Need help ID this gear box. Terrell Gear Drive Division
 

I need to find out how it works. It is mounted halfway between the transmission and differential. The truck is 87 L8000 7.8 turbo with 5 speed. The truck was purchased from a US Forestry Auction but has Small town fire department stickers on it. Currently the truck drives just fine but this gear box is taller than the bed. I want to get rid of it unless I can find out what it is used for and if it has any useful value to me.

Description of what I see and pics below.

Drive shaft input and output. These are no offset and located opposite of each other. Only way for these gears to be engaged is for the transmission to be in gear. For this to be much use, there must be a way to disengage the rear output shaft other wise the other stuff listed below will only operate as I drive down the road.

Massive 5 V Belt pulley on the top side. Does not rotate when I drive.

Huge hydraulic? pump mounted to the front side just above the input drive shaft.

Above the hydraulic pump there is a huge flange that matches the flange on the drive shafts. Almost looks like it would be a transfer case but the truck is 2wd and the output shaft would be way too high to hookup to the front drive train.

There are 4 small cylinders about 4" diameter and they have 1/4 air lines that have been cut. I assume that these cylinders work to engage/disengage the components listed above???

http://i118.photobucket.com/albums/o...psc37dcc67.jpg

Front side.
http://i118.photobucket.com/albums/o...ps087e1ce2.jpg

Back side.
http://i118.photobucket.com/albums/o...ps7bb33577.jpg

Close up front side.
http://i118.photobucket.com/albums/o...psc669170d.jpg

Probably to drive a pump using the drive shaft as the source of power.

Terrell Machine Company - History

Check the author notes, the company was bought out and rolled into Comer Industries in '92.

I find a lot of similar equipment, but can't find a hit using the model number in your pics.

Not sure what you would ever use it for. Since you don't have whatever those belts were driving.... Given the age and the facts surrounding equipment like this, I'd say it's probably headed to the scrap heap.

I looked at the site prior to posting. They don't have any current products that look similar. I would think it would have function for a truck with a lot of accessories. For me it is just a power robbing future oil leak. If that is a huge hydraulic pump on the front of the unit, I could find a use for that.

PTO
 

That is a PTO that was used to drive hyd pumps and whatever else you wanted to. I dismanteled a Ford pumper truck that had a similer setup in it , the PTO drove a high pressure water pump. It was designed to disconect the rear driveshaft and use the main trans as a speed control -- ie. the faster the pump runs the more pressure it makes. That unit could be worth something to somebody building up a service truck or farm truck. Having hydraulics and a pulley system to run a air compressor or pumps could be very handy.


Have A Great Day ------- Hotwrench}>

Great! I have a question. Can I rotate the gear box (input to output)? If I keep it I would like to rotate the box for the PTO shaft to face the back of the truck.

I dont think rotating it will work. When you kick it in neutral, the front driveshaft would be free and the rear driveshaft would be engaged.

Can you take the pulleys off and use that shaft?

PTO
 

Reversing the power flow won't work on most of this type of box. Some of them are reversable from front to rear with the power output shafts ie. dissasemble the power output shaft and install from the reverse side, usually there is a bearing boss on both sides of the box and shafts can be installed from either side, not saying that this one will but its possible with other brands of boxes.

Have A Good Day ----- Hotwrench}>