merc , 5 speed 717412 converting to 717.400. HELP

[mb aussie]

Hi, can anyone tell me what it is , that has to be changed out to convert a 717.402 into a 717.400. I know that the 717402 has an optical sensor for the speedo and the 717.400 has a mechanical drive, is it as simple as changing the drive shaft or must I replace the complete end housing of the tranny. Are there other options like modifying the dashboard speedo to accept optic or......... does anyone have the required parts ? I am hoping to fit this 5 speed to my 73 , 280 mercedes, also need the shift gate and linkages. thanks johnw

[Frank Reiner]

Originally Posted by mb aussie

Hi, can anyone tell me what it is , that has to be changed out to convert a 717.402 into a 717.400. I know that the 717402 has an optical sensor for the speedo and the 717.400 has a mechanical drive, is it as simple as changing the drive shaft or must I replace the complete end housing of the tranny. Are there other options like modifying the dashboard speedo to accept optic or......... does anyone have the required parts ? I am hoping to fit this 5 speed to my 73 , 280 mercedes, also need the shift gate and linkages. thanks johnw

The speedo pickup in the .402 is magnetic, not optical. There will be a toothed wheel, typically 4 teeth in MB, on the output shaft of the gearbox, and the variable reluctor (VR) pickup is inserted in the hole in the back housing.
Since the shaft for a mechanical drive is aligned off-center of the output shaft, and a mag pickup is usually aligned with the center of the output shaft, the back housing may be different between a .402 and a .400.
If Getrag, however, were clever, the mag pickup could have been made to align off-center, that is, the magnet would be on the side of the pickup body rather than the end. In such a case the back housing could be the same.
The gear to drive the mechanical speedo should interchange directly with the toothed wheel on the output shaft.

[mb aussie]

Originally Posted by Frank Reiner

The speedo pickup in the .402 is magnetic, not optical. There will be a toothed wheel, typically 4 teeth in MB, on the output shaft of the gearbox, and the variable reluctor (VR) pickup is inserted in the hole in the back housing.
Since the shaft for a mechanical drive is aligned off-center of the output shaft, and a mag pickup is usually aligned with the center of the output shaft, the back housing may be different between a .402 and a .400.
If Getrag, however, were clever, the mag pickup could have been made to align off-center, that is, the magnet would be on the side of the pickup body rather than the end. In such a case the back housing could be the same.
The gear to drive the mechanical speedo should interchange directly with the toothed wheel on the output shaft.

Thanks for your input frank, I need to get a parts listing for both gearboxes, I was hopefull in avoiding , the purchase of a new end housing.thanks again

[C.Doner]

I dont think you need the entire end piece swapped, but the removal and replacement of the speedo drive may be in order. To do that you have to r&R the tail piece. If i recall correctly the part number for the speedo drive was similar, maybe the same, to other gearboxes, even some automatics. Find the EPC that is your friend. The dealer should be of help. I have the teardown manual for help if you want it. Its for the gwagon version but it is the best book out there on these things. Only thing is the gwagon gearbox has no speedo drive, I think there is some good info for you anyway. I will try to find my paperwork on the 717.400. You would be best going to the dealer and obtaining a printout of the EPC list for the gearbox you have. You may want to get a gasket kit for it as well. Do not try to pull it apart without the manual there are some specifics to tail piece removal.

[mb aussie]

Originally Posted by C.Doner

I dont think you need the entire end piece swapped, but the removal and replacement of the speedo drive may be in order. To do that you have to r&R the tail piece. If i recall correctly the part number for the speedo drive was similar, maybe the same, to other gearboxes, even some automatics. Find the EPC that is your friend. The dealer should be of help. I have the teardown manual for help if you want it. Its for the gwagon version but it is the best book out there on these things. Only thing is the gwagon gearbox has no speedo drive, I think there is some good info for you anyway. I will try to find my paperwork on the 717.400. You would be best going to the dealer and obtaining a printout of the EPC list for the gearbox you have. You may want to get a gasket kit for it as well. Do not try to pull it apart without the manual there are some specifics to tail piece removal.

Thanks for your reply, think I will get a copy of the parts catalogue from the dealer.I hope that it is as easy as changing out the drive for the speedo as this would be a rather easy fix. Are there any tricks when removing the end housing ?