Tuning your Allroad C5 rear shocks
04-29-2015, 11:01 PM
#1
Audiworld Junior Member
Thread Starter
Tuning your Allroad C5 rear shocks
This is for Ur-Allroad (Allroad C5):
I have dismantled the load valve in Sachs rear shocks and investigated different options for making it (the shock) work better. And now I have found one easy way:
The valve controls mostly the OUTWARD move, not much the inbound. Also, the shock is the most stiff if the valve is fully closed and less stiff if the valve is fully open. In the middle there is no outward damping.
So, when the valve gets clogged and dirty, it usually stays just partly open. And then the shock works badly - no damping outward. The valve is easy to check and clean. Also, some people (like me) have put a plastic 2mm washer inside before the piston to keep it fully closed all times. THEN you have the biggest dampening inward and outward.
The Sachs shock itself is really good and becomes much "newer" and stiffer if you clean the valve piston or fully force close the valve.
If anyone is interested in knowing how to close the valve permanently, I can write english instructions in here. It can be done shock in place - only removing the wheel. Then the shock is stiffer than standard A6 shocks.
I have dismantled the load valve in Sachs rear shocks and investigated different options for making it (the shock) work better. And now I have found one easy way:
The valve controls mostly the OUTWARD move, not much the inbound. Also, the shock is the most stiff if the valve is fully closed and less stiff if the valve is fully open. In the middle there is no outward damping.
So, when the valve gets clogged and dirty, it usually stays just partly open. And then the shock works badly - no damping outward. The valve is easy to check and clean. Also, some people (like me) have put a plastic 2mm washer inside before the piston to keep it fully closed all times. THEN you have the biggest dampening inward and outward.
The Sachs shock itself is really good and becomes much "newer" and stiffer if you clean the valve piston or fully force close the valve.
If anyone is interested in knowing how to close the valve permanently, I can write english instructions in here. It can be done shock in place - only removing the wheel. Then the shock is stiffer than standard A6 shocks.
04-30-2015, 05:11 AM
#2
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This is for Ur-Allroad (Allroad C5):
I have dismantled the load valve in Sachs rear shocks and investigated different options for making it (the shock) work better. And now I have found one easy way:
The valve controls mostly the OUTWARD move, not much the inbound. Also, the shock is the most stiff if the valve is fully closed and less stiff if the valve is fully open. In the middle there is no outward damping.
So, when the valve gets clogged and dirty, it usually stays just partly open. And then the shock works badly - no damping outward. The valve is easy to check and clean. Also, some people (like me) have put a plastic 2mm washer inside before the piston to keep it fully closed all times. THEN you have the biggest dampening inward and outward.
The Sachs shock itself is really good and becomes much "newer" and stiffer if you clean the valve piston or fully force close the valve.
If anyone is interested in knowing how to close the valve permanently, I can write english instructions in here. It can be done shock in place - only removing the wheel. Then the shock is stiffer than standard A6 shocks.
I have dismantled the load valve in Sachs rear shocks and investigated different options for making it (the shock) work better. And now I have found one easy way:
The valve controls mostly the OUTWARD move, not much the inbound. Also, the shock is the most stiff if the valve is fully closed and less stiff if the valve is fully open. In the middle there is no outward damping.
So, when the valve gets clogged and dirty, it usually stays just partly open. And then the shock works badly - no damping outward. The valve is easy to check and clean. Also, some people (like me) have put a plastic 2mm washer inside before the piston to keep it fully closed all times. THEN you have the biggest dampening inward and outward.
The Sachs shock itself is really good and becomes much "newer" and stiffer if you clean the valve piston or fully force close the valve.
If anyone is interested in knowing how to close the valve permanently, I can write english instructions in here. It can be done shock in place - only removing the wheel. Then the shock is stiffer than standard A6 shocks.
05-01-2015, 02:31 PM
#3
Audiworld Junior Member
Thread Starter
Tuning your Allroad rear shock load valve
Yes, Sachs is the OEM shock.
Here is my procedure:
The Allroad rear shock load valve controls mostly the OUTWARD dampening, not much the inbound. Also, the shock is the most stiff if the valve is fully closed or fully open. The original idea of the valve is to be fully closed or fully open during the move up and down. In the middle there is almost no outward damping. There is two oil by-pass routes, bigger when valve fully open, both when in the middle and no flow when fully closed.
So, when the valve gets stuck or is under less load, like 402 mod, it usually stays just partly open. Especially, if you mod 402, the valve may not move enough and makes the ride sloppy.
The valve is easy to check and clean. See my guidance below.
Also, some people have forced the valve to be always fully closed (full outward dampening).
The Sachs shock itself is really good and becomes much "newer" and stiffer if you clean the valve piston or fully force close the valve.
Cleaning and tuning of the load valve goes approximately like this:
1. Day or two before, put some CRC Penetrating oil similar to the ring clip and valve cover cap under it
2. After a day or two, take of the wheel.
3. Unscrew the air pipe fitting from the valve
4. Take of the ring clip.
5. Gently wiggle and pull off the valve cover cap with pliers. Clean and oil the o-ring seal in it. Check the small air hole in the center.
6. With a strong magnet tool, pull the piston off. Remember the order of the washers under it. The two convex washers are against each other from the center and act as a spring. Clean and oil the washers and o-ring seal in the piston.
7. Now you can see the actual valve shaft on the bottom of the housing. Test it with a finger – it should move in and pop back easily about 2 mm. Spray some oil there as well.
8. Clean and oil the whole cylinder.
9. Now, this is the tricky part. Here are the two options:
11. Now either install the air pipe and fitting back (especially if you didn’t do any tuning) or remove the air piping and close the air outlets in the air spring AND the inlet in the shock valve housing. I did that by filling the air fitting screws with SIKA silicone.
