Thread: Just a question on centre diff locks.....

The CDL prevents any difference in speed of the front and rear axle, so a small degree of slip on the road surface is essential. So on bitumen or smooth hard dirt a CDL engaged leads to axle wind up and severely stressed CVs. It's because tyres aren't precisely the same diameter and front wheels track slightly different paths to the rear tyres. Loose gravelly dirt, no problemo.

Originally Posted by ramblingboy42

Just wondering.....are there any restrictions to having the cdl engaged on bitumen.

My mind says none as you still drive through your front and rear diffs.

are there any restrictions at all to having it engaged fulltime on dirt?

You'll get transmission windup and something will break. Diffs allow things to spin at different speeds ( hence name). Front and rear wheel sets will spin at slightly different speeds due to tyre wear etc. Friction from bitumen won't allow enough tyre slip whereas off road the surface allows tyre slip. So, sooner or later - bang. Same reason there's a diff at both front and rear axles.