Power Steering Pump

[JSBriggs]

Has anyone upgraded the pump to somthing more durable (ie domestic) Mine has developed an ominous groan, and it leaks a bit. My box is fine, it has been recently rebuilt with upgraded seals. Jst starting to look at my options.

-Jeff Briggs

[Way]

Greg Jevne has....

[Old Scout]

Hey WAY nice BOX, but Briggs is looking for a PUMP

[RockRover]

I bought a Lee Manufacturing pump...Same dimensions as the rover crap. I'll get some pics soon. Lee's known for their pumps.

--D

[Way]

Oops. Replied to quickly! Well enjoy the pic of the box!

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Hey WAY nice BOX, but Briggs is looking for a PUMP
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[JSBriggs]

I know this is an old thread,but my pump is making more and more noise as time goes by.
I have been waiting to see how Paul's saginaw goes, and will probably go that route. In the meantime, RockRover did you ever find pics of that Lee Manufacturing pump.

-Jeff

[Serious One]

Jeff,

Yours is on your '90 rr right?

I had to replace the one on the Falcon and the replacement unit, although factory LR, is indeed a Saginaw pump.

Same replacement part no., but probably a superior pump.

I have a new one in the shop if you want to look at it.

Isn't someone playing with the idea of putting the 'canned ham' type of pump on the LR block?

[PTSchram]

Gentlemen:
This is what appears to be a fairly straightforward and might even be a simple swap. Quite unfortunately, I have corrected the problem with my ZF pump and have far too many paying customer's vehicles to be finished before I can get back to this project. That said, I do have quite a bit of the background work already done.

Some of the following comments are based upon observations and ballpark measurements, however, I'm open to assisting others with this until such time as I can mass-produce the kit to do the swap.

The edge of the serpentine belt pulley is approximately 5-1/8" from the mounting face of the block. When using the Saginaw pump, one will need to space the pump forward on the block approximately 1-3/8" (the Saginaw pump is shallower than the ZF). I propose that one would make a plate that would bolt to the block out of 1/2" aluminum plate. Next, a mating plate would be made with provisions to bolt the two together from the front of the engine (bolt first plate to engine, bolt second plate to first). Using screws going from behind the second plate, one would drill holes to mount the Saginaw pump to the plate with ~3/8" spacers. The Saginaw pumps I have seen have provisions for mounting from the front or the back, however it is my opinion that mounting from the rear would be more robust. The plumbing fittings are compatible as is, although you might wish to invest in new flare fittings with swivels to allow for flexibility in mounting and assembly. Oops, the return line on some Saginaws is only 1/2", while on the ZF, it is 5/8". This shouldn't be a problem as the return line is at or near atmospheric pressure so one could fairly easily manipulate this to make it match.

The pulleys... The ZF uses a three hole flange that presses onto the shaft and the pulley is held onto the flange by three short bolts. The Saginaw uses a pressed on pulley. The shaft sizes of both appears to be identical, leading me to believe that the ZF flange could be pressed onto the Saginaw pump and the original Rover pulley utilized. I have not had any success in finding a GM pulley that will mate to the Rover belt.

The Saginaw has an integral reservoir, hence the original reservoir could be abandoned, making more room for your secondary battery.

The ZF develops approximately 1100 PSI, while the Saginaw develops a supposed ~1450-1500 psi. Some have indicated a need for a pressure reducing mechanism to keep from blowing the seals on the box, however, others who have actually done the conversion inform me this is not a concern. If one were to go the full route, the Saginaw gearbox can clearly withstand the pressure generateed by its mating pump. I do not have specs for displacement per revolution of the pump shaft for the Saginaw, but the ZF appears to displace about 4-5 mls per rev.

I haveexamples of each type of pump and a Saginaw gearbox should anyone wish to have photos. I also have a spare mounting bracket from the ZF that I will be using to make templates for the mounting plates, but if I were to make templates or mounting plates, that might get into the point where I would wish to be compensated. I might be cajoled into making measurements though if one were willing to share their research notes with me, too.

I made a phone call this morning to begin making arrangements to build a 100" hybrid that among other things will almost certainly include full Saginaw steering gear. Stay tuned, it might be done in the next five years! Oh yeah, should I extend an 88", or shorten a 109" body?

Hope this helps. I'm really pretty excited by the prospects this conversion offers and encourage anyone with comments or suggestions to keep the conversation going. Someday, this will be as common as using John Deere wheel bearings in a Rover!

My lawyer makes me say this: I can't be responsible for something you do to your truck. If I do it to your truck, I have insurance!

Paul