Swivel ball housing string arm mount studs

[Gazzar]

I'm working on a series 3 front axle at the moment, and replacing the swivel ball housing, due to a damaged thread on one of the stub axle holes.

The nos housing came with eight studs and nuts, which I thought interesting, but it was only when I compared it with the old one I realised why.

 

The new studs are much narrower than the original, and closer inspection showed that half of the studs were stepped to allow snug fitting to the steering arm.

 

I'm not entirely happy with this and am very tempted to tap the holes out to take the original, opinions?

[steve b]

The FPB shows 531043 dowel stud  x4 and 531494 stud x4 (axle set) so 2 of each per side.

The larger diameter plain section is the dowel and should be diagonally opposite - the arm should be machined on those two holes for a close fit. The top pin (Railko) plate is held with 4x 237357. 

Difference in thread size is the change from early BSF to later UNF or possibly Metric - have you checked what thread the NOS parts are?

Steve

[Gazzar]

I'll check when in the workshop again.

 

I'm going to tap them out to BSF (or whatever the studs are), the dowels aren't a snug fit to the arm, so that's a non starter.

[Gazzar]

I think the original damaged housing was late 2a specification:  7/6" studs.

 

This series 3 was one of the first of the line, serial number was less than 500.

[Snagger]

20 hours ago, steve b said:

The FPB shows 531043 dowel stud  x4 and 531494 stud x4 (axle set) so 2 of each per side.

The larger diameter plain section is the dowel and should be diagonally opposite - the arm should be machined on those two holes for a close fit. The top pin (Railko) plate is held with 4x 237357. 

Difference in thread size is the change from early BSF to later UNF or possibly Metric - have you checked what thread the NOS parts are?

Steve

Yep.