Lotus Elan

how to get peeved off!

PostPost by: worzel » Wed Apr 19, 2006 11:35 am

The attitude of some never fails to amaze me- I contacted a secretary of an E Type owners club with a technical question that if answered would considerably help me with a problem for another car.

Fair enough I got a quick reply but it was along the lines of "are you a member- we are soooooo busy we could only possibly spare our precious time to help fellow owners"

Good attitude eh?

I shot them a reply stating that Lotus owners don't discriminate because we're helpful.

John
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PostPost by: john.p.clegg » Wed Apr 19, 2006 2:41 pm

John
Well,what's the question?
John :wink:
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PostPost by: worzel » Wed Apr 19, 2006 4:36 pm

Hello there

Got your interest eh?

Basically I'm going to try an unorthodox way of removing a broken stud from an alloy gearbox casing- without removing the box.

The broken stud is protruding about half inch with about three quarter inch in the casting.

I know some of the usual ideas- possibly weld a nut to the stud- apply heat and then have a go or use a drill out extractor. The latter idea is not an option because of limited room.

My idea is based on something I read years ago in Practical Classics. The mag was rebuilding a XK engine but couldn't shift the head because the studs, which apparently run thru the water jacket corrode to the alloy.

Somebody came up with the idea of using a hardened tube with teeth cut on one end to slip over the studs (just) and use this to cut the bond of rust. The tube was obviously quite thin walled. The idea worked and I was thinking of trying the same trick.

The external diameter of the tube would then leave a hole ready to be tapped for the next size up. The half of the stud that protrudes is the same size etc as the original.

What I asked the Jag owners was "have you heard of this device and if so where could I get one?"

Very elitist sounding reply came back (or maybe I'm paranoid) but they certainly weren't at all helpful.

Incidentally the car in question with the offending stud is an Excel.

Regards

John
I know it would take a lot longer than for a jag because I'm effectively cutting sound aluminium but it would definitely beat removing the box.
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PostPost by: nebogipfel » Wed Apr 19, 2006 5:26 pm

Sorry to hear you got the brush off

I usually go for welding a nut on. If the bit sticking out is long enough it is a really successful method - the heat of welding helps the process
John

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PostPost by: Ztp » Thu Apr 20, 2006 2:41 am

Don't know if you have the room but there is a tool that is like an easy out (The one where you drill the stud, etc) but it is external.

They come in various sizes that slopp over the offending stud, bite in and allow you to turn the stud out.

Sears has them in there tool department here inthe colonies. Probably also get them at a vender of drills, taps, and th elike.

Keep the clean side up!
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PostPost by: cliveyboy » Thu Apr 20, 2006 7:49 am

John
If you want engineering advice always asked an engineer.

I personally think the tube cutting idea is suspect. As you mention it would need to be a thin wall tube but even this would be too thick in engineering terms to leave a hole small enough that you could use to replace the same thread.
Why would you want to tap it next size up before you have exhausted all possibilities of helicoiling it or using other methods to replace the correct thread. As soon as you tap it next size up you also have to enlarge the hole that the stud goes through on the matching component.

The other draw back with the tube is that it would take for ever to do as it would be rubbing more than it was cutting and it would constantly be blocking up and even seize in the hole.
The weld a nut on idea is a good one or if you have enough thread two thin locking nuts tightened together on the protruding thread if you do not have access to a welder or are near to fuel lines etc.

If the stud has undone slightly before it sheared you can also try screwing it back in as this can sometimes free any muck that has jammed the thread.

Is the stud in a blind hole? An example being on things like bell housings you can sometimes get to the back of the stud as the hole goes all the way through. this gives the advantage that you could drill out from the other side another advantage being when you drill you generate heat but also the twisting force of the drill is causing the stud to try and turn in the direct you want for it to unscrew.
(Alternatively using a reversible drill and buying some left hand drills can give the same effect.)
I find that when unscrewing a bolt/stud that has jammed. Try 1/4 a turn out then a 1/8 turn back in repeatedly. It helps to keep the muck from jamming the threads even more.

Some heat applied to the aluminium might help whilst unscrewing it as it expands more than the steel.
And lots of good old penetrating fluid

Clive
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PostPost by: worzel » Thu Apr 20, 2006 8:21 am

Hi to all who replied- and thanks.

