oil coming out off the hollow stud

[willy]

I have oil coming out off the Hollow stud for the CTIS
What is my problem .????
How do I fix it or what is involved.?????
Where is the oil coming from.
I hope the differential but it feels like 15W-40
Plese help if you can.??
Willy

 

[gimpyrobb]

You have a bad seal in your ctis system allowing gear oil in from the pumpkin. Thats all I can give you.

 

[wreckerman893]

The consensus among a lot of people that own CTIS vehicles is that it is best to disable them as a preventive measure......I was never a big fan of it anyway.

I plan to do the same to my new 900 series truck.....I see no scenario where I would need it and it does not seem to work anyway....I had to inflate a low tire with a gladhand airhose when I picked the truck up.

 

[Rustygears]

If the oil is thin, like crankcase oil and not heavy diffie oil, it could be blow-by from the air system. If the dryer isn't serviced and there are/were air leaks causing the compressor to cycle frequently, oil will collect in the CTIS system. It all depends on how much oil and how thick. If it is from the air system, you'll find it on other wheels as well. If it is a blown seal on that axle, it should not be visible on wheels on other axles.

 

[trukhead]

I have oil coming out off the Hollow stud for the CTIS
What is my problem .????
How do I fix it or what is involved.?????
Where is the oil coming from.
I hope the differential but it feels like 15W-40
Plese help if you can.??
Willy

Which wheel? Is it possible to sample the oil in the axle from which the oil is occurring?
What is the possibility of 10w-40 in the axle?
What is the appropriate compressor cycling pattern?
Mine inflated to the 100nsomething and releases through the air dryer down to70-80something and reflates about every minute or so

If the oil is thin, like crankcase oil and not heavy diffie oil, it could be blow-by from the air system. If the dryer isn't serviced and there are/were air leaks causing the compressor to cycle frequently, oil will collect in the CTIS system. It all depends on how much oil and how thick. If it is from the air system, you'll find it on other wheels as well. If it is a blown seal on that axle, it should not be visible on wheels on other axles.

I am very interested in this thread and diagnosis of the CTIS as mine functions well and I hope to keep it functioning well.
Is there a proximity factor of oil taking the path of least resistance or would the oil distribute equally from the compressor to the air dryer then to the axles?

What is the correct compressor cycling pattern? Mine inflates the system to 100n something and the airdryer then dumps the air to 70-80 something and the compressor then reinflates the system abut every minute and a half or so.
I also will be stripping an A3 axle of its wheel bearings and seal for reuse as spares for my A3 so I'll share pictures and relevant info.

 

[1 Patriot-of-many]

Gear oil has a distinctive smell.

Trukhead CTIS cycles as many times as it takes to inflate the tires. It will only allow so much loss of pressure( keep enough pressure that the brakes need) Air venting from the axle vent indicates quad seal is bad or axle nuts are not properly tight, your outer seals are bad too if venting. Also your outer bearing has probably been washed clean of grease by gear oil if you are getting venting from the top of the rear.


Willy, at a minimum your outer seal is bad, your outer bearing has been washed clean of grease and your outside quadseal is kuput. You'll have to take the wheel off, pull the axle, check the outer bearing and race(bet they're bone clean of grease). Quadseal replace, clean the race and inside of hub of any gear oil, clean the outer bearing and regrease, replace outer seal. Don't forget the oring on the inside of your outer bearing. Take a look at your inner bearing too, see if it looks okay greasewise. Follow the TM
ARMY TM 9-2320-386-24-1-1 page 786 Assuming here one of your rear axles.

 

[Rustygears]

If CTIS is off and the truck is sitting, idling, once the tanks are aired up the compressor should only cycle once every 10 or 15 minutes. If it's once a minute, you have a big air leak. The spec is for it to kick in at 90 PSI and shut off at 130 PSI.

If the dryer is fouled up (often seen in A3's with air leaks), you will have moisture and snot when you drain the air tanks. If the dryer is working right, the 'wet' tank is bone dry all the time - Always.

