Rear Shocks replaced some pics..

[MartinThorn]

Hi - MOT failed due to rear shocks with 'serious fluid leak'. I was a bit skeptical and when they said £400 I said no almost before they finished saying the word 'pounds'!

In the end the job turned out to be quite easy and of course cheaper..

edit - to be clear this post is to show how easy replacing the rear shocks was for me using non-workshop amateur methods gleaned from here and Youtube - it is not a how-to guide as was kindly pointed out in the replies Hopefully my posts and the replies (even the critical one) help others save a few quid too!

 

[MartinThorn]

First of all, jacked and then propped up the car.. Great news with these cars (in this case a 2014 2.0Tdi ST FR184) is that the rear shock is not in the springs and easily accessible.

Can see the 'serious' fluid leak on the old shock! Visible leak yes but the shock seemed fine in operation.. but I digress!

Youtube said jack up the spring a bit for some reason - not sure this was 100% necessary but it didn't do any harm.

Edit: should mention I was on a slightly slopey drive so car in gear and a chock of wood put behind one front wheel

 

[MartinThorn]

The other easy thing about the shock replacement is that it's just 3 bolts to undo - 2-off 16mm bolts at the top first and 1 off 18mm bolt at the bottom.

Minor issue with the 18mm is that you need either a deep socket or one at least that allows the threaded section to go into the socket more than a small standard socket (I used a £2 socket from B&Q in the end after I'd bought a deep socket set that only had 17mm and 19mm!! The 19mm to be fair did undo the bolt.. but it felt loose so: B&Q trip!)

If you look closely at the picture below when undoing or doing up the 18mm lower bolt you have to stop the other side spinning with a spanner..

Oh, and I borrowed a friends torque wrench as mine just wasn't man enough!

edit - rear discs looking a bit 'rusty-lippy' - might need attention next year!
edit2 - a critical poster may well reply saying don't use the torque wrenches to undo bolts. And they might be correct. Well however I did, so perhaps they are now a bit less accurate as a result..

 

[MartinThorn]

Ah, should have mentioned that you have to take off the wheelarch cover to get to the two upper shock bolts - pretty easy but about 15 star bolts to unscrew..

 

[MartinThorn]

Once the old shock is out, have to undo the top bolt to salvage the black plastic cover and the inner foam buffer thing. Needed molegrips to gently stop the shock spindle spinning as the top bolt is removed (old top bolt was 16mm, bolt with the new shocks was 17mm - again a deep socket may be needed).

When fitting the top bolt to the new shock (after putting the funny foam buffer on it) the instructions say not to use the molegrips.. but I did anyway without any problem. Then need to put the black plastic cover onto the new shock with a new cable tie.

edit: to be clear, the use of molegrips is not the recommended way to do this - see other posts below for the method that gives lower risk of damaging the shock's (albeit strong) piston rod!

For new shocks I went for nothing special but not bargain basement - a pair of KYB Excel-Gs (part # 3448024) for £85 off eBay - typically I found them between £85 and £110 for a pair.

Then reversed the removal above with the lower 18mm bolt tightened to 70NM and the 16mm bolts at the top set to 50NM.

 

[MartinThorn]

Oh, and I put a bit of copper grease on all the bolts before refitting them..

edit: whilst this should help prevent seizure, others have noted below this is not officially recommended and not mandatory

 

[MartinThorn]

Then wheelarch cover back on, wheel back on, lower the car and job done (on one side).

Repeat on the other side.

Like I said surprisingly straightforward compared to the last job I did on it (Heater Matrix replacement!!).

Or would have been if the locking wheel nut on the other side wasn't broken - ended up having to call someone out to fix it for £40!
Which is why the job was finished days after I started it!!

Two functional but slightly weeping rear shocks replaced.

 

[Mo_86]

Great job there, have you noticed any difference in the way it drives now?

 

[MartinThorn]

Or would have been if the locking wheel nut on the other side wasn't broken - ended up having to call someone out to fix it for £40!
Which is why the job was finished days after I started it!!

