ZF Steering Box Removal

[californiabristol]

The Pitman arm is finally off of the Pitman shaft from the ZF steering box.
The 4 bolts under the box have also been removed. The box is still fixed
to the sub-frame. Does anyone know the proper procedure to separate
the steering box from the sub-frame?

Thanks,

Greg

[GOFFJASON]

When you removed the ZF steering box, did you carry out any sort of refurbishment of the unit? I have a reasonable amount of slack in the steering column with the engine off (possibly moves through 5 to 10 degrees). Can this be adjusted out at all?

[californiabristol]

Sorry, but I have yet to remove the steering box from the sub frame.
I did email ZF Germany's "oldtimer" department but got no response.
There are authorized ZF specialists in various countries, and I plan to contact
the firm in the U.S. for service advice once the box is removed.
Peter Campbell at SLJ may be able to advise you also if you get no response through the forums. Maybe Bristol Cars can help.

Good luck,
Greg

tradition@zf.com
ZF Friedrichshafen AG | Oldtimer replacement parts

PETER CAMPBELL
Managing Director
Spencer Lane-Jones Ltd
Tel: 01985 847133
Email: office@spencer-lj.com
Web: Home - Spencer Lane-Jones

[californiabristol]

Peter Campbell of Spencer Lane-Jones kindly replied:

Dear Greg,

Sounds as though you are nearly there. Presume column and steering arm are
removed. Box should then come out. We do find boxes can corrode into the
mounting on the front cross member. We normally remove the radiator and
secure a long tie-bar to the horizontal surface on the top of the box. This
then provides leverage to "work" the whole box side to side in order to
release it from its housing.

Thanks again Peter!

[californiabristol]

The latest efforts to remove the ZF steering box have failed. A colleague
was convinced that a chisel gun working on a specially made steel cup tool
pressed up to the bottom of the Pittman shaft housing would crack any corrosion and free the stubborn steering box from the front sub-frame/cross member. This did not work. Sledge hammer blows on the same cup tool
also had no effect. We also tried a long bar to rotate the box. The sub-frame was clamped to a large welding table. Again, no movement was achieved.
as
The failure of the last method, might suggest some other issue beyond severe "rust welding." This is just speculation, however. So our next plan is to torch the sleeve on the sub-frame surrounding the Pittman shaft with the hope that this will cause enough expansion to separate the parts. I am concerned about possible damage to the steering box, particularly seals.

Before I continue, I want to get any advice, and any photographs of the ZF box separated from the frame. I also want to confirm that the ZF box is secured to the frame with only the 4 bolts mounted through the bottom of the steering box platform on the subframe.

Any help will be greatly appreciated.

Greg Woog

[californiabristol]

The Zf steering box was finally removed, most likely incorrectly. The photo shows the current state with a spacer ring still connected to the steering box at the end of the Pittman shaft. I created a cross section drawing showing the original condition. It seems like the "ring" was actually part of the sub-frame, but it ended up stuck onto the steering box. This necessitated removing the lip
at the top of the sub-frame tube in order to free the steering box.

If anyone can clarify the actual mounting design or has an image of the
the steering box and sub-frame separated please reply!

Thanks,
Greg