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Wishbone Making Disaster
locogeoff - 17/4/05 at 06:29 PM

Bought Bush Tubes and threaded bits from Lolocost, made my jig and wishbone arms, tacked and welded it all up, when I was finished but it was all still hot I popped the ball joint in it went in nice then jammed. In the process of getting it out I've buggered both the threaded sleeve and the ball jont, O.K. this is not that great a problem but I dont want to procede until I've settled my mind.

1) Dye reccon I've been a bit gungho with the welder and overheated and distorted the threaded tube which incidently is a wee bit thinner than an inch.

2) Should I have waited till the whole shebang had cooled to ambient temperature, thinking about relative thermal expansion rates between the bush tubes and the ball joint.

3) I borrowed the steel from a shopping trolley and dont have enough to make another mistake, should I just buy some bones from a reputable source.

4) Who makes the best bones

5) Anyone make bones with a corrected offset to correct the book anomoly about the castor problem.

This is the first time in ages I've worked on the car and am currently really cheesed off, though I shouldn't be so cause its the first time I've bogged up real bad on the project so far, all coments greatly received.

Geoff


splitrivet - 17/4/05 at 07:02 PM

You'll probably find the threaded tube from lolo was rusted to bollox internally, mine was and had to be retapped out.

So theres a good chance it wasnt down to you Geoff, so cheer up mate.
Cheers,
Bob


DavidM - 17/4/05 at 07:31 PM

I did that with one of my wishbones, screwed the balljoint in while it was still warm. Destroyed it getting it back out and had to make another. Leave them to go completely cold next time, whoever you get the threaded bush from.
I was equally distraught. Got over it though.

I used additional offset in the top wishbone to achieve 5 1/2 deg castor.

David


GaryM - 17/4/05 at 08:06 PM

By a strange co-incidence i've just had a similar experience.

I suspected the threaded tube when my ball joint would not screw in and a fellow builder (with the correct tap) kindly re cut the thread in the tube.

After thoroughly cleaning out the thread i tried again and the same thing happened.

I then tried a different ball joint which screwed in no problem so I tried the suspect ball joint in another threaded tube and it stuck.

It may be worth checking your ball joint(s)before you trash some more wishbones.


Liam - 17/4/05 at 08:58 PM

Exactly the same thing happened to me when i screwed in a rose joint while a rear wishbone was warm. Destroyed it getting it out but luckily the wishbone was saved by retapping the thread.

Liam


Simon - 17/4/05 at 08:59 PM

Appears it's not so strange.

Yep, I did it too. God, what an impatient lot.

Managed to get mine apart, but do believe treaded tube got distorted.

Weld it up, allow to go COLD, retap, then try. Should be OK

ATB

Simon


DaveFJ - 17/4/05 at 09:03 PM

as an aside - making wishbones out of old supermarket trolleys ? sounds like suicide to me


Mark Allanson - 17/4/05 at 09:22 PM

quote:
Originally posted by DaveFJ
as an aside - making wishbones out of old supermarket trolleys ? sounds like suicide to me



WHY?

You must know that every one is tested to over 200mph before it is allowed to be used at ASDA


locogeoff - 17/4/05 at 11:10 PM

quote:
Originally posted by DaveFJ
as an aside - making wishbones out of old supermarket trolleys ? sounds like suicide to me


Check out

http://www.locostbuilders.co.uk/viewthread.php?tid=16391&page=1

I was a bit dubious myself until I knackered a hacksaw blade cutting one up, welds nice as well once you remember to cut the laquer off. Its good to know I'm not the only one who's been tripped up by this, with a bit of luck, I might even be able to clean up the thread as the damage is very localised, will need to see though as I dont want the balljoint pulling out


craig1410 - 17/4/05 at 11:14 PM

I bought wishbones from Lolocost and if I did it all again I'd buy from a reputable source such as MK, Luego, GTS or Stuart Taylor. The GTS oval wishbones are nice and would be top of my list along with a set of Poly U bushes.

I had the same problem with the rusty threaded tubes and had to use loads of oil and patience, screwing the balljoint in and out until it all freed off. The wishbones were also bent and the pivots were not concentric which is very bad news for a wishbones as it will fracture due to fatigue. I had to spend ages carefully realigning the eye tubes until they were perfect.

Do yourself a favour and just buy a set from GTS.

Cheers,
Craig.


locogeoff - 17/4/05 at 11:19 PM

Thinking about this logically, the length of the threaded tube will have significantly increased due to the high temperature, thus the fine thread would now be a slightly coarser thread hence after a few threads in the joint sticks, or if the tube is hot enough the threads become crossed.

So after patiently making a jig and sweating as I cut the godam hard steel to fit, I bog it up at the last to get an impression of what the bone will look like with a balljoint hanging out of the end of it.

Bollox

cheers all

Geoff

Things always look better when you've calmed down had your tea and watched a good crap film on the box.


andyharding - 18/4/05 at 08:49 AM

MKs wishbones are the dogs and they make an oval upper now too.


britishtrident - 18/4/05 at 11:00 AM

MK, GTS NMR ----- all have an excellent reputation for wishbones.

After welding a wishbone it always makes sense to chase the threads with a tap or thread cleaner.


want2race - 18/4/05 at 12:41 PM

I just bought bolts that had the same thread and threaded them into the tubes before I welded.

That way I had added heat disapation as well as the threads would remain intact.

