Captive nut spinning V8 saloon

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marksimba
Posts: 17
Joined: Thu Mar 29, 2018 10:37 pm
Location: Hove, East Sussex

Captive nut spinning V8 saloon

Post by marksimba » Sun Aug 19, 2018 2:45 pm

Hi guys

As no doubt you all know, each antiroll ‘D’ rubber mounting is held in a yolk which is secured to the chassis by two bolts. I think there is a captive nut in the chassis rail. Anyway one of the bolts (on the offside) is spinning so I assume the nut is spinning. Any idea of how to solve this problem?

Cheers
Mark

Chris S
Posts: 13
Joined: Sun Aug 27, 2017 12:17 pm
Location: Purley, Surrey

Re: Captive nut spinning V8 saloon

Post by Chris S » Mon Aug 20, 2018 5:30 pm

Hi Mark, there are two solutions
1st Undo and remove the remaining 3 bolts. Also disconnect the a/roll bar verticals links so the a/roll bar is free. Remove the bracket, mounting bracket, and keeper plate from the non problem side.
On the problem side slightly bend the bracket down so the whole assembly including the a/roll bar can be rotated. Rotate the bar in one direction, and the mounting plate in the other. Eventually there will be enough space to remove the rubber bush. Replace bush and reassemble.
2nd To solve the spinning captive nut problem, remove all as previous, then grind off the head of the remaining bolt. Remove brackets etc.
Cut out a square containing the captive nut with a 1 mm cutting disc. The cuts should be on just on the inside of the verticals of the chassis rails. Take the square plate to the bench and remove the old bolt. Weld the nut back in place, or weld on a new nut if old one is damaged.
Use the mounting block to position the repaired plate, and tack weld in position. Remove block and weld plate back in place. Reassemble. Note Observe safety procedures when welding.
Hope this helps
Chris S

Sydsmith
Posts: 645
Joined: Sun Feb 14, 2016 11:15 pm
Location: Aberystwyth Wales

Re: Captive nut spinning V8 saloon

Post by Sydsmith » Mon Aug 20, 2018 6:17 pm

I have been successful in the past with a jemmy/pry bar (as in burglar).

Wedge or drive the pry bar in behind the bracket and lever downwards to force the nut tight into the chassis and turn the bolt, might just work with loads of Plusgas or WD40. Syd

tjt77
Posts: 394
Joined: Wed Mar 23, 2016 7:01 pm

Re: Captive nut spinning V8 saloon

Post by tjt77 » Wed Aug 22, 2018 10:59 pm

good advice given above. I'll add:- .if the captive nut is spinning its generally due to rust both within and ABOVE the captive nut..although sometimes they get cross threaded .. given the force it takes to break off the cage nut, its unlikely it will come out via any wedging.. cut off the bolt head..then cut an 'X' with die grinder across the hole where captive nut was placed.. carefully lever the metal down enough to open up the hole to get the nut out (assuming it has not fallen into the chassis rail..which they normally do) ..with this method there is no need for any patching.. you need a longer 3/8" bolt with an additional nut added near the head.. insert the new nut with bolt attached.. bend the metal back into place.. then do up the 'other' nut to make the hole flat again .. you can then weld up the X and secure the new cage nut in the process.. then remove the dummy bolt, add weld where necessary, grind away excess weld..check fit of bolt and re-tap the thread as necessary..and reassemble as normal..

marksimba
Posts: 17
Joined: Thu Mar 29, 2018 10:37 pm
Location: Hove, East Sussex

Re: Captive nut spinning V8 saloon

Post by marksimba » Tue Aug 28, 2018 3:13 am

Thank you for your advice! I report back on progress/success.
Mark

marksimba
Posts: 17
Joined: Thu Mar 29, 2018 10:37 pm
Location: Hove, East Sussex

Re: Captive nut spinning V8 saloon update!

Post by marksimba » Sun Sep 30, 2018 7:12 pm

Hi Guys

So problem solved: thanks Chris, your method was employed and it worked a treat. The other side (n/s as it happens) was ok. The threads cleaned, new bolts and all ok.

Thanks again everyone.

Mark

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