The 700/900 ZF steering rack rebuild thread

[940 16 valve]

Just got my hands on this good core ZF rack after searching for a couple of years. "supreme 940" saved my bacon on this one - and was an amazing seller. It looks to be in nice enough shape that it would probably be fine to run as-is for a bit, but I'm going to rebuild it before I install. Hoping to document it all here as I go. Very pleased with how things look after pulling the boots back - no water intrusion/rust on the shaft.

The nice thing with these racks is the OE Lemfoerder tie rods/ends/boots are still available.
Next up is ordering a seal kit. Please chime in if you've rebuilt a rack and put some miles on it to give your impression on the seal kit you used.

I'm trying to decide between:
Gates brand rack rebuild kit $
VP autoparts kit (https://vp-autoparts.com/en/artiklar/seal-kit-steering-rack-740-940-zf-83-92.html) apparently put together by a company in Sweden$$
Kit from Volvo $$$$$ who knows if it's actually an OE one at this point or just an aftermarket set of seals put in a Volvo box.

 

[94940]

If you find the time to continue this thread it would be appreciated. Hope your rebuild goes well.

 

[dl242gt]

I would chose VP autoparts. I've had good success with everything I've gotten from them. You could also try checking the Volvo price at Tasca.

 

[tbrcktch]

Just got my hands on this good core ZF rack after searching for a couple of years. "supreme 940" saved my bacon on this one - and was an amazing seller. It looks to be in nice enough shape that it would probably be fine to run as-is for a bit, but I'm going to rebuild it before I install. Hoping to document it all here as I go. Very pleased with how things look after pulling the boots back - no water intrusion/rust on the shaft.

The nice thing with these racks is the OE Lemfoerder tie rods/ends/boots are still available.
Next up is ordering a seal kit. Please chime in if you've rebuilt a rack and put some miles on it to give your impression on the seal kit you used.

I'm trying to decide between:
Gates brand rack rebuild kit $
VP autoparts kit (https://vp-autoparts.com/en/artiklar/seal-kit-steering-rack-740-940-zf-83-92.html) apparently put together by a company in Sweden$$
Kit from Volvo $$$$$ who knows if it's actually an OE one at this point or just an aftermarket set of seals put in a Volvo box.

I like the volvo factory seal kits, but that's all I've ever used (ZF, TRW, CAM). No problems.

 

[940 16 valve]

So I checked and the Volvo seal kit for the ZF racks is NLA, so I've ordered the VP kit.

I got to disassembly. First I made sure the rack was centered so I could make note of the orientation of the pinion for reassembly

Pulled this cover which holds a spring and piston

Next remove rubber cover on top and remove snap ring

This part was a bit nerve wracking cause the cover is NLA. I lightly tapped around the perimeter until it started to back out.

Hold pinion while undoing nut from under that cover

Another snap ring holds the bearing at the base of the pinion in

I gave the pinion the lightest tap and it came out very easily

She's out!

Bearing on the upper part of the pinon

I was thinking I would replace the bearings, but after inspecting them I can't feel any play or notchiness so I'm on the fence. The lower one is available (NTN6001) but the upper one looks like it would take some more digging to find.
A ring on the other side of the rack holds in the seal and it's carrier.

The main shaft out

And finally I drove the lower bearing for the pinion out - there's a tiny recess at the lower left that gives you a spot to tap it out without damaging it.

Bagged and tagged to keep everything clean and sorted until reassembly. Now I've got the bare rack housing to clean. It has what looks to be some undercoating on it, so I've got to figure out how I'm going to deal with that (maybe see if a machine shop can hot tank it?). Better than a bunch of corrosion though I suppose. I'm impressed with the condition of everything internal so now it's just waiting for parts!

First I ginerly tapped off this cover - its NLA as well.

 

[dl242gt]

Thanks for posting the progress of the rack rebuild.