Allison Governer screen filter

I was looking over the TM's and I can't find the pic again but there is a screen filter on the Allison on the bottom tailshaft on my M925.
They called it the governer filter. Anyone serviced this or seen the beast. I am not haveing any problems.

I asked that question and didn't get a reply. You can look up the pn and find a picture and its just a screen. Nothing fancy, I didn't change mine.

I've serviced mine when I did the fluid and filter change.... just a small 1-1/2 inch long screen tube looking thing removed the nut cap and pull it out and replace all done.

You talking about item #3?

Yep # 3 Was just wondering if anyone found it to be catching anything.

I actually ran across that in the TM about a month ago and had it on the list of things to check out. Never got to it though. Thanks for bringing it up again because I'll definitely check it out this time. I'll post my findings with pictures to this thread.

On a side note, since we're looking at this area of the transmission...

The tube in the pictures is at the base of the tail piece on the bottom. I haven't been able to find anything about it in the TMs but it appears to be a vent or drain. What is it for and can it be replaced? How is it replaced? I broke about half of it off when I replaced the jack shaft. The rest that is left is brittle.

Well that was easy enough...

The plug is at the bottom rear of the transmission.



The plug takes a 1" wrench to remove. An 1 1/16" will work if the CARC was thick like mine but the correct size is 1". I got about an eye dropper worth of fluid out of the little cavity. There was no pressure so a small cup will do to catch it. My truck has been sitting for 2 days so you might get more.



Take a small hook pick and catch the inside lip of the filter and gently pull it out. It's all metal but can still be damaged. It just sets in there.




The plug has an O-ring around it that might need to be replaced. Mine was shredded pretty good so it got a new one.




To reinstall, push the filter back in with your finger until it bottoms out and reinstall the plug. Mine was spotless. I hit it with some brake cleaner to remove the oil for the pictures but I found nothing, even with a magnifying glass.

I'm not sure what I expected to find, or what it would mean if I did find something, but my curiosity has been satisfied and it easy to check in the future.

The ends of the filter look to be brass but I'm not sure what the media is made of. If it's not stainless then it might be good to check, if water has made it into the transmission, as it might rust.

Finally! After all this time gaining loads of usefull info i can finnaly contribute!

That screen as there as a saftey measure to ensure govenor operation. It is not uncommon to find a very small black/grey particles in there after many miles of operation. Of the hundred or so of these i have rebuilt i have never found much of anything in one since the fluid flows from the pump to the valve body first eliminating the common contamination from the clutch packs. There is a service interval for them but i do not know it off the top of my head.

Fordnut85 said:

Finally! After all this time gaining loads of usefull info i can finnaly contribute!

That screen as there as a saftey measure to ensure govenor operation. It is not uncommon to find a very small black/grey particles in there after many miles of operation. Of the hundred or so of these i have rebuilt i have never found much of anything in one since the fluid flows from the pump to the valve body first eliminating the common contamination from the clutch packs. There is a service interval for them but i do not know it off the top of my head.

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Thanks for the info. So you used to rebuild these particular transmissions or just transmissions in general? You happen to know what the little tube is I asked about a couple posts back, and how to replaced it?

And...Welcome to Steel Soldiers!

Swamp Donkey said:

Thanks for the info. So you used to rebuild these particular transmissions or just transmissions in general? You happen to know what the little tube is I asked about a couple posts back, and how to replaced it?

And...Welcome to Steel Soldiers!

Click to expand...

I rebuilt Alison "Legacy" trannys (I.e. AT,MT & CT). That tube is just a drain tube for the rear housing. Not a big deal if its broke unless you have pieces floating around in the rear housing.

Fordnut85 said:

I rebuilt Alison "Legacy" trannys (I.e. AT,MT & CT). That tube is just a drain tube for the rear housing. Not a big deal if its broke unless you have pieces floating around in the rear housing.

Click to expand...

What does it mean when trans fluid is coming out of that small plastic tube? My 91 M923A2 leaks ATF at about 14oz per 250 miles. I know because I put a plastic bottle over that tube to monitor the leak. Is there a bad seal in the front of the tail shaft? I emailed Allison and they didn't answer my question. My trans is not overfilled and my vent is clear. Thanks