M109 Self propelled gun info needed

[rob love]

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.

[jdmcm]

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?

[rob love]

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.

[David Herbert]

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

[jdmcm]

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

[David Herbert]

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

[jdmcm]

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

IMG_20171004_142024_hdr_LI.jpg

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