Hydraulic propshaft disconnect

[C Lee Farquar]

At Autosport today I saw a rallycross car with a handbrake with two master cylinders. On further enquiry it seems they run a Sadev propshaft disconnect unit on the shaft to the front diff. The reason being that it's 4wd with no centre diff.

First point for discussion is do we agree that the disconnect on the rear diff would be better? It wasn't possible on the car in question as they ran a rear transaxle.

Anyone have any experience of the unit or another variant? I did go to the Sadev stand but there wasn't any body there who was familiar with the unit. I've only found diff mounted units on their website.

For clarity, the stand alone unit puts a permanent 4wd car into two wheel drive when you use the hydraulic handbrake. Permanent 4WD cars with no centre diff and LSDs front and rear do tend to be a handfull in tight corners, especially on dirt.

[C Lee Farquar]

Thanks, that was my thinking. If the figures stack up it would be much easier for me to fit it on the rear propshaft. My front diff is too close to the transfer box to fit one on the front without major work.

[C Lee Farquar]

If I'm understanding your question Sadev make a self contained inline unit that disconnects the shaft.