Omega Owners Forum

Chat Area => General Discussion Area => Topic started by: JamesV6CDX on 18 August 2007, 20:48:17

Title: Stripped sump thread :(
Post by: JamesV6CDX on 18 August 2007, 20:48:17
Did a service on VeccyB today. Tightened sump bolt, just kept turning. Thread is all gone.

That's me buggered for transport now, until I can change the sump.

If someone with the relevent software could please PM me the TIS procedure for removing/refitting sump I would much appreciate it.

Also, please can anyone tell me if, there is a difference in sumps, between the early 1.6 small block Veccys, and the later 1.8 ones like mine - as I may be able to get one from a scrap yard on monday

Cheers
James
Title: Re: Stripped sump thread :(
Post by: Taxi_Driver on 18 August 2007, 20:57:50
 :(

My local garage always complains when i take the vx's in for an oil change....

Their comment always is ...."bloody torx bolt.....one day were gonna strip the thread on this"

Looks like you just did  :( :'(
Title: Re: Stripped sump thread :(
Post by: Marks DTM Calib on 18 August 2007, 21:03:25
Time to change your garage TD!

The head design of a bolt has nothing to do with the thread (obviously).....its the use of a torque wrench which is important, something it would appear they do not use :-/
Title: Re: Stripped sump thread :(
Post by: Darth Loo-knee on 18 August 2007, 21:04:47
If the thread has stripped on the sump and not the actual bolt cant a Helicoil be fitted?
Title: Re: Stripped sump thread :(
Post by: lee4206 on 18 August 2007, 21:12:35
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If the thread has stripped on the sump and not the actual bolt cant a Helicoil be fitted?

should be able to i've done a couple.   Helicoil kit not cheap though i think i paid about £65 for mine
Title: Re: Stripped sump thread :(
Post by: Darth Loo-knee on 18 August 2007, 21:17:20
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If the thread has stripped on the sump and not the actual bolt cant a Helicoil be fitted?

should be able to i've done a couple.   Helicoil kit not cheap though i think i paid about £65 for mine


That sounds rather dear, i used to be able to aquire things like that where i used to work ;D
My bro-in-law just had one fiited to his ZX7R (that is in the motorcycle news for some calander) and it was only a few quid :-?
Link to Bro's bike if your interested, two pictures of it the one with number "9" on it :y
http://www.motorcyclenews.com/MCN/community/Britains-got-biking-talent---latest-entries/
Title: Re: Stripped sump thread :(
Post by: lee4206 on 18 August 2007, 21:23:54
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If the thread has stripped on the sump and not the actual bolt cant a Helicoil be fitted?

should be able to i've done a couple.   Helicoil kit not cheap though i think i paid about £65 for mine


That sounds rather dear, i used to be able to aquire things like that where i used to work ;D
My bro-in-law just had one fiited to his ZX7R (that is in the motorcycle news for some calander) and it was only a few quid :-?

depends on size of helicoil the small ones are cheap but m12 up are pricey.  we used to get a mobile guy to do it for us and he charged £40 per insert (you get 10 inserts per kit) so i got the kit and charge work "£20 a go
Title: Re: Stripped sump thread :(
Post by: CaptainZok on 18 August 2007, 21:37:38
Can't you tap it out, I think Tunnie has just done that on one of his fleet.
Title: Re: Stripped sump thread :(
Post by: nixoro on 18 August 2007, 21:40:48
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Can't you tap it out, I think Tunnie has just done that on one of his fleet.

I was thinking to post up the same thing but the biggest tap in my set would be no use, did'nt know you could get a big enough tap/ threader for the sump :-[ :y
Title: Re: Stripped sump thread :(
Post by: Taxi_Driver on 18 August 2007, 21:46:31
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Time to change your garage TD!

