A2 Rear Axle restoration – my journey

[Alan_uk]

The thread is not a “how-to” – there is an excellent thread by Phil @philward at https://www.a2oc.net/community/index.php?threads/how-to-repair-restore-your-audi-a2-rear-axle.44808/

This thread is to show my own progress and to ask for help from the experts on this great forum.

I’m intending to get a garage to do the swap, so this thread is about getting the drums disassembled, the axle shot blasted and painted, and maybe the drums reassembled.

Given the parts supply issue, I think it will be wise to get all the parts myself so may need help identifying the right parts.

Back Story

I had the suspension upgraded in 2015 at 72,000 miles by A2 Cars with their recommended Monroe dampers E1308 + Lesjofors springs. Every since I found the ride hard and with the current state of the roads now noisy. Basically, I’ve had enough and have considered ditching the A2 for an electric ID.3. I bulked at the cost given that I’m retired and my mileage is low though a diesel A2 is not good for the increasing number of ULEZ.

So at 92,000 miles one last chance for the A2! It seems sensible to also upgrade the bushes and then go the whole hog and replace the rear axle.

Donor Rear Axle

In 2016 Steve @Birchall kindly gave me his rear axle when he upgrade his A2 to disks – the famous white A2 with almost every bell & whistle you could have on an A2. I’ve covered the axle in Krust a number of times since. Here it is:

It looks pretty good though a cursory wire brushing behind the backplate showed it was not so good with some flaking. I think it will be OK:

 

[Alan_uk]

Today I wire brushed the drums but I cannot get all the rust off so may end up getting them shot blasted as well along with the back plates.

I hope I don’t hit the problem that some later drums were a slightly larger size and it can be a pain to get back old drums with new shoes.


Here are my first questions.


1. The manual has instructions when all is reassembled, for using a screwdriver to engage the brake shoe ratchet to push the wedge upwards. Can the reverse be done to push the wedge downwards on removal?
At the moment the drums are rotating freely so maybe it wont be an issue getting them off.


2. When taking the near-side hub off I believe it is a reverse thread, i.e. clockwise to undo. Correct?


3. How are the plastic clips that hold the brake pipes removed?

EDIT UPDATE: These clips just unscrew without any problem. They self tap on to a welded stud.

Thanks for reading.

 

[Deleted member 15819]

1. No the wedge has to drawn down by its spring. As the gap to the drums is larger than the diameter of the shoes several hard presses of the brake pedal should see the wedge drop down.

2. Nope both standard right hand threads.

3. Clipped in? Try gently prying between the beam and the clip and gently twisting at the same time. Difficult to tell from part picture...

brake pipe; brake hose; F 8Z-3-018 751>>; Audi A2 (A2) 2003 year Audi EUROPA 611036

brake pipe<br/>brake hose<br/>F 8Z-3-018 751>><br/> Audi A2 (A2) 2003 year Audi EUROPA 611036 spare parts

audi.7zap.com

 

[Little Dog]

I don't think that white 2 pipe clip is part 13, 1J0 611 797. it looks like an 811 611 797 that are common on VWs. On VWs they screw onto a stud welded to the the shell.
I don't think I've ever seen one on the A2 but I'll take a look the next time I'm under the car.
The one in the picture definitely looks clipped though.
Edit, tip, don't remove the three bolts each side holding the brackets to the space-frame. If you do you will have to find somebody who is prepared to and has the skills to perform 4 wheel alignment.

 

[Alan_uk]

Thanks guys @audifan and @philward I will attempt to first unscrew the clips whilst pulling. And I need to note which one goes where.

re "don't remove the three bolts" - they are already removed as the axle has been donated to me! So I have planned on a 4 wheel alignment and I've read that the bolts and the bush bolts need to be not be fully tightened until aligned and a person is sitting in the back seat!

 

[MickAli]

Alan,
If you're going that far, are you changing the axle bushes? I would.
Also try tapping the brake pipe clips laterally left or right as they look like the ones that are just clipped onto pegs.
Mick

 

[Little Dog]

Thanks guys @audifan and @philward I will attempt to first unscrew the clips whilst pulling. And I need to note which one goes where.

re "don't remove the three bolts" - they are already removed as the axle has been donated to me! So I have planned on a 4 wheel alignment and I've read that the bolts and the bush bolts need to be not be fully tightened until aligned and a person is sitting in the back seat!

The three each side need to be tight to get the car safely to a workshop (don't be concerned about use once only, just check that they are 10.9 grade and they can be reused). The bolts through the bushes and through the bottom of the rear shockers should be tightened with some weight in the back of the car before your trip to the workshop.

 

[Alan_uk]

More work today (been away) and got stuck removing the bolts securing the brake cylinder and the ABS sensor.

The online manual says the brake cylinder is secured with a Hexagon sockethead bolt 8 Nm but it looks a star sockethead to me. I tried both but it just started to get damaged. I could dremel this I think.

The online manual says the ABS sensor is secured with a bolt - very helpful - not. That looks more like a hex bolt. Again, the it just started to get damaged. Not so happy to dremel this as I'm bound to melt the ABS sensor.

