Im trying to find a basic explanation of what VLSD is supposed to do for winter handling. Anyone know exactly what it does? Does it just transfer power from the slip wheel to the grip wheel?
-Jesda
Winter time! So what is VLSD?
Re: Winter time! So what is VLSD?
Jesda wrote:...Does it just transfer power from the slip wheel to the grip wheel?
-Jesda
You got it. Any LSD transfers power away from the slipping wheel, and redirects it to the non-slipping wheel.
Do a "google" on Viscous LSD. Very interesting. There are mechanical LSDs but the fluid type is very elegant as a solution get the desired result.
You can find some draw backs. When I had my POS Goodyear Eagle HPs, my car would totally slip like crazy on very slick surfaces. Both drive wheels turn equally when friction on both tires are the same. This once caused my J to slip right off my driveway no matter how carefully I applied the throttle. With a conventional differential only one wheel will apply power and the other 3 will hold the car straight.
One thing to know about a VLSD is when slip occurs, do not completely remove power to the drive wheels. This is hard on the fluid. Let up on the throttle but keep power applied. This is actually quite fun.
You can find some draw backs. When I had my POS Goodyear Eagle HPs, my car would totally slip like crazy on very slick surfaces. Both drive wheels turn equally when friction on both tires are the same. This once caused my J to slip right off my driveway no matter how carefully I applied the throttle. With a conventional differential only one wheel will apply power and the other 3 will hold the car straight.
One thing to know about a VLSD is when slip occurs, do not completely remove power to the drive wheels. This is hard on the fluid. Let up on the throttle but keep power applied. This is actually quite fun.
Don't let go of the gas, the car will jerk into a direction and you'll piss her off. Just ease up on it and turn the wheel in the OPPOSITE direction of where the front of you car begins to point to. Again, don't jerk the wheel, just ease up on the gas, slowly turn the wheel, gotta be gentle with her and she'll be nice. At least that's how my J30 is. And whatever you do, if you begin to slip never slam on the brakes, you'll f yourself.
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Q45tech
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- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
The sealed viscous fluid assembly on takes a few rpms [rotations] of the right tire to heat up enough to quasi lock the shaft............if it hasn't been destroyed by over heating in the first place.
Why you change the diff fluid frequently to keep the oem viscosity as new and the heat as low as possible.
Hopefuly the viscous LSD has not been degraded like mechanical units that need rebuilding every 75-100k.
I swapped mine out at 180k for a wrecked 50k unit from a 93Q.
Remember the Q rear suspension has automatic toe [via bushing compression] .....extra toe in on deceleration [brakes or engine braking]..................hopefully zero toe on acceleration.............some of the change you feel in letting of power abruptly!
Why you change the diff fluid frequently to keep the oem viscosity as new and the heat as low as possible.
Hopefuly the viscous LSD has not been degraded like mechanical units that need rebuilding every 75-100k.
I swapped mine out at 180k for a wrecked 50k unit from a 93Q.
Remember the Q rear suspension has automatic toe [via bushing compression] .....extra toe in on deceleration [brakes or engine braking]..................hopefully zero toe on acceleration.............some of the change you feel in letting of power abruptly!
All your trying to do is make sure BOTH wheels spin equally, you should be able to feel/hear it. If your not certain get someone to look and see if they are both spinning.
I think its working!
I first had my diff fluid checked. Its full (maybe should change it soon).
Today we've had a tremendous amount of snowfall. I work in a somewhat undeveloped corporate park outside of town with some smooth, wide, flat, new roads without any buildings on them. Before the salt trucks worked their magic, I took a break from work and went outside for a spin.
Took off briskly, tried to spin the Q around a bit.When the tail started to fish out, it seemed to "catch" itself and go straight again. I eased gently off the gas and turned in the opposite direction of the slide.
Never felt quite as safe in a RWD sedan.
-Jesda
I first had my diff fluid checked. Its full (maybe should change it soon).
Today we've had a tremendous amount of snowfall. I work in a somewhat undeveloped corporate park outside of town with some smooth, wide, flat, new roads without any buildings on them. Before the salt trucks worked their magic, I took a break from work and went outside for a spin.
Took off briskly, tried to spin the Q around a bit.When the tail started to fish out, it seemed to "catch" itself and go straight again. I eased gently off the gas and turned in the opposite direction of the slide.
Never felt quite as safe in a RWD sedan.
-Jesda