PSC Gearbox Install

[Grant Lasson]

How did this project turn out? I'm in the middle of ironing out of my ZF gearbox on the rubi is toast. I have play when I remove my drag link and rotate the pitman arm by hand. Just a little play but enough to justify that this is where my steering wheel play is coming from.

Also there was mentions of some 70mph "marked hop" what is that exactly?

I'm happy. The wheel hop didn't have anything to do with the PSC. It's gone but I really didn't fix it. I haven't installed the hydro assist ram or a cooler yet--i don't need them right now.

I do have one issue that I'm going to call about. At full right turn stop the drag link loads the ps spring compressing it a bit. This doesn't happen when driving regularly. I had all my marks lined up on the install. Is there an adjustable stop?

 

[mrblaine]

I'm happy. The wheel hop didn't have anything to do with the PSC. It's gone but I really didn't fix it. I haven't installed the hydro assist ram or a cooler yet--i don't need them right now.

I do have one issue that I'm going to call about. At full right turn stop the drag link loads the ps spring compressing it a bit. This doesn't happen when driving regularly. I had all my marks lined up on the install. Is there an adjustable stop?

Don't call, that isn't the gear box. You have unequal travel side to side which is likely due to the axle not being centered.

 

[Grant Lasson]

Don't call, that isn't the gear box. You have unequal travel side to side which is likely due to the axle not being centered.

That is so helpful. Thank you.

 

[Grant Lasson]

How did this project turn out?

I thought about it overnight and I can give a more helpful answer.

I started this whole process because of a big dead spot in my steering which made it difficult to drive.

#1: I started with the toe. I made a version of the alignment tool and measured my toe at 5/16". I found ORO's guidance for the U Turn steering and it said 0-1/16" was appropriate. I set to 1/8". The dead spot was reduced quite a bit but the jeep became even more of a handful. It seemed that the road wanted to steer the jeep everywhere.

#2: I removed the U Turn crossover steering and replaced it with the Currie Currectlync because the U Turn had the reputation for having a large dead spot in the steering. There was improvement in steering responsiveness and reduced "road steering" but is wasn't sufficient to say it was "solved."

#3: BuildBreakRepeat asked me to post pictures of the front end. Blaine and he immediately identified the drop adapter for the track bar as a big source of bump steer (I wasn't even aware I had a drop adapter). I replaced the RockKrawler track bar with the Currie JJ track bar. On road steering was better for bigger bumps but the jeep still seemed to wander as much.

#4: There was a lot of play in the steering shaft (15-20+ degrees) into the ZF steering box. Time to install the PSC gear box, pump, and reservoir. This was a direction I wanted to go anyway because of 35" tires and the lockers. In all, the steering shaft play seems now to be reduced by about half but it is not zero.

#5: I took off the steering stabilizer.

My steering right now is dramatically improved but not as good as I would like. A) The steering sensitivity is very good--my dead spot is gone. If I turn the wheel at all I can feel the front tires responding. B) the jeep no longer wants to leap across the lane if there's a groove or edge that I encounter. While the bump steer is much reduced, I can still feel it occasionally. C) It wanders less but it still wanders. It's easier to manage but I'd like it to quit wandering.

Next I'm going to the knuckles, ball joints, etc. I installed the Synergy ball joints quite awhile ago (when they were fairly new). I can't see any inordinate play but it may be a source. In any case, I think the 15/16" brake/knuckle kit from BMB is likely. I'm out of ideas after that.

 

[Inca03rubi]

Alot of what your expressing is what I'm dealing with. So I'll be following. My current zf box has play in the steering wheel. When I had the steering drag link removed, I managed to grab the pitman arm and move it and was able to feel the dead spot that I was feeling in my steering wheel. I dont have much guidance on adjusting the gear lash adjuster so I never bothered to play too much with it.

As for the slight bump steer, my whole front end is more or less new and if I hit a bump, it's still pretty jolting and wants to dart over to the other lanes.

I also wander a lot and hold pretty heavy against crowns in the road. Even on fairly flat roads I still hold. (Right lane I hold left and left lane I hold right)

I see no crazy unusual wear on my tires that have roughly 4600 miles on them now. I know the tires are pretty stiff even with 28psi. (Cooper AT tires in an E rating). New 5100 shocks and double checked the alignment was correct although I'm sure I can still fine tune the toe for 33's.

Was the new steering straight forward to install? Seems the OE steering shaft will need to be shortened. I'd prefer a more OE fit without modifying steering shafts....

 

[mrblaine]

Seems the OE steering shaft will need to be shortened. I'd prefer a more OE fit without modifying steering shafts....

I am certain I have mentioned how to do that many times on here. Use a 97-02 lower shaft.

 

[BuildBreakRepeat]

I thought about it overnight and I can give a more helpful answer.

