Challenging Power Steering Gear Box Issue, sounds simple but... (1 Viewer)

[Slomo]

So I searched and read the FAQ on the steering gear box and general steering issues and found lots that is almost this but not quite. 2 core problems 1) excessive steering wheel play and 2) Rough steering feel. Sounds like whats been asked a million times I know but keep reading.

1. My steering has excessive play, at its worst it was 2.5" of steering wheel play but currently at 1.5". It was also darting all over the road very inconsistently which I traced to 2 separated radius arm bushings so I replaced all 6 and that is gone but the play remains. I know it will inherently have some and I do not expect rack and pinion type response but I feel I should be able to keep it in my own lane!

I have gone through everything. Trunion bearings are set to proper preload, wheel bearings set to proper preload, tire inflation even and good, all rod ends are EMF custom units adjusted and lubed, panhard good, power steering pump is rebuilt verbatim per FSM with parts from Cdan, new belts at good tension with no squealing, Redline ATF in system flushed per FSM no bubbles, high and low pressure hoses replaced with no leaks, and power steering box adjusted verbatim per FSM being careful not to over tighten. I even replaced the radius arm bushings with Cdan parts. Whew, did I miss anything?

I have a 6" Slee lift, knuckles cut and turned to set castor at +5* confirmed with alignment, I have Hellfire knuckles, 1" wheel spacers which I know affect the scrub radius but were on long before the issues came about, running 315s for a long time and it has done a lot of rock crawling and off roading in general since I got it at 124k miles with 176k miles on it now with a great service history.

2. I told you all that to tell you this. After the second gear box adjustment in almost year, again following FSM perfectly in small increments, my power steering is not smooth, it varies between normal ish and hard to turn and sometimes it almost wont turn at all, both returning to center and not returning to center, hot or cold. It is never too easy or does not work at all like a loose belt or air in the system. There is no regularity to it. It is behaving like the gear box is too tight but I only have it set to the MAX acceptable steering wheel play per the FSM, if I loosen it anymore it won't be driveable. Is it that the gear box is simply worn out and the adjustment used up? That doesn't seem to happen often but I don't know what else to do besides rebuild/replace the gear box. Ideas?

 

[-Spike-]

The adjustment screw that you can access on the outside of the box can only address a fraction of the potential play in the box. The box cannot be adjusted properly without taking it out of the truck, and most of the play comes from the input section anyway, which is not what that adjustment screw adjusts. Rebuild the box, pay special attention to the preload on the input bearings, and pray that you haven't trashed the piston and/or sector shaft by putting too much pressure on the gear teeth.

 

[Slomo]

Thanks Spike, I had a feeling that there was more going on than what the external adjusting screw was affecting. Might use this as an excuse to swap a 105 sector shaft and tap the box for a ram assist while its apart. Problem is it is my daily driver for a little while longer and I want to have someone I trust rebuild it/tap it with as little down time as possible.

Would a ram assist "tighten" up the steering on the highway? I want to do it to help turn 37s in the rocks but wondering as a side benefit.

 

[-Spike-]

You asked for my opinion, I'll give it to you. I have to credit Tools-R-Us for explaining it all to me though.

First, the 105 series sector shaft. Why? Because it's thicker? Only on the end where it interfaces the pitman arm (which you will have to replace as well, add that cost in). The rest of the shaft is exactly the same size as your current shaft. The 105 sector shaft is the same diameter all the way through the box- which means when it gets twisted, it twists all the way up, and usually turns into a banana, which makes it impossible to remove. The 80 series sector shaft rarely twists, usually only from a serious impact, and when it does it does so where it's thinner- just above the pitman arm, where you can clearly see the twist in the splines without disassembling the box. No mystery. If you're thinking it's worn, it usually isn't. Unless you trashed it by messing with the adjustment. I did the same thing you did (although I never pushed it to the point that it bound up) and did no damage. It's very likely you don't have damage either, but possible that you do. In your case, I might consider finding a spare box and rebuilding it so you can just swap it out. Then you can rebuild your old box and if it doesn't need a new sector shaft, offer it to a friend. For money. It's kind of a PITA, so get money.

