4106 fan clutch drive control

Bobert · January 13, 2021, 05:42:16 PM

Hi guys need help if possible. I have a 4106 that i am servicing to get ready for travel. Years ago the fan clutch drive control module.. this is the device that connects to the bottom of the engine and as best as I can understand, it controls the oil thermostatically from the engine to the fluid drive fan clutch so it will engage and disengage depending on oil temp. There are a lot of spare parts for this bus and I have been just about through everything looking for it. This is the only thing I have found that could be close (See pic) but it looks like it is a directional valve for something because of the arrow on the body. Can anyone supply a picture of what this module looks like along with a diagram on how it's should be run? Thanks

richard5933 · January 13, 2021, 06:09:31 PM

This should help.

Your picture does look like what is in the manual.

Bobert · January 13, 2021, 06:44:34 PM

Thanks Richard it does doesn't it. I'll check it out tomorrow. I was trying to find it and get it reinstalled before I put the radiator back in. Much easier to get to.

chessie4905 · January 14, 2021, 07:42:26 AM

Called a vernatherm. They can be bypassed and fan will run full speed all the time.

Bobert · January 14, 2021, 07:53:53 AM

Thanks much! Yes that is why it was removed at the time. The clutch was rebuilt just before it went into storage so my thought was to put it back to the original Configuration. I wonder if there would be any Real fuel saving to consider by doing this?

TomC · January 19, 2021, 06:33:22 AM

The fuel savings vs the reliability is why most lock the fan in full operation all the time. Yes there is some fuel savings, but in my book, not worth it. My 8 blade aluminum fan on my V-drive is running all the time direct drive geared-allows for running a right hand fan. Good luck, TomC

Bobert · January 19, 2021, 07:34:36 AM

Thanks Tom decided to leave it locked for continued cooling. Stay safe

chessie4905 · January 19, 2021, 05:43:31 PM

Yes, but Toms got the horsepower jacked way up. He needs the heat reduction a lot more than yours. You will probably be running cold in cool weather unless you have shutters.

Bobert · January 19, 2021, 08:51:00 PM

No shutters. I still have work to do before I turn the key as we live in the south so I still have time to rethink this.

B

fortyniner · January 25, 2021, 05:35:09 AM

If I understand how the venatherm thing works it closes when hot which lets the fan torus fill up with oil. If I have that correct then a bypass valve in line with the venatherm line would provided a manual override in case of problems.

chessie4905 · January 25, 2021, 06:13:35 AM

I had an old brochure on Cadillacs vernatherms which showed a model with an air connection port at the nipple end. Apparently an air controlled line connected there to do that.
Dont know if GM ever used them on city busses and have been unable to verify. Never seen them for sale anywhere, even on Ebay. So, I guess using an electrically controlled oil valve should work. Only thought would whether there would be any shock to torus when activating at full goverened speed. Maybe not an issue.

Bobert · January 25, 2021, 08:50:47 AM

My question is on the arrow of direction on the block. I assume the flow direction is from the engine block to the clutch? And then internally it bleeds back into the block or oil sump? Guessing on this one once the water cools down which closes the flow of oil.

As for connection points, I will take a picture to see if you guys can help me confirm this is where it should be connected. I'll get this sometime towards the end of the week.

Thanks and stay safe

B

Bobert · January 25, 2021, 08:53:12 AM

My question is on the arrow of direction on the block. I assume the flow direction is from the engine block to the clutch? And then internally it bleeds back into the block or oil sump? Guessing on this one once the water cools down which closes the flow of oil. This is also what fortyniner stated so it sounds correct.

As for connection points, I will take a picture to see if you guys can help me confirm this is where it should be connected. I'll get this sometime towards the end of the week.

Thanks and stay safe

B

richard5933 · January 25, 2021, 09:21:39 AM

From the manual it sounds like it's the other way around - the oil flows from the block to the torus drive, and the valve controls the flow out of the torus drive back to the engine.

Here's the piece from the manual: A fluid control valve (Fig. 11) is mounted in water return between radiator and engine water pump. Purpose of valve is to control flow of oil from torus housing. When temperature of water is such that cooling is required, the valve starts to close, thus flow of oil from torus is restricted. Speed of fan is variable depending upon the amount of oil being retained in to1·us.

Bobert · January 25, 2021, 10:21:22 AM

Got it and thanks!