Had a really good go at trying to 'steal' my rear wheel before I called someone out - even bought a £20 Amazon wheel nut removing kit - turned out to be no good as the outer walls of the special removing-nut (has a kind of spiral cut fit on the inner wall) was too thick to fit in the hole housing the stuck nut.

Also the method on Youtube didn't work: hammer on a slightly undersized 12-point Hex socket - the size to try (22mm) wouldn't go on and the next size up too large..

 

[MartinThorn]

Great job there, have you noticed any difference in the way it drives now?

Not really, but only driven up and down a short road as technically it hasn't passed its MOT yet! Seems ok so far, but then I hadn't noticed anything wrong with the old ones!

 

[RUM4MO]

A couple of comments, probably too late for you now, I wouldn't use any lub on bolts that have a self locking nuts, that ends up making a mockery of the torque you tightened these bolts to and probably also the effectiveness of the self locking nuts - though after being used once they should get replaced, so, all these fasteners should have been replaced, it sounds like you only replaced the self locking nut on the end of the damper piston rod, finally, as you can see on your picture at the end, the end of the damper piston rod has a couple of flats - they are there so that you can either fit a special tool to them to hold the piston rod from turning, or just use a small adjustable spanner to stop the piston rod turning.
What is annoying, at least for me, is that VW Group factory fitted and spares rear damper top nut is 16mm AF and the aftermarket replacements are 17mm AF, also the dimensions of the "flat end" of the original damper and the new aftermarket dampers are different! If you just use a small adjustable spanner this is not an issue, but I finally made the effort to buy the correct "socket" to stop the piston turning, using that and a Vortex socket set made that part of the job easy - but back to the small adjustable spanner for fitting the new aftermarket damper!.

Compressing the rear spring(s) is aimed at getting the position of the hub back to its natural position before tightening the bottom bolt as there is a bonded rubber mounting at the lower end of that damper, and that can not rotate so just gets flexed when the suspension moves up and down, so the plan with these bonded mountings is to ALWAYS have the suspension at its "unladen" or natural position BEFORE tightening fixing bolts, as that will mean these bonded mounts last instead of failing early due to being permanently distorted.

I'm sure that I even swopped over the "top plate" from the old dampers onto the new dampers as it was a different shape/type, also removed the cheap soft nasty semi-springish steel C-clip from the top of the piston rods on the new Sachs dampers and replaced them with the proper spring steel C-clips from the original dampers.

 

[MartinThorn]

A couple of comments, probably too late for you now, I wouldn't use any lub on bolts that have a self locking nuts, that ends up making a mockery of the torque you tightened these bolts to and probably also the effectiveness of the self locking nuts - though after being used once they should get replaced, so, all these fasteners should have been replaced, it sounds like you only replaced the self locking nut on the end of the damper piston rod, finally, as you can see on your picture at the end, the end of the damper piston rod has a couple of flats - they are there so that you can either fit a special tool to them to hold the piston rod from turning, or just use a small adjustable spanner to stop the piston rod turning.
What is annoying, at least for me, is that VW Group factory fitted and spares rear damper top nut is 16mm AF and the aftermarket replacements are 17mm AF, also the dimensions of the "flat end" of the original damper and the new aftermarket dampers are different! If you just use a small adjustable spanner this is not an issue, but I finally made the effort to buy the correct "socket" to stop the piston turning, using that and a Vortex socket set made that part of the job easy - but back to the small adjustable spanner for fitting the new aftermarket damper!.

Compressing the rear spring(s) is aimed at getting the position of the hub back to its natural position before tightening the bottom bolt as there is a bonded rubber mounting at the lower end of that damper, and that can not rotate so just gets flexed when the suspension moves up and down, so the plan with these bonded mountings is to ALWAYS have the suspension at its "unladen" or natural position BEFORE tightening fixing bolts, as that will mean these bonded mounts last instead of failing early due to being permanently distorted.

I'm sure that I even swopped over the "top plate" from the old dampers onto the new dampers as it was a different shape/type, also removed the cheap soft nasty semi-springish steel C-clip from the top of the piston rods on the new Sachs dampers and replaced them with the proper spring steel C-clips from the original dampers.

