M109 Self propelled gun info needed

[David Herbert]

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

[Lynn Eades]

Try Spicer?

[jdmcm]

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?


IMG_20171004_142006.jpg

[jdmcm]

And I believe this is the steering...

IMG_20171004_142218.jpg

[Paul Singleton]

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

[jdmcm]

Thanks Paul..I'm on it!

John

[Paul Singleton]

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/

[David Herbert]

Pinching this from Paul's post #22 : http://automotiveenginemechanics.tpu...34-35_30_1.jpg

That drawing is clearly marked up as if the whole pack is at the rear of the vehicle driving rear sprockets. M109s, M107 / M110 are front engine / drive so what vehicle is that instalation from ?

Does anyone have a list of vehicles this power pack fitted ?

David

[jdmcm]

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

s-l500.jpg

s-l64.jpg

IMG_20171004_142024_hdr (2).jpg

[Paul Singleton]

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

[jdmcm]

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!

[rob love]

Originally Posted by jdmcm

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

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.

[David Herbert]

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

[rob love]

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

[rob love]

Last photo I will show from the manuals is a shot from tm 9-2520-234-35. It shows what I suspect is the setup yours was meant for. In this case, the final drives are referred to as output drives. They do, in fact, have a planetary set of gearing in them. This manual does have some very nice coloured illustrations showing the paths of power.

[jdmcm]

I suspect that the problem is I have the flanges below which are bolted in with a bolt and washer, in place of the flanges I need which are in Rob's manual drawing

s-l64.jpg

DSC01316c.jpg

I think the confusion has come from the flanges being removable, I suspect if I were to take them out the output end of the transmission would look exactly like the drawing in Rob's manual. And I think David is also correct, that picture I posted is the brakes, not the steering, pretty clear after reviewing Rob's steering diagram. So I think I am still on the hunt for the original two flanges that Rob identified early on...Thoughts?

[Ed Storey]

To save rob a lot of trouble, TM 9-2350-311-20-1 is on-line as a pdf and can be found at:

http://www.liberatedmanuals.com/TM-9-2350-311-20-1.pdf

[rob love]

Thanks Ed...I mentioned it was available online in an earlier post, as so many of them are. However, it makes things a lot quicker if you can refer to someone who has worked on them, or at least look at the real thing. Especially when you consider some of these manuals will cover several different models of application.

To be totally honest, I wasn't an M109 guy when I was in the service. It was a trade specialty course, and every time they went to load me on a course, it would get yanked away. One time I didn't even make it away from the control office counter and the course was gone. By the time I left the regiment I was a Sgt, and had people who did that kind of work for me. Heck, I wasn't even supposed to have a toolbox. Big battle over that with my ET... I eventually won and got to retain the box. Eventually I got tired of being a data entry monkey and cat herder so I retired. I now find myself having to look after a pair of the M109s, so whatever peripheral experience I got on them has come in handy.

[Malcolm Towrie]

Ah, I see.
Looking at the photo in your post #11, that pack looks quite long from front to back. The t54 engine and tranny are quite narrow and really jammed tight together. Have you checked there is enough space between the firewall and the fan compartment?

And how would you drive the fan?


Malcolm

[David Herbert]

Good question about fan drive. A tracked armoured vehicle generally requires 10% of its engine power to drive the fans at max power. A Leo 2 disengages its fans if you kick down the transmission and releases another 200 HP !

This much power is needed because there is absolutely no natural ventilation in a tank engine bay and no gaps between units so heat just builds up if not removed unlike in a car where it is blown away by the movement of the vehicle and only needs to be extracted from the inside of the engine.

David