Maybe I should just buy everything new: ABS sensor, ABS ring (does this easily come out for the bearing housing?) and backplate?
Edit: Been compiling a list of parts and looks like the ABS ring is part of the hub with the wheel bearing.

Edit UPDATE: I looked more closely at the ABS sensor and it looks like the hex bolt goes into the wheel hub and not the axle flange. So that will be replaced with new along with a new back plate - in for a penny in for a pound

PS The workshop manual shows "handbrake retainer components" - parts 11 & 12. I don't have part 12 on my axle donated by Steve Birchall, just the bolts 11 that secure the backplate to the axle.

 

[TFG]

Today I wire brushed the drums but I cannot get all the rust off so may end up getting them shot blasted as well along with the back plates.



View attachment 108197 View attachment 108198


I hope I don’t hit the problem that some later drums were a slightly larger size and it can be a pain to get back old drums with new shoes.


Here are my first questions.


1. The manual has instructions when all is reassembled, for using a screwdriver to engage the brake shoe ratchet to push the wedge upwards. Can the reverse be done to push the wedge downwards on removal?
At the moment the drums are rotating freely so maybe it wont be an issue getting them off.


2. When taking the near-side hub off I believe it is a reverse thread, i.e. clockwise to undo. Correct?


3. How are the plastic clips that hold the brake pipes removed?


View attachment 108199

Thanks for reading.

For (3.), those clips are wound on to self-tapper type threaded studs that are welded to the axle beam. The plastic clips just twist off (unscrew). However, you'll probably find that the plastic is now so brittle that when you come to refit the brake pipes into the clip parts, the outer wings just snap off.

I gave up with mine and came up with a DIY solution. I had to anyway, because I bought a new (genuine) brake pipe from Audi and then fully sleeved it with weatherproof adhesive-lined heat shrink tubing, so it became way too fat to fit back into those clips. I'll see if I can find any photos of what I did for the pipe clips, if you're interested.

 

[Alan_uk]

Thanks @TFG. I've just removed the clips and they screwed off quite easily. I note your point about being brittle. I've identified the part number and will see if I can get some or something similar.

How did you get the heat shrink tubing over the connectors? I know the tubing starts bigger but if too big it wont shrink enough in my experience.

 

[TFG]

It's a while since I did it but I don't remember it being a problem. Use 3 to 1 heat shrink. I had to stop the heat shrink short of the nuts so that they could be backed off when fitting the pipes. I then gave the exposed bit of pipe a covering of axle grease to keep the weather out.

For the clips, this was my solution:

They work pretty well using nylon nuts. The clips themselves are stainless. for the ones in the trough of the axle cross beam, I put a nut on the studs before the stainless clips to act as a stand off.

Axle paint: In retrospect, I think it would have been better to use a heavy polyurethane paint for the axle instead of the epoxy 2-pack I used. The beam axle is in effect one big anti-roll bar and the polyurethane would cope with the flexing better.

 

[Alan_uk]

Thanks for the explanation. Looks very good. And a good point re the flexing and maybe using polyurethane paint.

 

[Alan_uk]

Today I looked at cleaning the insides of the drums but found corrosion - no doubt for being stored in the garden for many years (under canvas). So it's new ones.

I also looked more closely at the ABS sensor and it looks like the hex bolt goes into the wheel hub and not the axle flange. So that will be replaced with new along with a new back plate - in for a penny in for a pound

 

[carlston]

I had the suspension upgraded in 2015 at 72,000 miles by A2 Cars with their recommended Monroe dampers E1308 + Lesjofors springs. Ever since I found the ride hard and with the current state of the roads now noisy. Basically, I’ve had enough and have considered ditching the A2 for an electric ID.3. I bulked at the cost given that I’m retired and my mileage is low though a diesel A2 is not good for the increasing number of ULEZ.

Monroe E1308 are heavy duty rear shock absorbers for the VW Polo MK4, and other similar VAG cars.

Completely unsuitable for the lightweight Audi A2.

No wonder you found the ride hard.

A2 Cars shouldn't have selected them, because none of the OEM part numbers for the Audi A2 rear shock absorbers are listed against the Monrow E1308 rear shock absorbers.

Monroe 23948 rear shock absorbers would have been a much better choice for the Audi A2.

Monroe 23948 rear shock absorbers

https://www.autodoc.co.uk/monroe/7435684?search=MONROE%20Shock%20Absorber%20(23948)

 

[Alan_uk]

@carlston I would have pursued the issue with A2 Cars but sadly Tony had a brain tumour and died leaving a wife and two children. I didn't want to bother Petra as she was left with enough problems including closing the business down.

 

[Alan_uk]

Monroe 23948 rear shock absorbers would have been a much better choice for the Audi A2.

Monroe 23948 rear shock absorbers

https://www.autodoc.co.uk/monroe/7435684?search=MONROE%20Shock%20Absorber%20(23948)

If I went for these could the Lesjofors* springs stay or are they too firm as well? I rarely have and passengers in the rear or heavy loads. My original aim was to reduce the typical A2 roll on bends. [* invoice does not give model no.]

PS I find the front OK.

