After searching and scratching my head for a while I have come down to to options for a steering intermidiate shaft.

1
The shaft from my sierra is two peice variety, triangulare steel uper and either a cast or drop forged (not sure witch it is) the option would be to cut and insert a tube in either the upper or lower section.

The down side with this is that I doubt the lower shaft can be welded and upper shaft being triangulare is awkward to say the least with a round tube.


2
I have the shaft out of a mk2 escort column with rubber doughnut which could be shorted to the right length and then welded to the steel trianulare section from the sierra intermidiate shaft.

The query about this option is how best to weld and reinforce the weld. Would a butt weld between the 2, with a fish mouthed tube other the top of the butt weld be good enogh?

Any views or knowlage on the matter will be most apreciated.

The picture shows the 2 halfs of the sierra shaft and the escoet shaft + doughnut.
Rescued attachment DSCF0008 small.JPG

i used some tube over the escort column,it was pinned with roll pins and welded to the sleve

Same as 'Rod , sleeved into tubing and then welded..........

That was one part I did not weld myself, I got a blacksmith to MIG it with a more powerful machine....

I presume thats using the sierra upper section like the one in the my photo?

Taking a slightly different approach, does anybody know of either a chart of torsional strength for different size/shape materials, or a program for calculating the trosional strength.

To be more exact the particulare problem in this case, would 19mm CDS tube with a 1.6mm wall be stronger than 13mm diameter stock, which happens to be the smallest/weakest part of the escort steering column.

If it's not from a power steering rack the Sierra one will fit the Escort rack, unless you specifically needed the Escort bottom UJ.

The sierra splines will fit the rack, but the advantage of the escort column is that it will be a lot easier to turn down to size so an extension tube will fit firmly over it.

I could put the extension in the middle of the sierra upper section (and then use the lower section) but that would mean welding nearer the UJ and have less over lap to reduce flex.

I don't think you'll find any flex in the column, it's more likely to be the rack mounts where you'll get movement. I found some 3mm wall black pipe that was a good fit on the Sierra column, just had to knock it on with the hammer after fetching the paint off the column extension.

Have you got a picture of your extension peteff, the ones in your archive just manage to miss it.