Help , fan drive 8v71 detroit

[walkerv]

This is in a 79 brigadier , how does this fan drive work or supposed to work , cuz this one isnt working.hopefully these pictures are good enough for some help

 

[kshansen]

Can't really tel what it is from the pictures. Is this a new to you truck or a customer's?

I'd be just making a wild guess that it would be an air operated clutch. Could be air applied or spring applied and air released.

Are there any air lines connected to it or the mounting bracket?

Many trucks had an air line going to a valve on the engine in the water manifold or maybe thermostat housing that turned the fan clutch on and off. Sometimes this was done directly and other times there was a electrical sender that controled an air solenoid that turned on or off air to the clutch for the fan.

Any chance there is a tag somewhere on the drive or housing somewhere? Even a partial name might help identify it.

 

[Former Wrench]

This looks shade-tree to me. Most that I've had 4 lock bolts to loosen the screw operated tensioner. Can't say I ever seen this set up. Sorry.

 

[kshansen]

Maybe some different views from different angles?

 

[petepilot]

can`t be sure but it looks like a bendix viscous drive to me

 

[walkerv]

Can't really tel what it is from the pictures. Is this a new to you truck or a customer's?

I'd be just making a wild guess that it would be an air operated clutch. Could be air applied or spring applied and air released.

Are there any air lines connected to it or the mounting bracket?

Many trucks had an air line going to a valve on the engine in the water manifold or maybe thermostat housing that turned the fan clutch on and off. Sometimes this was done directly and other times there was a electrical sender that controled an air solenoid that turned on or off air to the clutch for the fan.

Any chance there is a tag somewhere on the drive or housing somewhere? Even a partial name might help identify it.

This is owners litter truck couldnt get a good pictures it was oveheated at this point i just janmed my phone in there i didnt see any tell tale air lines. This truck is only one year younger then me lol.

 

[walkerv]

Maybe some different views from different angles?

Yeah i will try in the morning when its cold

 

[walkerv]

can`t be sure but it looks like a bendix viscous drive to me

Possibly i will try finding some info on those for that era, sounds like a good place to start as any.

 

[walkerv]

Ok could this be an oil shear fan clutch? Never heard of one before seems to use engine oil to engage and disengage ? How i dont know gonna look for some info

 

[walkerv]

Found kits for them to rebuild oil shear clutch but absolutely cannot find any info or pictures online i dont know anyone with old Detroit books , not sure if the clutch is made by DD or someone else, i have a hankering this is what i have guess i will just have to wait till morning when i can get a better look at it .

 

[petepilot]

Found kits for them to rebuild oil shear clutch but absolutely cannot find any info or pictures online i dont know anyone with old Detroit books , not sure if the clutch is made by DD or someone else, i have a hankering this is what i have guess i will just have to wait till morning when i can get a better look at it .

theres a guy on the jot website glen akers who seems to be up on old detroits if you can get on that site look him up

 

[walkerv]

theres a guy on the jot website glen akers who seems to be up on old detroits if you can get on that site look him up

Is jot short for something

 

[petepilot]

Is jot short for something

sorry about that ( just old trucks)

 

[Truck Shop]

Those years the Bendix FD-1 and FD-3 were very common on Cat, Cummins & Detroit but those are
obsolete no parts available. The other air hub was the Horton S & HT/S models. If it is a viscous type
that may be a problem too. On most of the old stuff like this issue it becomes an updated repair.

 

[walkerv]

Those years the Bendix FD-1 and FD-3 were very common on Cat, Cummins & Detroit but those are
obsolete no parts available. The other air hub was the Horton S & HT/S models. If it is a viscous type
that may be a problem too. On most of the old stuff like this issue it becomes an updated repair.

Yeah it is a clutch type it freewheels, i found those models you mentioned and looked thru them all ,nothing looks like this thing, asked boss man if this truck was all original , it is minus one overhual. Cant find any pictures of what is called an oil shear fan clutch at all just the repair kit that has seals and what looks like wet clutch disks. Havent gone back to it yet boss man said it was a gallon and a half low on coolant and he was gonna try it again, i have my doubts but we shall see.

 

[walkerv]

Ok gallon and half low on coolant after sitting overnight ran fine all day till the top rad hose blew up, orielly auto parts has this hose in stock in there georgia pdc 33 bucks will be here tommorrow evening. I think it was air locked i replaced lower rad hose on it and this was first time it had been run. Gonna take and post some better pictures of this fan drive and figure put how it works because it bugs my brain that i cant even find a picture of anything remotely similar. This truck and the other litter spreader are going to be sold when he can get another large case spreader. If money was no object i would buy it shorten the frame back up fix it all up nice pretty with a lift axle on it and give it back to him , this old truck was his very first lowboy tractor then it was a dumptruck now it spreads **** and oil in the fields lol

 

[walkerv]

Ok so the part i have circled in below picture is the fan drive, it is a large circular housing behind the pulleys , it has oil lines running to it . The way the housing looks it could very well have a couple wet clutch plates in it like shown in the repair kits , im not quite sure how it works cuz im way to busy on trucks to investigate a 1979 farm truck at the moment. Fan drive does seem to be working correctly , the cuase of my overheat was definitely an air lock when i did lower hose, just did the upper hose and proper test drove it screaming around a field for 30 minutes, then topped of coolant when done . My question is this a dd assembly or is it made by someone else my curiosity has to know lol.

 

[Tenwheeler]

Could it be a Rockford. There was another one back then I cannot recall the name. For the application take it apart and find a way to make it run all the time.

 

[Nige]

Rockford was the first thought in my mind also.

 

[Truck Shop]

Well if it is bast@rd GM or Ford will step up to use it in their trucks. IIRC I have seen one of those before but not in a truck.