What does the little seal in the steering arm cover do?

[diesel_dave]

I am servicing the hubs on my M1152 and the steering arm cover on the left rear wheel was leaking from a bad RTV job. When I took the cover off, I found the little seal that goes in the cover was all mangled. I removed it but it goes in the area shown in the photo I attached. What does this seal actually do? I can't figure out what purpose it serves but it obviously does something or it wouldn't be there. Anyone have any ideas? If it doesn't seem to do anything vital, I'd like to just put it back together without the seal because I obviously don't have a spare lying around.

Thanks!

 

[Action]

If it lines up with the center of the spindle, CTIS.
central
Tire
Inflation
System.
newer trucks can have a shield to protect a hose, if there was one.

 

[diesel_dave]

If it lines up with the center of the spindle, CTIS.
central
Tire
Inflation
System.
newer trucks can have a shield to protect a hose, if there was one.

My truck does not have CTIS. Think I can get away without it? I guess I'll see if it leaks somewhere weird without it installed.

 

[Action]

99.9% of hmmwv dont have it. Byou may have a plug on the outside, center of hub.

 

[Mogman]

If you do not have CTIS then remove the seal, that way it will not cut a groove in the the piece the seal rides on so if later you want CTIS you should not have to replace that piece also.

 

[diesel_dave]

If you do not have CTIS then remove the seal, that way it will not cut a groove in the the piece the seal rides on so if later you want CTIS you should not have to replace that piece also.

Perfect! Exactly what I was looking for. I do see what you are talking about regarding the wear on that shaft. It's just barely visible right now but I could definitely see how the damaged seal would wear it down over time.

Side note for anyone who just got their truck or will be getting one soon and is reading this thread: DO NOT drive anywhere without first doing a hub inspection and service. I thought I would be fine putting it off for a few weeks but was forced to act sooner because one of my hubs is leaking pretty badly. Well, when I went to fix the leak, the drain bolt was barely finger tight and the fill port was barely finger tight but even worse was the 4 large bolts that hold the steer arm cover to the hub were also FINGER tight. If that thing comes loose at freeway speeds, you are going to have a bad time. I still need to service the other 3 hubs but a did hit a few of those bolts with the torque wrench and they were all way too loose. So yes, listen to the advice here on this forum and don't drive anywhere without doing this service and inspection.

 

[Mogman]

Exactly why it is best to do a FULL fluid/filter change and a good inspection on any HMMWV immediately upon receipt.
Unless of course you get one from a reputable dealer like RWH, even then a good mechanical inspection is highly recommended, different mechanics tend to look at different stuff, why you don't have your airplane inspected by the same A/P every year, unless he is really anal...

 

[T9000]

Perfect! Exactly what I was looking for. I do see what you are talking about regarding the wear on that shaft. It's just barely visible right now but I could definitely see how the damaged seal would wear it down over time.

Side note for anyone who just got their truck or will be getting one soon and is reading this thread: DO NOT drive anywhere without first doing a hub inspection and service. I thought I would be fine putting it off for a few weeks but was forced to act sooner because one of my hubs is leaking pretty badly. Well, when I went to fix the leak, the drain bolt was barely finger tight and the fill port was barely finger tight but even worse was the 4 large bolts that hold the steer arm cover to the hub were also FINGER tight. If that thing comes loose at freeway speeds, you are going to have a bad time. I still need to service the other 3 hubs but a did hit a few of those bolts with the torque wrench and they were all way too loose. So yes, listen to the advice here on this forum and don't drive anywhere without doing this service and inspection.

On my hub fill port bolts someone drew a white line across the bolt and part of the hub with some paint that is not easy removable after the bolts were torqued so it can be quickly inspected visually if the bolts are loose. I think the spec is 8-13 ft lb and it seems like that paint line says the loose bolts are a known issue, even with the nylon washer.

By contrast, the drain ports required a breaker bar to open, it felt tighten to at least 100 ft lb, the Allen wrench bent so much I thought it would break. I have one left that still didn't let go and I pumped the oil out as I much as I could thru the fill port and replaced it for now. I put some penetrating oil on it and will give it another shot, I don't want to strip the drain plug as it would be a major pain to extract it after that, therefore I use an Allen key with a very tight fit, 5/16" IIRC.
I tested several from around the garage because there are some small fit variances between different manufacturers. In some cases I use the closest metric equivalent to get a tighter fit, like the 5/16" = 7.9375mm, so a 8mm key running on the negative tolerance side could be a tighter fit than a 5/16" running on the same negative side especially if they are from the same set. Lots of fun with these trucks lol

 

[diesel_dave]

On my hub fill port bolts someone drew a white line across the bolt and part of the hub with some paint that is not easy removable after the bolts were torqued so it can be quickly inspected visually if the bolts are loose. I think the spec is 8-13 ft lb and it seems like that paint line says the loose bolts are a known issue, even with the nylon washer.

By contrast, the drain ports required a breaker bar to open, it felt tighten to at least 100 ft lb, the Allen wrench bent so much I thought it would break. I have one left that still didn't let go and I pumped the oil out as I much as I could thru the fill port and replaced it for now. I put some penetrating oil on it and will give it another shot, I don't want to strip the drain plug as it would be a major pain to extract it after that, therefore I use an Allen key with a very tight fit, 5/16" IIRC.
I tested several from around the garage because there are some small fit variances between different manufacturers. In some cases I use the closest metric equivalent to get a tighter fit, like the 5/16" = 7.9375mm, so a 8mm key running on the negative tolerance side could be a tighter fit than a 5/16" running on the same negative side especially if they are from the same set. Lots of fun with these trucks lol

So far, I have done both rear wheels and both the drain and fill ports were very loose. I will be putting a paint line on them so I can easily see if they come loose again despite torqueing them. I found the tie rod super wobbly on the right wheel so now I need to find new bushings for it. The left side was completely fine which is weird. I just checked and both 5/16 and 8mm fit in my drain ports. Will be doing the front hubs and glow plugs tomorrow. Can't wait to see what awaits once I dig in to those things.