But remember to use some sort of anti seize compound..

Additionally you could just dunk the part in water after welding..


Fred W B - 18/4/05 at 02:19 PM

I would have though that both of the above suggestions are not very good ideads . .

I plan to fabricate the wishbones with the bushes having only the tap size plain hole brilled, then tapping the thread afterwards.

Cheers

Fred WB


Alan B - 18/4/05 at 03:21 PM

My suggestion too Fred....

If you have the tap anyway you may as well tap the complete thread.

(unless of course they are pre threaded, which is probably the case)


britishtrident - 18/4/05 at 05:38 PM

Most Locosters in the UK making wishbones buy in the tubes ready tapped with faces lathe cut.

18mmx1.5 taps aren't cheap but spark plug chasers are found in most tool boxes or can be borrowed and the 18mm end is the correct 18mmx1.5 thread.

Tapping the tube and facing tube ends really is a job for a lathe which most builders don't have.

[Edited on 18/4/05 by britishtrident]


Alan B - 18/4/05 at 05:53 PM

quote:
Originally posted by britishtrident
Most Locosters in the UK making wishbones buy in the tubes ready tapped with faces lathe cut.

18mmx1.5 taps aren't cheap but spark plug chasers are found in most tool boxes or can be borrowed and the 18mm end is the correct 18mmx1.5 thread.

Tapping the tube and facing tube ends really is a job for a lathe which most builders don't have.

[Edited on 18/4/05 by britishtrident]


Points noted.

However, anyone with a lathe (and tap), would be better off following Fred's method...i.e. make the bush with tapping size hole (on the lathe) then weld, then finally tap.

I acknowlege that most people won't be able to that.


craig1410 - 18/4/05 at 08:42 PM

I definitely wouldn't dunk the freshly welded wishbone in cold water as this is likely to make the welds very brittle. Ideally cool it as slowly as possible by wrapping it in rockwool insulation.

Cheers,
Craig.


locogeoff - 18/4/05 at 10:44 PM

quote:
Originally posted by craig1410
I definitely wouldn't dunk the freshly welded wishbone in cold water as this is likely to make the welds very brittle. Ideally cool it as slowly as possible by wrapping it in rockwool insulation.

Cheers,
Craig.


Ahhh... Good old Time Temperature Titration diagrams, its been a long time

I've been back and had a look at the bone and I think it may be saved with a tap as the damage is only to a couple of threads, although I've noticed that the bush tubes are not perfectly aligned, close but not perfect, think I may end up redesigning the jigging system to force this alignment to be better, the current one could be used as an emergancy spare.

Thanks to all for help, all comments and advice still welcomed.


James - 19/4/05 at 10:18 AM

quote:
Originally posted by locogeoff
although I've noticed that the bush tubes are not perfectly aligned, close but not perfect, think I may end up redesigning the jigging system to force this alignment to be better, the current one could be used as an emergancy spare.
.


Don't cut it just yet!

Correctly aligned w/bones do look out. It's an optical illusion (maybe caused by the Castor?). I was worried about mine but a bar fitted through the bush tubes proving they're in line.

Also, to garantee they're inline you can always leave the bush tubes as one long bar (maybe partially cut) and once it's all cooled cut the middle piece out.

HTH,
James

EDIT: As for jigs- The Book method is ridiculous. If I was doing mine again (which I may well have to as Castor is wrong) I would use a board of MDF and angle iron fixed to the board to keep the tubes inline.
It works for a equipment made by an F1 team so it's good enough for me!

[Edited on 19/4/05 by James]


clbarclay - 19/4/05 at 10:40 AM

When making wishbones i did a few tacks, take the wishbone out of the jig (only made from wood) and checked the bush outer tubes alignment on a lenght of steel box (adjust with hammer etc. if necissery). Then back in jig for more tacks, check again, then weld fully.

It the allignment is only slightly out the bush should be able to compensate.


Oilburner - 19/4/05 at 04:01 PM

I am just about to start wishbone fabrication and have had 2 brass bushes machined to the ID of the tubes, centre bored out to 10mm which allows a piece of silver steel to pass through both bushes on the jig, ensuring alignment.


britishtrident - 19/4/05 at 06:14 PM

quote:
Originally posted by Oilburner
I am just about to start wishbone fabrication and have had 2 brass bushes machined to the ID of the tubes, centre bored out to 10mm which allows a piece of silver steel to pass through both bushes on the jig, ensuring alignment.


Thats the way mine were done be aware it is very easy to damage (burn a hole) in the ends of the bush tubes adjacent to the welds.


craig1410 - 19/4/05 at 08:02 PM

My Lolocost wishbones come with Nylaspa (Nylon) bushes and so they have virtually zero "give". That makes it doubly important that the alignment is perfect. I didn't go to the extent of using silver steel but I did use a piece of mild steel threaded rod which fitted nicely through my crush tubes. I checked the rod for straightness before using it of course...
The same rod was then used later to help position the wishbones with respect to each other using nuts on the rod to hold the wishbones at the correct relative positions. This method has been described within this forum many times so I won't go into it again.

Cheers,
Craig


kaymar - 19/4/05 at 09:45 PM

i to have the lolocost type w/bones that require nylapsa bushes, i felt that although firm and a tight fit this was only going to add stress, so i have used book herald bushes and have made steel sleeve to adapt to fit the eyes, have also made alluminium sleeves also. have not decided which will be the final fitment as yet. martin