Shoulder bolt problem

[Puglet1]

Hello all.
I am not an experienced engineer and am struggling to understand something that to you guys is quite simple.
The shock absorber on my 1971 Triumph Vitesse has what I think is called a shoulder bolt through it.
I need x2 bolts with the same width shoulder and thread but need length of the shoulder and thread extended.
To be honest I don’t know if it’s metric imperial sizes so I have measured the dimensions in both.
The only way I can show you what I’m trying to describe is by using a hotpotch photo.
Can anyone tell me if a bolt of the required sizes ( as shown in upper figure on photo ) are obtainable or do you think I need a couple made?
If it’s the latter, can anyone on here please give me estimate for doing so?
This is a suspension bolt so I guess it will need to be coated or stainless if you consider best?
Thanks in anticipation.
Pete.

 

[Haz87]

Any good?

BOLT REAR SHOCKER UPPER 118599 TRIUMPH SPITFIRE GT6 HERALD VITESSE

SPECIAL SHOULDERED BOLT CORRECT 5 /16 NYLOC NUT FOR THE REAR SHOCKER UPPER MOUNTING , PART NUMBER 118599 FITTED TO ALL TRIUMPH SPITFIRE GT6 HERALD

www.sportscarsupplies.com

 

[Puglet1]

Any good?

BOLT REAR SHOCKER UPPER 118599 TRIUMPH SPITFIRE GT6 HERALD VITESSE

SPECIAL SHOULDERED BOLT CORRECT 5 /16 NYLOC NUT FOR THE REAR SHOCKER UPPER MOUNTING , PART NUMBER 118599 FITTED TO ALL TRIUMPH SPITFIRE GT6 HERALD

www.sportscarsupplies.com

Hi Haz.
I think that is the standard length one which I already have. I have added a rear shocker conversion which necessitates the longer bolt. Thank you for your help.

 

[Agroshield]

I think that is the standard length one which I already have.

To complete your drawing, you need to measure the thread pitch.

Does the shock conversion have a rubber bush with a steel sleeve bonded to its inside? A possibility might be to reduce the length of that sleeve so the existing bolt can be used.

 

[6ply]

Is that a 5/8" shoulder bolt? If so, they are readily available. Is the end thread size important?

 

[Agroshield]

Is the end thread size important?

That is the challenge. He dimensions it as 3/4" long and 1/2" diameter. You can count 13 threads in the picture, so it is a fine thread series and they are difficult to find.

 

[Melvyn Best]

Probably 1/2 UNF thread? I would be looking for a couple of 3” x 1/2UNF bolts with a suitable crush tube for each of them. Can’t see any need for a shoulder bolt . If your not sure of the thread pitch invest in a set of thread gauges and a zuess chart or take your old bolt to your local fastener suppliers

 

[premmington]

Probably 1/2 UNF thread? I would be looking for a couple of 3” x 1/2UNF bolts with a suitable crush tube for each of them. Can’t see any need for a shoulder bolt . If your not sure of the thread pitch invest in a set of thread gauges and a zuess chart or take your old bolt to your local fastener suppliers

That would work a treat....

 

[6ply]

I've got about 20kg of 1/2" unc partially threaded studs, various lengths, to get rid of.

 

[mr haynes]

At first cursory glance i thought it was a bolt with a crush tube on it ala removed from car with it stuck on

 

[Puglet1]

To complete your drawing, you need to measure the thread pitch.

Does the shock conversion have a rubber bush with a steel sleeve bonded to its inside? A possibility might be to reduce the length of that sleeve so the existing bolt can be used.

The shocker is a polybushed Koni unit and doesn’t have an insert so I am stuck with its current design.
Thank you for your help.

 

[Puglet1]

Is that a 5/8" shoulder bolt? If so, they are readily available. Is the end thread size important?

Just did a conversion, 5/8 shoulder is pretty much the same dimension as my bolt so that has helped me as I didn’t know how to convert 0.620.