In the A3 CTIS system, all tires are connected in parallel. There is no provision for monitoring or separately filling individual tires. The tires will all reach equilibrium at some common pressure. If that pressure is less than the set point, CTIS fills them. It if is higher, CTIS vents the excess. If the vent rate exceeds a set CFM, the wheel valves on each wheel slam shut to isolate the tire from the system to avoid running the tire flat. When not operating, all the CTIS plumbing is purged to save the wheel hub seals and to force the wheel valves to close & isolate each tire.

When the system starts up, the CTIS 'puffs' a short burst of air into the system to open the wheel valves and let the tires charge the lines while it monitors the pressure. This is the puffing sound you hear when you turn it on. It puffs and sees if the line goes above 20PSI. If it doesn't get there, it tries again and measures. It will repeat a few times and if no joy, displays 'Flat' on the screen. All this means for sure is that the system could not get the lines to charge over 20PSI either due to plumbing leaks or the tires were less than 20PSI.

If there is oil in the system, it will gum up the valves in the CTIS manifold system (under the truck, aft of the battery compartment). It will work its way to the axles and the wheel valves over time and gum them up too. A bad axle seal will put gear oil into the wheel valves for sure. This is why people were asking whether the oil was thick/thin/had distinctive gear oil smell, etc. This is a way to easily diagnose the oil source.

The comment asking if you have checked your axles to confirm someone didn't fill them with 10w motor oil is a very good question and more important than the CTIS consideration at this point until you can confirm. Light crank oil will destroy the axle & Diffie.

 

[willy]

Today I took the front CTIS system apart What a mess
I have bought from Eastern the M35A2 change over system and are putting A2 bearings up front what a mess this CTIS makes found oil and smut in the lines after the original airhose from the sytem is nice and clesn but not in the hub it pickup a lot off grease and smut I did this to have spare bearings for the rear oil coming from the hollow stud.
I need to find a brass drift to nock out the bearing from the hub or is there a other way.????
And I need to get out the hollow stud may be I will go to my friend at a tire place and have them puss it out with a press.
Willy

 

[1 Patriot-of-many]

The outer bearing just pulls right out after you get the two axle nuts, the piece in between them and the outer seal.

 

[trukhead]

The outer bearing just pulls right out after you get the two axle nuts, the piece in between them and the outer seal.

Will the hub then slide off of the inner bearing without force?

Without disturbing-destroying seals?

Will it be possible to remove the inner bearing and seals for reuse or save for latter as a spare?

I've got a spare axle sitting and I want to remove the A3 bearings and seals to keep as spares.

Great thread and input!

 

[1 Patriot-of-many]

Will the hub then slide off of the inner bearing without force?

Without disturbing-destroying seals?

Will it be possible to remove the inner bearing and seals for reuse or save for latter as a spare?

I've got a spare axle sitting and I want to remove the A3 bearings and seals to keep as spares.

Great thread and input!

The outer quad seal is behind the outer race. It may be possible to drive
Them out if you drive it on the outer part of the retainer. If you drive it from the inside of the retainer it gets bent up. I had a shop do mine and had to buy a new quadseal retainer.

As far as the inside bearing, it slides off with the hub. I havent tsken the inside bearing or race out of the hub. GLcaine would be the one to contact about that.

 

[willy]

I removed the A3 rear bearing without to much damage but now having the problem that they milled the rear off the hub and the seal has no place to be installed.
So I am looking for 2 or 1 front hubs if any one has some for sale let me know at
willyd at hughes.net.
I like to go on the Alcan Hwy trip I am not sure that I have enough time to fix this A3 truck
The front rear passenger side has a leak and diff oil is coming out off the hollow stud I will remove it next week after I can fix the front may be just missing the cork plug.
live is color full never a dull moment
Willy

 

[timntrucks]

willy im looking for a update on this post. today i seen a small amount of thin oil coming out that line.. i am taking off all the parts to that ctis system. now i need to close those holes up

 

[HDN]

When I did my tire replacement I discovered gear oil leaking from three of my rear axle hollow studs. I plan on doing the seals this spring, but I'm wondering now: could a malfunctioning CTIS power manifold cause blown seals? The CTIS ECU on my truck doesn't turn on and the wheel valves are disconnected, but the power manifold is still hooked up to the axles and air system. The last thing I'd want are my new seals to blow out because the power manifold is letting 120 psi air into the axles. I might consider disconnecting and capping air lines to the power manifold.

Any thoughts?