Tips on rebuilding a 3 bolt steering box

[85 county]

With the cost of fitting a 4 bolt including purchase and mucking about being about a grand. I decided to looking into rebuilding my 3 bolt.

Now having been told that it will cost about 600-700 to have it rebuilt I was then quite surprised that a seal kit only cost about 37 bucks delivered.

There must be some great trick in all this??

Anyway as I had a few laying about the place, I ripped the first one down.

Now the best I can sort out is that there are 3 different 3 bolts. Different lower seals and different piston and valve sizes however they don’t differ in any other way, just parts are not interchangeable.

The seal kit will fit two of the boxes but not the third, this is with the one with the smaller valveing, so to be honest I would just dump this box.

The other two are identified as having different external pipe, one is horizontal and the other has an angled fitting at the bottom. Horizontal like a 4 bolt

What I would do that is different to the book on rebuilding.
1 with the box out, I would back off the rack backing plate, this is the big screw with a grub screw holding it in place, 2 turns is enough
2 Back off or actually tighten the worm adjustment bolt on the top of the box a couple of turns. You will see the bottom of the shaft or spline where the pitman bolts on recede into the box a couple of mm.
3 Remove the lower seals ( pitman arm again) no if there is any slop side to side in this shaft you will probably have shaft wear as well as bush wear. Just get another box. I actually made up some sinderd bronze and machined down the shaft and then hard chromed and ground, (but I know what I am doing) to be honest this is way over the top.
4 Reassembly is as per the book. BUT I would fit the steering input shaft seals last as with the pitman shaft seals last. Not first as the book says. It’s just to hard mainly the searing shaft because you also have the 3 valve seals to get in.
5 Valve seals, easy or a pain. Hot water for the seals so thay streach over expressly the first one that has to hop over the first two. Then let them sit for a few hours to go back into shape. Now they can be a bit of a tight fit, so I left my one in the freezer for a couple of hours to shrink and harden them up then it was a breeze.


That’s it all rather simple really.

I pulled down a 4 bolt, apart from having more bits to replace I was disappointed that the bottom bush is only about ½ the length of the 3 bolt. Since this is where all the torque from steering is applied I would sagest that the 4 bolt is actually weaker than a 3 bolt. Though it has got a better bottom seal.

[clubagreenie]

The three bolt will almost certainly have bushes in it (as opposed to bearings of the later ones). Anyone worth having do the job will bore it out and fit bearings. Then if the shaft is damaged, usually around the bottom where the lower seal and dust seal are (water/dirt get between the two and it rusts) then it'll need to be ground and re-chromed. Not cheap.

The 4 Bolt is better as it has the bearings in it shouldn't see anywhere near the force. You have a 4 bolt by the sound of the last paragraph? I'd be rebuilding it, far less work should need to be done, even if the shaft needs chroming.

[85 county]

The three bolt will almost certainly have bushes in it (as opposed to bearings of the later ones). Anyone worth having do the job will bore it out and fit bearings. Then if the shaft is damaged, usually around the bottom where the lower seal and dust seal are (water/dirt get between the two and it rusts) then it'll need to be ground and re-chromed. Not cheap.

The 4 Bolt is better as it has the bearings in it shouldn't see anywhere near the force. You have a 4 bolt by the sound of the last paragraph? I'd be rebuilding it, far less work should need to be done, even if the shaft needs chroming.

There is little difference between the 3 and 4 bolt. the 4 bolt has a few more bits in it and is quite a bit harder to rebuild, its actually a pain and fiddly, apart from the very old 3 bolt, the 3 other main components apart from the housing almost fit inside a 4 bolt, apart from valveing there is very little difference.
As for dirt getting in the lower seal, I doubt this will happen since the body of the box is under pressure constantly.

There are no more bearings in a 4 bolt and a 3 bolt. my concern is the steering shaft IE the one with the pitman arm is has a shorter bush than the 3 bolt. Since this is where the majority of torque will be applied, the reduced surface area of the 4 bolt with indicates that it may be weaker than the 4 bolt. However it has a much better seal on the bottom, and much better than the older box with the chevron packing, those ones can just go in the bin.

