Friday, June 12, 2009

G and Reverse synchronizer

A problem that shows up in the Syncro gearbox after installing a TDI diesel is that the original bronze synchronizer rings get loose on the pins, which break and fall down in between the rotating gears.
They then end up smashing a hole in the transmission housing.

I made some stronger steel rings and brazed a bronze layer on, milled the grooves in the back side where the small springs fit in and finished the friction surface.
I then made a set of pins out of a special steel bolt and tapped internal thread in it.
The new steel synchronizer rings are then bolted to the pins with flat head Allan type bolts which have a tapered seat. I have put a small spot weld on it to prevent it from loosening itself.

I think that this problem is caused by the harsh vibrations of the TDI engine running without a dual mass flywheel, this causes the pins to loosen off in the softer bronze synchronizer rings and eventually it will break.

If you have problems shifting into Low or Reverse don't wait too long and take your transmission apart, it could self destruct within a 1000 KM.
Time will tell if this mod will work.