The Triumph Dolomite Club - Discussion Forum

I know Helicoiling is usually used on castings to repair stripped threads, but I've stripped a thread on my Sprint style 3/8UNF alloy wheel nut. Can this be Helicoiled ?
O.K. it has to be drilled out but there looks to be plenty of aluminium wall thickness on the sleeve.
I was wondering if there might be a problem with seizing of the new thread due to corrosion as its an alloy nut with a stainless steel Helicoil on a mild steel wheel stud ?
Thanks Tony.

I have had to helicoil sprint heads where idiots torque the small 5/16 unc cam bolts to oblivion, so yes indeed it can be done but the expense of the helicoil kit would make it expensive when a new nut can be the cheapest and best route.
Rolls Royce use helicoil when new as you end up with a stronger thread.
The alloy used for wheel nuts is 2014 which is a hard alloy.

I think if it were a 7/16 nut, which are plentiful, replacing it wouldn't be an issue. But with 3/8 Sprint nuts being like hens teeth served on a bed of rocking horse poo and garnished with unobtanium, helicoiling suddenly seems like a cost/time effective solution.
My only concern is how many removal/refitment cycles a helicoil will tolerate before it stays on the stud.

Steve

Carledo wrote:But with 3/8 Sprint nuts being like hens teeth served on a bed of rocking horse poo and garnished with unobtanium, helicoiling suddenly seems like a cost/time effective solution.

I may have some soon, my rear axle which I've just fitted is the larger thread..

I too am looking for a full set of 3/8" Sprint wheel nuts. I don't mind steel ones. The ones sold by Rimmers seem very expensive.

Mike

If I could be certain about the grade of aluminium alloy used, these would be in production, but as a safety critical item, I dare not!

I may have a single spare 3/8" nut Tony...

Don't know what the drill size for 3/8s coils is, but would it be big enough you could helicoil a 7/16ths nut with a 3/8ths coil?

Graham

Went and looked, and the drill size for a 3/8ths helicoil is 25/64ths, i.e. 3/64th smaller than 7/16ths. So it wouldn't be safe.

Graham

xvivalve wrote:If I could be certain about the grade of aluminium alloy used, these would be in production, but as a safety critical item, I dare not!
I may have a single spare 3/8" nut Tony...

Alun I wish I could remember where I read it but Porsche 944's have alloy nuts too and the material is definitely Aluminium 2014 grade.

The designer of the alloy sprint nuts did had the rest of his working life after he left BL a career at Porsche.

Jeroen

soe8m wrote:The designer of the alloy sprint nuts did had the rest of his working life after he left BL a career at Porsche.

Jeroen

What was he doing there? was he helicoiling stripped Porsche nuts