gearbox mount mk1

[willjan]

can anyone remember whether the bolts to the subframe are meant to be threaded all along,or plain shank with threaded ends.
CW does not seem to list them.

bill.

[CAR]

Mine were this morning on the estate I think Dad, a mk2 though obviously.

Colin

[Alan Chatterton]

Do you mean these Bill?............


http://www.ebay.co.uk/itm/justriumph-NE ... 470wt_1396

[willjan]

sorry alan,its my wording,i mean the bolts which pass through the mounting and crossmember.should have made that more clear.i think colin knew what i meant,because i had asked him already.

bill.

[Alan Chatterton]

oh, ok.............!!

Got the wrong end of that one!!

[Alec]

Hello Bill,

strangely the parts book shows a screw (part number HU0918) and the workshop manual gives a description in the Tightening Torques table as a 3\8" UNF x 2 1\4" setscrew, personally i would rather see a bolt in that application?

Alec

[David Withers]

I'd ignore what the manual says, since its use of the term "setscrew" is wrong anyway. A setscrew has a point, knurl or other locking means at its end, used for example to lock a pulley to a shaft (i.e. to set the pulley in position).

They meant either a "bolt" or a "screw". A bolt is threaded for a length of 1.5 x diameter as standard, but can be threaded further as a 'non-standard'. A screw is the same as a bolt but fully threaded except for a run-out of about two pitches under the head.

Bolt & nut stockists tend to keep Unified fasteners in a limited range of lengths, and normally only in screw form so that they can be cut to the required length. It might be necessary to buy 2.1/2" long screws and then cut and re-chamfer them. It helps if you wind on a nut before cutting and chamfering; winding it off afterwards makes sure that the end is correctly formed.

I agree with Alec that a bolt is preferable, but I'd be happy with a screw since (a) precision of location isn't important, and (b) there should be no fretting if it's done up correctly.

[andy harrison]

Bill, most if not all those I've worked on / repaired / broken have been fully threaded, if my memory serves me correctly.....however I .have seen several "bodges" in that area, one in particular started with an odd vibration and difficulty selecting reverse ... turned out to be the bit Alan referred to, except that someone had used long nuts and bolts, with a wheel nut as a spacer where the proper tube spacer should be (most often found on the J - type overdrive version --- the tube spacer, I mean !!)....there must have been 2 brains involved in that idea, as even in my younger days I don't see how you could tighten a nut under the car at that point and hold a spanner on the top of the bolt ?? hope that helps, all the best Andy

[Alec]

Hello David,

a good friend of mine's father worked as a tool maker for Wilmot Breeden and I soon found talking to him that the Midlands seemed to have a slightly different engineering vocabulary to mine. Perhaps that is how the term setscrew came about.


Alec

[David Withers]

A bolt is threaded for a length of 1.5 x diameter as standard, but can be threaded further as a 'non-standard'.

Correction: Standard bolts are threaded for 2 x diameter.

Anyone know a cure for senility?