Last Minute Q’s Before Overhaul

[chroniclesofcf]

Evening guys!

as the title says, a little bit of an overhaul is happening over the course of the next week.

- new shocks all round using the Koni FSD kit.

- new rear wheel bearings.

- new calipers, brake rotors, pads and shrouds all round. (Have purchased bigger brand new 312/272mm oem VW TRW in Blue from Germany) one of the rear calipers was stuck and would say the other isn’t far behind.

- new dog mount insert from power flex. Bought the red (diesel) variant for the softest polyurethane for the least NVH increase.

- Fresh full service kit standing by

She’s coming up on 145k miles now. Currently has ST springs and shocks installed for the last 50k ish miles. A fear 2 of them are dead. Hence the new konis.

my questions are:

what springs are you pairing with the konis? I’m looking for minimal to no lowering as I think the FR being slightly lower from factory already looks fine especially with spacers.

The bolt on the dog mount insert, is that a stretch bolt? If so, where could I find one of these? And does it need thread locking?

I'm also looking to replace the stretch bolts on the front subframe that I never replaced (shoot me I know) last time I had them out to do the sway bar bushes. Does anyone have the part number or know where I could find it. That would be appreciated. I think I remember there being 4x bolts? Also should I be thread locking them?

I think that’s everything for now.
Appreciate any help.

 

[nd-photo.nl]

Springs: if you are not chasing any lowering, just buy a good brand OE replacements

Dogbone mount: yes its a stretch bolt. I reused mine without thread locker when I did the Powerflex insert. I have the yellow insert for my Cupra and am experiencing no side effects (fortunately!).

Subframe bolts: contact the dealer/stealer, they can sort you out. Original bolts usually have some thread locker applied to them.

If you want to search for yourself: https://seat.7zap.com/en/e/leon+seat/le/

 

[RUM4MO]

Front subframe bolts, yes, they should get replaced - maybe 5.5 years after VW dealership had investigated "a clunking coming from the front" of my wife's 2015 Polo under warranty - and the job sheet included checking subframe bolts tightness, I opened the garage door to drive that Polo back in one winter's day - and spotted what I immediately knew was the head of a front subframe bolt! Now, that was lucky, I wonder just how long it would have taken me to spot that was missing if it had not dropped off while parked in the garage!

My old S4, I got a proper indie to replace the engine mountings (a huge job on that version of B8 A4) - and they used my supplied bolts for the engine mountings etc, but reused the front subframe and chassis stiffener bolts - I quickly bought in a full set of bolts - cost under £100, but have not yet swopped them over - "shoot me" too!

 

[chroniclesofcf]

Bunch of legends. Last time I dropped the frame and that, I never replaced the bolts. Got a bit of a knock at the moment, hoping it is just that as I’ve not long done Tie rods and ends as well as drop links and sway bar bushes.

 

[SuperV8]

The 4x large subframe bolts are :
N10785401 Hexagon flange screw M12X1,5X95
The genuine bolts don't contain any thread lock.

The bolt for the Dogbone mount is
N91201001 hexagon head bolt M14X1,5X50
Again - no thread lock. It has a serrated washer - to act as a locking mechanism.

Regarding your springs - personally I would only change my springs if the car is riding low/sagging or they have heavy corrosion.
I found both my front and rear springs to be in good condition (130,000 miles) - and my car is not sagging so I re-used my springs when I did my front and rear dampers.
My previous car (audi A4 B6) was sagging a bit at 200+k miles - so I would have changed those springs if I had kept the car.

When you changed your anti-roll bar bushes - what condition were your old ones?
How was the job? straight forward - or tricky?
Thanks,

 

[SuperV8]

Speaking of overhauls - How are your front wheel bearings?
I had to change mine - I forget the millage - but less than 100k! which I thought was a bit rubbish!
I had a feint rhythmic whump/whump at high speed. Feint enough that the misses couldn't hear it! but I could - and new front wheel bearings cured it. I couldn't feel any roughness or play which is the usual test for bearings, but did hear a brake rubbing noise when turning into my road at slow speed.
I don't think the genuine wheel bearings are that durable - like the rear shocks!

 

[chroniclesofcf]

The 4x large subframe bolts are :
N10785401 Hexagon flange screw M12X1,5X95
The genuine bolts don't contain any thread lock.

View attachment 46011

The bolt for the Dogbone mount is
N91201001 hexagon head bolt M14X1,5X50
Again - no thread lock. It has a serrated washer - to act as a locking mechanism.
View attachment 46012

Regarding your springs - personally I would only change my springs if the car is riding low/sagging or they have heavy corrosion.
I found both my front and rear springs to be in good condition (130,000 miles) - and my car is not sagging so I re-used my springs when I did my front and rear dampers.
My previous car (audi A4 B6) was sagging a bit at 200+k miles - so I would have changed those springs if I had kept the car.

When you changed your anti-roll bar bushes - what condition were your old ones?
How was the job? straight forward - or tricky?
Thanks,

Part numbers are majorly appreciated! I did find awesome or progressive selling an “MQB subframe bolt” but couldn’t get a definitive answer as to if they are all the same on MQB or do some use one bolt and others another. I did try looking for the workshop manuals to get numbers but the link on here seems to have expired.

