two small metal teeth on transfer case drain plug

[Lostchain]

Are you saying that for those to be in the transfer case they couldn’t have come from the transmission. If yes, is it possible for me to just drop the transfer case take it apart and find the damage bearing. Or take the transfer case to a local Allison shop in Salt Lake. I don’t know logistically how to get the entire transmission with their integrated transfer case out I’m guessing it weighs about 1000+ pounds I live on the top of a mountain and if I’m not supposed to drive at this kind of puts me in a spot and did I mention, I am totally broke

Well, if your broke anyways, just run it until it blows. You never know, that thing might run for a long time. In the mean time start saving your pennys for the eventual rebuild.

 

[87cr250r]

I don't believe the above will be true. A broken cage in a bearing is a big problem. This will strand you, it will require expensive recovery, and will cause extensive damage. It's probably a $25 bearing at this time.

 

[Keith Knight]

I built this which allowed me to change the transmission by my self. In the TM it shows how to make a lifting bracket that bolts to the transmission and is a perfect balance point for a single point lift. Using a small chain hoist I lifted it just enough to take the weight off then after removing the cross member behind it rolled it backwards far enough to clear everything then dropped it down onto a cart that I made then rolled it out. I purchased a slightly used one from a wrecked Fmtv, way cheaper than a rebuilt or getting it rebuilt.

 

[GeneralDisorder]

I live on the top of a mountain and if I’m not supposed to drive at this kind of puts me in a spot and did I mention, I am totally broke

......This is not the truck to own or even consider buying in the first place if that is your budgetary situation. My only advice at that point is to sell the truck and buy one again when you have the means to pursue this type of project. Next time - whatever you pay for the truck - have at least triple that on hand after the purchase for "contingencies". Even if you just decided to drive this truck - what's going to happen when you have a tire blow out or it needs an alternator or a starter or?

28k miles is on the WAY high end of what the military puts on these trucks. I'm not sure I've even seen one come from service that high..... In fact their maximum service life is estimated to be about 35k miles. So this thing has been USED. And the way these run at redline and run their drivetrain at double their road speed really puts the abuse to them so maintenance is critical.

I don't feel like this is the truck for you at this time. Just my honest opinion.

 

[Zach_M1078A1]

......This is not the truck to own or even consider buying in the first place if that is your budgetary situation. My only advice at that point is to sell the truck and buy one again when you have the means to pursue this type of project. Next time - whatever you pay for the truck - have at least triple that on hand after the purchase for "contingencies". Even if you just decided to drive this truck - what's going to happen when you have a tire blow out or it needs an alternator or a starter or?

28k miles is on the WAY high end of what the military puts on these trucks. I'm not sure I've even seen one come from service that high..... In fact their maximum service life is estimated to be about 35k miles. So this thing has been USED. And the way these run at redline and run their drivetrain at double their road speed really puts the abuse to them so maintenance is critical.

I don't feel like this is the truck for you at this time. Just my honest opinion.

I make between 250 and 300 K a year broke is specific to some major expenditures at the beginning of 2023 and Biden has me running tight. My cost of living has gone up about 40% above the historic norm. I have a mechanical engineering degree, as well as an electronics engineering degree I don’t pay people to fix anything I haven’t ever paid someone else to fix anything literally ever I think it’s sad when people just literally buy everything and act like they’re handy if something breaking causes someone to just buy a new one or pay someone else to replace it they are not handy, nor did they fix it writing a check isn’t fixing anything

 

[Zach_M1078A1]

Actually, my previous post is not 100% accurate. I don’t paint and I don’t do roofs

 

[Keith Knight]

I'm also a Mechanical engineer and fix my own things. I outlined how you can do it in my earlier post if you have any questions let me know.

 

[GeneralDisorder]

I make between 250 and 300 K a year broke is specific to some major expenditures at the beginning of 2023 and Biden has me running tight. My cost of living has gone up about 40% above the historic norm. I have a mechanical engineering degree, as well as an electronics engineering degree I don’t pay people to fix anything I haven’t ever paid someone else to fix anything literally ever I think it’s sad when people just literally buy everything and act like they’re handy if something breaking causes someone to just buy a new one or pay someone else to replace it they are not handy, nor did they fix it writing a check isn’t fixing anything

I agree. I'm a Motorpool veteran and a former software engineer and I currently own a performance shop building race cars and chassis dyno tuning, etc. No hands other than my own have ever touched my truck.

If that's the situation then I would leave it till the money situation improves or build yourself a hoist to get that transmission down so you can get that rear cover off or move the cross-member or whatever it takes. That's what the majority of guys on here would do I'm guessing. We don't have a lot of members in this section of the forum that just pay to have stuff done - there's some but I don't think that's the majority. Most of us do our own work like you.

 

[Zach_M1078A1]

I agree. I'm a Motorpool veteran and a former software engineer and I currently own a performance shop building race cars and chassis dyno tuning, etc. No hands other than my own have ever touched my truck.

If that's the situation then I would leave it till the money situation improves or build yourself a hoist to get that transmission down so you can get that rear cover off or move the cross-member or whatever it takes. That's what the majority of guys on here would do I'm guessing. We don't have a lot of members in this section of the forum that just pay to have stuff done - there's some but I don't think that's the majority. Most of us do our own work like you.

I see that you said you are a motor pool veteran do you have any idea why this bolt would be marked in such a way?

