4 replies to this topic

[Minwah]

I just tried compressing a front cone to fit some hilos...

A mate lent me a cone compression tool but he wasn't sure if it was imperial or metric...tried screwing it in and it felt absolutely fine. However on screwing up the handle, after it started to become hard it let go. On checking the tool the threads on the inner part (not the tip) have been stripped.

This leads me to believe I have an imperial tool and the car is metric ('79) - if the imperial thread is slightly bigger this would probably make sense. Can anyone confirm that an imperial tool would even screw into a metric cone? As I say it went in easily enough. Also the car is on the wheels so the cone is partially compressed already.

Just hope I haven't ******* the threads on the cone or god knows what I'll do...

[dklawson]

I don't know when the transition took place but the early inch threaded cones were tapped 1/2-20. The later cones are tapped M14x2. Therefore, the later puller is 1.1mm bigger in diameter and won't fit early cones. You can indeed run the imperial puller into a later cone and strip the threads.

Stripped threads aren't the end of the world though. I believe the common wisdom follows two possible paths. The first is to remove the upper suspension arm pivot shaft to free the cone and trumpet. It's a little tricky but can be done. The second is a little more destructive. Since you're fitting Hi-Los, shatter the old cast trumpet to free the donut. I presume you're fitting new donuts with the Hi-Los. If so, stripped threads on the old part aren't an issue.

[Minwah]

Great, thanks for your help

I wasn't planning to replace the cones as the car has only done 39000 miles...I thought they would be ok. However if after inspection I need to then I certainly will.

Thanks again

Edit: just for anyone else's info, I believe the cones became metric on all cars '76 on.

[Dan]

The transition took about 2 years to complete as they used up all the stocks of imperial units, I think it was 74 - 76. Between those years a mixture was used.

It is possible to do as you suspect you have done, I've done it. The thread in the cone will still be fine for compressing it using the other bar.

[Minwah]

It is possible to do as you suspect you have done, I've done it. The thread in the cone will still be fine for compressing it using the other bar.

Ah good news, thanks I'll be doing the front end this coming weekend...