I’ll stick with the ST springs then and see how it feels. Worse case scenario I’ll replace them later down the line.

I didn’t replace the old sway bar bushes due to deteriorating, more so an “upgrade”.

They were a NIGHTMARE to get off!

I thought it would have been like the Golf MK6/7/7.5, where you can loosen off the two bolts on the coupling and pull it out. How naive I was. It turned out on our car the coupling is welded on and the bushes were glued/welded to the bar. In order to remove anything, I had to drop the subframe out, remove the sway bar from the car, drill the brackets out, melt the bushes off with a burnzo and do it all in reverse. I wouldn’t recommend it unless your bushes have given up.

 

[chroniclesofcf]

Speaking of overhauls - How are your front wheel bearings?
I had to change mine - I forget the millage - but less than 100k! which I thought was a bit rubbish!
I had a feint rhythmic whump/whump at high speed. Feint enough that the misses couldn't hear it! but I could - and new front wheel bearings cured it. I couldn't feel any roughness or play which is the usual test for bearings, but did hear a brake rubbing noise when turning into my road at slow speed.
I don't think the genuine wheel bearings are that durable - like the rear shocks!

Mine were roughly around the 90-100k mark too. I had a lot of vibration and when I turned in one direction while leaving on the bearing it made a horrid noise.

I’m on 140k odd miles now and they’ve been great. I even cheaped out, and got AutoDocs own brand Ridex bearings. I accidentally ground away one of the abs sensors when cleaning up the knuckle. Easy to replace luckily.

 

[SuperV8]

Mine were roughly around the 90-100k mark too. I had a lot of vibration and when I turned in one direction while leaving on the bearing it made a horrid noise.

I’m on 140k odd miles now and they’ve been great. I even cheaped out, and got AutoDocs own brand Ridex bearings. I accidentally ground away one of the abs sensors when cleaning up the knuckle. Easy to replace luckily.

I'm on 137k+ so mine have done 40+k miles and have been perfect so far.
I also got cheap ones, as a bit of a 'test' as they were a lot cheaper than branded ones which I presumed would probably come out of the same factory!

 

[SuperV8]

Part numbers are majorly appreciated! I did find awesome or progressive selling an “MQB subframe bolt” but couldn’t get a definitive answer as to if they are all the same on MQB or do some use one bolt and others another. I did try looking for the workshop manuals to get numbers but the link on here seems to have expired.

I’ll stick with the ST springs then and see how it feels. Worse case scenario I’ll replace them later down the line.

I didn’t replace the old sway bar bushes due to deteriorating, more so an “upgrade”.

They were a NIGHTMARE to get off!

I thought it would have been like the Golf MK6/7/7.5, where you can loosen off the two bolts on the coupling and pull it out. How naive I was. It turned out on our car the coupling is welded on and the bushes were glued/welded to the bar. In order to remove anything, I had to drop the subframe out, remove the sway bar from the car, drill the brackets out, melt the bushes off with a burnzo and do it all in reverse. I wouldn’t recommend it unless your bushes have given up.

Thanks for the feedback on the ARB bushes. I heard they were a pain! What a dumb design! They will be a last resort then!
I have an occasional knock on the front - and I was wondering if it could be my ARB bushes?
Did yours seem fine until you removed them?

I've done new top mounts, dampers and drop links - so that only really leaves the lower arms or ARB bushes! (or an engine/dog bone mount?)
I've got some new lower arms on order to try as I did have an MOT advisory on cracked bushes.

 

[chroniclesofcf]

Thanks for the feedback on the ARB bushes. I heard they were a pain! What a dumb design! They will be a last resort then!
I have an occasional knock on the front - and I was wondering if it could be my ARB bushes?
Did yours seem fine until you removed them?

I've done new top mounts, dampers and drop links - so that only really leaves the lower arms or ARB bushes! (or an engine/dog bone mount?)
I've got some new lower arms on order to try as I did have an MOT advisory on cracked bushes.

Not a problem!

Ridiculous design. Mine seemed fine right up till I removed them. They were surprisingly hard rubber. But not dried out hard, just hard.

I have quite a big knock at the moment too, front left, which I’ll aim to eliminate with this small overhaul. Having only changed the control arms and bushes, lower ball joints, tie rods, tie rod ends and drop links early this year, so I’m hesitant to say it’s any of them. I’m thinking the damper itself maybe, or the stretch bolts I reused and probably didn’t torque perfectly

 

[nd-photo.nl]

@SuperV8 which brand bearings did you choose?

 

[SuperV8]

@SuperV8 which brand bearings did you choose?

None branded/white box from ebay.

 

[Frostybear]

Curious to know how you find the Koni FSDs once you have them fitted, when my shocks eventually need replacing I'm thinking of them to pair with my eibach lowering springs.
I have this article saved which gives a very good review of them on a audi a3 8V (very similar to leon mk3 as far as I know).
https://www.audi-sport.net/xf/threads/421761/