Hi,
Ok, now I understand.
This could be a ATC chassis, however I notice a few things that may not indicate this.
All of the BLM firetrucks were originally integrated at S&S Fire, a company located in Gas City, Indiana. S&S went out of business about a year after the TATRA truck sale to the BLM. This caused problems, because, of course it was their truck. The Bureau of Land Management had problems having the trucks serviced as a result.
1) I notice that the fuel tank is on the opposite side of the S&S trucks when equipped with the 4-door cab. It could have been moved when the fire package was taken off, but that would put the exhaust outlet right behind the fuel tank. It could also have been an early truck, or a chassis not sold or configured differently.
2) I can see the bottom of the TD transmission sticking out, visible below the fuel tank.
3) A small matter, but the grill badge is TATRA all the BLM trucks and IMOD trucks have an ATC grill badge.
3) If you had some photos of the inside of the cab there would likely be some left over controls from fire apparatus.
As far as the Twin Disc TD61-1177 transmission and remote mount 8-FLW-1750 TC, it is a drop-box style transmission TD developed for the unique TATRA central tube frame and drive-line. The transmission bolts directly into the frame tube becoming a structural component. The TC bolts to the engine with a wet flywheel housing, there is a prop-shaft from the TC to the transmission input shaft. The drive-lines fit directly front and rear attach to the transmission outputs with a spline coupling.
It is a very compact transmission installation. There are 3 high-power PTO located on the backside of the PTO where the transmission charge pump, bell-housing scavenge pump and ancillary systems hydraulic pump(s) are located.
There are other TD transmissions ATC used with the TATRA chassis. Twin Disc transmissions generally have a rather large bronze data plate located near the bottom of the housing if you have a chance to look for it.
The truth is that Twin Disc transmission are not commonly used in trucks in the United States or Canada! They are limited to special applications. The US military uses and has used for a long time almost exclusively ALLISON transmissions for logistic trucks.
There were some transmission problems reported with trucks in-service with BLM, from my observation they resulted from poor transmission/torque-converter plumbing integration/installation rather than the transmission itself. I personally managed test vehicles equipped with the TD61-1183 TD drop-box type transmission during grueling testing for the USMC. The TD transmission performs very well. The TD61-1187 transmission system in a TATRA chassis successfully completed USMC first-article-testing including two vehicles undergoing a 20,000 mile whole-life reliability evaluation during the LVSR 10X10 competition. I think an issue arises when service personnel unfamiliar with the TATRA chassis must remove the transmission for service. It is not particularly difficult, but it is necessary to split the frame tube flanges away from the transmission for removal. Service personnel in the US are simply not accustomed or properly equipped. We have split ATC fire and IMOD 6X6 trucks here at IC. It is important that the transmission/TC plumbing integration supports transmission R&R. I attached a photo of the TD61-1177 tranission below the inspection hatch in a ATC IMOD 6X6.
I received the installation Engineering data package for the transmission and torque converter used in the ATC IMOD 6X6 and ATC BLM trucks today from TD. I think maybe what is more important for you is perhaps Twin Disc, and TATRA service and operating manuals?
All the best
Geof