Hard chroming cost 120, all the machining I did myself, but with the abundance of 3 bolt boxes laying about the place in addition to every one following the sheep trend of swapping out for 4 bolts. When in reality 1 day and 35 bucks will do the job (including dropping out and refitting). Add 30min if its an Isuzu.

[isuzutoo-eh]

Any comments on the quality of the steering response? I have heard that the 3 bolt is vague compared to the 4 bolt, but that could be a comparison of a worn 3 bolt to fresh 4 bolt.

[85 county]

Any comments on the quality of the steering response? I have heard that the 3 bolt is vague compared to the 4 bolt, but that could be a comparison of a worn 3 bolt to fresh 4 bolt.


i think the last part off your comment may be more often the case. but also harder for me to qualify.

the first box with the chevron packing's and the smaller pistons actually seemed about the same as the latter box i took out. but had light steering but a slow return, the piston seals looked ok when i ripped it down.

the last carnation of the 3 bolt feels the same as a 4 bolt to me.
But, diffident 110s all feel diffident ride height tiers etc all have an effect.

what i am trying to say is. for the cost i doubt that swapping to a 4 bolt is better than a 3 bolt

[AdsLandies]

What usually causes the vagueness? Mine still feels vague after changing all the suspension bushes and tie rod ends. Steering box shaft has no sideways or up-down play, and drop arm isnt loose. Im thinking its something internal. Any ideas?

[85 county]

What usually causes the vagueness? Mine still feels vague after changing all the suspension bushes and tie rod ends. Steering box shaft has no sideways or up-down play, and drop arm isnt loose. Im thinking its something internal. Any ideas?

if your sure every thing is tight, then i would still check Rocco?? bushes wheel bearings, and pan-hand rod. the one from the chassis to the dif ( front)
wheel aliment and choice of tiers and pressures.

check every thing again. pump up the rubber say 50psi. play around with alinement, say from 1mm out to 1mm in at the rim

[isuzurover]

FWIW - I bought a NEW 4-bolt box recently - with new drop arm fitted.


Sent: Tuesday, 17 April 2012 6:04 AM

...

Hi Ben,
Thanks for your enquiry,
We have a brand new Genuine Power Steering Box in stock for your vehicle.
The price is $650.00 inc GST (not including freight)

...

Regards,

David Harris
Parts Sales Manager
All Four x 4 Spares
david@allfourx4.com.au
All Four x 4 Spares - Home (http://www.allfourx4.com.au)
Phone: 02 4957 1117
Fax: 02 4957 3237

[85 county]

that's a good price, i have never seen them that cheep,

now all you have to do is drill out your chassis, and change the ends of your oil lines

[isuzurover]

that's a good price, i have never seen them that cheep,

now all you have to do is drill out your chassis, and change the ends of your oil lines


No I don't, I was replacing a 4-bolt.

[isuzutoo-eh]

I didn't have to drill out the chassis when changing box type. Just hoses.

[AdsLandies]

Thanks for your comments before 85county. How did you set up the adjuster on the side of the steering box after rebuilding it? Im tempted to try and see if changing the setting on this will tighten up the box, but dont want to stuff up anything else at the same time. BTW have checked pretty much everything you suggested, including different wheel alignments but with little benefit. Not keen to just get another box yet - knowing my luck the vagueness will still be there.

[Dougal]

It's the top adjuster that sets the free-play. It loads the sector shaft (main shaft) against the worm that turns it.
Too tight and you can get binding and wear, too loose and you get play.

If you have play with the adjuster up tight, then you've got loose bushings either in the top or bottom of the box. Loose bushings in the bottom are easy to spot, it'll **** oil. The top bushing can be replaced with a DU bushing for a few dollars that is exactly the right size. It took my 3 bolt from being awful, to being quite good.

3 bolt boxes have only bushings supporting the sector shaft, no bearings. 4 bolt have bearings.

[85 county]

Thanks for your comments before 85county. How did you set up the adjuster on the side of the steering box after rebuilding it? Im tempted to try and see if changing the setting on this will tighten up the box, but dont want to stuff up anything else at the same time. BTW have checked pretty much everything you suggested, including different wheel alignments but with little benefit. Not keen to just get another box yet - knowing my luck the vagueness will still be there.

As dougal has commented above but that’s only 1/2 the story.

