Different Diff Output Shafts

[AlfaLofa]

Can anyone enlighten me as to when the change from narrow, shiny shafts to thicker black output shafts was made?

Presumably the change happened because there had been problems with the narrower shafts

[512BB]

Steve,

I believe the uprated output shafts were introduced in 1972. I cannot believe that there were many problems with the original design, as I remember doing some crazy things with my Elan in the early years of my ownership, yet when I rebuilt the diff, it had the skinny output shafts, that looked like new, no sign of any twisting of the splines.

And in all those diffs that I rebuilt, approx 20, only 1 diff had twisted shafts. I shall post a picture if I get the time.

Leslie

[Peter +2]

I broke a diff out put shaft on my S4 whilst traveling over a hump on the road, on my Plus 2 I discovered the splines where twisted when I had the diff stripped, so I replaced them with TTR ones.

Better safe than sorry I thought.

Peter

[stugilmour]

Interesting. My Plus 2 shafts were slightly twisted. Replaced with new shafts that came with the RD Enterprises supplied CV conversion. Maybe the extra weight of the Plus 2?

[Elanman99]

I gave my S4 a hard life in its early years and in about 1973 fitted 3 new oil seals to the diff because the nose seal was leaking. When I removed the shafts they were both slightly (but very visibly) twisted. I thought it best to refit them on the opposite sides thinking they would then straighten themselves.

I cannot remember what thickness of shafts I have (I assume thin) but the twist is most visible as it shows as a kink in the splined part as the shaft spline is longer than its female counterpart.

For some reason I did not change sides, but just re-installed them, that was 30 years ago and they have now done the best part of 200k miles.

I hope I have not woken any sleeping demons (in my shafts) after mentioning them!

Ian

[richboyd]

I also found a twisted spline on my 1969 S4, but that was many years ago.
Common wisdom (at the time) was "an original output shaft is a weak spot."