Ram assist- It can be done, but it's very difficult- there's no place to mount the ram. Ram assist is great as a steering dampener, and gives you the power to seriously fxxx up your steering components. Know why 100 series owners that wheel their junk trash their rack-and-pinion so often? They have no feedback to the steering wheel. They think it's awesome that they can turn the wheels when they are against the rocks. Well, something has to give. Sometimes it's the rocks. Sometimes it ain't.

I don't know if it would tighten the steering. I know that I pulled my box and pump and had Tools-R-Us rebuild them (because he's done quite a few and knows his s***, and I haven't and don't) and now I have exactly 0 play in the wheel on the freeway. We (I was there, watching) adjusted the preload on the input side so that the input assembly registered 6.5 inch/pounds of resistance- 50% higher than the book calls for- because that's where the play usually comes from in that type of steering system. Now my 220+K miler has as good or better steering response than it had new.

When I got sick of my junk wandering all over the road and decided to do something about it, I was convinced I wanted a 105 sector shaft and that I would be replacing stuff in the box that was worn out, because I had a crapload of miles on a box that I had adjusted incorrectly, and I am a serious wheeler. (Just ask me, I'll tell ya.) It turns out that the recirculating ball system that Toyota put in the 80 is nearly indestructible (who'd have thunk it?) and doesn't wear. The 44 balls they use to apply the torque from the input section to the piston and sector shaft have so much surface area that they don't wear. Like, ever. So typically, rebuilding the box properly, with just seals- no new parts- (and you don't even change half the damn seals, fer Chrissakes) nets you as good as a new box.

So, rebuild the box. Better yet, send it to Tools-R-Us and have him do it (because he's done quite a few and knows his s***, and you probably haven't and don't). Toss in a 105 sector shaft if you want, you probably will never twist it anyway. See how you like it. If you still feel the need for hydraulic ram assist, the box itself is easy to modify for it, you just have to find a place for the ram. And probably a few steering arms, or whatever ends up being the weakest link. Me personally, I don't see the need- on 37's, in the desert (where we are known to have a few rocks laying around). But that's just my opinion. Which you asked for.

 

[-Spike-]

Glad I reread that- made me go find the 'curse filter' in Settings and get rid of all those annoying asterisks.

 

[Slomo]

You asked for my opinion, I'll give it to you. I have to credit Tools-R-Us for explaining it all to me though.

First, the 105 series sector shaft. Why? Because it's thicker? Only on the end where it interfaces the pitman arm (which you will have to replace as well, add that cost in). The rest of the shaft is exactly the same size as your current shaft. The 105 sector shaft is the same diameter all the way through the box- which means when it gets twisted, it twists all the way up, and usually turns into a banana, which makes it impossible to remove. The 80 series sector shaft rarely twists, usually only from a serious impact, and when it does it does so where it's thinner- just above the pitman arm, where you can clearly see the twist in the splines without disassembling the box. No mystery. If you're thinking it's worn, it usually isn't. Unless you trashed it by messing with the adjustment. I did the same thing you did (although I never pushed it to the point that it bound up) and did no damage. It's very likely you don't have damage either, but possible that you do. In your case, I might consider finding a spare box and rebuilding it so you can just swap it out. Then you can rebuild your old box and if it doesn't need a new sector shaft, offer it to a friend. For money. It's kind of a PITA, so get money.

Ram assist- It can be done, but it's very difficult- there's no place to mount the ram. Ram assist is great as a steering dampener, and gives you the power to seriously **** up your steering components. Know why 100 series owners that wheel their junk trash their rack-and-pinion so often? They have no feedback to the steering wheel. They think it's awesome that they can turn the wheels when they are against the rocks. Well, something has to give. Sometimes it's the rocks. Sometimes it ain't.

I don't know if it would tighten the steering. I know that I pulled my box and pump and had Tools-R-Us rebuild them (because he's done quite a few and knows his s***, and I haven't and don't) and now I have exactly 0 play in the wheel on the freeway. We (I was there, watching) adjusted the preload on the input side so that the input assembly registered 6.5 inch/pounds of resistance- 50% higher than the book calls for- because that's where the play usually comes from in that type of steering system. Now my 220+K miler has as good or better steering response than it had new.

