IRD,VCU Problem

Hi Guys, Just bought my first landy, its a w reg 3dr td (L series) came cheap because of of a blown IRD, and I mean blown, the transfer box for the rear diff was completely ripped out! and sitting on the front subframe. there is also oil all over the underbody above the rear diff. I work as a mechanic but on old Volkswagen Type 2 Bays. When I was an Apprentice I was told two things, tell the TRUTH and if you dont know ASK! On this occasion both apply. Too date ive changed the IRD but with lack off knowledge of landys (TRUTH) can you guys please explain the reasons for such a major mechanical failure and advise me on what i need to be aware of (ASK), kindest regards johnboymech

1) take your email address off before you get spammed. Anyone who wants to contact you can send a pm.
2) what usually happens is the VCU seizes in the middle of the rear prop, which then is effectively a permanent diff lock between front and back axles. As the wheels need to be able to rotate at different speeds, this then causes undue stress on the rear diff and IRD until something (or everything) breaks. Before you do anymore with the IRD or rear diff, you will need to replace the VCU, otherwise it will just happen all over again. You will probably have to change the VCU / prop bearings as well, as they usually get damaged when you remove them.

good luck, be wary of some VCU vendors, bell or ashcroft are highly regarded, there are a couple of rogues floating about who sell "refurbed" vcu's who either don't deliver and run off with your money or drain the silicon fluid out so it will never transmit drive to the rear.

And more important than any of that,


post a Hello in the introduce yourself section before bursting in asking questions and telling the truth

Mismatched tyres can also cause IRD and Diff failure. Larger diameter tyres to the rear and matched across axles. New tyres must be fitted to the rear only (as long as all wheels and tyres are the same size)