On the top of the box there are two bolts, well 1 bolt and a thread and nut. The nut is just a lock nut. the thread is taped in the top of the box ( housing) so winding this screw out lifts the main steering shaft, this is the one that passes all the way though and out the bottom.

Lifting this shaft will push the wheel on the side of this shaft into the worm. The book says 2Kg on a spring balance but that’s on the bench with no seals.

How i would do it in place would be disconnect the steering shaft and turn it by hand while the wheels are strait ahead. and just adjust until there is no slack, be careful as 2kg on a worm is nothing really and over tightening will cause damage. Now go from lock to lock. If the steering tightens up close or when not dead center. Your worm is worn, time to get a new one. I doubt this would be the case in a PS box but was common back in the day of non PS boxes where the oil was lower and the box wasn’t pressurized. But then if the PS fluid was never bleed it could happen. NB the bolt on top is for bleeding the PS fluid.( motor running)

Once that is done you need to look at the very big screw on the side. This holds a slide in place that pushes against the back of the rack. if this is set to far back there will be slack between the rack and pinion. i would sagest that this could add to the vagueness.

Its simple, the big screw is held in place by a grub screw ( have fun finding it! a good clean will help) this grub screw pushes against a plastic dowel which in turn locks the thread.

Tighten this screw hand tight and back off about 1/8 a turn. do the lock to lock thing again.

if things tighten up on lock to lock ( wheels off the ground or better pitman arm off) adjust every thing for the tightest point and go shopping.
Again if this is the case and you are looking for a replacement box, either a fee rebuildable 3 bolt or shelling out for a 4 bolt

[85 county]

4 bolt has bearings. Don’t think so

well I can understand the confusion after reading the manuals for both the 3 and 4 bolt. but those of us who grew up with books and not I pad know that a bearing is a bush and a bearing is actually a ball bearing etc.

bearing being a generic term

in fact it was worse while doing my time, to refure to a ball race as a bearing would result is a quick and forceful laced up No 11 heading at high velocity towards my rearasanus.

a wheel bearing for example was infact an assembly consisting usually of no less than 2 taper roller races.

The fact is the 3 bolt manual refers to bushes and the 4 bolt refers to bearing. But the guts is the 4 bolt on my bench in bits ( was now in bin) has no bearings needle rollers but a BUSH. as to my first post. i said i was surprised that the 4 bolt bush is shorter than the 3 bolt bush ( which has 2)

Now unless there is another version, update, upgrade, mod etc I have not seen a 4 bolt with a bearing in the selector shaft lower!!!!!

[clubagreenie]

I remember we used to mod the 3 bolt to take needle rollers. That I know, pretty sure that we used the same rollers that were part of the 4 bolt. Reason being that they didn't wear like the bushes and the 4 bolts were expensive and changing hoses was garder as there were 2 or 3 different types of pumps which had different ends and then the boxes were different fittings as well. Modding the 3 bolt was just simpler.

[isuzurover]

The bottom line is I know more people who have broken a 3-bolt than have broken a 4-bolt.
Plus IRC the 4-bolt is lower geared, making it better offroad.

[Dougal]

As dougal has commented above but that’s only 1/2 the story.

On the top of the box there are two bolts, well 1 bolt and a thread and nut. The nut is just a lock nut. the thread is taped in the top of the box ( housing) so winding this screw out lifts the main steering shaft, this is the one that passes all the way though and out the bottom.

[COLOR=black][FONT=Verdana]Lifting this shaft will push the wheel on the side of this shaft into the worm.

Winding the top adjuster screw in, pushes the sector shaft wheel down onto the worm and reduces play. The shaft comes out the top.

My 3 bolt box had the sector shaft replaced about 11 years ago and the arc is slightly different. I can adjust for no play in the straight ahead position, but at full lock I've got considerable backlash.
The replacement shaft had the usual corrosion around the lower seal area, but simply grinding this back to clean on a lathe (maybe 0.3mm undersize) worked fine and it's still in use.

The 4 bolt in my 93 I haven't been into. I note Rave says the bearings in the 4 bolt box aren't servicable.

[PhilipA]

AFAIR the 4 bolt changed fromn bush to bearing in mid 1991.
There was a VIN list that was issued.
My 92 model RRC is supposed to be the VINs after the change.

