Has anyone done this mod? I'm curious to hear any feedback, how difficult it was, what else needed to be changed (I'm guessing the driveshaft at least). Most importantly, is the benefit worth the work involved?
Adding a Viscous Coupler from an 80 Series to the 100
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Carl did this IIRC
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I'll give him a call.
Curious to your opinion on it, Dan? Not sure if there is enough real world benifit or if it's just a "cool mod to complete"
Dunno. On one hand I do like how the 80's VC performs more like posi-traction/limited slip in the unlocked mode. OTOH...if it isn't broke...
If you opt to do this then you might want to consider Marlin's 3.14:1 low range gear set..."while you're in there..."
If you opt to do this then you might want to consider Marlin's 3.14:1 low range gear set..."while you're in there..."
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I've got a bad output seal, and you gotta open the case to replace it. So.... While I'm in there....I could learn something new and try something cool.
Just the rear nose needs to be removed...to R&R the seal.
Here's an interesting tidbit I found for you:
"...One big problem is that VC interferes with the operation of the ABS brakes. The VC keeps the wheel speeds linked together, while the ABS may need to brake one side (or end) of the car harder than the other. The VC may cause a tire to lock and slide while the ABS is trying to prevent it from sliding. Most VC AWD systems have some sort of disengage mechanism that takes the VC out of commission as soon as you step on the brakes." (http://www.houseofthud.com/differentials.htm)
...I could see this as a problem for VSC but not sure ABS or ATRAC would mind.
Other questions that come to my mind would be; drivetrain bind on very very slick surfaces? fuel economy changes? Tire wear changes?
Are you leaking at the front or rear output?
"...One big problem is that VC interferes with the operation of the ABS brakes. The VC keeps the wheel speeds linked together, while the ABS may need to brake one side (or end) of the car harder than the other. The VC may cause a tire to lock and slide while the ABS is trying to prevent it from sliding. Most VC AWD systems have some sort of disengage mechanism that takes the VC out of commission as soon as you step on the brakes." (http://www.houseofthud.com/differentials.htm)
...I could see this as a problem for VSC but not sure ABS or ATRAC would mind.
Other questions that come to my mind would be; drivetrain bind on very very slick surfaces? fuel economy changes? Tire wear changes?
Are you leaking at the front or rear output?
There is no drivetrain bind through the VC on the 80, even on ice. I don't think the VC is aggressive enough to cause any detrimental effects in this regard.
Slightly off-topic, I've often though it would be awesome to have a torsen-type center diff. ATRAC "should" be even more effective through a torsen.
Slightly off-topic, I've often though it would be awesome to have a torsen-type center diff. ATRAC "should" be even more effective through a torsen.
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Interesting.... Thanks Andy. When we were texting yesterday, I thought that ATRAC wouldn't be an issue for the fact that it senses individual wheel slippage, but maybe it will? Wondering if a smoother transfer of power between the f/r will reduce the rear slipping and remove some of the clunky-ness of ATRAC?
Leaking at the front output. Just weeping, not losing oil onto the ground, but it's getting spun from the ds and flung onto the cat and I smelled it the other day. That prompted me to crawl under and have a look, which prompted me to look at the FSM to see that it wasn't 30 minute R&R, which prompted this thread, and here I am.
Calling Christo and Carl today. Will report back.
To be clear, I think ATRAC will be fine just as it is in open or locked stock configurations. But note that ABS and VSC get disabled when the center is locked... I agree that it might actuall smooth out and help ATRAC. But VSC as we know can do some interesting things on the highway at speeds on slick surfaces so that is the one I can't get my head around.
What about the 80's with ABS? Did they stay with the viscous center?
If the main goal is to improve something (or spend $$$) I agree that the low gears would be the way to go, especially since your pushing 35's with stock R-P's... better climb, better decent control, slower crawl, etc...
What about the 80's with ABS? Did they stay with the viscous center?
If the main goal is to improve something (or spend $$$) I agree that the low gears would be the way to go, especially since your pushing 35's with stock R-P's... better climb, better decent control, slower crawl, etc...
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After speaking with Carl and Christo today, their consensus was that's it's not really worth it for me. It's better for 100's with the 4spd and a supercharger. I have neither of those, so it would be more of a "cool mod", but not too much more.
@AimCOtaco my goal is to never spend a lot of $, you know that, but learning something new is always fun. In this case, I guess it's not worth it. If I regear something, it will be differentials. Although, the lower tcase gears are interesting and the price isn't bad for what you're getting..... the wormhole just gets deeper and deeper. I just wanted a fishing/camping truck, remember.
@AimCOtaco my goal is to never spend a lot of $, you know that, but learning something new is always fun. In this case, I guess it's not worth it. If I regear something, it will be differentials. Although, the lower tcase gears are interesting and the price isn't bad for what you're getting..... the wormhole just gets deeper and deeper. I just wanted a fishing/camping truck, remember.
80s with ABS have a viscous coupler, although the ABS system in the 80 is 3-channel (front L, front R, rear).
ABS disabled with the center locked.
ABS disabled with the center locked.
...and 35's, that's where you stepped into the ether
Bigger tires have been many a poor boys ruin and God I know I'm one
...via IH8MUD app
...via IH8MUD app