Steering box will definitely not cause a wobble, but excessive play in it may allow it to happen.
Same as play in TREs and Panhard rod bushings.
And wobble - shimmy - may happen with perfectly new and round tires as well.
Steering Box rebuild
- Thread starter mjbrox
- Start date
Same as play in TREs and Panhard rod bushings.
And wobble - shimmy - may happen with perfectly new and round tires as well.
Wobbles all the time when your driving down a flat smooth road ? or does it wobble really bad after you go over a railroad crossing or some other bumps ? Like a death wobble .
I finally had some time to do the full rebuild on the steering gear box (1997 D1). Now that I have it completely apart the reason for the leaking rebuilt units becomes obvious. Looking at the kits for the D1 (including the one I bought from an LR parts seller on ebay) most are missing the single most important parts: valve seals. 
The D1 workshop manual outlines the procedure for installing new valve seals. It requires a special mandrel and warming up the teflon seals to install them. These seals are missing from the kits. The mandrel I can spin up on a lathe with little effort.
The valve is a torque actuated flow divider. If the seals on the valve are worn or the valve bore is worn the high pressure fluid bypasses the valve by leaking into the box cavity. The pressure is much more than any of the seals are designed to hold so it leaks, leaks, leaks. A "rebuild" with one of the D1 kits will hold for a while but is dependent on the condition of the valve. I have not yet disassembled the valve to look at it's interior condition. That too could be a contributor. The last potential culprit is the relief valve but less likely unless there is contamination or damage.
There are some D1 kits that appear to have the valve seals at double or triple the price of the STC2847 based kits. I have found one kit from a seller in Oz that has the valve seals.
So now here I sit with my steering in pieces and missing parts. :banghead: Being in rural AZ there is a good chance I can't get a COMPLETE kit here in any reasonable time frame. :ack:
The lesson: Don't waste your time and money with the STC2847 based kits if you have a leaking, higher mileage steering box and want to do the rebuild yourself. Make sure you get a kit with the three teflon valve seals included. Without these the bypassed fluid will cause the box to leak.
The rebuild is simple and easy to do IF THE KIT HAS ALL THE PARTS.
Do any of our lurking vendors have the teflon valve seals?
The D1 workshop manual outlines the procedure for installing new valve seals. It requires a special mandrel and warming up the teflon seals to install them. These seals are missing from the kits. The mandrel I can spin up on a lathe with little effort.
The valve is a torque actuated flow divider. If the seals on the valve are worn or the valve bore is worn the high pressure fluid bypasses the valve by leaking into the box cavity. The pressure is much more than any of the seals are designed to hold so it leaks, leaks, leaks. A "rebuild" with one of the D1 kits will hold for a while but is dependent on the condition of the valve. I have not yet disassembled the valve to look at it's interior condition. That too could be a contributor. The last potential culprit is the relief valve but less likely unless there is contamination or damage.
There are some D1 kits that appear to have the valve seals at double or triple the price of the STC2847 based kits. I have found one kit from a seller in Oz that has the valve seals.
So now here I sit with my steering in pieces and missing parts. :banghead: Being in rural AZ there is a good chance I can't get a COMPLETE kit here in any reasonable time frame. :ack:
The lesson: Don't waste your time and money with the STC2847 based kits if you have a leaking, higher mileage steering box and want to do the rebuild yourself. Make sure you get a kit with the three teflon valve seals included. Without these the bypassed fluid will cause the box to leak.
The rebuild is simple and easy to do IF THE KIT HAS ALL THE PARTS.
Do any of our lurking vendors have the teflon valve seals?
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Visit a hydraulic supply co near you, they usually have all the seals and O rings you might need.
That's where I got all the seals I needed to rebuilt most of my shit, including the infamous D2 jack.
That's where I got all the seals I needed to rebuilt most of my shit, including the infamous D2 jack.
I think the pitman shafts are warped and causing the big leaks at the pitman seals . That's what rover was telling us back when they where paying .
I am sure there are several failure modes like the bent shaft. In my truck the shaft is fine. It is the valve seals and shaft seals that are worn.
I put my pitman/sector shaft in a lathe and indicated it. It has less than 0.0005 TIR across the journals. Most seals will tolerate a great deal more (about 0.010).
