What's the difference between the steering boxes for a 7500 GVWR vs an 8800 GVWR?

I need a new steering box for my truck, but money is tight as I have not had a job for a long time, so buying a nice one from Borgeson or Red Head is out of the question right now. I need the box because I also need new tires on the front because mine are down to the cords on one side, because the alignment is screwed up. But no one will do an alignment while the box is leaking. So, it's a situation where one thing leads to another which leads to another. I need new tires, but won't spend the money on them until I can get the alignment, and I can't get the alignment until I get a new box.

I don't drive my truck hard at all, I don't tow, I don't pull, I don't haul anything, just drive it around town and to the neighboring town on occasion. Calling the local salvage yards looking for one is only turning up steering boxes for 1500's and the occasional 7500#.

So my question is, can I use a 7500# steering box and be okay since I really don't work my truck hard at all? My intent is to put a non-leaking box on so I can rebuild my original box, put new seals in it, and then re-install it when the 7500# box starts going bad. If I can get a year or two out of it, maybe I will have a job by then when I can afford something better.

Thanks in advance for any information you can offer.

 

Are you sure the steering box is leaking? Usually its the steering pump leaking and drips down on everything below, including the steering box mounted to the frame.

I cant believe that no one will align your truck because of a leaky steering box (if its really leaking). Thats just silly. I'm not sure how comfortable you are doing the alignment yourself but really aligning these trucks couldn't be more simple. Unless there's something bent on the front axle (rare and usually from abuse) which has the camber out of wack, there's nothing else you cant do yourself. And checking to see if the front caster is off would be completely noticeable by strange outer tire wear and you could also see the front tires are not sitting straight up and down in relation to the rear tires. If they straight up and down are then all else is totally easy.

Just take a measuring tape or string and measure from the middle of back of the front rims against the front middle part of the rims. There should be about 1/8 to 1/4" difference with the front edges being closer together than the rear. I made that seem more complicated that it should have but really.....you just want a 1/8"-1/4" toe in. A string or alignment string will tell the same thing.

As for caster, all you have to do is leave it alone if there's more positive caster on the passenger side then you're on the right track. Positive caster means the arrow on the control arm adjuster is pointing forward. To adjust the caster you simply lift the front axle and set it on some jacks. Then loosen the nut on the control arm adjustment and turn the adjuster so that the arrow on the drivers side is pointing at least straight up and the arrow on the passenger side is pointing around a 1/4 turn more towards the front. I like them both more forward than straight up because these trucks respond really well to more positive caster. Negative caster is where the death wobble comes from.....and worn steering components too.

Thats all there is too it. If this was a rack and pinion system and if there was a camber adjustment setting then the whole process would be completely different. So since there's none of that, this is one of the easiest vehicles to align. I've done mine and my tire wear is perfect. Note.....these trucks have a notorious pull to the right no matter what you do. Some pull more than others and adding more caster on the passenger side is supposed to help.....but they still tend to pull.

 

I'm 99% sure its the box. The pump doesn't appear to be leaking but its hard to tell because I have to add fluid so often and I always spill some on the pump. The fluid is never dripping off the bottom of the pump, but is always dripping off the bottom of the gearbox and the steering stabilizer bar. It appears to be leaking on the gearbox at the adjusting nut for the preload. It started leaking after I tightened up the slack in the preload. I saw in the auto parts store the other day they have dye you can put in any auto fluid to find leaks using a UV light. Maybe I should get some of that and check it just to be absolutely sure what's leaking.

I've been thinking about doing the alignment myself the last few days. I've watched a few videos on YouTube that are almost exactly as you describe and figured Id give it a shot. I've got nothing to lose but a little time, right?

So, as far as the difference between the 7500# and the 8800# gearbox, any ideas? If my box is leaking, I'd like to get this 7500# model that is at a local salvage yard because they are way cheaper than anyone else I've seen. Is it maybe just a different steering ratio?

 

^Some good advise right there, I had terrible luck with "alignment" shops until I did my own. Used a tape measure after all the front end joints were tight and now the fronts wear as good as/better then the rears. I'm right at 1/8" toe in, and just need paitence with getting the over-center adjustment right on. Still pulls a little into a leaning highway (either direction) but it's predictable.

 

I cant say for the differences in those steering boxes but I dont think I'd want a 1/2 ton steering box in your Cummins truck.

 

Well, it's not that I want it so much as I just don't have the extra money to get the one I'd really like to have. If I could find a decent used 8800# box I'd get it, but I can't. Which is why I'm asking what the difference is. If it's something that would survive under the front of my mildly driven truck for a year or so until I can save up the money for a nice gearbox, then I'll get it. If it won't last a month, then I won't bother.

I did get some of that dye to put in the power steering fluid. As soon as it gets dark I'm going to check to see where it is really leaking.

 

From what I could find on the intraweb they will bolt up, but the ratio is not the same? So it may not be nice in a parking lot but would be fine on country roads/highway. I guess take some measurements with you to the pick n pull and make sure it's the same, especially on the sector shaft.

Also, it's common for the sector shaft to move around (pitman arm) under stress, causes the seal to leak. Steering stabilizer supports the end of that shaft so it won't move, cleans up the steering a bit (or a bunch) also. Highly recommended.

 

Yeah, I already have a stabilizer bar installed, and it did feel like it improved steering control a little. Ironically it was shortly after installing the stabilizer that I decided to tighten up the slack in the preload adjustment. Almost immediately after that is when I noticed it was leaking. I can't find my UV light right now so I can't see where the leak is coming from. So I'll look for my light tomorrow hopefully and find the leak tomorrow night.

 

Okay, it's verified. The power steering pump is not leaking. The steering gearbox is leaking, but not from below next to the pitman arm, it's actually leaking from around the adjustment nut. Is there an O-ring under it? I can't find any indication of one in any exploded diagrams of the box assembly to see what could be leaking under that nut. If there's not an o-ring, then what seals it?

 

...........I could be wrong but I think its a soft copper washer............kim.......

 

I'd think something has to be there, but there is nothing shown in the seal kit for the gearbox and nothing shown in any diagram. I'm going to remove the existing locknut and install a new copper crush washer along with a new nylon locknut. Hopefully that'll seal it up nicely.