Bolt size & type

[Drover]

Hey all,

Fitted TF heavy duty steering rod / Panard rod set during the week. Very nice gear but I now have to space the diff guard to clear the over sized rods, no biggy.

The original bolts supplied with the bash plate are not long enough. They screw into the threaded holes cast into the bottom side of the front diff.

I took the short bolts to the local bolt shop for some longer versions and was given 9mm x 25mm - "fine metric".

They don't fit. Took them back the guy measured and insists they are the same - they're not - they won’t screw in. He did say the original bolts are under size by .25mm ?

So, does any body know what size and thread type these bolts would be ?

Cheers

[Yorkshire_Jon]

Sounds like whitworth or some other imperial thread.

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[Bigbjorn]

Get yourself a cheap plastic vernier caliper. These read in mms and fractions. Get a set of screw pitch gauges in UN, BS, and Metric. Get some thread charts and sit down with a bucket of bolts and learn to recognise thread diameters and pitch. Commercial bolts are made slightly undersize so keep this in mind. ALWAYS quote the pitch and thread system when buying or seeking information about fasteners. Don't just say M9 but M9 x 1.25 or 5/8" NF but 5/8" x 18 NF. Don't assume that staff in bolt shops have useful knowledge. They are shop assistants not fitter-machinists. Most were born after BSW, BSF, BSC passed from common use and have no knowledge whatsoever of obsolete threads.

[Drover]

Went to small industrial shop "Gosford bolts and bearings" and the chap there was all over it.

Within a small amount of time he had identified the type size and supplied two bolts......turned out they were BSF and yes obsolete but in stock.

You gotta love these small shop who just know and have everything you never knew you needed.