Friday, Jun 01, 2007 at 20:37
Okay 4be....here goes.....
Diff wind-up and Transmission wind-up are two terms used to describe what occurs to the drive-train of a 4x4 (usually part-time but can also occur to a full-time 4x4 with a centre diff lock).
FIRSTLY:.......Diff wind-up occurs when you drive a 4x4 on a solid surface (bitumen, concrete or even "good" gravel that doesn't have a loose surface).
Your diffs are designed to allow the wheels on either side of your vehicle to travel at different "speeds", as is the case when you go around a corner.....the outer wheel needs to travel further/faster than the inside wheel. If you have a front or rear diff lock and have it "locked" whilst trying to go around a corner, you will get diff wind-up in that diff, because the 2 wheels are forced to turn at the same speed. This
places a LOT of strain on the diff components and will eventually break the diff or CV joint, or axle etc.
SECONDLY:.......In the same way, you can get "transmission wind-up". This is similar to diff wind up, but instead of the 2 sides of the front and/or rear axle being the culprit, we are now talking about the transfer case/gearbox getting the wind-up. The transfer case, when you're in 4H or 4L, forces the front and rear tailshafts to spin and the same speed. Once again, as you turn a corner or go around a bend, the front wheels take a different path to the rear wheels, requiring the front and rear tailshafts to turn at different speeds; if only by a relatively small amount. If you are driving on a hard surface in 4H or 4L with the front hubs locked, then the the 2 tailshafts are trying to go at the same speed and something is gunna break.
You can generally "feel" diff or transfer case wind-up through the steering wheel and hopefully you can stop and correct the situation before it becomes expensive!!!
When you're on loose gravel, wet roads, snow etc; there is enough "give" in the surface to allow the components to work through these issues and no damage is caused.
Hope this helps...
Roachie
FollowupID:
504987