replacing rear coffin arms - can't remove concentric bolts! help!

[joeluth]

This has been painful, after a good few of hours of blood, sweat and tears, I've admitted defeat.

It seems the concentric bolt is seized onto the metal centre of the rubber bushing,  the rubber has now completely let go, so the bolt and centre piece are spinning as one.

I've tried heat, an ocean of plus gas and release spray, hitting it,  I think I've just about moved it about 1mm!   but it just won't give up.

I think I'm going to have to hand saw through the bolt but I don't have anything suitable to hand right now.

Any suggestions?!   

Edited August 15, 2021 by joeluth
pics

[Tony Daniel]

Its going to be a reciprocal saw or by hand I'm afraid 

[joeluth]

21 minutes ago, Tony Daniel said:

Its going to be a reciprocal saw or by hand I'm afraid 

Cheers Tony, yeah I thought as much. Hopefully I'll find something suitable that's not too big and do it by hand.

[red rocket]

I ( and many others) have had similar issues on front. Used a reciprocating saw (£40 ish) from Screwfix and some decent blades and cut down through the bushes, being careful not to damage anything else. Just go carefully and take your time.  I think @½cwt had similar issue on rear so could confirm.

[myfirstboxster]

1 hour ago, Tony Daniel said:

Its going to be a reciprocal saw or by hand I'm afraid 

☹️ Yup , this is how I did mine , best of luck

[deanmr2]

19 minutes ago, myfirstboxster said:

☹️ Yup , this is how I did mine , best of luck

+1

[Christopher2110]

Been there done that 😔

Chop them out

[½cwt]

28 minutes ago, Christopher2110 said:

Been there done that 😔

Chop them out

+1, Steel bolts seized into the alloy bushes inside the rubber bushes in the coffin arm and toe links and all 4 needed cutting on mine plus the drop link bolts as I was changing the dampers too.

Edited August 15, 2021 by ½cwt

[joeluth]

Cheers all,  any recommendations for a saw &  saw blade lads?    Assuming I'll be needing to remove a fair few bits to get anything powered near the bolts as there's no space currently , so thinking hand tool is the way to go, like a jabsaw kinda thing.. 

[½cwt]

1 hour ago, joeluth said:

Cheers all,  any recommendations for a saw &  saw blade lads?    Assuming I'll be needing to remove a fair few bits to get anything powered near the bolts as there's no space currently , so thinking hand tool is the way to go, like a jabsaw kinda thing.. 

You'll need to be keen to do it by hand.  I got a cheap reciprocating saw from Screwfix, approx. £40 (and I've used it for a couple of other things around the house/garden and loaned it to a neighbour since), but get good blades.  I blunted the one that came with the saw in about 15 seconds and hardly touched it as the bolts are hardened steel.  A good Bosch Sabre blade or similar (about £13) is essential and you'll be through in 30-45 seconds.  Once you loosen the nut you can get access to cut the bolt by pushing the arm downwards to the maximum droop without cutting the arms off to a short length first that some people mention, but just don't damage the sub-frame.

[joeluth]

10 hours ago, ½cwt said:

You'll need to be keen to do it by hand.  I got a cheap reciprocating saw from Screwfix, approx. £40 (and I've used it for a couple of other things around the house/garden and loaned it to a neighbour since), but get good blades.  I blunted the one that came with the saw in about 15 seconds and hardly touched it as the bolts are hardened steel.  A good Bosch Sabre blade or similar (about £13) is essential and you'll be through in 30-45 seconds.  Once you loosen the nut you can get access to cut the bolt by pushing the arm downwards to the maximum droop without cutting the arms off to a short length first that some people mention, but just don't damage the sub-frame.

👍 thanks! Been reading up on the blades, and a saw like that will be handy no doubt, I've still got a giant dead Christmas tree at the bottom of the garden! 

The plan was to just do the coffin arms and drop links at the back this time, I'm  hearing the classic knocking from the rear on rough roads. 

Wasn't planning on taking everything off but looks like I'll have to to get a reciprocating saw in there.

