Viscous Coupling

djsy934

djsy934

Active member
Took my transfer case apart to put my 4L80E input shaft in and found this rubbery material in the planetary gear area. Could this be the viscous coupling failing? I read this thread I am thinking it could be the VC fluid leaking out?? Or what else could it be?

http://www.syty.net/forums/showpost.php?p=230010&postcount=12

I didn't do the DaveP test as the case only has 45K on it and was surprised to see this.





 
Slyclone

Slyclone

Well-known member
Re: Viscous Coupling

I recently ripped down a typhoon case for a visual inspection and a potential rebuild. When I opened it up I saw the same stuff in the larger piece and nothing else looked worn or severely damaged. I do rember being over concern about wobble/slop on the part in the bottom photo. I saw the rubber looking material and suspected something wore out. I kept looking for something to be wrong but it seemed to be OK. I still never figured out what the black grease/spatter was but probably some seal material .

What I ended up doing was cleaning everything really good and I used a drum brake tool with a hook on it to clean or evacuate the grooves.

I am pretty sure I put up a panic post too but I was told if it passes the tq test , everything is good. I cleaned mine sealed it up and its ready to be plugged in.
 
djsy934

djsy934

Active member
Re: Viscous Coupling

After further dis-assembly and cleaning I found a badly worn thrust washer under the planetary gear on the output shaft side and the oil scoop not attached and slightly ground up. Could this be the debris I found?

What could cause a thrust washer to wear like that? Case only has 45K miles.

 
Slyclone

Slyclone

Well-known member
Re: Viscous Coupling

I highly doubt the debris has anything to do with the thrust washer. ( I could be wrong?)

The washer has a brass or bronze surface that would wear... The oil scoop not attached has me. Makes me wonder if some one cracked it open at some point.

Again, I opened a typhoon case to do a visual inspection and saw that same black gunk. Yes I kept looking for a reason for something to be worn or wrong and kept taking it apart.

DaveP told me in a message the one thrust washer does usually wear.. I can't remember exactly which one.. But I seen the similar wear and I think its a common thing on them.

Thinking about it a little more right now.. It could be factory rtv? I remember a heavy bead cracking mine open like it squirted out the exterior of the case, could some have squirted on the inside and eventually get ground up and mashed into nothing? I think the only other black matter in side one of these is the seals on the shaft ?
 
djsy934

djsy934

Active member
Re: Viscous Coupling

I don't think this case has ever been opened, had the black RTV sealant you mentioned.
This is my dilemma, I have a another transfer case which I have taken apart and cleaned that has 120k on it and no signs of the rubbery debris. It has been re-built at some point and the thrust washers look perfect. Which VC should should I run? Would like to be able to bench test the VC's and compare. Did you do the DaveP test after re-assembly
 
Quickstop [UK]

Quickstop [UK]

Combating adversyty.
Re: Viscous Coupling

When I took my case apart, I had a bunch of ground up stuff in it as well. It was the same colour as the material that sealed the two halves of the case. I believe that the stuff in there is just excess gasket material and that the transfer cases were reassembled manually with the SyTy shafts. There weren't that many made that they'd need to automate the production line so it probably depended on the worker that day and how liberal he was with the sealant.

It overflowed into the case and got chewed up. It's harmless.

Your oil scoop however... that's weird.
 
You must log in or register to reply here.
Top