Looking for a shot fan clutch...

[jaluhn83]

Anyone got one? Junk, shot, blown up, whatever.... looking to cut it up for a project. All I care about is the threads where it screws onto the waterpump nose, and all I need there is the actual threads - trashed hex is fine also.

Thanks,
~John

 

[ironworker40]

I hope your going to make an electric one like on the 6.0

 

[riotwarrior]

Got one here can be shipped from 98844 on yer dime....

Let me know its yers for the taking

 

[jaluhn83]

Ironworker,

Not sure how the 6.0 unit is, but I'm guessing it's an electric controlled viscous clutch through the ECM. No easy way to make one.... What I am doing is better I think - found a spec for a electromagnetic fan clutch that should work (DT466 IIRC) and found one on ebay NOS but it turns out to have the wrong threads - looks like the unit was mismarked, but either way I'm going to have to bore it out and braze in a properly threaded insert. Was going to machine one but that pending if I get another lathe I'm looking at - current one doesn't have the change gears for thread cutting. Option 2 is to take a shot fan clutch and machine the insert from that shaft - hence the post.

I'll post a better write up and more info when/if it actually works....

Al, pmed you.

 

[jaluhn83]

Been meaning to find a junk clutch to cut open and take some pics of what's inside of one too, so 2 birds with one stone here....

 

[typ4]

I have given this some thought Also. A Cummins fan has a smaller diameter and could be bored and threaded if there was s way to grab the hub. An electric clutch for Idi,s would be awesome.

 

[jaluhn83]

Horton 996135 is what I started with - EC450 clutch for a DT466. There were a couple on ebay for $299 for round about a year that I was looking at but never got the money. Finally did get the cash but they'd sold. However, I found a different one, made by NREC, I think? Looks like it's actually a German unit. Thread was right, but wrong direction, I think because it was misboxed somehow. Aside from the thread mismatch this looks like it will work quite well, and I should even be able to reuse the stock fan. The horton clutches mount the fan on the front of the clutch which would have moved it about 2" forward and caused problems. Was figuring I'd need to just get a new fan from Horton as well. But, this one is setup where I can mount the fan close enough to the stock position for it to work I think. It's also a 2 speed clutch - most are on/off, but this one has a front plate with a row of permanent magnets that should cause some drag even with it off, so instead of on/off I should get something like 25% or 100% flow... hopefully.

The clutch I got was pretty easy to strip down to where I can machine just the center shaft assembly - not sure if any others are built the same way.

I had also thought about getting one with a 4 bolt flange and making an adapter and/or machining the clutch/water pump shaft to mount the clutch using the pully bolts - this would also get rid of the fan clutch nut either coming loose or being impossible to remove....

 

[ironworker40]

Here are the specs for our fan clutches I found in the Hayden catalog.

Part Description : Heavy Duty Truck Fan Drives

Rotation : STD = (CW)

Overall Diameter : 7.4

Pilot Dia. / Thread Size : 1-1/4-16 LEFT

Pilot Depth : 0.64

Flange or Hex Dia. : 1.88 Hex

Fan Mount Height : 1.2

Fan Hole Bolt Circle : 6

Fan Mount Dia. : 5

Overall Height : 3.52

 

[icanfixall]

The water pumps that fit the international 1600 rigs has a 4 bolt flanged hub like many gassers have. They also run a clutch similar to what ours are. We can bolt the 1600 water pumps directly to our engines too... Unless I'm wrong about the bolt pattern to the gear cover plate on the 1600 idi engines..

 

[jaluhn83]

Biggest problem I see is the fan mounting - fairly easy all things considered to rethread or install and insert to get the clutch to mount on the stock pump. Problem is the fan clearance. Every clutch I've looked at would put the fan 1-1/2 to 2" to far forward and not be nice to the radiator... I thought about cutting the center of the fan out and rewelding it with an offset but was concerned about balancing it. Not many folks likely have the setup to be able to accurately do the work either - I was going use a cnc mill - would either need that or a 24"+ lathe.

 

[ironworker40]

Been meaning to find a junk clutch to cut open and take some pics of what's inside of one too, so 2 birds with one stone here....

I found this

 

[ironworker40]

The water pumps that fit the international 1600 rigs has a 4 bolt flanged hub like many gassers have. They also run a clutch similar to what ours are. We can bolt the 1600 water pumps directly to our engines too... Unless I'm wrong about the bolt pattern to the gear cover plate on the 1600 idi engines.

I'm thinking we could use the 4 bolt flange pump, if it is the same bolt pattern, make an adapter that is 4 bolts on one side and the correct thread on the other side to adapt an electric fan clutch. No balancing issues and its easier to machine than trying to hold the fan clutch in a lathe and cut new threads. It is going to depend on how long the shaft plus adapter would be, if there is enough fan to radiator clearance. Something to think about. Someone needs to put the two pumps (ford and ih) next to each other to check bolt pattern and distance from gasket surface to end of the shaft.

 

[jaluhn83]

I doubt making the adapter would be easier than rethreading the clutch - likely a fair bit more work in fact. The clutch I have took about 10 minutes to take apart, and once apart the shaft is a nice simple easy to chuck fitting - center it up, bore it out a bit and then braze in insert. Not hard.

The fan is the problem, specifically the length of the fan clutch and location of fan mounting. Looking at the design of the water pump I don't think you can reduce the shaft length much at all even if you got rid of the threaded end. Maybe if you made a new pump shaft and/or flange you could, but lots of work there. The S1600 is certainly worth looking into, but I'd be very surprised if it let you mount the fan clutch and closer to the block. I'd bet it would even be worse than the Ford, since there was tons of room to play with on the MD truck.

 

[ironworker40]

I doubt making the adapter would be easier than rethreading the clutch - likely a fair bit more work in fact. The clutch I have took about 10 minutes to take apart, and once apart the shaft is a nice simple easy to chuck fitting - center it up, bore it out a bit and then braze in insert. Not hard.

I didn't realize you could get it apart that easily
I Would not use an insert then. Clean out the old threads and build it up with weld them machine new threads. Wrap it in insulation and let it cool slow. I don't think that that shaft is hardened, but a file will tell you that.

 

[jaluhn83]

Well, you either know a lot more than me about fab work or less.... not sure which.

My immediate concerns with that are the difficultly of making a good solid consistent weld on the wall of a small pocket like that, possible warping due to uneven heating, loss of hardness in bearing seats if they are hardened and finally the difficulty of machining the welded material. In contrast making an insert is a simple straightforward operation, as is a simple boring operation on the fan clutch. There's some risk of thermal damage brazing but it would be a lower temp more controllable even heating so less likely to cause problems. Also, if you machine down an old fan clutch so make the insert you don't need to deal with internal thread cutting and the machining operations reduce to simple boring and turning.