Propshafts - Advice needed.
 

Hi clever peeps. Just been scratching my head regarding the propshaft. The one that came off the sierra is in two pieces. It would seem that it could be fitted while the box and diff are in situ as it has a splined joint which would allow the two ends to be manipulated in to place by sliding the two prop halves up together. Am I correct in assuming that a single piece shaft would be used in the roadster and that the engine and box would need to be moved forward to get the thing in place? My box is an MT75, it has the big rubber donut fitted.
If I need to move the engine / box, I would prefer to do it now before the exhaust and all the other bits are fitted.
Thanks in advance,
Enoch

I may be wrong,

but

is there not enough travel on the splines for you to slide a one piece prop into the gearbox end and then slide it back to be bolted to the flange on the diff?

(seem to have distant memories of doing this on mk1 and 2 escorts)

But you have to make sure it is short enough when the suspension is fully compressed that it doesn't go solid in gearbox end.

Your supposed to leave about 20mm of travel fore aft on the sliding joint, which is just enough to flop the UJ over the pinion nut.

TT

That's the bit where I am stuck - there does not seem to be a sliding joint. From memory the type 9 box had a splined drive that the end of the propshaft went in to. The prop could slide so that as the engine moved in relation to the diff it would not go tight. You could push the end of the shaft all the way in, line up the rear of the prop with the diff and just bolt it up. The sierra seems to have a different arrangement where the splined, sliding part if half way along the prop shaft. It looks like the donut assembly is fixed ie it does not slide in and out of the output shaft but the movement is in the joint half way along the propshaft. Does that make sense?
I can't see how a 1 piece prop can work:confused:

Ahh MT

It's a long time since I looked at one on an RWD car.

I Imagine the propmaker can build a sliding prop easily enough.

TT

Hi TT, I think I will have to call them tomorrow and see what they say. I hope I don't have to go the split shaft route, I don't fancy having to put a centre bearing in, they need to be very accurate. Thanks for the help, I just had a look round the net but clearly need to speak to the blokes that make em.
Best and all that...

You need to take off the rubber donut thing, it should just pull out leaving the standard 1" 23 spline output shaft.

snapper, I don't think mine has a splined shaft on the output. The donut attaches to a large round steel "thing" that is then bolted on to a mounting with 3 large bolts. I do not know if or how that mounting can be removed. Think I need to have a better look at it....

Right then, having spoken to a couple of propshaft companies, here is the low down. If you are using the MT75 box the rubber donut is removed, along with the round steel part and associated bolts. You are left with a three pronged mounting, there is a plane shaft sticking out rather than a splined one. An adapter plate is required which provides a splined shaft for a prop to fix to. This shaft provides a sliding drive for the prop - a bit like on the old type 9 boxes. This allows for movement of the box relative to the diff and also allows for the prop to be fitted without removing the engine / box. When ordering you need to give the length for the prop, which is measured from the diff flange to the flange on the gearbox, you also need to give the diameter of the shaft that sticks out from the back of the box and allows the prop to be centred. Best price I have found so far is from Dunning and Fairbank at about £150 plus VAT.

Just seen this Dave and i had a full new Type 9 prop made up by Dunning and Fairbank and was very good service, and for the peace of mind very good value.

Regards...AndyH