Viscous Coupler removal and AWD

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I have mine, it's sitting in a trans fluid bath under my counter. I took it out when I did my 3.11 T case gear because I was moving towards going part-time. I've since decided I don't want to go part-time. Soon I will drop the T-case to put it back in and replace some seals... just putting it off..
 
Well I guess you don't notice it then. Regardless I stand by my statement 100%

What T case do you have? If it's a 93 with a 1fz-fe it should have a HF2AV (V stands for viscous coupler), I am not aware of any 93+ 1fz-fe drivetrains in the US that came with a HF2A. Someone correct me if I am wrong, but I thought the HF2A was paired to the 3FE in the 91-92.

so.... You probably have the VC but think you don't, which would easily explain why you have never "experienced what I described"
 
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SmokingRocks said:
Well I guess you don't notice it then. Regardless I stand by my statement 100%

What T case do you have? If it's a 93 with a 1fz-fe it should have a HF2AV (V stands for viscous coupler), I am not aware of any 93+ 1fz-fe drivetrains in the US that came with a HF2A. Someone correct me if I am wrong, but I thought the HF2A was paired to the 3FE in the 91-92.

so.... You probably have the VC but think you don't, which would easily explain why you have never "experienced what I described"
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Nope, I'm very clear on what I have and don't. There are oddball transition year trucks and my '93 was one of them. 1FZ, semi-float rear axle with drum brakes, no ABS, HF2A tcase. I have a friend locally that has a '94 with the same configuration. 100% factory original on both trucks. I no longer own my '93
but the configuration described is accurate.. Current truck is a '95.
 
hum Yea I forgot about the semi floats.....

Regardless the VC was installed for the exact reason I pointed out and it works well. If you ever try to get wheels to slip on ice without the VC you will indeed notice it's absence, very clearly that's just how open diffs function.
 
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Nope, but I have been trying to get a used one to try for years. Most are too burnt up to use. No one takes them out unless they are dead.

But I do think you should be able to add new oil and increase the VC quality.

andrea-PE-ITALY said:
does anybody know datas about what kind of silicone oil used inside the VC? I WHISH TRY to restore it
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scottryana said:
Nope, but I have been trying to get a used one to try for years. Most are too burnt up to use. No one takes them out unless they are dead.

But I do think you should be able to add new oil and increase the VC quality.
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I have a perfectly good one sitting in my garage. I pulled it about two months ago when re gearing my t-case. Want it?
 
I will definitely take it! I have been wanting to drill one out, drain the oil in the oven not unlike the fan clutches and see if it could be replaced.

I will PM you my address and just let me know so I can PayPal you shipping.

LC4LIFE said:
I have a perfectly good one sitting in my garage. I pulled it about two months ago when re gearing my t-case. Want it?
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I just took one out too, so you are welcome to that one @andrea-PE-ITALY. Send me your address.
 
scottryana said:
I will definitely take it! I have been wanting to drill one out, drain the oil in the oven not unlike the fan clutches and see if it could be replaced.

I will PM you my address and just let me know so I can PayPal you shipping.
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I have a frozen one, and so want to open it up, and restore it, and maybe do others I just need to find out what fluid it uses
 
From all of the ones I have seen once they are locked up, the fluid is so burnt and charred it is impossible to get it out.

I am running off the assumption the fluid is very similar to what is in the fan clutch. I need to do a little more research to see if there is something like that for higher power applications but the mechanism of action is the same.

Development of Viscous Coupling Oil (Part 1)

High Viscosity Pure Silicone Fluids

shocktower said:
I have a frozen one, and so want to open it up, and restore it, and maybe do others I just need to find out what fluid it uses
Click to expand...
 
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scottryana said:
From all of the ones I have seen once they are locked up, the fluid is so burnt and charred it is impossible to get it out.

I am running off the assumption the fluid is very similar to what is in the fan clutch. I need to do a little more research to see if there is something like that for higher power applications but the mechanism of action is the same.

Development of Viscous Coupling Oil (Part 1)

High Viscosity Pure Silicone Fluids
Click to expand...

When they are frozen, the fluid is garbage, but I have seen many taken apart that where frozen, and I have nothing to lose since it is frozen :flush:
 
They are welded together, not intended to be serviced. When the "fluid" is junk, it's like a sticky paste, without full disassembly, don't see how it would be cleaned out? According to the NCF, it is partly filled, has air space, but it is fully packed with disks, like hundreds, not much space in it, how much fluid and what viscosity? How to fill it, vacuum pump and a couple of small holes the could be welded closed?

A most of them we are seeing are tight or locked. At some point, they all are likely to be dead?
VC_1.webp

VC_2.webp

VC_3.webp
 
Yeah i think if you can get to them before they lock up, it might be possible to drill a small hole in the side and drain the fluid out. Measure the amount of silicon fluid you get out and then yes replacing it with an amount and a CST rating would be both a guess and trial and error. Then tap the hole and lock tight in an Allen head plug.

And you’re right getting the fluid to drain out maybe next to impossible but I am in no rush. I will let it sit for a couple days and see what happens.
 
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