Captive nut replacement...a little help here please
Discussion
Hi guys, after waiting all week for my TVR Power sports exhaust to arrive (it came yesterday), I now have a little problem (at least I hope it's little).
Whilst removing the rear diffuser I discovered that one of the hex bolts securing the near side edge (just behind the rear wheel) was just rotating and not unscrewing. I have cut away the head of the bolt leaving just the threaded shaft so that the diffuser is free to fall away. My problem is that the captive nut which would normally be fixed just rotates.
What's the best way for me to proceed? Do I replace the captive nut...if so how? Is there a way of getting in behind the panel to perhaps glue the nut in place so that the bolt shaft can be unscrewed?? If anyone has had anything similar happen can they please give me the benefit of their experience.
Hope it's not causing a problem....I was going to pop this on the main TVR page also.
Cheers
Mark
Whilst removing the rear diffuser I discovered that one of the hex bolts securing the near side edge (just behind the rear wheel) was just rotating and not unscrewing. I have cut away the head of the bolt leaving just the threaded shaft so that the diffuser is free to fall away. My problem is that the captive nut which would normally be fixed just rotates.
What's the best way for me to proceed? Do I replace the captive nut...if so how? Is there a way of getting in behind the panel to perhaps glue the nut in place so that the bolt shaft can be unscrewed?? If anyone has had anything similar happen can they please give me the benefit of their experience.
Hope it's not causing a problem....I was going to pop this on the main TVR page also.
Cheers
Mark
Edited by m33ufo on Sunday 11th June 16:42
I had the same prob when I took the rear diffuser off when fitting a reverse camera - but for the life of me I cannot remember how I overcame the prob regarding the captive nuts turning with the bolt - sheer perseverance I think! I ‘think’ I managed to hold the nut in place with enough pressure so as to turn the bolt – I used epoxy resin glue to fix the nut back in place when fitting it all back together.
I know its not much help, but I do know how darn fiddly it is, so I know what you’re going though!
Edited to add - Ah, it's a T350 you have, I should have looked first, probably different to a Tam........
I know its not much help, but I do know how darn fiddly it is, so I know what you’re going though!
Edited to add - Ah, it's a T350 you have, I should have looked first, probably different to a Tam........
Edited by chris watton on Sunday 11th June 17:00
chris watton said:
I had the same prob when I took the rear diffuser off when fitting a reverse camera - but for the life of me I cannot remember how I overcame the prob regarding the captive nuts turning with the bolt - sheer perseverance I think! I ‘think’ I managed to hold the nut in place with enough pressure so as to turn the bolt – I used epoxy resin glue to fix the nut back in place when fitting it all back together.
I know its not much help, but I do know how darn fiddly it is, so I know what you’re going though!
I know its not much help, but I do know how darn fiddly it is, so I know what you’re going though!
What a pain in the arris. Thankfully I at least have the diffuser off but after cutting the head off the bolt I still have the threaded shaft protruding from the captive (actually not so captive!) nut. Worst of all it's one of the side nuts which I don't think I am able to get behind to cover it in epoxy.
Not knowing how this all looks on the car you may need to ignore this advice
1 -I am assuming that when the diffuser is bolted in place it covers the captive nut.
2 -Therefore you firstly need to drill out the old captive nut.
3 -Then you need to have a nut welded to a strip of metal with two rivet holes.
4 -The nut on the strip fits in the hole and the strip is riveted to the body.
5 - The nut strip can be homemade or a proprietry item is available from "Bigheads" who supply most grp laminators.
1 -I am assuming that when the diffuser is bolted in place it covers the captive nut.
2 -Therefore you firstly need to drill out the old captive nut.
3 -Then you need to have a nut welded to a strip of metal with two rivet holes.
4 -The nut on the strip fits in the hole and the strip is riveted to the body.
5 - The nut strip can be homemade or a proprietry item is available from "Bigheads" who supply most grp laminators.
Maybe...but I don't really know what the nut looks like....i think they would probably have a large base for bonding to the grp??? Also, once pulled out not sure how effective the bond would be if I cant get behind the new one to plaster it with epoxy.
Probably a good idea to call a TVR dealer later and see how they would approach it.
Probably a good idea to call a TVR dealer later and see how they would approach it.
pistolar said:
3 -Then you need to have a nut welded to a strip of metal with two rivet holes.
You can buy these, although they're normally designed to be fitted behind the panel rather than in front. But if you don't have access to the back of the panel, I guess the approach you're describing might be necessary.
GreenV8S said:
pistolar said:
3 -Then you need to have a nut welded to a strip of metal with two rivet holes.
You can buy these, although they're normally designed to be fitted behind the panel rather than in front. But if you don't have access to the back of the panel, I guess the approach you're describing might be necessary.
The proprietry items are available from Bigheads www.bighead.co.uk/
m33ufo said:
but I don't really know what the nut looks like....i think they would probably have a large base for bonding to the grp??? Also, once pulled out not sure how effective the bond would be if I cant get behind the new one to plaster it with epoxy.
It does not have a big base - thats the problem! Its like an expanding threaded tube - works a bit like a rivet back. You should be able to pull it out without too much damage especially as it is turning freely. Mine just fell out and I epoxyed(?) it back in!
Edited by purpleperil on Monday 12th June 12:31
GreenV8S said:
So could you just use a rivnut?
Not sure what a rivnut is.
