No propshaft = trashed viscious coupler?

420

Broke Ass Racing
The truck is almost ready to tune, so we are shaking out the bugs and ran into an interesting transfer case issue.

We started putting miles on the truck initally with the front prop shaft out. We noticed that the trans felt like it was slipping under throttle. Additionally, when the truck was stopped and placed into park, it would make a brief clicking noise, as if you had tried to put it in park while stil moving. The trans and transfer case were pulled, and it was determined that the viscious coupler had been trashed. No other signs of damage or wear in either unit, so the coupler was replaced and everything buttoned back up. Pulled it out of the shop, and same exact slipping feeling. The truck was immediately pulled back in, and the builder reinstalled the propshaft. Oddly enough, this cured the problem.

I have driven this truck many times without the front propshaft in before upgrading the internals of the transfer case, without issue. The transfer case does include one of the George Blake billet planetary setups, but it appears to be free of any binding and everything else looks normal. It also has upgraded input and output shafts.

I can't help but feel like we are missing the actual problem, and having all 4 wheels driven is just masking the real issue. Not being able to run rwd will also make it a bit more difficult to dyno tune the truck. Not impossible, but most likely more expensive.

Any ideas? Anyone ever seen anything like this before?
 

sy#2716

SyTy 4 Life
Re: No propshaft = trashed viscious coupler?

It is a known problem. If you have the propshaft out and on a hill without the parking brake it will slowly roll down the hill.

it is just how the viscous coupler is designed. It did it on my first truck that had a transcase that had 150k miles on it and also on my truck with 50k mile trans case that is in my truck now.


Do not drive around with the propshaft out alot or you will trash the VC.
 

420

Broke Ass Racing
Re: No propshaft = trashed viscious coupler?

Man, that's weird. Never had an issue without the propshaft on the old one, and must have logged several thousand miles and a few dyno pulls that way. New build of the transfer case, and it rears its head right away.
 
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