SmokingRocks
hopelessly addicted to Cruisers
Keep us posted @scottryana, I'm interested in what you come up with.
Viscous Coupler removal and AWD (2 Viewers)
- Thread starter hank14
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I'm trying to figure out if mine is toast or not. When trk was still driving did not notice axles binding when making tight turns. With T/C out of trk now, front and rear output feel locked together. I cant hold one and turn the other. Is VC tight enough to do tht when only hand pressure is applied? Would like do take of problem while T/C is on bench. Want to keep VC since I live in WYO and roads can sometimes get bad.
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Back in the day, they could be turned by hand, took some effort, but not all of that. Now most take a pry bar, if not pretty much locked. When they worked, it would take a pretty good amount of wheel spin, then would get tight, as soon as the shafts turned at the same speed the effect would be lost. So jerky, somewhat like traction control. Now most are just tight, causing bind, heavy steering, etc, the intended effect lost.
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Maybe a couple of holes, use a vacuum pump to pull it out into a container, heat/time/suck? But even when good, the stuff is sticky, clings, most of it would be in the tight spaces between the plates, don't see it coming out?
Yeah it is pretty thick and viscous I would imagine, but it is exactly the same fluid as in the fan clutches, which we drain all the time. I know the fan clutch doesn't have the 40 thin discs inside, but there really isn't anything inside the VC that would be hurt by some sort of solvent to flush around inside. I don't know, I haven't tried yet, but I don't know anyone else that has either. haha.
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More like hundreds of disks. Naphtha is pretty effective on silicone, but, how to remove all of that? Any remaining silicone will be contaminated, effecting the new fluid? Best bet, get a junk one chuck it in the lathe and see first hand what you are dealing with?
Damn is it really that many? The information I found on the NP Quadratrac cases that use a similar system is that they had 35 discs inside.
SmokingRocks
hopelessly addicted to Cruisers
hmmm the VC might be the best indicator of mileage. My rig had a swapped odometer in it, so I have no idea. Bought it with 150k on the "odo" but thought it was closer to 200k. The VC still had slip through.
You can kill a VC through abuse, even if miles are low, by doing something like mixing tire sizes so the VC may not be as clear of an indicator of mileage as odometer and paper trail.
SmokingRocks
hopelessly addicted to Cruisers
True^ also Nice thumbnail photo!
Ha, thanks @SmokingRocks maybe one day I'll get it cleaned up and shiny like yours 
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So, did a bit of ciphering. The stack is a disk spline to the outer shell, a wire ring that is a spacer to the next outer disk and the inner spline disk. The disks are ~.016" and the spacer is ~.028". So the stack is ~.044" per layer. The area were they fit is ~1.84", so about 42 layers or 84 disks. The inner disks ride in the space made by the spacer, so have ~.012" end float, if centered, ~.006" on each side for air/fluid. It's basically solid steel, with very little space for anything else.
It has two holes in one end, sealed by pressed in balls, likely how it was filled? If all of the slits in the disks were lined up, may make channels through the stack. The plugged holes look suspiciously like they may line up with the slits. Assuming that all of the disks are installed in the same orientation, maybe able to use a pin through the hole(s) and line up the slits. Possibly be able to pump fluid through it? Still, with the tight spaces, not sure how it would be successful? IIRC, the fill is ~80% fluid to air, but even that would be a small number.
ppc
M Go Blue
Based upon your description and photos I think the only procedure that could work would be a complete disassembly, cleaning and reassemble each layer already precoated with the viscous fluid and then reseal the assembly.
inkpot
SILVER Star
ppc
M Go Blue
Yes, agree with that 100%. I just felt I didn't need to state the obvious.
Eh we will see
Thx
Bumping this old thread because I suspect either my VC is on its way out or my rear driveshaft yoke needs to be cleaned of old grease.
Getting some weird driveline vibes when decel or just as I give barely any throttle.
I did the one wheel in the air test with trans and tc in N. The wheel can spin, but it does take effort. I'm wondering "how much effort" is normal? I feel like I expected it to move more freely and "shouldn't" lock up until there is some heat or a lot of spin?
Going to remove the rear drive shaft and drive around with my CDL locked. But not sure how this will tell me if it is my rear DS is the issue or my VC? or both? I saw somewhere another test of with rear DS removed, unlock the CDL and see if the truck moves. Sounds like it should move, but sluggish? Like how sluggish? lol
Getting some weird driveline vibes when decel or just as I give barely any throttle.
I did the one wheel in the air test with trans and tc in N. The wheel can spin, but it does take effort. I'm wondering "how much effort" is normal? I feel like I expected it to move more freely and "shouldn't" lock up until there is some heat or a lot of spin?
Going to remove the rear drive shaft and drive around with my CDL locked. But not sure how this will tell me if it is my rear DS is the issue or my VC? or both? I saw somewhere another test of with rear DS removed, unlock the CDL and see if the truck moves. Sounds like it should move, but sluggish? Like how sluggish? lol
@b16 I had my front shaft out for a few weeks, and was also messing with dash/climate lights a bunch. Once when I reinstalled the climate button assembly, I forgot to re-lock the CDL and drove off. It kinda felt like a trans slow to engage/slipping, but would still get me moving and felt pretty normal once I was cruising. RPM rose higher before a whole lot happened. Then I had my DOH! moment, locked the CDL back up, and returned to normal. Basically, IMO you’ll feel the difference, whatever it is. Mine felt the way I’d think it would, with a shaft removed and unlocked center w/ VC or LSD, but could vary if yours is having an issue. I’d try shaft out/locked to see if you can isolate a shaft problem, then try unlocked and see how it feels.
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