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Recommendations for a steering box replacement?


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I am fairly certain that I need a replacement steering box for my '88. I had a lot of play in the steering and the steer ahead was way off when I started working on the truck. I started looking for play by having someone turn the wheel while I was under the vehicle and was able to identify things that should move but did not. With that diagnosis in mind, I have replaced the track bar (helped a lot) and the steering stabilizer (helped a little). I also replaced the shocks, just for fun.

 

Now I am to the point where I don't see any play from under the truck, but I still have slightly vague steering, particularly at highway speeds. Several (trusted) mechanics have suggested the steering box, but given my mechanical abilities, they said to tackle it myself (hence part of why I trust them), as the MJ is not my daily driver.

 

I have searched on here an dlooked to my typical parts vendors, but I see a lot of brands with mixed reviews. Any suggestions on a particular brand and/or vendor?

 

Thanks!

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Besides stock replacements, there is a quicker ratio box from certain V8 ZJs that is an upgrade (if you want quicker steering), which I plan to do eventually.

That's the 12.7:1 ratio. It's also available from Borgerson if you decide to go that route. Stock XJ/MJ steering is usually 14:1, although I believe the very early (AMC) XJs and MJs used an 18:1 box if you bought the off-road suspension package.

 

I would definitely go with the 12.7:1 for an MJ that's used as a daily driver.

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A few months back, I saw several threads about the ZJ box being an option, but I never saw a thread that talked about a successful install.

 

I'll be looking into that for sure.

 

As for current status, I drove it about 60-70 miles today (most single-day use in a while) at speeds up to 70 mph, and sometimes it feels fine, while other times it feels dead at the center. Also, the steer ahead is not correct.

 

At certain speeds, there is a little (barely noticable) shimmy in the vehicle, but I would not say that I felt it in the steering wheel as much as I felt it in the whole truck.

 

Hard to describe. Part of the problem is that driving the truck just feels so different from driving my daily.

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As for current status, I drove it about 60-70 miles today (most single-day use in a while) at speeds up to 70 mph, and sometimes it feels fine, while other times it feels dead at the center. Also, the steer ahead is not correct.

"Steer ahead"? You mean the steering wheel isn't centered when driving straight? That's not in the steering box, that's a simple adjustment of the drag link.

 

At certain speeds, there is a little (barely noticable) shimmy in the vehicle, but I would not say that I felt it in the steering wheel as much as I felt it in the whole truck.

That's tire balance. The steering box can't cause shimmy.

 

Hard to describe. Part of the problem is that driving the truck just feels so different from driving my daily.

It's a 20+ year old truck. It can't feel like a new car with rack-and-pinion steering, and should not be expected to. If that's what you are looking for, you're doomed to disappointment regardless of how much money you throw at it.

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As for current status, I drove it about 60-70 miles today (most single-day use in a while) at speeds up to 70 mph, and sometimes it feels fine, while other times it feels dead at the center. Also, the steer ahead is not correct.

"Steer ahead"? You mean the steering wheel isn't centered when driving straight? That's not in the steering box, that's a simple adjustment of the drag link.

I meant to say that the steer ahead (yes, that the truck tracks straight when the wheel is aimed straight) actually is "on" at times, while at other times the truck does NOT drive straight when the wheel is at the center position. It actually feels dead-on at times, then I look down latere to see that i have the wheel about 10* to one side or another.

At certain speeds, there is a little (barely noticeable) shimmy in the vehicle, but I would not say that I felt it in the steering wheel as much as I felt it in the whole truck.

That's tire balance. The steering box can't cause shimmy.

First, I'll openly admit that I may have mis-used the word "shimmy" in my explanation of the problem.

 

The issue (the loose feeling in the handling) was the same with a different set of wheels and tires, but checking tire balance is a good idea before putting any more money into hard parts. Because the problem was there before my current wheel/tire setup, and because I bought them used, I never thought to check this.

 

Hard to describe. Part of the problem is that driving the truck just feels so different from driving my daily.

It's a 20+ year old truck. It can't feel like a new car with rack-and-pinion steering, and should not be expected to. If that's what you are looking for, you're doomed to disappointment regardless of how much money you throw at it.

No, that is not it at all. I was just mentioning that the comparison makes it hard to describe the differences in terms of how the truck used to behave versus how it feels now. I drove this truck on the highway many times when I was younger, and I did hundreds of thousands of highway miles in my 86, 95, and 98 XJs (all of which had more miles than my MJ does now). I can't accurately put my finger on (nor describe) what feels wrong with the handling and steering of the MJ right now, but I never would have wanted to drive an XJ on 5+ hour trips to and from college if it felt this shifty at 75 mph on the highway. They felt much "tighter" on the open road than does my MJ.

 

I don't need (nor do I expect) this to feel like my WRX, but I do want to have a little more faith in the truck. As it stands, I won't drive it on the highway with my kids in the vehicle until I can resolve the loose feeling in the steering.

 

I do appreciate the suggestion on checking tire balance. It would not fix the variance in the straight ahead steering,bu tit might explain the shimmy or shake that I feelat times, which does seem to be somewhat speed-dependent. Sometimes the simple solutions are the right ones.

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I noticed that my wheel is dead on at certain times and off just a bit at others, I have found it to be the road and the amount of crown it has built into it for water drainage.

Easy way to test is if your in the right lane and you have to put some left pressure on the wheel, move to the far left land and see if you have to compensate the other way.

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It sounds like you just have some "slop" (excuse my use of such highly technical terminology) in the steering. That can sneak up on you, and then it may be easy or difficult to pinpoint the cause. It may or may not be one thing.

 

In the XJ/MJ front suspension, there are four ball joints, each of which is subject to wear -- especially if not lubed regularly. There are also five tie rod end type joints, plus a bushing. All of those are also subject to wear and can cause slop. After about 175,000 miles, my '88 XJ (which I bought new) finally got to where I had at least a quarter turn of free play in the steering wheel before the road wheels began to respond. In my case, the culprit was the upper end of the track bar -- which is the fifth tie rod end in the XJ/MJ front suspension. On the early XJs and MJs, the track bar upper end didn't have a grease fitting. The replacements DO have a grease fitting. A new track bar fixed my problem.

 

The way I inspect for which joint (or joints) is/are causing slop is by feel. You can feel flex in tie rod ends that you can't see by looking. To do it, you need a helper to turn the steering wheel. The procedure is to unlock the steering wheel. I don't start the engine, but you can. The problem is that power steering makes it too easy for the assistant to turn the wheel too far. The helper should stand OUTSIDE the vehicle and reach in through the driver's window to turn the steering wheel back and forth. The helper should watch the front tire, and turn the steering wheel only to a point in each direction where the tire sidewall starts to flex, but the tire doesn't quite turn on the ground. What you want to do is load the joints to the max in each direction. Once the tire starts to actually turn, the load in the TREs is released.

 

While your helper is turning the steering wheel back and forth, you get to crawl under the vehicle and grab each TRE to feel for how much flex there is. It should be about zero -- they should be free to rotate, but not to flex or have any lateral movement. While you're under there, you can also watch the pitman arm and see if the steering box has free play across the center (in other words, the input shaft connected to the steering wheel turns, but the pitman arm DOESN'T move).

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