300 SL-24 gearbox swap?

[bombhead]

I'm posting this on behalf of my non-internet mate who has a 1993 R129 300 SL-24v with 5-speed auto tansmission. It has a few issues with the tranny such as hanging onto gears too long and not kicking down.

He's now got ideas of binning this transmission in favour of a manual from an SL (or other model?) assuming that sorting his auto will be prohibitively expensive..

The questions to the large brains on the forum are, any ideas what the current transmission problem could be and is it relatively affordable to fix? And, secondly, is there only the corresponding 5-speed manual SL transmission that would fit if indeed the current auto needed binning or do other Merc 'boxes fit?

Cheers, Bombhead

 

[Ady1983]

Problem could be Fluid, Pressure cable Or something worse like Bands... To have the box reconditioned is about £1200, good second hand one £350 ish, what’s the mileage??

I know of a 5 speed Dog leg manual 24 Valve, but I am not sure if that was standard fit for any of the 300-24 so it is possible but not sure of the work involved...

 

[Hibbo]

Holding on to gears too long is normally a vacuum leak or pressure control cable (aka kickdown cable) adjustment issue.

The 'no kickdown' issue is strange, although it could just be that the 'box won't kick down as it's still in the lower gear it would kick down to. If that makes sense!

 

[television]

No kick down on 124 and SLs should be the fuel pump relay open circuit on one of the PCB tracks, bridge the track with a thin piece of copper wire soldered on over the break.

For the rest, As Hibbo, vacuum problems