 

[Zach_M1078A1]

I wonder if that marked bolt is indicating that this modification was already done and those pieces were messed by the technician or are from a different bearing. This truck was being serviced through 2014 and most of the upgrades that I have seen other people doing. We’re already done on this truck by the Army. Everybody talks about how everything rubber was absolutely falling apart on their truck, but every hose and bushing on this truck seems to be in relatively good condition except for one cracked CTIS valve hose. There has not been even the beginning signs of a leak anywhere on this vehicle, so I think it was regularly used and serviced

 

[Skyhawk13205]

I am doing an oil change on the transmission and found these on the magnetic drain plug to the transfer case. Oil looked clean and no shavings. Don’t know if this is the initial service or if it was done before it has 28,000 miles and is direct from govplanet.

what is the SN of the transmission. I think it was an aluminum cage on the C6 thrust bearing. It was changed to a steel then finally to a composite based on the service letter.

 

[Zach_M1078A1]

what is the SN of the transmission. I think it was an aluminum cage on the C6 thrust bearing. It was changed to a steel then finally to a composite based on the service letter.

6510426470
I think that leading six might be a G or eight I don’t know I think it is six

 

[GeneralDisorder]

I see that you said you are a motor pool veteran do you have any idea why this bolt would be marked in such a way?

I don't have an explanation of that. It's not practice at the unit level to mark such a bolt AFAIK.

Sadly the military isn't even going to get inside a transmission at the unit maintenance level (my direct experience). The military will simply swap the entire transmission assembly with a new or remanufactured unit based on either the determination by the technicians and their direct superiors or sometimes based on the results of oil analysis - the military operates depot's staffed by either full time or dual status reserve technicians. One such facility that I know handles Allison transmissions is Red River Arsenal.

The quality of some of these remanufactured units has been hit and miss and when you mention "reman unit from RRA" you will often get the eye roll from the active duty guys that have had to pull them back out when they fail to function as promised.

Which could play into these pieces being left over from insufficient cleanliness, etc.

Look for plaques or stickers that indicate remanufacturing has taken place - usually located prominently on the outside of the unit.

 

[Zach_M1078A1]

I don't have an explanation of that. It's not practice at the unit level to mark such a bolt AFAIK.

Sadly the military isn't even going to get inside a transmission at the unit maintenance level (my direct experience). The military will simply swap the entire transmission assembly with a new or remanufactured unit based on either the determination by the technicians and their direct superiors or sometimes based on the results of oil analysis - the military operates depot's staffed by either full time or dual status reserve technicians. One such facility that I know handles Allison transmissions is Red River Arsenal.

The quality of some of these remanufactured units has been hit and miss and when you mention "reman unit from RRA" you will often get the eye roll from the active duty guys that have the pull them back out when they fail to function as promised.

Which could play into these pieces being left over from insufficient cleanliness, etc.

Look for plaques or stickers that indicate remanufacturing has taken place - usually located prominently on the outside of the unit.

No plaque other than the original one from the previous photo that I posted. There are a couple of pristine barcode stickers, but they just say whatever cover they are stuck on

 

[Zach_M1078A1]

Barcode sticker

 

[Skyhawk13205]

6510426470
I think that leading six might be a G or eight I don’t know I think it is six

It is not in the SN range, I would pull your screen for the transfer case to see if there is more material.

 

[Zach_M1078A1]

It is not in the SN range, I would pull your screen for the transfer case to see if there is more material.

I was going to today, but lightning storm

 

[Suprman]

On the tcase line going to the scav pump if you take the line off there is a catch screen you can unscrew. Look there for more pieces.

 

[Ronmar]

It is not in the SN range, I would pull your screen for the transfer case to see if there is more material.

Ok, that sheds a little more light on this mystery. It appears Allison has re specced this part 2 if not 3 times.

A question I had in the other discussion was that the part number for the old bearing in the service information letter(SIL 17-WT-11en) that Langstonhs referenced, was not the same as that listed in the 24P. That pic of service information letter 29-WT-96 you posted above on the left references the old part number in the 24P for the roller thrust bearing. Its hard to read but if I read it correctly, they updated the part but kept the same (original?) P/N23015799
This also agrees with the tech manual(ch21) saying all before the S/N listed in that SIL need to be replaced during any major trans service. I put a screenshot of that manual page in the other discussion.

So here is how I read this:
1. In 1996, at S/N 6510072174, they updated P/N 23015799 with an improved roller thrust bearing But kept the same P/N. SIL 29-WT-96 directs all previous s/n transmissions to be retrofitted and further troubleshot if debris Is found at the drain (This was the first change).

2. Somewhere between 1996 and 2011, that original roller thrust part number 23015799 changed to roller thrust bearing P/N 29544806. Was it re-specified again? Is there another SIL-??-WT-?? Floating around specifying another serial number change/update point? It could also be that it changed when they introduced the 3700SP, the mostly similar follow-on to the MD3070PT...

3. In 2011, at S/N 6511014364, they released SIL 17-WT-11en, directing roller thrust P/N 29544806 was discontinued and it was to be replaced with composite thrust washer P/N 29545936.

What I get from this is that if you have a MD3070PT transmission prior to S/N 6511014364, your roller thrust bearing can be retrofitted with the composite thrust washer, as it appears that every type roller thrust they have tried in that location has had higher than expected failure rates...

I have a question into an Allison rep to clarify this, and will let you know what I find...

 

[Zach_M1078A1]

Finally, the lightning storms passed. I got out there and checked the screen on the hose returning to the transmission from the transfer case and this is what I found. If the transmission was still working and not making any noise, did I catch this fast enough that I can just replace it with the new bushing