I shall have a go pulling it through this evening and see what I end up with. Hpefully it shall become more clear then.
So are these things fitted from the inside (now inaccessible) or are they just pushed into the hole from the outside? If the worst comes to the worst then I shall have to let my local bodyshop take a gander at it.
GreenV8S said:
So could you just use a rivnut?
Just looked up a rivet-nut in google....I imagine that may well be what is used.
Hmmm....feeling a little more positive now, if I can get it out then hopefully it should be quite simple to replace it - once I get my hands on a replacement.
Cheers
I had a similar thing on my T350. I managed to get the threaded insert out of the fibre glass in the body, leaving just the hole. I used 2 big plasterboard fixings to replace the thread, you know the type that have a front flange with 2 little teeth and a bit at the back that expands when you tighten the bolt. Have took the diffuser off twice since had no problems, cost about £5.00 for a pack of 4.
J
Yep...I know the fitting you mean. My nut (maybe a riv-nut) refuses to pull free. Don't want to force it in case I damage the fibreglass. Ideally I would like to replace it with another (if that's what it is) riv-nut.
It's in the bodyshop tomorrow so I may ask them to do it. Now I have the diffuser off I was considering asking them to spray it for me too. There are a number of scrapes underneath - mainly at the sides where the two fins are. I know you can't really see it, but now I know they are there!!!
It's in the bodyshop tomorrow so I may ask them to do it. Now I have the diffuser off I was considering asking them to spray it for me too. There are a number of scrapes underneath - mainly at the sides where the two fins are. I know you can't really see it, but now I know they are there!!!
Hi Mark, yes i had the same with my T350c!!
Having worked in fibreglass and with these type of fitting for 25 years, here's how they are used...The threaded sleeve is usually bolted onto the mold even before the gel coat is applied, then the subsequent layers of glass applied around the sleeve, when the car is required to be removed from the mold, the bolt which held the sleeve in place is removed, if these sleeves are not abraded prior to the bonding in, then they don't stand a chance of being stuck properly, mine were alluminum and shiny, thats why they pull out!!! Here is how i fixed mine, you don't need to get plates made!!(daft idea)ooooops. just go to any good boat chandlery and buy half a dozen high quality number 12 or 14 panhead self tappers and washers, mine has been mended that way for over two years now, one more small tip though...when winding in the selftappers, put a small amount of araldite type glue up the thread,not only does it lubricate the screw on the way in but stick well too!! don't worry you will be able to undo them if you need to in the future.
Good luck..Dave
Having worked in fibreglass and with these type of fitting for 25 years, here's how they are used...The threaded sleeve is usually bolted onto the mold even before the gel coat is applied, then the subsequent layers of glass applied around the sleeve, when the car is required to be removed from the mold, the bolt which held the sleeve in place is removed, if these sleeves are not abraded prior to the bonding in, then they don't stand a chance of being stuck properly, mine were alluminum and shiny, thats why they pull out!!! Here is how i fixed mine, you don't need to get plates made!!(daft idea)ooooops. just go to any good boat chandlery and buy half a dozen high quality number 12 or 14 panhead self tappers and washers, mine has been mended that way for over two years now, one more small tip though...when winding in the selftappers, put a small amount of araldite type glue up the thread,not only does it lubricate the screw on the way in but stick well too!! don't worry you will be able to undo them if you need to in the future.
Good luck..Dave
valhalla said:
Hi Mark, yes i had the same with my T350c!!
Having worked in fibreglass and with these type of fitting for 25 years, here's how they are used...The threaded sleeve is usually bolted onto the mold even before the gel coat is applied, then the subsequent layers of glass applied around the sleeve, when the car is required to be removed from the mold, the bolt which held the sleeve in place is removed, if these sleeves are not abraded prior to the bonding in, then they don't stand a chance of being stuck properly, mine were alluminum and shiny, thats why they pull out!!! Here is how i fixed mine, you don't need to get plates made!!(daft idea)ooooops. just go to any good boat chandlery and buy half a dozen high quality number 12 or 14 panhead self tappers and washers, mine has been mended that way for over two years now, one more small tip though...when winding in the selftappers, put a small amount of araldite type glue up the thread,not only does it lubricate the screw on the way in but stick well too!! don't worry you will be able to undo them if you need to in the future.
Good luck..Dave
Having worked in fibreglass and with these type of fitting for 25 years, here's how they are used...The threaded sleeve is usually bolted onto the mold even before the gel coat is applied, then the subsequent layers of glass applied around the sleeve, when the car is required to be removed from the mold, the bolt which held the sleeve in place is removed, if these sleeves are not abraded prior to the bonding in, then they don't stand a chance of being stuck properly, mine were alluminum and shiny, thats why they pull out!!! Here is how i fixed mine, you don't need to get plates made!!(daft idea)ooooops. just go to any good boat chandlery and buy half a dozen high quality number 12 or 14 panhead self tappers and washers, mine has been mended that way for over two years now, one more small tip though...when winding in the selftappers, put a small amount of araldite type glue up the thread,not only does it lubricate the screw on the way in but stick well too!! don't worry you will be able to undo them if you need to in the future.
Good luck..Dave
Hi Dave, thanks very very much for your reply. At least I now know what is actually there!!!
Tell me, should I be able to pull out the insert without causing to much damage?
Cheers, mark
Gassing Station | Tamora, T350 & Sagaris | Top of Page | What's New | My Stuff