How to seal the input shaft on a manual steering box

[nrramse]

I have two questions about the manual steering box and how to fix it's leaks:
1) Last time I had it apart, I used a seal like this: http://broncograveyard.com/bronco/i-12809-manual-box-worm-gear-seal.html. Maybe I put it in wrong, but it leaks pretty bad. It's a different design than the original one which is much thicker and has two lips instead of just one. Does anyone sell an OEM style seal?
2) How do I seal the shims that go under the worm gear retainer?

Newell

 

[DirtDonk]

Hard to tell by the pic, but it looks at least similar to the one I did many years ago. However, if like you say, it's not the same as the original, that might not be helping matters. Mine was exactly like the one I pulled out, so I didn't have that issue to deal with or wonder about.
Not sure where to get an original nowadays. I used to just go down to the dealer and they'd have that stuff in stock! Even had a new box the same day when I replaced my original.

For the shims, I put a thin layer of silicone on every darn one of 'em! Wasn't easy, and I only did the outer edges too. Now I think I'd use the spray-on type, like Permatex Ultra Copper in the can. Goes on real thin and should work great.
Get the smallest can they have though, since it doesn't seem to have a long shelf-life with regards to spraying out the nozzle.

Sorry I can't help with the seal, but maybe contact a steering box rebuilding company to see what they use?

Good luck.

Paul

 

[nrramse]

... I think I'd use the spray-on type, like Permatex Ultra Copper in the can.

Why didn't I think of that?? I even have a can sitting on the shelf.

I have a spare steering box and it's seal looks fine - I'm tempted to give it a try.

Thanks Paul!

Newell

 

[DirtDonk]

I would. Swap out the seal, and maybe even the whole end-cap, on the boxes and keep the leaky one as the spare.
If the old one doesn't leak, get another new one for the spare box before you put it back together. Maybe it's bee nicked or something? Maybe it just isn't a good design? Would 2 of them fit into the same spot maybe?
Worth looking into anyway.

Are you verifying the end-play when messing with the shims? Might as well too, since you've got it all apart.

Paul

 

[nrramse]

Are you verifying the end-play when messing with the shims? Might as well too, since you've got it all apart.

Paul

My manual says the worm gear preload is 5-10 inchpounds. Two problems there:
1) My torque wrench doesn't go that low
2) I don't have a torque wrench that fits on the end shaft.

Any suggestions?

The way it is right now, with the retainer and all the shims bolted down, it can be moved by hand but not easily (I have to grip the shaft with my fist to turn it). I do have more shims if needed.

Newell

 

[DirtDonk]

Sounds to me like it's a bit tight. Can't say for sure of course, but even 10 inch lbs is less than one foot lb, so one would think that you could turn it without too much strain.
If I remember, when a box is quite a bit too tight, you can feel the roughness of the bearings. Just a little tight and things still felt pretty smooth. Just right and it was, like smmooooooth, man.

Not scientific, but at least you know one thing. You want smooooth.

Paul

 

[nrramse]

I agree - it seemed too tight. I swapped out shims until it was easily turned by my fingers, but has no noticeable endplay. I'll post back if anything bad happens!

Thanks Paul

Newell

 

[nrramse]

Follow up -

I think I got it shimmed right. It drives as good as it ever has. Unfortunately, its still leaking out past the seal and past the shims.

I tried the copper spray on the shims but surprisingly it still lets a little out so I think I'll try a thin amount of RTV black unless someone has a better suggestion.

I'm confused about the seal. Yes, its used and probably original but the rubber seems good and it makes a snug seal against the shaft. I have a theory that maybe its because the box isn't vented and pressure is building up with heat. I'm thinking of tapping a hole into the fill plug and venting with some fuel hose and a fuel filter (like many do with their axles). Thoughts?

Another thought I had is to buy a redi-sleeve and put it over the input shaft to increase its diameter. I'll try that if the vent doesn't work.

Wow - it sure would be nice to have something on this truck that doesn't leak!

Newell

 

[nrramse]

I may be talking to myself now, but I'll write anyways

The RTV black is definitely holding up well for sealing the shims. I put a light bead around the perimeter of each shim, tightened it all up, and let it sit for 24 hours. It stayed nice and dry yesterday after driving around town for a bit. I also put a rubber washer (for oil pan drain plugs) under the adjustment lock nut, and some thread sealant on the same nut so, for the first time since I've had the truck, most of the steering box is clean and dry.

My theory about needing to vent didn't work - oil is still coming past the seal! I'm about to try a redi-sleeve if I can find one, but a neighbor had an interesting idea I wanted to ask you guys about which is to put a little carb cleaner on the rubber seal and try to swell it enough to make a tight seal. Has anyone tried this? Or maybe tried some of that engine oil treatment that is supposed to stop engine leaks?

Newell

 

[DirtDonk]

Not a half-bad idea Newell. I'd try it at this point too. You've tried practically everything else I'd say.
I've used things like Seal-Swell and other similar chemicals too, with mostly good results. Never had to try it on a steering box seal before, but if it's made of the same materials, it should work.
Might try the carb clean, but the last time I dipped a seal into the real nasty stuff (Chem-Dip), it must've swelled to three times it's size!!! Good stuff that.
A soaking in water for a few days brought it back to almost normal. Worked real good after that.

Good luck.

Paul

 

[nrramse]

I ended up using two redi-sleeves. I also put a rubber oil pan plug washer under the adjustment lock-nut, and some thread sealant. The box is leak free!

Newell