Right, cheers all,  off to screwfix! 

 

[½cwt]

To be honest to get the toe links done whilst you are in there is very little extra work or cost.  Get the links form Spyder Performance and the eccentric bolts from your local Porsche Centre (About £9 each) and nuts if you want to fit new, I reused.

Another tip, once it ahs been tracked get in there again with your torque wrench as it is virtually impossible to get full torque on the bolts from under the car with the wheels on.

[joeluth]

5 hours ago, ½cwt said:

To be honest to get the toe links done whilst you are in there is very little extra work or cost.  Get the links form Spyder Performance and the eccentric bolts from your local Porsche Centre (About £9 each) and nuts if you want to fit new, I reused.

Another tip, once it ahs been tracked get in there again with your torque wrench as it is virtually impossible to get full torque on the bolts from under the car with the wheels on.

On it!  ordered control arms and new bolts this morning and I'll pickup a saw on my way home later on.   

  Nearly bought a pair of those long rear tuning forks too but out of stock at the moment, I hope they aren't the source of the knocking sound!! 

[½cwt]

2 hours ago, joeluth said:

On it!  ordered control arms and new bolts this morning and I'll pickup a saw on my way home later on.   

  Nearly bought a pair of those long rear tuning forks too but out of stock at the moment, I hope they aren't the source of the knocking sound!! 

Rear tuning forks are about the only bits I didn't change on mine and all the clunking, creaking and knocking has gone.  Fairly easy to do as stand alone parts later if necessary, no too much dismantling of other bits required.

[joeluth]

 

On 8/16/2021 at 6:34 PM, ½cwt said:

Rear tuning forks are about the only bits I didn't change on mine and all the clunking, creaking and knocking has gone.  Fairly easy to do as stand alone parts later if necessary, no too much dismantling of other bits required.

 

Phew! cut through the bolts and got the coffin and control arms out without hacking into my subframe or exhaust so I'm pretty pleased with myself! 

did you put copper slip or anything on the alignment bolts when you re-installed? 

I've got new ones here, not sure if it's a good idea or not really, don't want to have to go through that again,

but at the same time don't want my new alignment to slip either.. 

 

 

 

[½cwt]

42 minutes ago, joeluth said:

 

 

Phew! cut through the bolts and got the coffin and control arms out without hacking into my subframe or exhaust so I'm pretty pleased with myself! 

did you put copper slip or anything on the alignment bolts when you re-installed? 

I've got new ones here, not sure if it's a good idea or not really, don't want to have to go through that again,

but at the same time don't want my new alignment to slip either.. 

 

I used an aluminium based assembly compound on all the key parts that like to seize up.  Keep the compound on the shaft of the bolt and not on the faces of the bush,  alignment won't slip anyway as the bolt clamps the subframe to the bush and the eccentric bolt/washer are in recesses to keep them in place.  Just set the torque right on them, 100Nm and check it again after the alignment.

BTW I have all the torque tables for the suspension if you PM me your email I'll send them across to you.

Edited August 18, 2021 by ½cwt

[BBB]

On 8/16/2021 at 3:45 PM, joeluth said:

On it!  ordered control arms and new bolts this morning and I'll pickup a saw on my way home later on.   

  Nearly bought a pair of those long rear tuning forks too but out of stock at the moment, I hope they aren't the source of the knocking sound!! 

Spyder are out of stock of the rear tuning forks, but design911 have the TRW ones in stock, which are OEM. 

I asked Porsche how much they were when I was ordering the camber bolts....£340 each and a delay while they came from Germany!! The TRW ones are £65 + VAT.

[½cwt]

4 hours ago, BBB said:

Spyder are out of stock of the rear tuning forks, but design911 have the TRW ones in stock, which are OEM. 

I asked Porsche how much they were when I was ordering the camber bolts....£340 each and a delay while they came from Germany!! The TRW ones are £65 + VAT.

Carparts4less usually stock 986 tuning forks from TRW for about £75 each after their discount codes are applied.

Edited August 19, 2021 by ½cwt