Gearbox flanges needed & clutch advice - edited, need coarse spline

[PeterK]

My ‘79 gearbox was poorly, but I now have a (hopefully) healthy ‘76 box



I need a pair of coarse spline, small flange output shafts (hoping that Angus @ Greatworth has me covered), but if you have a pair please let me know



Advice please - should I try to swap brackets, clutch shaft, etc from my ‘79 so that I can keep the original (new) cable and the omega helper spring or go with the ‘76 arrangement without the helper spring.  If the latter, will my ‘79 cable fit or will I need to buy the earlier cable ?

Thx

[911hillclimber]

Sorry, thought I could help, but my memory is not good enough, so deleted my response.

[Mike911scrs]

Hi Peter

"I need a pair of thin spline, small flange output shafts" are these for the 76 box?, if it a late box from a SC and not the 3lt Carrera, the flanges out of the 79 box should fit

swap the clutch arangment over from your 79 box and cut off the hole casting from the 76 box and make it as your 79 box and swap ove the 4 studs to mount the brackets, if needed i have a S/S addapter bracket to convert it back (rally tested), it also fits early damaged box to re-fit the cable

regards mike

[PeterK]

Thanks Mike
Just noticed that I got things very wrong - unfortunately my ‘79 output flanges are thin spline and those in the ‘76 are coarse spline. I’ll edit the original post.


Cheers for the confirmation that swapping the Omega spring setup to the ‘76 is the right approach.

I’m away sailing again as of today, but hopefully can get the clutch arrangement swapped early next week. The output flanges are obviously needed for me to go to Le Mans Classic, but can be fitted with the box in the car, so after the clutch is sorted, I can start refitting the engine & box. I only have 2 weeks to get the work done (I am sailing way too much)

[Mike911scrs]

Hi Peter

as the box you are fitting is 1976, it could be from the 3lt Carrera and the flanges where only made from 1975 through to 77 when the SC came out (1978 model year), then the flange chenged to the fine spline.

I will have a look to see if I have any, I know I have 1 (somewhere) as a well known rally team snaped one and took one of the pair I had, I may have 2 more, if you could check the depth from the end of the diff (where the bearing is below the oil seal) to the bottom, inside the diff, also if there is a stub inside at the bottom with threads in it for the retaining bolt

regards mike

[PeterK]

Not able to go get all of that just now, but …

Flange needed is 100mm OD, with 6 off M8 bolts on 86mm PCD

To suit the ‘76 box I now need 18 splines, OD 33.7, about 17mm long.

There is a shoulder on the inside of the ‘76 flanges, about 15mm long, which looks more cast. Next, and machined is an undercut, a smooth 35mm long, 35mm diameter section, another undercut, then the 17mm of splines. Total length from the inside of the shoulder to the end of the splines is 56mm (or about 71mm from the outer edge of the shoulder to the end of the splines


Is that of any help ?

[PeterK]

Mike B to my rescue

[anglophone1]

Mike B to my rescue

Just the man!
C