All good points, especially explaining why the springs needed compression, thanks! And I did say that the molegrips were a bit of a bodge - the correct alternative as you say is to grip the end but then you can't use a socket on the hex nut..

Only used a bit of copper grease on the end of the old reused bolts, think it came from a YouTube video that recommended it.. I'll let you know if they fall off!

 

[DEAN0]

Quick suggestion - if you MUST use mole grips on the shaft - slide the bump stop down first and then grab the shaft near the top mount where it never slides in to the shock body.

 

[MartinThorn]

Quick suggestion - if you MUST use mole grips on the shaft - slide the bump stop down first and then grab the shaft near the top mount where it never slides in to the shock body.

Yes, that's what I did on the new shocks. Old ones didn't care!

 

[RUM4MO]

Actually, I've normally found that you can get the rear damper top nut off using a swan neck ring spanner, then doing that will let you still fit an adjustable spanner on the end, once the nut has been tightened to roughly the correct torque value, there will be no easy way to torque that nut correctly by using a torque wrench and deep socket as from memory, there is a free running thrust plate built into these top mounts.

I suppose that is where buying a bespoke tool comes into play - though as I've said already, that probably only works if you buy VW Group spare parts, why there is always a slight change in sizes between original and altermarket rear dampers is just blinking annoying!

I've watched a few Autodoc YouTube videos and find it a bit silly that they all start off with doing a quick "brush clean" which is okay, then follow that with a generous application of basic WD-40 - which is not a release oil and once you have soaked rusty fixings with that, then spraying it with proper release fluid will not do much as the area has already been "wetted" - and then they finish off with a quick spray of copper ease or similar, that is a good idea, well at least covering the exposed of fixings with a suitable grease is a good idea and one that that I do, but use a suitable grease or waxoyl and apply it using a brush to prevent overspray.

 

[RUM4MO]

I found, when I was having problems getting the threaded bush off the front strut that had been attacked by professionals, that hammering a large Stilson wrench over the piston rod of the front damper did nothing in a way to cause it any surface damage - the outer surface is as hard as F**K, which meant that I couldn't grip it in a way to stop it turning - and I started to think that cutting through it would not be easy either - I was desperate to retrieve the dustcover lower retainer plastic "basket" - so had to keep on working away as the threaded bush slowly came off!

 

[MartinThorn]

Well it passed its MOT recheck so that's it for another year. And opinion was divided around the lunch table as to whether or not a bit of copper grease would compromise a bolt done up to whopping 70NM!

Also had to get another pair of front tyres for the MOT and got seduced by 225/40/18 Maxxis HP5's and their alleged AAA 69dB rating for about £90 a tyre!

 

[DEAN0]

Well it passed its MOT recheck so that's it for another year. And opinion was divided around the lunch table as to whether or not a bit of copper grease would compromise a bolt done up to whopping 70NM!

Also had to get another pair of front tyres for the MOT and got seduced by 225/40/18 Maxxis HP5's and their alleged AAA 69dB rating for about £90 a tyre!

Grease/lube on bolt threads is not generally recommended ( Unless the manufacturer calls for it )
The reason is not because they could come loose - the reason is because a lubricated thread will allow a higher clamping load for the same torque.
This could snap the bolt.

Around half of the torque you apply is taken up with thread and nut face friction.
The engineers take this friction in to account when specifying the torque to use.

This is one of the reasons that many fasteners now have a low seating torque applied - then get finished off by angle fastening.

 

[RUM4MO]

I think that there is a lesson to learn here for anyone that feels the need to try to be helpful and place a guide to "how it is done" on to a public forum - make sure that all you write is spot on and will make sure that the work carried when following your guide to the letter ends up with a safe working period while doing that task, and a safe car to drive at the end of it.

I seem to remember advising caution to someone years ago, that seemed to be a new member and new to VW Group products, who started creating "how to do it" guides which were not quite fit for public consumption.

 

[DEAN0]

Just to add - I'm not trying to belittle the OP - the guide is still a good one.

I have worked in the industrial fastening business for 20+ years.

We work with the manufacturers when creating fastening strategies for assemblies.