What should happen when there is no demand for assistance is that the fluid should bypass and circulate (low pressure). When the valve moves it blocks the fluid causing pressure to rise and divert fluid to the front or rear of the piston (dependent on steering direction). The valve seals control circuit the fluid takes. When they are worn the fluid leaks into the bypass as well as the L/R circuits. Voila! Leaks!
So now I am looking for valve seals for a D1.
Tucson is 80 miles away and their industrial supply infrastructure is pretty lame. Next best is Phoenix (225 miles).
It sucks but ordering from Amazon is faster and less expensive than driving up to Phoenix, or even Tucson for that matter.
The good part is that some of these pieces (like the shaft seals) are standard stuff (1.25x1.75 or 32x45 metric for the sector shaft) so backorder shouldn't be a big deal.
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I'm sure all the shafts aren't warped . They used to tell us that it was caused by the heat of the fluid , right hand drive trucks had a cooling loop in them . Who knows , thats just why I never try to seal them .
The fluid would have to get mighty hot for it to warp shafts IMO, the plastic reservoir tank will melt before the fluid is hot enough to warp those shafts. Or they used shit metal or warped shafts to begin with.
Given that the shaft is hardened and ground the fluid would have to reach annealing temps before the shaft would yield due to heat.
But I hear ya, they had to have something to tell folks.
I think your right about needing to say something . I dont think they trust us Yanks to fix one . One of them told me us Colonies bastardize the english language.
I know . The ass hole was asking me "what position is the knot in ? " I had no fucking clue what this guy wanted to know . A switch is called a knot , just in case you care .
I bet. This was on a 98 I was in a parking lot and while turning it became hard to turn then pop! No steering. The box locked up causing the steering column to fail.
Locked box or not, I still don't get how turning a wheel is enough torque to shear off a metal shaft.
I bet it was loose or binding for a long time then one of the u joints snapped . I haven't seen a steering box lock up . Loose power assist maybe , never totally locked up .
After going through one of these boxes completely I can see how the shaft could be bent or broken. It would be due to the rack pad adjuster being too tight or the sector shaft adjustment being too tight. Or both.
Of course if it is too tight on the sector shaft the steering doesn't center on its own. The rack pad would be a possible culprit especially if the wear is in the center of the rack and it tightens when turning to either lock. Too close and it will bind in the root of the teeth stressing the sector shaft. It wouldn't be instant but over time would fatigue the metal.
The next time I do one of these I'll add the step of surface grinding the back of the piston/rack to flatten it (a little wear in the center).
Of course if it is too tight on the sector shaft the steering doesn't center on its own. The rack pad would be a possible culprit especially if the wear is in the center of the rack and it tightens when turning to either lock. Too close and it will bind in the root of the teeth stressing the sector shaft. It wouldn't be instant but over time would fatigue the metal.
The next time I do one of these I'll add the step of surface grinding the back of the piston/rack to flatten it (a little wear in the center).
Never been inside one. Is the adjustment nut on the top one of those two adjustments? Is the other only adjusted internally or on assembly?
I once over tightened the play with the top adjustment. The outside range of steering had little play but as the wheel approached center it became too tight and made a popping sound as it rolled over center. I quickly re-adjusted.
I once over tightened the play with the top adjustment. The outside range of steering had little play but as the wheel approached center it became too tight and made a popping sound as it rolled over center. I quickly re-adjusted.
The rack pad adjustment is on the side. Looks like a big straight slot screw next to the trans cooling lines. This controls the mesh of the rack gear and sector gear. It is adjusted on assembly. Could be done in-situ.
The top adjuster is for the worm preload. The sector/pitman shaft has a follower on it that runs in the groove of the worm/input. Too tight and it will bind in the center. If adjusted correctly there will be a bit of effort at the center. Too loose and the truck won't track.
Sorry, I should have taken photos while I had it open. Maybe I'll ask for one of those eyeglass or headband cameras for Father's Day. Then it would be full video complete with bloody knuckles and muttering.
The top adjuster is for the worm preload. The sector/pitman shaft has a follower on it that runs in the groove of the worm/input. Too tight and it will bind in the center. If adjusted correctly there will be a bit of effort at the center. Too loose and the truck won't track.
Sorry, I should have taken photos while I had it open. Maybe I'll ask for one of those eyeglass or headband cameras for Father's Day.
Then it would be full video complete with bloody knuckles and muttering.
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