 

[Puglet1]

Probably 1/2 UNF thread? I would be looking for a couple of 3” x 1/2UNF bolts with a suitable crush tube for each of them. Can’t see any need for a shoulder bolt . If your not sure of the thread pitch invest in a set of thread gauges and a zuess chart or take your old bolt to your local fastener suppliers

Unfortunately, part of the crush tube fit into a box section which I cannot access so once the tube crushed by the bolt in the shocker I won’t be able to remove it. Thank you for your suggestion anyway.

 

[Puglet1]

Is that a 5/8" shoulder bolt? If so, they are readily available. Is the end thread size important?

Looks like it is a 5/8 bolt thread diameter needs to be 1/2 inch, currently a fine thread, would fitting a unc type thread be ok?

 

[Brad93]

View attachment 451248Hello all.
I am not an experienced engineer and am struggling to understand something that to you guys is quite simple.
The shock absorber on my 1971 Triumph Vitesse has what I think is called a shoulder bolt through it.
I need x2 bolts with the same width shoulder and thread but need length of the shoulder and thread extended.
To be honest I don’t know if it’s metric imperial sizes so I have measured the dimensions in both.
The only way I can show you what I’m trying to describe is by using a hotpotch photo.
Can anyone tell me if a bolt of the required sizes ( as shown in upper figure on photo ) are obtainable or do you think I need a couple made?
If it’s the latter, can anyone on here please give me estimate for doing so?
This is a suspension bolt so I guess it will need to be coated or stainless if you consider best?
Thanks in anticipation.
Pete.

Berger Tools

 

[DaveB]

I've just had a look at shocker upgrades for the Triumph Vitesse on the Rimmer Bros website and it looks like you change the shouldered bolt for a plain one when fitting the brackets to extend the chassis so that the shockers mount nearer to vertical.
Did you kit come with bolts, nuts and distance tubes.
Looks like you need a tube to go in the old shocker upper hole in place of the shocker so you don't squash the chassis.

 

[Bullet2012]

Moss show the same conversion kit , if you are changing from lever arm to telescopic.

Telescopic Damper Conversion Bracket Kit - Rear Suspension - Steering & Suspension - Spitfire - Triumph - Select Model

Moss Europe

www.moss-europe.co.uk

 

[Puglet1]

I've just had a look at shocker upgrades for the Triumph Vitesse on the Rimmer Bros website and it looks like you change the shouldered bolt for a plain one when fitting the brackets to extend the chassis so that the shockers mount nearer to vertical.
Did you kit come with bolts, nuts and distance tubes.
Looks like you need a tube to go in the old shocker upper hole in place of the shocker so you don't squash the chassis.

Yes. I’ve fitted the brackets to the chassis using the spacers, nuts and bolts supplied in the kit.
The shock absorbers I’m using are not the usual telescopic ones as suggested by Rimmers/ Moss etc.
A lot of research has been carried out by members of the Triumph club I’m in and I’m fitting Konis of a different length that’s normally fitted to old style Mini.
This involves drilling out the bottom bush tube and replacing the top bushes with a specific polybush and spacers (no steel tube) .
I have looked at the top mounting and decided that the original Mk1 bolts give the best result but are too short to go through the brackets - which sit over the original chassis . That’s why I’m looking for shoulder bolts of the same dimension width wise - but longer .
Thank you for taking interest in this and spending time on Rimmers etc.

 

[Puglet1]

Moss show the same conversion kit , if you are changing from lever arm to telescopic.

Telescopic Damper Conversion Bracket Kit - Rear Suspension - Steering & Suspension - Spitfire - Triumph - Select Model

Moss Europe

www.moss-europe.co.uk

Hi Bullet2012.
I actually bought the kit from Moss and am looking for a longer bolt as explained to DaveB.
Thank you for your support.

 

[Beanwood]

Well if you find out what thread you require... buy some 16mm stainless rod, (buy a lathe) turn it down to 15.84 for the shoulder, then turn both ends down and cut the right sized thread. Stick a nylon nut on one end to act as the nut head.. Jobis done