Bearings in LSD?
#2
Rotary Enthusiast
all internals are lubed by the fill gear oil. Only rolling element bearings are the carrier bearings. friction at gear mesh and thrust surfaces define the degree of lock-up .... extra modifiers ( slippery stuff from GM or redline) will reduce lock-up.
#3
Losing Traction on 335s
Thread Starter
Join Date: May 2004
Location: NYC
Posts: 225
Likes: 0
Received 0 Likes
on
0 Posts
Thanks very much for the reply- I'm getting the LSD cryo treated and was just making sure there wouldn't be any problems due to grease packed bearings.
Thanks
Ben
Thanks
Ben
#6
Former Rx7 *****
Join Date: Nov 2001
Location: Mississauga
Posts: 4,534
Likes: 0
Received 0 Likes
on
0 Posts
Cryo treating aka freezing metal to temperatures at which nitrogen or helium are liquids do not change the grain structure of the metal. The grain structure is determined by the rate at which the metal cool when brought up to a tempering temperature. For iron alloys you are looking for martinsite grain structure, which is accomplished by rapidly cooling the metal such that it passes through certain regions on the phase diagram. For aluminum it is not largely dependant on the grain structure, it is more dependant on the alloying content and the heat treatment of the aluminum to relieve internal stresses by tempering at temperatures above zero degrees C.
If you look at any phase diagram in any metalurgical text book you will see the phase diagram stops at around room temperature, since nothing happens beyond that point.
If you look at any phase diagram in any metalurgical text book you will see the phase diagram stops at around room temperature, since nothing happens beyond that point.
#7
/\ ok. well nascar is spending a ton of money on it now that they have limited engines for qualfying and racing. some places may not do it correctly but race teams do report better life/wear etc...
Trending Topics
#8
Losing Traction on 335s
Thread Starter
Join Date: May 2004
Location: NYC
Posts: 225
Likes: 0
Received 0 Likes
on
0 Posts
more info
Here is more info on cryo treatment "bs"-
http://lennon.pub.csufresno.edu/~rlk16/cryo.html
http://www.memagazine.org/backissues...ig/thebig.html
http://lennon.pub.csufresno.edu/~rlk16/cryo.html
http://www.memagazine.org/backissues...ig/thebig.html
#9
Senior Member
iTrader: (2)
Join Date: Sep 2002
Location: Mississippi
Posts: 287
Likes: 0
Received 0 Likes
on
0 Posts
Cryotreatment is done to acchieve the same effect as shot peening which is to create compressive residual streeses on a part to improve fatigue performance and not to change it's grain structure.
#10
Losing Traction on 335s
Thread Starter
Join Date: May 2004
Location: NYC
Posts: 225
Likes: 0
Received 0 Likes
on
0 Posts
from what I've read- shot peening only affects the surface of the piece (and just under the surface) as opposed to treating the whole piece like cryo does.
#11
Rotary Enthusiast
Originally Posted by Slacker7
Cryotreatment is done to acchieve the same effect as shot peening which is to create compressive residual streeses on a part to improve fatigue performance and not to change it's grain structure.
shot peening is as stated, and mainly to avoid cracking due to fatigue. I've spec'd it many times.
Cryo does change the grain structure, and is mainly for improved wear in heat treated med/high carbon steels (gears, tooling dies). Also works on brake rotors. I have not seen any data to support any fatigue life improvements.
Nitriding carbon steel creats hard, compressive layer in steel that resists wear and fatigue.
A torsen lsd has lots of thrust loads on the planet gears, and may benefit from cryo treatment. It may also change the degree of lock-up.
Last edited by KevinK2; 10-26-04 at 05:24 PM.
Thread
Thread Starter
Forum
Replies
Last Post