Technical Tie rod threads

[heraldsteve]

I'm not sure of its proper name but the threads on my Stilo inner steering track rod bar that comes from the steering rack (the bit the tie rod end screws on to) could ideally do with replacing due to corroded threads, but I would like to first try re-cutting the threads. Does anyone know what size die I would need?

Failing that does anyone know if these rods can be changed in situ or does the steering rack have to come right out?

This is the part I'm referring to if anyone is unsure - http://www.ebay.co.uk/itm/400244553216?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

 

[heraldsteve]

Having done a bit of online research and a bit of measuring I think the thread is 14 x 1.5 mm. Anyone know if that is correct?

 

[Davren]

The Stilo eLEARN workshop manual says M12 x 1.5. Not unknown for it to be wrong though.
.

 

[heraldsteve]

Thanks Davren. It's definitly not M12 as I have M12 nuts in my box of bits and they're too small. I have used a vernier and it measures 14mm across the top of the threads so I'm guessing that means it's M14. However, you have clarified that the pitch is 1.5 (assuming the manual isn't wrong!) and that's the bit I wasn't too sure about. Anyway, I've taken the plunge and ordered an M14 x 1.5 die (£10 off ebay) so hopefully I'll be back on the road in a few days. I'll let you know how it goes.

 

[Davren]

Too late now as you've already ordered a die, but if it's only to clean existing threads, get a spare appropriately sized nut and cut 3 or 4 slots through the thread. (hacksaw blade through the hole). It won't cut a new thread, but it's OK for cleaning existing ones.

 

[heraldsteve]

I tried to find a nut to do just that but I haven't got one as it's such an unusual size. I tried using the existing nut but it knackered up so is now useless. Luckily the new trackrod end came with a nut!

 

[Andy Monty]

Think they are metric fine... (my mates stilo drop links were)

 

[pycoed]

If you have a new trackrod end, then measure the threads in that. Oil the thread, bung a bit of Blue Tac into the hole & screw it out carefully, then measure the distance between say 5 threads on the BlueTac & divide by 5 to get the pitch.
Note - you may find the die will cut the thread undersize & too slack a fit on the rod end unless you are very careful. Hopefully you have an adjustable die, so start it opened up as far as possible & see how it goes.
Had this problem way back with a Tempra tie rod & solved it by slitting the rod end with a hacksaw, closing it up in the vice & welding the slit. I ran a tap into the hole to clean up & 'twas fine for years.

 

[heraldsteve]

Well it was a pig of a job but it's done now. Both rod ends had seized on to the tie bar and even the blowtorch would not free them. I had to angle-grind them to within an inch of their lives, being careful not to go through to the threads, before they relinquished their grip.

I then discovered my die wrench was too small for the die so I had to use mole grips, which is not a great solution for a split die! To prevent the threads from being over-cut I managed to wedge a thin slice of metal in the split of the die. Worked a treat!

If anyone needs to do the same then you need a 14mm x 1.5 die