Steering box rebuild - not quite gone to plan

[mickeyw]

A while back my 4-bolt PAS box suddenly started gushing fluid from the input shaft seals. Having borrowed a box while I rebuild mine, I started to pull it apart, armed with the green bible and a seal kit.

Now like we know, anything that's been on a LR for a while tends to be on the rusty crusty side.

First thing to remove is a whopping great internal circlip that retains the rack piston cover. Well I got that out OK, but the cover was not going anywhere. The suggested method to push it out is to turn the steering input shaft to full right lock. Clearly this wasn't going to work.

Next on the list is to remove the sector shaft adjuster nut and top cover. No problems encountered here. Rotating the sector shaft allows it to be withdrawn from from the top of the box. Now I'm not sure how necessary it is to remove the rack.

Here is a close up of the part of the shaft the lower seals run on, a regular source of leaks, but not on this box yet. This surface doesn't look great but I reckon it'll polish up.

Next to remove the worm shaft, first the adjuster lock nut needs to come off. Not the correct tool, but a large set of Stilsons worked well, and brought out the adjuster with it.

The adjuster has a square section seal in its outer diameter.

The shaft can then be gently tapped out.

[Nigelw]

How do you intend polishing up the shaft Mickey, watching this very closely as got a genuine seal kit sitting on my bench for the day I have time to pull the PAS box out and have a play.

[Nigelw]

The steering shaft, is it the same part for LHD as RHD boxes? Sorry bit techy but might be good to know the answer.

[mickeyw]

Cleaning the oil of the worm and its bearing surfaces brought an unpleasant surprise.

The front bearing outer race was in near perfect shape, as was its corresponding surface on the worm.

The rear race looked pretty good too, but the rear bearing surface of the worm was not at all pretty!

I'd thought the shaft was a little lumpy before I began dismantling the box, but I'd put it down to a lack of oil in there. I certainly wasn't expecting this though.

Further inspection of the ball race found the culprit. Check out the ball in the middle.

All the other balls on that race were perfect, I would have expected to see more damage.

The track is damaged, but I don't reckon it's been like it long judging by the fact that it doesn't go all the way around.

Also if this occurred recently it would explain the sudden extreme fluid loss. The damaged bearing would have allowed the shaft to move out of line when under load, and the aging seals would not have been able to move enough to keep the fluid in.

Unfortunately I think this is the end of the road for this particular steering box

Beyond economic repair.

[mickeyw]

The steering shaft, is it the same part for LHD as RHD boxes? Sorry bit techy but might be good to know the answer.

From what the green bible tells me I'd say that LHD and RHD boxes are opposite hand internally.

How do you intend polishing up the shaft Mickey, watching this very closely as got a genuine seal kit sitting on my bench for the day I have time to pull the PAS box out and have a play.

I was planning put it up between centres in the lathe and polish up as best as possible with some wet and dry paper. The steel will be uber hard, so it won't be possible to shift much metal, but damage can often be smoothed out enough to give the seal a better chance.

If I still had access to a cylindrical grinder I could have taken the diameter down a small amount, without being too small for the seal to work OK.

[Nigelw]

bu66er, got a perfect RHD box sitting under the bench but a leaking LHD box, also got a brand new box sitting in my spare room but am holding off fitting that until I know the seal kit has not worked out for me, oh well better think about getting the old box out and re-sealing it then, something for my next day off I think

[steve_a]

I did a rebuild on one here and when put back together it leaked from the top plate and gushed under presssure from the output shaft

[Aragorn]

tbh trying to reseal things like this just seems like an exercise in futility.

Same as putting new seals into a worn out brake master cylinder.

The parts 15+ years old and worn out, trying to tart it up with some new bits of rubber just isnt going to cut it.

[cackshifter]

Might have been possible to use a speedi sleeve

[CwazyWabbit]

Might have been possible to use a speedi sleeve

That looks to me to be a curved bearing race, do they do speedisleeves for that application? I'd have thought the pressures would just deform the thin sleeve to follow the existing damage.

[mickeyw]

No, SpeediSleeves are for restoring sealing diameters, not bearing faces, espcially radiussed ones

Last night I pulled apart another steering box that used to be fitted to my truck. this one had been leaking from the bottom, not profusely, but enough to make a mark wherever the truck was parked.

I dived in through the top cover and removed the sector shaft. Now if you look at the area the bottom seals run on (outlined in yellow), you will appreciate why just throwing new seals in tends to be unsuccessful. This area is well pitted and worn, so no point in trying to reuse or even reclaim this shaft.

Even more significantly the area outlined in red is what runs in the needle roller bearings. The surface is pretty well chewed up and a significant step is worn in the shaft.

The top bearing surface is also well worn. It can't be seen in this photo, but I'd say the box was over adjusted, as the needle rollers have left distinct markings in the shaft.

The gear teeth also look like they have had a hard life.

I think my next move is to see what state the worm shaft is in. If this looks usable I feel a game of mix n match coming on.

The box I started the thread with came from a 160k mile rangey that I broke, and the innards are in far better shape (the damage to the worm shaft bearing journal is clearly recent) than this 'reconditioned' unit that can't have been in my 90 for that many miles.

What is clear though is that when these steering boxes start to leak, it is likely that it's due to a worn bearing, permitting the shaft to move about beyond what the seal can accommodate.