The head design of a bolt has nothing to do with the thread (obviously).....its the use of a torque wrench which is important, something it would appear they do not use :-/

Their comment is when trying to undo the bolt......not tightening it.....but then i guess as they tightened it the time before.....its there fault its too tight.... :-/

I can vouch they have three torque wrenches  :y Wether they use em all the time.....is a different matter.....you got a torgue wrench yet James   ::)

Plus they make an excellent coffee while you wait  ;D
Title: Re: Stripped sump thread :(
Post by: CaptainZok on 18 August 2007, 21:55:05
I was right tunnies sump saga (http://www.omegaowners.com/forum/YaBB.pl?num=1184449537/0)
Title: Re: Stripped sump thread :(
Post by: lee4206 on 18 August 2007, 22:21:15
If you dont have any luck elsewhere i have helicoil kit (i'll have to confirm its the right size) and tap and die set up to m24 that i'll post to you if your happy to pay postage and a returnable depost ..
Lee
Title: Re: Stripped sump thread :(
Post by: tunnie on 18 August 2007, 23:03:22
yep i had the same problem, paid a local guy in town who had a professional tap set. If you plan to keep the car avoid helicoil, get it re-tapped or a new sump.

Or have my Senator!  ;)
Title: Re: Stripped sump thread :(
Post by: TheBoy on 18 August 2007, 23:27:17
On old tractor engine, I retapped and put bigger sump bolt in.
Title: Re: Stripped sump thread :(
Post by: hotel21 on 18 August 2007, 23:35:05
I would suggest a retap and larger bolt...

Just ensure you have a bolt of the corresponding pitch first!

Title: Re: Stripped sump thread :(
Post by: JamesV6CDX on 19 August 2007, 02:13:23
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Time to change your garage TD!

The head design of a bolt has nothing to do with the thread (obviously).....its the use of a torque wrench which is important, something it would appear they do not use :-/

Their comment is when trying to undo the bolt......not tightening it.....but then i guess as they tightened it the time before.....its there fault its too tight.... :-/

I can vouch they have three torque wrenches  :y Wether they use em all the time.....is a different matter.....you got a torgue wrench yet James   ::)

Plus they make an excellent coffee while you wait  ;D

Yep, I have (and used) a torque wrench capable of 8nm.

The bolt stripped well before the required torque, though...
Title: Re: Stripped sump thread :(
Post by: Marks DTM Calib on 19 August 2007, 08:13:56
Why avoid helicoil.....if done correctly, its better than a tapped thread and is much smoother.

Most top race engines have helicoiled everything!
Title: Re: Stripped sump thread :(
Post by: TheBoy on 19 August 2007, 08:37:21
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Why avoid helicoil.....if done correctly, its better than a tapped thread and is much smoother.

Most top race engines have helicoiled everything!
I don't have much understanding of such things, but if you have room to retap, isn't that a better fix?
Title: Re: Stripped sump thread :(
Post by: Marks DTM Calib on 19 August 2007, 08:54:27
You cant re-tap reliably.....by stripping the threads, the extra metal required to get a good tap has been removed, you can only go over size.

And over size isn't as good and as strong as a helicoil.
Title: Re: Stripped sump thread :(
Post by: TheBoy on 19 August 2007, 08:59:14
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You cant re-tap reliably.....by stripping the threads, the extra metal required to get a good tap has been removed, you can only go over size.

And over size isn't as good and as strong as a helicoil.
Yes, I was referring to drilling and retapping to a larger size.

As said, don't really understand why helicoil would be stronger that a (oversize) retap.  Not in anyway disagreeing with you, just lack of understanding on my part.
Title: Re: Stripped sump thread :(
Post by: Martin_1962 on 19 August 2007, 09:17:49
The helicoil is quite a hard steel, AFAIK the sump is aluminium
Title: Re: Stripped sump thread :(
Post by: TheBoy on 19 August 2007, 09:24:27
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The helicoil is quite a hard steel, AFAIK the sump is aluminium
But it can never be stronger than weakest point - in this case the helicoil against the sump?
Title: Re: Stripped sump thread :(
Post by: Martin_1962 on 19 August 2007, 09:41:36
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The helicoil is quite a hard steel, AFAIK the sump is aluminium
But it can never be stronger than weakest point - in this case the helicoil against the sump?

