Changing Rear Shock Absorbers. Replace or reuse bottom bolts?

[Big Dave]

Hi folks,

Sorry, I'm actually asking about an Astra-J, not an Insignia, but the rear shock absorber changing is the same procedure on both cars.

I'm about to change the rear shocks on my car, and according to the info on the Vauxhall workshop manuals website the bottom bolt that connects the shock to the suspension arm should not be reused, but a new one fitted.

The torque settings given are to tighten initially to 150 Nm, and then tighten a further 65 degrees. This suggests to me that it's a stretch bolt. Am I correct?

In all the years I've replaced shock absorbers on various Vauxhall cars, this is the first time I've ever seen mention of replacing the bolts.

So, do I throw caution to the wind and just reuse the bolts, making sure they're FT, and a bit of thread lock for good measure.

Or should I replace them as suggested?

Thanks.

[northpole]

I actually think the reason for them to be replaced is because the lot likes to seize on (rust) and as soon as you remove them they break... so to make sure you don't get left without a bolt, just buy new ones they're not that expensive

[Big Dave]

Thanks for that.

That makes sense. Trouble is the local Vauxhall garage haven't got any bolts in stock, and couldn't say when they would be in because of Covid 19 restrictions.
I wanted to get on with the job of changing them tomorrow, and when I placed my order with autovaux, I wasn't aware the recommendation was to change them.

I've just popped out and given them a liberal spraying with WD40. Here's hoping they're not rusted in.

Talking of autovaux, I was a bit disappointed they didn't give me a discount this time. They have always done in the past.

They quoted me nearly £90 each for Genuine GM shocks. I ended up buying a pair of Meyle branded ones at £37 each. The other ones they had were Continental Direct (same price), but he said the Meyle ones were of better quality.

I could've shopped round and got something like Sachs, as I know Vauxhall have used that brand in the past. I think I'm getting to that age where I couldn't be bothered faffing about too much

[northpole]

if you look in the epc on 7zap you can look at the type of the bolt used and just buy them from ebay rom a bolt manufacturer, if you buy hardened bolts they'll do just fine ( i've been doing that for a while now) if i manage to break a bolt or loose it... because in the end if the bolt is the same type and length than why pay over the odds?

[Big Dave]

Confession time. I ended up paying a someone to do the job for me.

Apart from my trolley jack playing up, I had an operation back in March on one of my legs. Was due to go back in April for a scan to see if all was ok. The scan was cancelled because of Covid-19, so no idea if the operation was a success. Still painful to bend my knee, and also kneeling down for any length of time.

Also, what any diagrams failed to show was that offside lower bolt that holds the shock to the suspension arm is close to the Watts linkage arm, and trying to get any swing on a breaker bar is near on impossible unless you've got the vehicle high off the ground. Yes, I suppose I could have undone the Watts linkage out of the way.

So, I parted with £50 and let someone else who has a 4 post vehicle lift do the job for me.

He re-used the same bolts btw. Came out quite easy with a windy gun

[Big Dave]

Another question. Does it matter if the dust/grit protection cover and bump stop slide up and down the piston rods of the shocker?

I would have thought they would be fixed into position at the top of the shock, like the original ones were. The ones fitted to the Meyle shocks move up and down the piston rod quite easily. I was wondering whether to glue them into the same position as the originals.

The link below is similar to what I'm trying to describe.

https://www.autovaux.co.uk/bumper-1046926

[northpole]

they are stuck to the top to keep the shock and piston clean from debris and dirty water ... if you want it stuck at the top 2 options.. cable tie or glue... I usually go for the cable tie option but that also means i have the car up and the wheel off so i can get the cable ties setup right...

[Big Dave]

they are stuck to the top to keep the shock and piston clean from debris and dirty water ... if you want it stuck at the top 2 options.. cable tie or glue... I usually go for the cable tie option but that also means i have the car up and the wheel off so i can get the cable ties setup right...

That's what I thought. There is nothing other than friction itself to stop the dust shield sliding down the piston. Very poor design.

No room for cable ties. What I ended up doing was to give the top of the cover (i.e. the bump stop) a liberal coating of silicone sealant and then pushing it up into the cup of the fixing bracket that holds the shocker to the wheel arch. The sealant I used also has adhesive properties. I've used it before to waterproof solar lights in the garden. No sign of degradation in the 2+ years the weather has been on the solar lights. Will have to wait and see if they start sliding down again.

[Big Dave]

I sent Meyle an email.

This is their reply.

"The dust plastic dust/grit covers should have a slight clamping effect on the piston rod.
However, if they slip a little, this is not to be seen as a defect.
The dust plastic dust/grit covers are fixed to the strut mount via the rubber buffer.
We hope you're satisfied with our response.
If you have any further questions, please feel free to contact us again"

And a photo also sent by them.

suspension bracket.jpg



Needless to say, no I'm not satisfied with their response.