M109 Self propelled gun info needed
 

Does anyone have any TM's or pictures for the M109? I am looking for part numbers and pictures of whatever pieces connect the Allison XTG cross drive to the final drives, any help would be greatly appreciated. I know the M109 shares the same final drives as the M2 Bradley, are these the same as the M113 family?

I maintain a M109 in running condition at the museum, and we have others in either monument or preserved state. The museum also has pretty much all the CFTOs for the M109 and the ARV. I'll provide photos of the prop shafts later today when I get to work.

The shafts are much larger than the M113A3/TLAV family. The M109 weighs more than twice what a M113 weighs, consequently, the drivetrain is much heavier.

Rob that would be fantastic, I have a nice running powerpack with attached Allison XTG-411 I was lucky enough to obtain from MCB Pendleton in California, but no ancillaries so I am trying to figure out not only how they hook to the final drives but the steering, shifting and breaking...The Israeli's have a company called Nimda that would put these packs in captured T-55 and T-62's, I want to attempt the same...but I am not clear on how they took the pack which drove the front sprockets of the M109 and had it driving the T-55 from the rear...they must have some way to reverse the gearing? From my rudimentary understanding if you simply swapped it to the back you would end up with several reverse gears vs one forward gear would you not? Thoughts?

I am not familliar with the final drives of a M109 but it is possible that there is one more stage of gearing and the input shaft turns the other way. If so problem solved. If not it must be possible to reverse the bevel gear drive within the transmission. The older GM two stroke engines could be built up to turn either way quite easily but I doubt the transmission would accept that, particularly the torque converter !

David

The reversal could also be done in the final drives. Not saying that's the way they did it, but just spitballin here.

The M109 transmission was not something we ever worked on the internals. You worried about any external stuff, but rebuilds were done at a central contractor.

I'm going to try the local Allison dealer, and if unsuccessful then Tecmotive in Ontario regarding the fwd-reverse issue. Any luck on some info regarding final drive to transmission coupling Rob?

John
Here is a cut and paste from a online manual. Basically it's a pair of ujoints with a small center shaft that fits between the two flanges.

A T55 / 62 has a spur geared first stage in the final drives which then drives into an epicyclic seccond stage so the input shaft from the transmission turns the OPPOSITE way to the sprockets.

If a M109 has a purely epicyclic or a two stage spur geared final drive the input shaft will turn the same way as the sprocket and problem solved.

David

Thanks Rob, that's a great start...and David you might have just solved the other question! I will get a picture of the output on the Allison and then maybe we could figure out what is missing, I sure do appreciate the help

John

John,
There are double UJs like that in some heavy construction plant. The challenge would be the fit to the transmission. The actual UJs will be standard commercial parts.

David

Exactly...its the splined part of the U-joint assembly that slides into the transmission I need to identify...

Attachment 101812

if I had this part of the U-joint holder for both sides I could fabricate the rest

John

You are looking for flange(s) 2520-00-818-0510. Shown as item 10 in photo below. The ujoint associated with that flange is (I believe) a 5-6128X.

That's exactly what I need...now to find somewhere to buy two that isn't an ITAR regulated vendor...there must be a civilian application to this somewhere...I imagine all the M109's that got cut up and these parts just hitting the scrap bin...frustrating! Rob would you have anything that showed how the steering and shifting was accomplished? I know they are both by cable, as well as the service brake pedal. Does the M109 have tiller bars or a steering yoke, my guess it is a steering yoke with a push/pull cable that activates the brakes on either side depending on which way you are pushing?

M109 is a steering wheel. There is a lock for the brake pedal for parking purposes.

I'll dig out illustrations showing the brake and steering systems tomorrow.

Thanks Rob!

The output shaft flanges shown in Rob's post #12 do not look compatible with the transmission shown in John's photo in post #11. The flanges in the drawing look as if they have a rather smaller internal spline than the larger external spline that would be needed to plug into the transmission in the photo. Am I missing something ?

I have an idea which could be completely wrong that M107 / M110 SPGs and M578 ARV have a very similar power pack to the M109. If so could John's photo be of one of those ?

David

Try Spicer?

I am pretty sure the pack came from a M109, that being said it is definitely an Allison XTG-411...perhaps there is a further piece that attaches to the transmission I am missing?


Attachment 101850

And I believe this is the steering...

Attachment 101851

Manuals
 

I just did a search on eBay for “xtg411-2a” and there are two manuals for sale. Parts and a maintenance manual.

Thanks Paul..I'm on it!

John

Picture
 

http://automotiveenginemechanics.tpu...34-35_30_1.jpg

This might answer a few questions, and create a few more. More here:

http://automotiveenginemechanics.tpu...9-2520-234-35/

Went on Ebay and there were these parts for sale, looks exactly like the output flanges on my transmission now

Attachment 101852

Attachment 101853

Attachment 101854

Coupler
 

From the picture that I posted it looks like a planetary reduction unit attaches to the transmission on each side.

From those pictures Paul provided it seems like the final drives slide direct into the transmission, but they must have some kind of a coupler that would allow transmission removal without having to de-track both sides and remove both final drives...there must be a coupler like Rob indicated between the two or maintenance would be a nightmare...Rob actually has M109's he maintains so I am sure he can clear this up! No pressure Rob!

So many questions. Unfortunately our M109 is tarped right now, but I can foresee having to un-tarp it and opening up the front covers. We also have a spare pack (takeout from a monument) that will answer the questions about the flanges, but it is out back and wrapped up tighter than a drum.

We have more than a regiments worth of manuals here on the M109 and the ARV. Unfortunately, most of the pictures are line drawings. One manual that is sitting before me now, TM 9-2350-311-20-1 has some good line drawings of the various systems. The manual is online if you google that TM number. Here is a photo of the complete steering for instance from page 9-17.

Here is a photo from p 10-46 of the same manual showing the flanges and U-joints. Perhaps the photo Paul shows was from a different application. There is no planetary on this output setup.

TM9-2520-234-34P gives 6 different setups of the XTG-411 xmsn. The first three are for the XTG41-2a like you have. Two of them are with a coupling, one of those is with "drive assys, output left and right", and one of them is with a yoke/adapter by the number I listed earlier (2520-00-736-3581). So your transmission may not be out of a M109.

John, I THINK that the photo you posted in post #19 is the equalising mechanism for either the service brakes or more likely the parking brake. I stress though that I have no literature or experience with M109s

David

Below are the photos of what the left and right output of a M109 look like.