[CwazyWabbit]

......

What is clear though is that when these steering boxes start to leak, it is likely that it's due to a worn bearing, permitting the shaft to move about beyond what the seal can accommodate.

So unless recon companies are replacing major components inside these boxes then you are unlikely to get a good box going that route.

[mickeyw]

Having seen the insides of THIS re-con box I would say they don't do that.

So I agree you are less likely to get a good box that way. I think many of us on here have already come to that conclusion. A new or non-leaky 2nd hand would be the options to consider.

[jbs]

Having been through the re-sealing of the PAS box route and it failing miserably(Now we know why they won't ever work properly even with a genuine seal kit) even when following the instructions to the letter with genuine seals, I ended up putting a second hand but good box on my 90-then when the new to me PAS box started leaking and I was better off money wise I decided to go to adwest and not bugger about, At least then I knew It'd work properly and I'd have some come back If nessacary, they're service was spot on and friendly people to deal with too, As much as I like to save money as we all do It's a case for me now of buying cheap-buying twice when It comes to things like this.

John

[aldus]

Hi I am a newbie here. I know this is an old thread,but I am sure that it gets looked at a lot. Now I may be wrong , but in my humble opinion steering boxes. especially power steering ones which do not have to develop the force mechanically do not have significant loading on the internal components and should not show significant wear after only150K. In my mind there are only two possibilities for this, to me, excessive wear, running the steering with low fluid levels which will cause cavitation pitting,I believe that is the correct term. The other possible reason is that Land Rover does not know,or bother to properly case harden the parts that require it. Spending the "big bucks" and getting a genuine steering box will probably only buy you approximately the same mileage you got out of the old one. I have a 95 discovery and a 74 series3 88 and I love driving them, both have manual transmissions and I love the way they drive, as long as the power steering is working in the discovery Ha Ha. But I have found many examples of shoddy engineering.

Many thanks to Mickey W for posting the great pictures Especially the "special tool" for removing the locknut. Cheers

[mickeyw]

Aldus, I'm glad you enjoyed the photos ?

The internals of these boxes take a lot of strain. The sector shaft and its bearings take the full load of steering the car, as does the rack.

The input shaft is under far less load, but it's a complex and precision assembly, and is not exempt from breakage.

Why its bearings broke up is difficult to say, but contamination with any debris could cause such damage. That is not to say that inferior metallurgy couldn't be an issue too.

[reb78]

Is this in the tech archive?? (If no, it should be)

[Shackleton]

Is there a rebuild kit available for these. I have one that I had assumed I'd have to send out to be rebuilt. It's not really leaking, there's been a weep from the seal over the arm for a long time and there's a lot of play in the steering. I could only assume it's too far gone, but all the more reason why I'd love to have a go at renewing it.

[mickeyw]

There are seal kits available, but IMO a rebuild kit for any mechanical assembly should include bearings too.

The problem we have here is that the surfaces the ball races and needle races run against are part of the shaft, thus non-replaceable.

Engineering-wise these areas nay be reclaimable, but it would be a mighty expensive job.

The bottom diameter of the sector shaft could be ground down and built up with hard chrome, before grinding back to original size.

To do the same with the radiused journals on the input shaft would be far fidlier, but not impossible with the right equipment - alas that job was years ago ?

[Les Henson]

The output shaft can be repaired in much the same way that a crankshaft journal can be - The worn part of the shaft is welded over and then machined back to the correct diameter. Not sure if a bearing track can be done in the same way, but I guess if it could it would be expensive.

Les.

[Shackleton]

Did you ever do this professionally Michael? Begs the question how are the specialists who do steering boxes as bread and butter sorting the bad boxes? I couldn't see them sending you one with the chrome works you've described above, which is probably why the reports on quality from various suppliers are so polarised.

The bearing type and races put me in mind of the exact same problem with push bike forks, there are always new bearings available but on older bikes the race shoulder is invariably toast because of brinelling. I just googled the bicycle problem and happily stumbled on this: http://www.stangerssite.com/CanISteeringBox.html

I'll pull mine apart when the time comes and see how bad it looks. Where do I look for the seals/bearings?

EDIT: as I read through that site I see that there are many things that'll render a box rubbish. I don't hold out much hope for mine if the internal parts aren't available

[Boydie]

When I rebuilt mine I had both the shafts hard chromed and then polished, by doing so it removed all the score marks that were on the shafts when I took the box apart. The hard chroming and polishing was less of a cost than trying to obtain new shafts which unless you buy the entire box - new or reconned - seem to be made from unobtainium.

[pat_pending]

Currently trying to get my drop arm off, I've had some tight ones in the past but this takes the biscuit.

I've left it in the press overnight to contemplate the stern talking to I gave it.

I've had to reinforce the framework as it was just bending the bars. I suspect it will be a job for the grinder.

Anyone got a spare Gemmer drop arm?

[western]

Anyone got a spare Gemmer drop arm?

Yes still on my old 6 bolt gemmer box.

[pat_pending]

Yes still on my old 6 bolt gemmer box.

Wont be popping that in a jiffy bag then!

The box has allways been dry, then yesterday it suddenly started leaking badly from the sector shaft seal.

I thought it might be worth a go trying a seal kit, but if I have to cut the drop arm off I may cost up fitting a 4 bolt box.