I have now replaced the box with a brand new ADWEST one for about $500 landed complete with Pitman arm and end. So I haven't opened up the 4 bolt. However it last almost 220Kks before leaking which is MUCH longer than any bushed one I have seen has.

Having rebuilt a 3 bolt from an 81 RRC and sized the bottom bush with 6 hours and a brake hone, I reckon just buy a new one!!!!LOL

Regards Philip A

[85 county]

The bottom line is I know more people who have broken a 3-bolt than have broken a 4-bolt.
Plus IRC the 4-bolt is lower geared, making it better offroad.

well i know no one who has broken a 3 bolt but know of a few with broken 4 bolts.

3 bolts wear out, 4 bolts break. i have seen 2 with broken selector shafts, where the wheel attaches.

[85 county]

Winding the top adjuster screw in, pushes the sector shaft wheel down onto the worm and reduces play. The shaft comes out the top.

.

Rubbish

the selector shaft wheel is BELOW the worm not above it. Dougal its been to many years since you had your box out,

[Dougal]

Rubbish

the selector shaft wheel is BELOW the worm not above it. Dougal its been to many years since you had your box out,

Suggest you take another look. My memory is clear.

It is definitely above, because I have never taken my box out. I've changed sector shafts in-situ and this would not be possible if they went in from below.

[isuzurover]

well i know no one who has broken a 3 bolt but know of a few with broken 4 bolts.

3 bolts wear out, 4 bolts break. i have seen 2 with broken selector shafts, where the wheel attaches.

As I said, I have seen (more) broken 3-bolts than 4-bolts. Which renders your statement incorrect. The only person I know who has broken a 4-bolt is RangierRover on here - in a 120 that works VERY hard.

3-bolts were manufactured for ~15 years, and fitted to 2 vehicle types (at a time when a large percentage of vehicles were sold without PAS). 4-bolts have been manufactured for ~27 years currently, and sold in far greater numbers than the 3-bolt ever was. So even if 4-bolt shafts were breaking in larger numbers, it probably wouldn't be statistically significant.

[isuzutoo-eh]

My 3 bolt skipped a notch in a high stress situation, that was near-enough broken for me to replace it asap. Prior to that the vehicle hadn't been very well maintained, and I hadn't adjusted the box since I bought it so no idea if it was well adjusted or not, so granted it may have happened to any box that hadn't been cared for.

[clubagreenie]

My last box in the D2, the sector shaft actually twisted after being t-boned. Bent panhard rod and track rod, drag link stayed straight by some miracle and the drop arm bent (very slightly but was out by comparison to the new one)and the shaft twisted below the wheel.

Either way, the shaft must come out from above through the lid. Doesn't the worm on the input shaft act on the wheel? And in so doing means the worm is level with the wheel (input shaft centreline level with centre of wheel). The sector shaft needs to be removed before removing the input shaft.

Unless referring to the assistance gear which is below the wheel on the sector shaft.

[Dougal]

My last box in the D2, the sector shaft actually twisted after being t-boned. Bent panhard rod and track rod, drag link stayed straight by some miracle and the drop arm bent (very slightly but was out by comparison to the new one)and the shaft twisted below the wheel.

Either way, the shaft must come out from above through the lid. Doesn't the worm on the input shaft act on the wheel? And in so doing means the worm is level with the wheel (input shaft centreline level with centre of wheel). The sector shaft needs to be removed before removing the input shaft.

Unless referring to the assistance gear which is below the wheel on the sector shaft.

Same thing happened to mine. But it was driven into a bridge and I wasn't driving. Sector shaft was slightly bent, but mostly twisted. Steering wheel was about 90 deg to drive straight.

The wheel on the sector shaft is just a bit higher than the worm, it meshes down from above and that top bolt is the free-play meshing adjustment. The assistance gear (or piston or rack, whatever you want to call it) doesn't get any adjustment.

[Rad97]

Thanks 85 county with the research you have done bushes are far superior when it comes to load ratings and have a longer life before instant failure as there are always signs leading up to.
Bearing have a tendency to fail catastrophically.

This is all well and good because there is no bearing in the bottom of the 4 bolt steering box any way.