Difference between 2.6 and 2.25 propshafts on a 109?

1972 2a. I know it was originally a 2.6 but now has 200di fitted. Gearbox is from a series 3 I believe (unless the last of the 2a's had full synchro?)

Rear prop has a bit of play in it so could do with replacement but there are two types available.

591279 is 4 cylinder
591283 is the 6 cylinder

What is the difference between them so I can check what is fitted at the moment? Hopefully I have the 4 cyl one because it seems to be way cheaper..

Why not just fit new UJs ? far cheaper and not to hard to do. You will need to measure across the width of the "Spider" to see which size you have. All of that is a load of tosh if you are reffering to worn splines on the sliding joint.

The gearbox is further back in a six pot to make room for the engine, so the props are different lengths ie shorter rear and longer front.

Yes it is the sliding joint that has the play in it and I don't think there is any way to sort it without replacement? I have been packing with grease as a temporary measure.

Ok if it's the length that is different I'll take off the current one and measure it up.

Thanks a lot!

Now that I have the prop off and the ends aren't anchored to anything I can't feel any play in it. There was definitely a small amount when it was attached though. Does it definitely need replaced or would cleaning it out and reassembling be any good?

Does it "clunk" when on/off throttle? It may be UJ play or a bit in the diff. Whilst the prop is off twist the diff flange back and forth to see how much play is there.

The play isn't rotational. It can wiggle up and down a tiny bit at the sliding joint.

If its only slight up/down movement, check the alignment spline arrows line up, then strip>clean>reassemble>regrease>refit and forget about it....