When I got sick of my junk wandering all over the road and decided to do something about it, I was convinced I wanted a 105 sector shaft and that I would be replacing stuff in the box that was worn out, because I had a crapload of miles on a box that I had adjusted incorrectly, and I am a serious wheeler. (Just ask me, I'll tell ya.) It turns out that the recirculating ball system that Toyota put in the 80 is nearly indestructible (who'd have thunk it?) and doesn't wear. The 44 balls they use to apply the torque from the input section to the piston and sector shaft have so much surface area that they don't wear. Like, ever. So typically, rebuilding the box properly, with just seals- no new parts- (and you don't even change half the damn seals, fer Chrissakes) nets you as good as a new box.

So, rebuild the box. Better yet, send it to Tools-R-Us and have him do it (because he's done quite a few and knows his s***, and you probably haven't and don't). Toss in a 105 sector shaft if you want, you probably will never twist it anyway. See how you like it. If you still feel the need for hydraulic ram assist, the box itself is easy to modify for it, you just have to find a place for the ram. And probably a few steering arms, or whatever ends up being the weakest link. Me personally, I don't see the need- on 37's, in the desert (where we are known to have a few rocks laying around). But that's just my opinion. Which you asked for.

Perfect, that is exactly the type of input I was looking for because I haven't done a bunch of these and don't know my s*** either. Where you were before is where I am now. Tools is EXACTLY who I would want to rebuild my box but I didn't know I could send it to him. I will have to PM him.

Regarding the ram assist, I have Hellfire knuckles with the 1" billet 6 stud high steer arms so I figure as long as I keep my brain attached to my right foot I should do ok. Plus I figure the 105 shaft is a moot point with ram assist because much of the load is taken off the sector shaft itself.

 

[-Spike-]

I didn't check out the build on your truck, sounds like you know more about the ram-assist setup than I do, and you're far enough into mods to know whether you need it or not. I agree with the sector shaft being moot with ram assist. As far as Tools taking work via UPS, I don't know, but he's doing a lot of work for locals lately, definitely worth asking him if he'd do that. I don't know if he'd have a concern with providing customer service long-distance after the work is done.

 

[Slomo]

I just remembered something that I had forgotten as I retread your last post Spike. I hit a partially submerged rock at speed with my pass front tire and it actually resulted in my steering wheel about 30 degrees spun to the right when the truck was driving straight on the highway. I expected pretty good damage but couldn't find anything obvious and it drove perfectly normal otherwise. I couldn't get to it to diagnose for a couple of days then the steering wheel returned to center on its own! I could not find any physical damage on inspection. Anyone heard of this or had it happen?

 

[Slomo]

I didn't check out the build on your truck, sounds like you know more about the ram-assist setup than I do, and you're far enough into mods to know whether you need it or not. I agree with the sector shaft being moot with ram assist. As far as Tools taking work via UPS, I don't know, but he's doing a lot of work for locals lately, definitely worth asking him if he'd do that. I don't know if he'd have a concern with providing customer service long-distance after the work is done.

I figured it would be asking a lot but can't hurt. I have a hard time trusting people to work on my rig so I would much rather use someone I know is good.

 

[-Spike-]

Funny you mention that, after the box rebuild I have been sensitive to the steering wheel position. I set it straight, and then a few days later (and at least one wheeling trip, since that's the only thing it gets driven for) I noticed it was off a bit. I checked the tie rods, figuring I had bent something (again, btdt) but everything was straight. Next outing, back on pavement and the position is changed slightly. It seems to move around randomly whenever I drive (wheel) it. All my front control arm and panhard bushings are new and I recently fixed the crack in the frame where the panhard attaches. I checked for other cracks and had Tools look it over as well, thinking the axle must be shifting around a little. The only thing we can come up with is that the rear suspension bushings are trashed, and maybe the rear axle is shifting around and getting out of alignment, which has to be corrected by steering the front axle. I don't have a solid answer yet, haven't ordered new bushings for the rear, but that's my next step.

 

[-Spike-]

The only other thing I wondered about was the steering arm moving on the knuckle. My lower knuckle nuts are all tight, not positive that the plate can't move a tiny bit but that's possible. 30 degrees is a lot for that scenario, mine is only moving maybe 10.

 

[Slomo]

Very interesting, I have noticed a slight variation in the past as well (I am very OCD ) but nothing like that one occurrence. I hadn't considered the rear bushings but coincidentally, or not, mine are all old as well with all new fronts.