Not moving though, so should last, Mark seems to know about this.

I made my own equivalent once for an exhaust bolt on a bike barrel, Drilled and tapped bigger hole, made one on a lathe with bolt hole in the middle and a bigger thread on the outside, it lasted
Title: Re: Stripped sump thread :(
Post by: Marks DTM Calib on 19 August 2007, 10:04:04
Not wanting to be to technical but....

The shear strength of the female thread in the aluminium will limit the axial load on the bolt (hence it strips IF its over tightened.....). If you then fit an insert, the area under shear increases as radius squared, and you can allow the bolt to take more of its design strength axial loading. This is because the yield stress in shear of the helicoil material is much higher than that of the aluminium.


Basicly, the aluminium thread is now longer and hence gives more support, the stainles steel helicoil is way stronger than the aluminium and the result is....a much stronger thread.

Plus they are much easier to work with as the helicoil is a precision formed thread and not a rough cut thread in an casting!

 :y
Title: Re: Stripped sump thread :(
Post by: TheBoy on 19 August 2007, 13:43:28
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Not wanting to be to technical but....

The shear strength of the female thread in the aluminium will limit the axial load on the bolt (hence it strips IF its over tightened.....). If you then fit an insert, the area under shear increases as radius squared, and you can allow the bolt to take more of its design strength axial loading. This is because the yield stress in shear of the helicoil material is much higher than that of the aluminium.


Basicly, the aluminium thread is now longer and hence gives more support, the stainles steel helicoil is way stronger than the aluminium and the result is....a much stronger thread.

Plus they are much easier to work with as the helicoil is a precision formed thread and not a rough cut thread in an casting!

 :y
Makes a lot of sense once explained.

Thanks for the explaination :y - as said, certainly wasn't disagreeing with anyone, just trying to understand :y

When undoing, does the helicoil ever come out?
Title: Re: Stripped sump thread :(
Post by: Marks DTM Calib on 19 August 2007, 14:45:51
No, there usualy stainless (although other types are available like phosphorbronze for nasty salty environments) so dont corrode to the bolts inserted and they are designed so they are larger then the hole they are being fitted into hence you have a sprung setup applying contact to the outer material into which it is inserted over the whole area of the helicoil....

....in fact they can be a swine to remove unless you bend one end in and wind them out...
Title: Re: Stripped sump thread :(
Post by: JamesV6CDX on 19 August 2007, 15:04:07
Really stupid question, how do you fit a heliciol, and how does it hold in place? Never done one...
Title: Re: Stripped sump thread :(
Post by: lee4206 on 19 August 2007, 15:34:25
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Really stupid question, how do you fit a heliciol, and how does it hold in place? Never done one...

Quite simple you just tap out the existing hole with the tap supplied with the helicoil screw in the helicoil insert break off the tang and its as good as new. The insert holds itself in place because of the spring tension on it
Title: Re: Stripped sump thread :(
Post by: JamesV6CDX on 19 August 2007, 16:46:14
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Really stupid question, how do you fit a heliciol, and how does it hold in place? Never done one...

Quite simple you just tap out the existing hole with the tap supplied with the helicoil screw in the helicoil insert break off the tang and its as good as new. The insert holds itself in place because of the spring tension on it

If I don't have any luck mate, I may take you up on the offer of lending the helicoil kit. OF course, I'm happy to cover cost of postage insured both ways, if we do go that way
Title: Re: Stripped sump thread :(
Post by: lee4206 on 19 August 2007, 19:30:35
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Really stupid question, how do you fit a heliciol, and how does it hold in place? Never done one...

Quite simple you just tap out the existing hole with the tap supplied with the helicoil screw in the helicoil insert break off the tang and its as good as new. The insert holds itself in place because of the spring tension on it

If I don't have any luck mate, I may take you up on the offer of lending the helicoil kit. OF course, I'm happy to cover cost of postage insured both ways, if we do go that way

I'll double check that i've got the right kit tomorrow and let you know.  I've got sump bolts and washers too so im sure i'll have something to fit..