Parabolic a give it too much lift and s britpart prop shaft will not fit it runs out of length and the yokes will bind
 
Thought as much. Is it possible to machine up a spacer to make up the length? I reckon a 1" thick spacer would do it.
 
Yea but what happens when the axle drops it will bind up destroying itself. Need to let the axle hang and put weight on it to make sure the propshafts do not bind at full articulation. Compressed and drooping. A spacer may well work but you really need a longer prop with wider yokes or a decent std propshaft.
 
I've had a propshaft spit out at me because they fitted para's and 2 inch longer shocks. And when on droop the propshaft hit the crossmember yanking it off and throwing it my way after clubbing the injection pump and loosening an injector pipe. These things need to be sorted change of springs or shocks means you need to test the suspension in its fullest extent before finding out issues that can render you stuck or broken when you least need it.
 
OK, thanks. At this stage I've only got a rolling chassis with engine and gearbox fitted. I might wait until I've fitted the bulkhead, tub etc. and some other heavier parts to see how much lower it sits before making a decision.
 
Have you checked the distance of the front springs after fitting new bushes. The front axle is not sitting at correct height. Distance is in the workshop manual. My help to drive a few miles and re-check the height. Sensitive to torgue settings.
 
FYI the spring hangers at the front are different for 88" and 109" as is the top bush. If its not got the whole vehicle weight on it it could be the problem. Good luck!
 
Right your prop problem is because your chassis is from a Straight 6 109

On a straight six the gearbox is further back than a 2 1/4 petrol

The front prop on a 109 six cylinder is longer than a 2 1/4 petrol

Question does the bulkhead fit ok? and does the gearbox cab panel fit correctly? If the gearstick is in the wrong place for your cover panel you def have a 109 six cylinder and will need to make a cover panel to fit, or cut off the engine cross member and gearbox crossmember and move it to where the 109 2 1/4 crossmember and gearbox crossmembers are located, which will then mean you can fit standard 109 2 1/4 props front and back
 
Last edited:
It's a 76 SWB S3 soft top with a 2.25 petrol. I've pulled it apart to refurbish and it had std springs and I've not changed the front prop shaft. I've checked all the chassis sizes against the Haynes manual and it seems OK. At this stage I think either the new parabolics are sprung too high or the car just needs more weight on it.
 
I measured the nose of the original front diff as I thought that there may be a difference, but both were the exact same length. then I stripped the diff and leaf springs, thinking that the centre pins on leaf springs were off-set, but both distances from centre of mounting bush to centre of pins were exact same length. I re-fitted the lot, took the front wheels off and rested lower shock mounting plates on blocks either side too see if the weight of the engine and gearbox will depress the leaf springs and shorten the distance between flanges. this has happened, but if I bolt the drive shaft on, it will still be in fully extended position.
 
Hey iaanb, did you ever come up with a reason/solution for your too short front prop shaft? I am doing a rebuild of a 64' IIA and have the same problem....rear shaft fits fine, have checked measurements for frame at front end, all original front end and prop shaft (except for new universal joint), I go to put it back together and come up 1cm short on the length of the shaft at full extension...weird. seems to me it should fit between the flanges with about 50% of the length still available for travel. I have the engine and gearbox in, but nothing else. Any light you could shed would be appreciated.
 

Similar threads