I started this whole process because of a big dead spot in my steering which made it difficult to drive.

#1: I started with the toe. I made a version of the alignment tool and measured my toe at 5/16". I found ORO's guidance for the U Turn steering and it said 0-1/16" was appropriate. I set to 1/8". The dead spot was reduced quite a bit but the jeep became even more of a handful. It seemed that the road wanted to steer the jeep everywhere.

#2: I removed the U Turn crossover steering and replaced it with the Currie Currectlync because the U Turn had the reputation for bumpsteer. There was improvement in steering responsiveness and reduced "road steering" but is wasn't sufficient to say it was "solved."

#3: BuildBreakRepeat asked me to post pictures of the front end. Blaine and he immediately identified the drop adapter for the track bar as a big source of bump steer (I wasn't even aware I had a drop adapter). I replaced the RockKrawler track bar with the Currie JJ track bar. On road steering was better for bigger bumps but the jeep still seemed to wander as much.

#4: There was a lot of play in the steering shaft (15-20+ degrees) into the ZF steering box. Time to install the PSC gear box, pump, and reservoir. This was a direction I wanted to go anyway because of 35" tires and the lockers. In all, the steering shaft play seems now to be reduced by about half but it is not zero.

#5: I took off the steering stabilizer.

My steering right now is dramatically improved but not as good as I would like. A) The steering sensitivity is very good--my dead spot is gone. If I turn the wheel at all I can feel the front tires responding. B) the jeep no longer wants to leap across the lane if there's a groove or edge that I encounter. While the bump steer is much reduced, I can still feel it occasionally. C) It wanders less but it still wanders. It's easier to manage but I'd like it to quit wandering.

Next I'm going to the knuckles, ball joints, etc. I installed the Synergy ball joints quite awhile ago (when they were fairly new). I can't see any inordinate play but it may be a source. In any case, I think the 15/16" brake/knuckle kit from BMB is likely. I'm out of ideas after that.

Is your axle perfectly centered using the trackbar? Not just from looking at the tires but hanging a plumb bob (or socket tied to a string) from the center of the axle, center of the from bumper, and the front body mount? Then by sitting in front of the Jeep do all three of those string line up? Also, if the track bar is perfectly aligned is your axle square? Aka, is the measurement from the center skid plate bolt to the axle tube the same on both sides?

Picture is getting the track bar set right.

 

[Grant Lasson]

Was the new steering straight forward to install? Seems the OE steering shaft will need to be shortened. I'd prefer a more OE fit without modifying steering shafts....

The steering shaft shortening was the easiest step of the process. If that's the step that's worrying you it may be a good idea to have a professional install it for you. Getting the steering box installed took some time. It's a tight fit because it' s so much longer than the ZF box. Make sure you buy both hoses if you're not going with the PSC pump.

I paid a little extra tuition because of my ignorance about clocksprings and how they work. If you're going to take out the steering box for any reason I recommend learning where they are and how they work. Actually, that advice applies if you're going to take out the steering shaft as well.

 

[Grant Lasson]

Is your axle perfectly centered using the trackbar?

Also, if the track bar is perfectly aligned is your axle square?

I will check this. When I installed the track bar I used a plumb bob from the body. My axle looks pretty centered on the vehicle but it wouldn't surprise me if it's a little off. WRT the spring loading, it happens just at the very end so I don't think I'll have to shift the axle much to fix that.

I know the control arms are the same length but I haven't tried to measure how "square" it is. I'll do that as well.

 

[Inca03rubi]

I am certain I have mentioned how to do that many times on here. Use a 97-02 lower shaft.

I'm not saying you did or did not mention it. My post was simply being relatable to the OP and openly saying that I'd like to not remove, alter or mess with my ORIGINAL EQUIPMENT currently installed and was more or less looking for an upgrade that has OE drop in ability. But thank you for the heads up. I do greatly appreciate it.

 

[Inca03rubi]

The steering shaft shortening was the easiest step of the process. If that's the step that's worrying you it may be a good idea to have a professional install it for you. Getting the steering box installed took some time. It's a tight fit because it' s so much longer than the ZF box. Make sure you buy both hoses if you're not going with the PSC pump.

I paid a little extra tuition because of my ignorance about clocksprings and how they work. If you're going to take out the steering box for any reason I recommend learning where they are and how they work. Actually, that advice applies if you're going to take out the steering shaft as well.

For me the gearbox is most definitely the easiest to do. The factory steering shaft is by no means difficult but I would prefer to NOT alter factory steering shafts. Still sends shivers up my spine from prior experiences involving modified steering equipment.

 

[Grant Lasson]

For me the gearbox is most definitely the easiest to do. The factory steering shaft is by no means difficult but I would prefer to NOT alter factory steering shafts. Still sends shivers up my spine from prior experiences involving modified steering equipment.

