Rear Damper lower bolt query

[chris75]

Just fitted a pair of rear dampers and have a query . The bottom bolts are torqued up very tight to 114 lbs.ft and have a large diameter washer between bolt head and damper . Having managed to finally achieve that torque whilst reaching in under the car I am concerned that I got up to 110 and the big washer was still free to turn . Only with the last nip did the washer get clamped .
Shouldn't that washer have been clamped before that at a lower torque, or is it not meant to be clamped up tight ?
I am worried that the bolt , which is a dog bolt with a guide pin end, has bottomed-out before the clamping force was achieved
I used new bolts from Rimmers . Could always try the old bolts again or fit another washer under the head .

[marinabrian]

Originally Posted by chris75

Just fitted a pair of rear dampers and have a query . The bottom bolts are torqued up very tight to 114 lbs.ft and have a large diameter washer between bolt head and damper . Having managed to finally achieve that torque whilst reaching in under the car I am concerned that I got up to 110 and the big washer was still free to turn . Only with the last nip did the washer get clamped .
Shouldn't that washer have been clamped before that at a lower torque, or is it not meant to be clamped up tight ?
I am worried that the bolt , which is a dog bolt with a guide pin end, has bottomed-out before the clamping force was achieved
I used new bolts from Rimmers . Could always try the old bolts again or fit another washer under the head .

It won't have bottomed out as the threaded section in the rear hub is open ended.
If the harmonic damper is not rotating, and your torque wrench is accurate, then it'll be fine

Brian

[chris75]

Thanks for that Brian , but two things The threaded section on mine is not quite open -ended ; it steps down to the thread root diameter into which the plain nose of the "dog bolt" protrudes ( see picture) - sort of a guide arrangement , so it could bottom out .
dog bolt 2.jpg
Secondly , my dampers do not have the harmonic "damper weight" on the bottom mount , just the large failsafe washer ( item 11 on here http://www.rimmerbros.co.uk/Item--i-GRID001548.) I have had the car since it was very low mileage so I am pretty sure they have never been removed . Was this an alternative arrangement ? Rimmer's listing suggests they were used on 16 and 17" wheels .My copy of Haynes shows the "Damper Weight" but my copy of Rave doesn't !

[Mike Noc]

The harmonic dampers were added during Project Drive.

[T-Cut]

The PD Guide indicates 75 diesels and all MGs got the damper. Presumably petrol 75s don't apply according to this (Item 27): http://www.the75andztclub.co.uk/foru...ad.php?t=34369

TC

[chris75]

Originally Posted by Mike Noc

The harmonic dampers were added during Project Drive.

Originally Posted by T-Cut

The PD Guide indicates 75 diesels and all MGs got the damper. Presumably petrol 75s don't apply according to this (Item 27): http://www.the75andztclub.co.uk/foru...ad.php?t=34369

TC

Thank you both for that ; happier now I know nothing is missing !
Still not sure that I have adequately "clamped" the shock ; think I may need to add an extra washer under the bolt head .

[Bolin]

Odd - from my personal experience, I am sure that the washer would have been tight before 110lbs.ft.

I would personally take it apart and check everything - did you have the washer dished away from the damper mounting? It is supposed to be dished away, not towards.

I had the problem that the bolt wouldn't undo, I just about managed to get it undone but it destroyed the thread as it came out

[chris75]

Originally Posted by Bolin

Odd - from my personal experience, I am sure that the washer would have been tight before 110lbs.ft.

I would personally take it apart and check everything - did you have the washer dished away from the damper mounting? It is supposed to be dished away, not towards.

I had the problem that the bolt wouldn't undo, I just about managed to get it undone but it destroyed the thread as it came out

Thanks for that My concern is indeed that the washer should have been tight long before that . The washer is dished facing away from the damper
They did undo relatively easily , with a 30" breaker bar !!!

[Bolin]

Yep, I think I used something similar.... maybe I should have tried some heat, that stripped thread cost me £90

I would be tempted to remove the bolt and then compare the old and new bolts and the old and new dampers, and check the hub attachment point to see if it has been 'skimmed' or something like that.

This might all be totally unneccessary and pointless, but that's what I would do just for peace of mind

[chris75]

Originally Posted by Bolin

I would be tempted to remove the bolt and then compare the old and new bolts and the old and new dampers, and check the hub attachment point to see if it has been 'skimmed' or something like that.

Agreed , that is what I will do It has occurred to me that perhaps the new shocks ( Sachs) might have a slightly narrower mounting at the bottom