometown. They restore vintage/veteran vehicles and manufacture vintage engines from nothing. Was advised, whilst carrying in the ‘box, not to drop it on the car we were passing as the current owner had bought it as a non-runner for £4.2M.
They did the job straight away and I left with the job complete at 7PM. Whilst the guy was doing the job I was shown around the rest of the workshop containing 20 odd cars in various states of rebuild. I think going to work there would be rather pleasant.

Steve

[milesallen]

Hi,
Im not sure if you are allowed to post other threads on threads, please tell me if you aren’t, however I feel you could be just the person to answer some of my question! If possible could you take a look?

many thanks


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