I've had similar problems like this one solved by the nut welding method and I may well have to use this approach. My idea was that if it fails/or the snaps even shorter I at least have an alternative to try.

It's almost all or nothing because the offending stud (which is actually the remains of a bolt) is one of two fastenings securing the clutch slave cylinder. At present I've replaced the sound one with a stainless stud and the snapped bit is acting as a dowel. It's never been a problem- yet- but manufacturers don't normally fit two fastenings where one will do.

I've actually had a cutter made for me but the big problem is cutting the teeth at the right angles etc. The hole cutters on the market (in effect what this is) are unfortunately too big for the job.

I'll let you know if the idea works anyway- somebody else might have a similar problem.

Anyway thanks to all.

John
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PostPost by: purplepete » Thu Apr 20, 2006 8:47 pm

Hi,
I havent actually seen one,but i believe theres an attachment you can put on a mig that allows you to weld a new stud to the protruding remains of the old one-i think its basically a hollow stud with an insulating liner-apparently theyre common in exhaust fitting places??
the external stud extractors are v.good,but they need a fair bit to bite onto,but if you want to try one give me a yell!
is there space to try something like a dremel to drill it oot??
good luck!!
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PostPost by: bill308 » Fri Apr 21, 2006 12:22 am

I'm in inclined to try the weld-a-nut method, but have a pretty good welder do the job. I think you want to get in there quickly and make a good weld, using a substantial nut. I'd then try a hand impact wrench, like the motor cycle guys use. A sharp impact may persuade it to move and the limited turn would likely ensure that the nut or shaft would not yield or plasticly deform. I would think a significant mumber of blows could be delivered without harm. If this doesn't free the bolt, go for the brute force method with a pneumatic impact wrench, using increasing pressures, but start reasonably.

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PostPost by: M100 » Fri Apr 21, 2006 9:06 am

The hole cutter idea sounds crazy to me. I'd continue to heat cycle it a few times with a blowtorch/hot air gun followed up with freezer spray and lots of proper penetrating fluid (not WD40!!!!) The odd light tap on the end with a copper hammer couldn't go amiss either.

Depending on access and especially with that much stud remaining I'd drill though a big nut to just slip over the stud and tack it on with a blob of weld.

If it sheared off then I'd drill the remains out in stages or use a parallel splined extractor tool. Forget using any that are tapered.
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PostPost by: andrewdmoore » Fri Apr 21, 2006 11:42 am

John,

Sorry if I'm stating the obvious here but I'm an Excel & Elan owner aswell - have you tried a post on the Excel Website (did you know about it?). Speaking from experience you'll probably get a quick & very informative reply.

Regards, Andrew

http://excel.ansrallying.org.uk/phpbb/
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PostPost by: worzel » Fri Apr 21, 2006 2:30 pm

Hi Andrew

Yes I do make use of the Excel forum- the only reason I didn't post it there is because it's more of a general type of question rather than being Excel specific. Might be worth trying though in case others have had a similar problem.

Incidentally- where are you. I'm in Merseyside. Tell me about your cars. I've had the elan since 1978. It's a 2 owner sprint fixed head. Modified a fair bit- but not externally/bodily. Very modded interior, 5 inch minilites, stainless tank custom made. Plus 2 wide rad with Citroen BX fan. 5 speed box, stainless exhaust, dismantleable vacuum pods for the lights (fibreglass to my own design). Has a std sprint engine (the original). Believe it or not the head has never even been skimmed.

I've had the excel since 2000. Bought it with the intention of using it as an everyday car and that's what I've done without any real hitches. 89 model not SE and it's a "bitsa" car- it has twin fans but isn't air con, uses the later improved SE cam belt and the (apparently) improved later head. Doesn't have the cold start tricks of the SE and uses the later cam belt tensioning arrangement. Uses 14 inch wheels. Bog standard and low mileage when I bought it -42k. 2 owners only before me and never shunted. Only had minor problems really- if you ignore the excess backlash in the diff caused by the pinion nut working loose and the rad needed recoring. Fitted 2 galvanised door beams and new pins with a grease nipple now installed.

Can't complain about anything really- except rear visibility when reversing.

John
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