I think the modification to the steering shaft is simpler than you might have in your mind. There's no cutting or welding involved. Mark the 2+" on the shaft that need to be reduced. Take a dead blow hammer and hit the end. There are two small plastic pins that will be sheared. The shaft will now slide to the new location. Because it's now 2+" more deeply seated, there's no room for it to come apart. The length is fixed by the gearbox and the firewall--it's not like a suspension that is extending and contracting.

 

[Steel City 06]

You can buy a 97-02 steering shaft so you don't have to modify the old one. Bolts right in, no modifications required. Still has a collapsing safety feature built in.

I collapsed my 03-06 one. Problem is I collapsed it all the way, and it ended up being too short. I couldn't pull it back apart so I just ordered a 97-02 shaft.

 

[Inca03rubi]

You can buy a 97-02 steering shaft so you don't have to modify the old one. Bolts right in, no modifications required. Still has a collapsing safety feature built in.

I collapsed my 03-06 one. Problem is I collapsed it all the way, and it ended up being too short. I couldn't pull it back apart so I just ordered a 97-02 shaft.

That was my concern, the pins are set as a safety feature and not having that collapsible feature when I was in a accident in the past caused me a lot of issues when I was dealing with the insurance company and lawyers. I won't get into greater details but the feature is there for your safety.

So as you and MrBlaine said, the 97 thru 02 will be shorter and still have the appropriate collapsible feature length? Safety is key for me, sorry for the thread highjacking and I thank everyone for their time.

 

[Steel City 06]

That was my concern, the pins are set as a safety feature and not having that collapsible feature when I was in a accident in the past caused me a lot of issues when I was dealing with the insurance company and lawyers. I won't get into greater details but the feature is there for your safety.

So as you and MrBlaine said, the 97 thru 02 will be shorter and still have the appropriate collapsible feature length? Safety is key for me, sorry for the thread highjacking and I thank everyone for their time.

Correct. It will bolt in right out of the box, assuming you have the PSC gear installed. No need to collapse it. It appears to have the same collapsible feature as the 03-06 shaft. It also comes with the bearing, which for some reason is next to impossible to find for later TJs.

 

[mrblaine]

That was my concern, the pins are set as a safety feature and not having that collapsible feature when I was in a accident in the past caused me a lot of issues when I was dealing with the insurance company and lawyers. I won't get into greater details but the feature is there for your safety.

So as you and MrBlaine said, the 97 thru 02 will be shorter and still have the appropriate collapsible feature length? Safety is key for me, sorry for the thread highjacking and I thank everyone for their time.

They are not pins. There is a hole in the outer sleeve that has the plastic slide bearing material injected into it to stop the bearing from moving while letting the inner shaft still collapse. There is no need to drill it, just shorten it by smacking it a bit. The inner has no corresponding hole, it is just a smooth shaft. You are not changing the safety feature of it being pinned in place because it is just friction that holds it.

 

[Inca03rubi]

They are not pins. There is a hole in the outer sleeve that has the plastic slide bearing material injected into it to stop the bearing from moving while letting the inner shaft still collapse. There is no need to drill it, just shorten it by smacking it a bit. The inner has no corresponding hole, it is just a smooth shaft. You are not changing the safety feature of it being pinned in place because it is just friction that holds it.

Correct, this IS an oem safety feature directly related to high speed front end collisions. It's designed to prevent the steering wheel and steering shaft from going thru the driver in a collision. By collapsing the 2 parts to its limits, you essentially remove this safety feature which now permits little to no collapsed movement.

All I'm saying is, just like no one wants to advise emissions defeat advice to prevent lawsuits, the same should be considered for collision safety features mandated on nearly all vehicles.

 

[Lou]

Correct, this IS an oem safety feature directly related to high speed front end collisions. It's designed to prevent the steering wheel and steering shaft from going thru the driver in a collision. By collapsing the 2 parts to its limits, you essentially remove this safety feature which now permits little to no collapsed movement.

All I'm saying is, just like no one wants to advise emissions defeat advice to prevent lawsuits, the same should be considered for collision safety features mandated on nearly all vehicles.

You are not collapsing it to its limits.

 

[Inca03rubi]

But I entirely understand what your saying with regards to steering shaft nomenclature and how it can be shortened. I will take your prior suggestion and seek for an early model TJ steering shaft before looking into this particular steering gearbox. Again, much appreciated and had zero intentions of dragging this out much farther. I was only intending to reach out to the OP and see how his project came out and relating to his original issues that he was experiencing.

 

[Inca03rubi]

You are not collapsing it to its limits.

Correct. And I'm thankful for your reassurance. But the TJ has little safety as it is. My luck runs like trash . So I'd hate to defeat what little safety features I do have.