 

[carlston]

If I went for these could the Lesjofors* springs stay or are they too firm as well? I rarely have and passengers in the rear or heavy loads. My original aim was to reduce the typical A2 roll on bends. [* invoice does not give model no.]

PS I find the front OK.

Lesjofors only list two different rear springs for the Audi A2, depending if it's an early or late car, ie. based on the car's VIN number.

Do you have OSS? The two rear springs that Lesjofors list are only suitable for cars without the OSS, so I guess you don't have OSS or A2 cars shouldn't have fitted them.

Kilen 50194 and Lesjofors 4204247 rear springs (sold to replace 8Z0511115L and 8Z0511115R)
until VIN number: 8Z*2*070 000

Kilen 50195 and Lesjofors 4204248 rear springs (sold to replace 8Z0511115AM and 8Z0511115J)
from VIN number: 8Z*3*000 001

Kilen and Lesjofors are identical springs, because they are both made in the same factory in Sweden. Just sold under different brands names for marketing purposes.

Kilen and Lesjofors don't give the specification of their springs, other than saying what OEM part numbers they are sold to replace. However, Eibach R10474 matches 8Z0511115R and from its specification it would appear that its a hard sports spring. Therefore, Kilen 50194 and Lesjofors 4204247 are also hard springs, because they are also sold to replace 8Z0511115R.

Eibach R10474 (matches 8Z0511115R) (appears to be a hard sports spring)

https://www.autodoc.co.uk/eibach/13828866

I suggest that you change the rear springs and the rear shock absorbers as the current Lesjofors rear springs might be part of the problem, ie. contributing to a hard ride.

KYB RH5514 and Sachs 996648 both match 8Z0511115AS and are both suitable for non-OSS models, ie. without sunroof. However, KYB are by far the best value, being available from carpartsinmotion on ebay for £18.10 each including shipping. The Sachs are almost twice the price.

KYB RH5514 (matching 8Z0511115AS)

2x Coil Springs (Pair Set) Rear RH5514 KYB Suspension Quality MULTIBUY SAVER | eBay

Find many great new & used options and get the best deals for 2x Coil Springs (Pair Set) Rear RH5514 KYB Suspension Quality MULTIBUY SAVER at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

If you were changing the rear springs yourself, you could measure them and count the number of coil turns to assess if they are harder than OEM part number 8Z0511115AS. However, it should be possible to measure the wire diameter (using digital calipers) and count the number of coil turns while the old rear springs are still fitted. If the wire diameter is 9.75mm and the number of coil turns is about 8 or at least 7.8 then they should give a similar ride to 8Z0511115AS. A thicker wire diameter than 9.75mm and/or less coil turns than 7.8, such as only 7.2 or 7.5 coil turns, and they will be contributing to a harder ride.

Monroe 23948 rear shock absorbers listed on ebay (shipped from Germany)

2X GENUINE MONROE SHOCK ABSORBER 23948 GAS PRESSURE REAR LEFT+RIGHT 4058632153768 | eBay

Find many great new & used options and get the best deals for 2X GENUINE MONROE SHOCK ABSORBER 23948 GAS PRESSURE REAR LEFT+RIGHT at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

 

[Alan_uk]

Many thanks @carlston for a comprehensive reply. I will get the calipers out tomorrow. No, I don't intend to fit myself as I don't have the facilities or confidence to change the rear axle myself. I'm refurbishing a donor axle and getting all the parts together.

 

[Alan_uk]

Hi @carlston As suspected they are thicker than standard: 10.5mm (range 10.4 to 10.6). It's difficult to count the rings as they are a bit hidden where they start and stop but I calculate 7.5 turns.

In these photos the finger is on the middle (4th) turn.

 

[carlston]

Hi @carlston As suspected they are thicker than standard: 10.5mm (range 10.4 to 10.6). It's difficult to count the rings as they are a bit hidden where they start and stop but I calculate 7.5 turns.

In these photos the finger is on the middle (4th) turn.

With a wire diameter of 10.5mm, they appear to be heavy duty rear springs from the Polo MK4.

These rear springs are probably about 20% stiffer than they should be, and that is massive because even 10% stiffer can give a car with an acceptably compliant ride an unacceptably hard ride.

The good news is that your rear end will be much more comfortable once the correct rear springs and rear shock absorbers have been fitted.

 

[Alan_uk]

I'm waiting for the shocks. Ordered from APT but transpires coming from Germany. Seems to be stuck in customs in Essex. I hope it comes in time to fit before a long journey.

Meanwhile I dremel off the ABS sensor hex bolt head. I removed the ABS sensor but the remains of the bolt (C in the photo) wont shift using pipe pliers and mole grips - just gets worn away. Yes, it's had numerous dousings of Plus Gas penetrating fluid. Anyway, I concluded the hex bolt goes into the hub so if that gets replaced it doesn't matter.

But the hex bolt to the cylinder is more problematic. I dremel the head off (A in the photo) but it wont shift. I cannot figure out if the back plate has a raised area for this bolt. If not then I can dremel a bit more. Anyone know?

It appears that the cylinder bleed hole B is not fixed to the back plate.