Continuing from my note on the 'Rest and Be Thankful' report in the general forum, here is an update on my diff. failure.
Having found the failed splines and being wary of rebuilding with old shafts of uncertain heritage, I did a bit of research: Salisbury still exist in the form of Dana Axles U.K. Ltd., but have no more of the early two part output shafts. Moreover I took a close look at the surviving shaft -
As you can see the splines on the 'good' shaft are not far off being worn half way through.It follows that rebuilding with a second hand shaft on the failed side would only result in another spline failure, on the surviving shaft, in the near future.
Salisbury replaced these early two part shafts with a single piece shaft which is a stronger design. Not sure if any Cobras used them, but certainly Jaguar went over to them. I am not sure if the later shaft has stronger splines, but if you go this route they will at least start off as zero time new items. It seems that there is a U.K. based competition transmission specialist who replicate the later single piece drive shafts, but in a stronger materiel.
In any event, wherever the new style shafts come from, they will only fit the original Salisbury casing if it is machined to accept different bearings.
You can see where this is going: The replacement shafts dictate some machining and there is no point in doing this and using the old bearings and seals, LSD clutches or differential gears. The crown wheel and pinion may pass crack testing, or may not. Whatever there is a sizeable bill to be paid.
Given the years and abuse which older Cobras have endured this cost should be regarded in the context of half a century of service - leastways this makes it less painful.
I have decided to bite the bullet and use the upgraded competition shafts, with machining and all the replacement overhaul items. I'll report again when it is all back together.
Having found the failed splines and being wary of rebuilding with old shafts of uncertain heritage, I did a bit of research: Salisbury still exist in the form of Dana Axles U.K. Ltd., but have no more of the early two part output shafts. Moreover I took a close look at the surviving shaft -
As you can see the splines on the 'good' shaft are not far off being worn half way through.It follows that rebuilding with a second hand shaft on the failed side would only result in another spline failure, on the surviving shaft, in the near future.
Salisbury replaced these early two part shafts with a single piece shaft which is a stronger design. Not sure if any Cobras used them, but certainly Jaguar went over to them. I am not sure if the later shaft has stronger splines, but if you go this route they will at least start off as zero time new items. It seems that there is a U.K. based competition transmission specialist who replicate the later single piece drive shafts, but in a stronger materiel.
In any event, wherever the new style shafts come from, they will only fit the original Salisbury casing if it is machined to accept different bearings.
You can see where this is going: The replacement shafts dictate some machining and there is no point in doing this and using the old bearings and seals, LSD clutches or differential gears. The crown wheel and pinion may pass crack testing, or may not. Whatever there is a sizeable bill to be paid.
Given the years and abuse which older Cobras have endured this cost should be regarded in the context of half a century of service - leastways this makes it less painful.
I have decided to bite the bullet and use the upgraded competition shafts, with machining and all the replacement overhaul items. I'll report again when it is all back together.