Mk10 power steering issues

Thanks very much.
Yes, the conversion is complete and your old box worked out splendidly. I’ve talked to Dale about getting together and documenting the conversion of the 3.8 from Burman to Varimatic for future reference, but have not had time yet. I have not had a ride in it yet. The 3.8 beam requires drilling of one hole, I believe adding a bolt where there was previously a stud.

I changed out the power steering pump today, rebuilt Saginaw. Not too bad a job, does require reusing the pulley and studs for the bracketry, the return pipe was a little different, but bent a tad to accommodate the bracket.
Unfortunately, did not solve the problem, which seems to only occur when the car is fully warmed up. I don’t see any other option than to have the Varimatic gone through. Will report back in a few weeks.

dont totally discount the hoses, I have had my HP hose rebuilt using the original fittings and replaced the return hose.

Most every part on these cars need dong after 50+ years

Good thought. Pirtek did mine on the XJ6. Silver soldered my couplings to modern compression fittings and made up a hose. Old one was leaking and delaminating internally.

I was planning to do the hoses while the steering box is away, but it would be interesting to see if that solved the problem, so maybe I will do them first. It’s definitely something exaggerated by heat, as the steering seems fine when cold. I do have a good local resource for making the high pressure hose.

with your skills Ron, tbh, after the hoses, I would just follow this and rebuild your box yourself

Adwest steering rebuild youtubes MKX-420G-420-Daimler - Saloons - Jag-lovers Forums

The Landrover has the same internal seal kits, and they are much cheaper

On the Adwest box, there is also a big screw with a 1" long slot, anchored by an allen key

This presses the rack up against the worm, and may be too tight

If all else fails, and the centre junction of the worm and rack were they take the most wear (in centre position), can apparently be built up with hard chrome and machined

Thanks for the compliment and I’m tempted, but because of the possibility that it may need plating or replacement of internal parts, I’m going to send it off. I talked to George at PS Systems this morning and they are pretty reasonable for their service, plus they can pressure test the unit, send out parts for plating if needed, and they have a very fast turn-around. George said that the symptoms I’m having could be due to bad seals in the control box. I’ll be away this week, so I’ll send it off next week.

On talking with PS Systems, I found that their address has changed slightly, now

1184 NW 163rd Dr

same physical location.

I will be interested what they find

I read a scary post (on this forum) about these Adwest boxes in the larger Jags, and thats is, according to the author, the Sector shaft is known to snap in half, he claimed to have seen several examples, so it would be a good idea to mention this and ask to have it crack-tested

Their is more play than I want in my replacement steering box

It has taken awhile to get the necessary tasks done, but here is follow-up.

I sent the steering box to PS Systems in Miami. Jorge seemed very knowledgeable, remembered the one they recently rebuilt for the local museum here, and promised to test my Varimatic thoroughly. He put it on their test machine for one hour and could not get it to fail. I had them tear it down and rebuild it anyway - btw, they crack-tested the shaft for me and it was fine. In fact, they said the inside of the box looked very good. It got delayed in transit because of the hurricane down there (I was sweating bullets, as I don’t know where I’d get another LHD box), but I did finally get it and reinstalled it last week.

Unfortunately, I still have the problem, perhaps a bit improved, although I didn’t go for a long, hot drive like before. The power to the steering at slow speeds or stopped will sometimes drop but comes back after reversing the wheel, and might stop again in a different place. At high speed, where the assist isn’t doing anything anyways, it’s fine, and the car drives pretty well overall.

I though one of the ball joints might be a little tight, so I put a shim back in, and the suspension moves freely by hand with the front end jacked-up under the lower a-arms, made no difference.

I was going to have my local hose specialist redo the hoses, but he looked at them and said the high pressure line had been rebuilt and didn’t need it, didn’t want to do it.

I still think it’s the steering box control unit, but I don’t know what else to do. If I ever find another box, I’ll buy it. For now I’m going to drive it (although other things continue to break) - maybe it will free up. Jorge did mention that there is a check valve in the Saginaw pump that can be sticky. I think it’s pretty unlikely that two different pumps, the latest one rebuilt would have the same problem, but I might tear one down to look at that.

500+$ later, Any other suggestions?

There is a complex valve mechanism with “trim screw” that the manual says not to take apart. I believe in a discussion with the late, learned Andrew Waugh, he said he took this apart and found a cut seal. May be worth discussing this issue with your rebuilder

One test you can try, referring to my earlier issue (too much play)

I have tighted up both the 1" sunken screw, and top adjuster locked screw as much as possible, and while it has reduced play, there is still more than I want

I was able to tell this (on my own) my laying under the car, and turning the lower column, whilst observing both the sector shaft, and Pitman Arm

I can see that the sector shaft moves a bit before the Pitman arm

This means there presumably must be wear inside the box

Translates to about 1-2" freeplay at steering wheel

Not saying thats your issue, but you should check this anyway imo

I have a 3rd RHD box, I will do some experiments with the other 2 outside the car, using multigrips to turn the sector shaft

I have inner and outer rebuild seal kits

further investigations will be carried out, I believe there are shims in the box

Having a helper turn the steering wheel while laying underneath, even with an engine stethoscope on the box, may help you identify an issue

Well, it sounds like you might have some significant internal wear in your boxes. Not so in mine, which is nicely snug, and the rebuilder said the internals looked fine. I do intend to call him again, but I don’t expect any revelations. I’m not sending it back at this point.