Does anyone know the ins and outs of matching power steering pumps to steering gearboxes?

This winter (and likely spring and summer) I'll be installing a VW TDI engine in a 1984 W123 wagon. I'd like to retain the nice load-leveling rear suspension, but of course the VW engine does not have the head-mounted hydraulic pump of the OM617.

I'm therefore looking at the tandem pumps used on the later cars. Obviously a good deal of fabrication will be required to get one of these pumps to package and work with the VW accessory drive, but the real worry for me is that the hydraulics match up.

I took a look at www.mbpumps.com and see that the pressures for the W124 pumps are considerably higher than that of the W123. Do you think the combination of W124 pump and W123 steering box will work?

Any advice is much appreciated!

Ted

__________________
1983 240D automatic, Orient Red, 174K
1983 240D manual, Biscayne Blue, sold at 341K

The pump pressure ratings are for MAX pressure output. 65bar is a common max pressure for MB pumps & that only happens when you hold the steering at LOCK either right or left. Doubt if any pump stays at max for over a few seconds at any time!

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Thanks -- so do you think it will work?!


Ted

__________________
1983 240D automatic, Orient Red, 174K
1983 240D manual, Biscayne Blue, sold at 341K

interesting!how did you work out the driveline?specifically going from frontwheel drive with transaxle to rear wheel drive in the 123

Well, it's not completely worked out yet but looks like it will fit. Of course the VW engine will go north-south like the original 617.952. I have the european 5-speed manual transmission already; am still looking for an engine. Interestingly, the clutch disc diameter is identical to the TDI, so I hope to be able to use the nice VW dual-mass flywheel (very good NVH) with pressure plate and the M-B disc. Obviously a custom adapter plate will be needed.


The engine will need a Passat 1.8T or maybe Audi Fox oil pan to clear the crossmember. Custom motor mounts will be required. I plan to make them out of wood and have someone who knows how to weld do it right.

Then there's the wiring -- as you might know the VW engine is drive-by-wire so I'll have to install an electronic pedal. Then the intercooler.... But the good news is that the cruise control is inside the ECU and much more reliable than the Benz system!

Wish me luck -- I'm going to need it! I will document the process here and at TDIclub.com for sure.

Ted

__________________
1983 240D automatic, Orient Red, 174K
1983 240D manual, Biscayne Blue, sold at 341K