Jump to content


Welcome to Ultimate Subaru Message Board, my lurker friend!

Welcome to Ultimate Subaru Message Board, an unparalleled Subaru community full of the greatest Subaru gurus and modders on the planet! We offer technical information and discussion about all things Subaru, the best and most popular all wheel drive vehicles ever created.

We offer all this information for free to everyone, even lurkers like you! All we ask in return is that you sign up and give back some of what you get out - without our awesome registered users none of this would be possible! Plus, you get way more great stuff as a member! Lurk to lose, participate to WIN*!
  • Say hello and join the conversation
  • Subscribe to topics and forums to get automatic updates
  • Get your own profile and make new friends
  • Classifieds with all sorts of Subaru goodies
  • Photo hosting in our gallery
  • Meet other cool people with cool cars
Seriously, what are you waiting for? Make your life more fulfilling and join today! You and your Subaru won't regret it, we guarantee** it.

* The joy of participation and being generally awesome constitutes winning
** Not an actual guarantee, but seriously, you probably won't regret it!

Serving the Subaru Community since May 18th, 1998!

Guest Message by DevFuse
 

Photo
- - - - -

LSD clutch type vs viscous type?


  • Please log in to reply
1 reply to this topic

#1 camosuba

camosuba

    USMB is life!

  • Members
  • 137 posts
  • Brisbane Australia

Posted 06 November 2003 - 01:03 AM

Ive just recently fitted a clutch type (resonably tight clutch pack too) rear Lsd diff to my 5spd Manual AWD liberty/legacy sedan and was wondering if there are any ill effects that could be caused by this specificaly the viscous coupling in the rear of the transmission? I understand the theory of the clutch type workings but i need some enlightening with regards to how a viscous lsd works does anyone have a schematic of one ?

#2 Commuter

Commuter

    Subaru Master

  • Members
  • 1,857 posts
  • Niagara area, Ont Canada

Posted 06 November 2003 - 05:11 PM

I don't have time to dig it up right now, but I think the "How stuff works" site has some info on viscous couplings.

They are a sealed unit with thin closely spaced (not touching) discs that have holes and slots in them. The odd numbered disks are attached to one shaft, the even number discs to the other shaft. The whole unit is filled with a silicone oil.

Silicone oil (fluid) thickens dramatically when it heats up. There is a huge swing in the viscosity around 100C. If both wheels are turning at the same speed, the discs are as well, there is no relative movement between the disks and the fluid is at it's low viscosity, allowing slight movement for turns, etc. When one wheel spins, there is relative movement between the discs, the fluid is sheared, it heats up, thickens and "locks" the plates together, thereby transferring torque to the wheel with grip. This happens very rapidly, but not instantaneously.

The center differential in most manual transmission Subaru's use a VC to power the drive shaft to the rear wheels. (Auto's have the clutch pack.)

Commuter




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users