My Mercedes SL’s automatic transmission (R129) got busted recently which was a real nuisance. The gearbox is a 722.509; where the 4 speeds are hydraulic with the 5th gear being controlled electronically.
If anyone had the same issue; I had it fixed by these guys in San Po Kong, their contact details are below:-
德寶汽車維修有限公司 (Pronounced Tak Bo)
新蒲崗七寶街3 號振發工廠大廈地下B座 (Tsat Po Street is the street where these guys are)
tel : 23289222
I was really satisfied with their service because after the first round the overdrive stopped working and the 5th gear did not kick in; I took it back and they honoured their 1 year guarantee and made sure that everything was shipshape before returning the car.
Their fees were very reasonable and they charged me less than HK$ 10K for the whole thing; in England this would have costed at least 2000 GBP.
If you have transmission issues - these guys are good.