ZF oil pump question

Can someone tell me what the pick-up and delivery points of this type ZF5 DS25 oil pump (circa 1968) are? Any other info, like whether this was a ZF or aftermarket part, would also be appreciated.
 

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Julian

Lifetime Supporter
What you show in your photograph is a speedo cable drive, onto which a 90 degree adapter would normally thread. Two types were used VDO or Veglia Borletti, one has a flat drive the other a square drive, so if looking for a cable to match be sure to get the correct matching one.

To install an oil pump (cooler) you will need to have ports drilled into the ZF, there are apparently cast boss locations to do this, although I'm not sure of their specific locations.
 
What you show in your photograph is a speedo cable drive, onto which a 90 degree adapter would normally thread. Two types were used VDO or Veglia Borletti, one has a flat drive the other a square drive, so if looking for a cable to match be sure to get the correct matching one.
Close, but not quite.

Take a look at this diagram from the Panteras by Wilkinson website:

ZF Gearbox Parts

Specifically, look at the parts #801-806; that's the speedometer drive gear and associated bits and pieces. The 90-degree drive is the unnumbered part which appears above it (and is formally listed on a separate page, here)

The piece in the photograph is actually a straight variation of the 90-degree angle drive; it's ready to have a speedometer cable attached directly to it. It's interesting; I've never seen one like that before, although I admit I haven't paid close attention to that detail on GT40 gearboxes. Could it be an original GT40 part?

The GT40 parts book shows the straight output gear etc. (also numbered #801-etc.) but nowhere does it show the adapter or the cable. So perhaps that's what you have?

To install an oil pump (cooler) you will need to have ports drilled into the ZF, there are apparently cast boss locations to do this, although I'm not sure of their specific locations.
In a GT40 application, one line is installed on the right side of the shifter mechanism case, above the shifter. It uses the threaded hole that is normally used for the oil filler plug in Pantera applications. The return line comes from a threaded hole which appears on the bottom of the shifter case, and was the drain plug for GT40s that weren't equipped with a cooler setup.

Early Pantera gearboxes (Dash-1s and early Dash-2s) have a seemingly useless hole here with a plug (on the top of the gearbox in Pantera orientation); those are there because ZF was using leftover pieces for their manufacture. Starting early in 1972, as the supply of leftover parts from the GT40/Mangusta/etc. production ran out and gearboxes were being built specifically for the Pantera, that boss was left undrilled. It's critical that this piece be drilled and tapped for a drain plug when a later Pantera gearbox is flipped over to be used in a GT40, otherwise there's no way to get the oil out!
 

Brian Magee

Supporter
Mike/Julian. If you don't need the 90 degree drive then the speedo cable fits direct to the gearbox, which is what I have done on my car. What you are looking at is a minature oil pump driven off the speedo drive. Oil lines are attached to either side but the ports don't show in the picture. The cable is then driven off the end as you can see. I have seen these on a couple of original cars.

Brian.
 
Jay-
That is exactly what the pump in my photo looks like, although without the bracket. The AN fittings on the bottom don't show up so I'll take a couple more pictures with better resolution. It appears that a hose from one port on the pump in your photo goes under the transaxle and connects to the opposite side with a banjo fitting. Is that correct? I had assumed the pump was connected directly to a heat exchanger, so I'm glad you posted the pic. Would you describe the fluid circuit?
Thanks,
John
 

Julian

Lifetime Supporter
Brian/Jay,

Thanks for the correction and photos, this is indeed new to me and in hindsight it makes sense to use the speedo drive to run a pump. With no visible ports in the originally posted photo I wrongly assumed it was a speedo gear reduction device. I wonder how efficient the oil pumps are? I assume there is a air to oil cooler in the circuit we cannot see.

Jay, you mention an M1 oil pump running from a different location, out of interest do you have photos of that animal too?
 
Jay-
Thanks for posting your photos. It appears that the pickup point would be the drain plug on the bottom of the gearcase, and the line from the pump discharge runs under the transaxle, up over the driveshaft, under the exhaust collectors, around the front of the engine and to the top of the cooler shown in the third photo. The return follows the same path, ending at the banjo connection to the side of the gearcase. It seems a circuitous routing, but I may have misinterpreted it. Is there a filter in the circuit, and do you know if there are any internal modifications to the gearbox to distribute the oil injected at the side of the box?
Thanks,
John
 

JimmyMac

Lifetime Supporter
I have now made some identical castings for this pump and intend to fit them with trochoid gerotors and sealed bearings.
Does anybody know the operating pressure and flow rate for the OEM version and would it be better to optimise it by fitting higher pressure internals?
 
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Guys,

Thanks for the clarification about the oil cooler pump--I happily stand corrected!

One thing that confuses me still. Normally you'd expect two oil lines--a gozinta, and a gozouta. But the GT40 setup seems to have three.

There is one line attached to the right side, to the cooler. There is a second line that goes from the bottom up to the pump on the left side. And a third one that goes from the pump back to the cooler.

Jay--can you explain the mechanics of this?

FWIW Lloyd Butfoy has an original gearbox from a Gulf car sitting on his shelf, it has the pump, and the line from the bottom to the pump, but the others are missing.
 
Mike,
Are you referring to the outlet drive to the speedo ?
Yes--the photos above show that there are three lines in the system, with two of them connected to the drive at the speedo gear.

I think I figured it out myself though. The pickup is at the bottom of the gearbox (the drain). A line connects that to the inlet of the pump, which pumps the fluid through the other line back to the cooler. It then passes through the cooler, and then returns to the right side of the gearbox case, near the top (using what is the filler hole when the gearbox is in Pantera orientation).
 

JimmyMac

Lifetime Supporter
John,
Your pump arrived this morning so thank you very much for your help.
I opened it this evening and to my great surprise I found that ZF was fitted with a trochoid gerotor with the exact same dimensions and geometry as the ones I had originally planned to use and I had bought several of these, albeit longer in length.
How lucky is that ?
Here is a photo of your gerotor on the left and the donor.
 

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JimmyMac,

Just my 2 cents (euro of course) regarding Grotors: When/if you plan to machine the parts, pay particular attention, cause it's probably made out of powder metal baken (don't know the english word for that), and it may be pretty hard and brittle...
It's also pretty hard to design the profiles, even with cad, there are several softawres doing it, but otherwise, pretty hard. Using cad allow to have your own design EDM cut... If you have any experience regarding designing g-rotor, I'd be really interested to hear it.
Olivier.
 
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