AWD Viscous Coupling Fluid

[trucku]

AWD Viscous Coupling Fluid (4x4 to AWD swap)

I bought an AWD transfer case some months ago. I think it is a working case with no issues with the viscous coupler. I however have been reading and watching videos on YouTube about AWD viscous couplers. I recently watched a viscous coupler rebuild on YouTube. I believe that I have found the proper fluid used in the coupler. It is a Pure Silicone Fluid at 100,000 cSt (centistokes).


Video I was watching, not in English, just read the comments below.

I called a company that makes the same fluid in Philadelphia. The smallest amount sold is by the gallon. One gallon is $110.




If I can verify that this is the correct fluid and that the viscous coupler for my AWD transfer case can be rebuilt, I might just go ahead and buy the fluid. It is a lot cheaper than a new coupler. It might be advantageous for a number of members to do a group buy on this product for those who want to rebuild their viscous coupler.

If anyone can verify the info please do. I just wanted to put this out in case someone can help me confirm if this is the right fluid.

Thanks
Vishant

What is used in the video
Another link

In English here

 

[IZwack]

Have you seen this thread? http://explorerforum.com/forums/showthread.php?t=225515

Its from a different generation but the VC info is still legit.

 

[trucku]

Have you seen this thread? http://explorerforum.com/forums/showthread.php?t=225515

Its from a different generation but the VC info is still legit.

Thanks!

I read it a week ago. Great thread. It is what sparked my interest in looking for options other than buying a replacement if my coupling is seized or not working properly. Watched a few videos on testing viscous couplings on Youtube. Some use weights on a breaker bar and calculate how long it takes to fall from horizontal.

Right now If I turn my input shaft on the transfer case, everything turns. BUT I want to test the transfer case properly before I stick it in my truck for my 4x4 to AWD swap.


Thanks for the link.

 

[trucku]

Installed AWD transfer case

I swapped out my 4x4 transfer case to the AWD one I bought from junk yard. Hardest part was getting out the bolts from the crossmemeber. One broke. Dealer worked on my truck some time back, replaced torque converter and they tightened the bolts to death. Also had a one missing bolt and a stripped head on the transfer case. Thanks "Best Ford", friggin morons! Anyway the swap is straight forward. Take out one transfer case and install the other in reverse order. The AWD transfer case is from a 2004 explorer.

After Install:
On jack stands I was able to spin the rear wheels by hand slowly with no movement on the front. With little effort I was able to get the front wheels to spin. I inflated all of my tires to 35#

Tested truck in the snow today and wifey verified front wheels turned when I accelerated hard. Truck drove great in the snow. I also did a 240 mile round trip last week with no issues. That was the test to see if my mileage would suffer and I can't say that mpg was decreased much if any.

A buddy of mine is making up a wheel speed display for me. I will be able to monitor how fast each wheel is turning while driving. So regardless of tire wear,within reason, (not one bald and one new), I can control total wheel speed with tire preasure. An AWD system loves it best when all the wheels are spinning at the same speed and the front and rear drive shafts experience minimal speed differential. The less shearing in the viscous coupling, the longer it will last.

 

[fusseli]

Can you post results with what tire pressures may result in matched wheel speeds? Makes me curious how much of a difference a few psi can make.

The label on my Mounty (early 02) shows higher pressure in the rear than in the front, I had read that that was a mistake corrected later by Ford and I have since always kept all four at the same pressure... There is strong wisdom in maintaining equal wheel speed for viscous coupler AWD systems. When I bought my vehicle with 111k on it, the front tires were worn maybe 3/32" more than the rears. I didn't know any better at the time, and it ended up with me needing a new t-case (failed closed) about 20k later.

 

[trucku]

Can you post results with what tire pressures may result in matched wheel speeds? Makes me curious how much of a difference a few psi can make.

The label on my Mounty (early 02) shows higher pressure in the rear than in the front, I had read that that was a mistake corrected later by Ford and I have since always kept all four at the same pressure... There is strong wisdom in maintaining equal wheel speed for viscous coupler AWD systems. When I bought my vehicle with 111k on it, the front tires were worn maybe 3/32" more than the rears. I didn't know any better at the time, and it ended up with me needing a new t-case (failed closed) about 20k later.

I will defantely post my results. Right now my friend is looking into modifying my current scanguage to accept speed inputs from the wheels. If that does not work, he will build me a separate display for cheap.
Definitely in an AWD case you want front and back wheels spinning at the same speed to keep the viscous clutch happy.
I am very happy with the AWD transfer case. I have constant and consistent power. Driving up to my house on a snow covered road was no issue. I could not tell if and when I was losing traction on the ice.

Long as you can maintain matching front and rear wheel speeds, worn tires will not be a major factor. Just adjust the tire pressure to give the proper radius from the center of the wheel to the ground.

Hopefully I will have the display soon. Until then I have the front tires 2 lbs higher than the rear tires.