Prop shaft too short?

[Bradmoneypit]

Sorry didn't explain it very well, I hooked the tape measure over the very front edge of the front spring hanger and measured back to the centre of the shackle hole in the chassis. I did it a couple of times as well just to double check the measurements. I will check it again, centre hole to centre hole to make double sure. I was just about to start measuring up for the spacer as well, your comments have put me off that idea. Thanks for checking and suggestions.

[bmcecosse]

The diff is angled downwards far too much - why is that ? Should be more or less horizontal, oe evn slightly upwards - it must lie in aparallel plane to the engine-gearbox centreline - is there a problem with the perches that locate the springs to the axle ? The rear shackle hangers look ok to me. The front spring mounts can't be wrong - or the wheelbase would be wrong........

[taupe]

Hi

The dimensions are in the manual page R16

centre of front spring hanger bolt to centre of rear shackle (on chassis) is 43 3/32" this is measured horizontally so the actual centres will be slightly greater - say 43 1/2" as a rough check.

The centre of front spring hanger bolt to front of main crossmember equals the wheelbase 86"-39"(torsion bar)-21 7/8" less 1/8" to centre of crossmember. Therefore it should be dead on 25" from back face of centre web of main crossmember to front spring hanger bolt.

Trusting this helps.

I agree with BMC that the axle looks like its tipping down, perhaps this is because the spring centres are too little?

[Bradmoneypit]

I will pop out this evening to have a another measure.

Looking at the prop, eye level, it does look pretty parallel to gearbox, but I will lift the nose a little to improve the angle.

I must have a stretchy metal tape as even when I plumb line points to the floor I still can't get the measurements to add up, either than or just a worse mechanic than I thought!!!!!

I have to admit I have booked into a local garage who do a lot of work on classic cars and the owner is a friend of mine.

[bmcecosse]

But you can't 'lift the nose' - the axle is fixed to th springs by the 'perches' on the axle casing - these determine the angle of the diff - in your picture it's angled downwards far too much - hence my suggestion that something may be wrong with the perches - either rusted away - or new ones welded on at wrong angle ?
PS Hope this is technical/scientific enough for you!

[Bradmoneypit]

Well its official, Brad (the Moggie) has been driven down to the local garage and they have confirmed the front spring hangers have been welding in the wrong place. It looks like a little more surgery with a welding torch is needed to make it better!!!

Thanks everyone for the help with this one, with a little bit of luck I will be wandering around the streets of York in the next week or so with a car that hasn't been out of its garage for nearly 2 years!!

Thanks again everyone.

[bmcecosse]

Well - you said the wheelbase was correct - so I really can't see that's right! From your pics - the only problem I can see is that the diff is angled too much downwards - which would account for the problem. How does the 'garage' equate springs in wrong place - if the wheelbase is correct ?? Also - if the springs are too far back - it would be sitting super high at the rear - is it ?

[PSL184]

I don't get it either. The spring hangers look OK in your pics and the axle is located correctly due to the wheel position in the arch. If you attempt to move the hangers to the wrong place the axle will be wrong also....

[taupe]

Hi

On your diagram on page 3 of this thread you have shown a measurement of between 1659 and 1664mm between the front eyebolt and rear spring front hanger bolt. From the dimensions given in the manual (R16) this dimension should be approx 1629mm (64 1/8") therefore assuming you have measured correctly - you have established that the spring mounting is some 30 to 35mm too far back.

This would certainly account for the propshaft length problem.

[bmcecosse]

Well - if that's a definitive measurement it obviously needs to be right - but the wheelbase also should be right!