Following on from my post of a few months ago I have now re-built the back suspension, corrected the diff alignment with wedges and 'low and behold' the transmission vibration has disappeared - a result!
I would still like to know how it came about in the first place, I find it difficult to believe that the ZB was designed to be like that.
My rear springs needed re-building, de-scaling, rust removal, painting, new leaf clips, rubbers, etc. They are symmetrical in as much as the flat bit in the middle is parallel to the center line through the two spring eyes. The rear mounting points on the chassis are 5" higher than the front ones (according to the dimensions given in the workshop manual) the rear shackles have 3" centers so the spring is bound to point down at the front by 2" equivalent to about 2.5 degrees. This is the angle that the diff was pointing down at the front.
On reassembly I fitted steel wedges between the spring and the rear axle (extended the location tube on the saddle plate to ensure axle location) to raise the front of the diff so that it was pointing up at about 1 degree.
This has resulted in the engine/gearbox axis being parallel to the diff axis which is the correct alignment for a drive shaft having 2 U/Js.
Anybody interested in the theory visit
www.baileymorris.co.uk/technical5.asp
Why, Why, Why was my car like that ??
Has anybody got access to original design data, drawings, etc ?
Are the springs supposed to be symmetrical or are those on my car some cheapy replacements?
Has the rear axle casing been changed for one having the spring mountings fitted at a different angle.
Any ideas would be welcome.