So this was my way of closing the valve. I went through different other options, like a strong spring replacing the piston, one way check valve in the air pipe, or an adjustment screw bored in to the cover cap.
The last option is propably the sturdiest and most flexible because you can test different settings with the screw. The screw would then press the piston. But this option also destroys the cover cap and prevents going back to the original air operation. I think I might try this next.
Now, this guidance is just based on my study. If you have any doubts with it, just clean the piston and cylinder and have a second thought. I can’t take any responsibility of the results since the shock can really be worn out and this guidance doesn’t help or the construct of the shock is somehow different. Also, remember, you can't purchase any of the valve construct parts separately.
Here is my procedure:
The Allroad rear shock load valve controls mostly the OUTWARD dampening, not much the inbound. Also, the shock is the most stiff if the valve is fully closed or fully open. The original idea of the valve is to be fully closed or fully open during the move up and down. In the middle there is almost no outward damping. There is two oil by-pass routes, bigger when valve fully open, both when in the middle and no flow when fully closed.
So, when the valve gets stuck or is under less load, like 402 mod, it usually stays just partly open. Especially, if you mod 402, the valve may not move enough and makes the ride sloppy.
The valve is easy to check and clean. See my guidance below.
Also, some people have forced the valve to be always fully closed (full outward dampening).
The Sachs shock itself is really good and becomes much "newer" and stiffer if you clean the valve piston or fully force close the valve.
Cleaning and tuning of the load valve goes approximately like this:
1. Day or two before, put some CRC Penetrating oil similar to the ring clip and valve cover cap under it
2. After a day or two, take of the wheel.
3. Unscrew the air pipe fitting from the valve
4. Take of the ring clip.
5. Gently wiggle and pull off the valve cover cap with pliers. Clean and oil the o-ring seal in it. Check the small air hole in the center.
6. With a strong magnet tool, pull the piston off. Remember the order of the washers under it. The two convex washers are against each other from the center and act as a spring. Clean and oil the washers and o-ring seal in the piston.
7. Now you can see the actual valve shaft on the bottom of the housing. Test it with a finger – it should move in and pop back easily about 2 mm. Spray some oil there as well.
8. Clean and oil the whole cylinder.
9. Now, this is the tricky part. Here are the two options:
a. If you want a full outward dampening, you can now force close the valve for good like this: Push the piston back WITHOUT the washers. Test the movement of the piston with a finger. It should move about 1.5 mm and bounce back easily. Now, I put 4mm of polyester washers between the piston and the cover cap. Also an o-ring 4.5-5 mm thick does the job. It is easier since it is flexible. If the washer is too thick, you can’t install the final ring clip. If the washer is too thin, the valve stays open. So measure the movement, i.e. needed washer thickness carefully. The washer or o-ring should then press the piston fully down when installing the final cover cap and ring clip. The diameter of the piston is 22mm.
b. If you don't want a full outward dampening, assemble the piston back with its' washers.
10. Push in the oiled valve cover cap in and install the ring clip. 11. Now either install the air pipe and fitting back (especially if you didn’t do any tuning) or remove the air piping and close the air outlets in the air spring AND the inlet in the shock valve housing. I did that by filling the air fitting screws with SIKA silicone.
So this was my way of closing the valve. I went through different other options, like a strong spring replacing the piston, one way check valve in the air pipe, or an adjustment screw bored in to the cover cap.
The last option is propably the sturdiest and most flexible because you can test different settings with the screw. The screw would then press the piston. But this option also destroys the cover cap and prevents going back to the original air operation. I think I might try this next.
Now, this guidance is just based on my study. If you have any doubts with it, just clean the piston and cylinder and have a second thought. I can’t take any responsibility of the results since the shock can really be worn out and this guidance doesn’t help or the construct of the shock is somehow different. Also, remember, you can't purchase any of the valve construct parts separately.
Last edited by Torsti Tenhunen; 05-11-2015 at 12:50 AM. Reason: Clarifications
The following users liked this post:
Leebo8 (06-24-2021)
05-09-2015, 08:05 PM
#5
Banned
05-09-2015, 08:15 PM
#6
AudiWorld Member
One question, what would happen if the air inlet from the air bag is plugged on both sides? as if it's deleted.
Would it be stiffer, softer or neither? Cheers!
05-09-2015, 11:08 PM
#7
Audiworld Junior Member
Thread Starter
Sachs & Continental - same shock. Just branding issue. Some shocks have both labels 
. Sachs texts stanced to the metal body, Continental as a sticker.
. Sachs texts stanced to the metal body, Continental as a sticker.Trending Topics
05-09-2015, 11:10 PM
#8
Audiworld Junior Member
Thread Starter
With OEM shocks, if the air is just plugged, the load valve stays fully open at all times which means medium outward dampening. Some (incl. me) think it is too soft. Best results if you close the valve as in DIY and also plug the air inlets.
06-24-2021, 07:59 PM
#9
9. Now, this is the tricky part. Here are the two options:a. If you want a full outward dampening, you can now force close the valve for good like this: Push the piston back WITHOUT the washers. Test the movement of the piston with a finger. It should move about 1.5 mm and bounce back easily. Now, I put 4mm of polyester washers between the piston and the cover cap. Also an o-ring 4.5-5 mm thick does the job. It is easier since it is flexible. If the washer is too thick, you can’t install the final ring clip. If the washer is too thin, the valve stays open. So measure the movement, i.e. needed washer thickness carefully. The washer or o-ring should then press the piston fully down when installing the final cover cap and ring clip. The diameter of the piston is 22mm.
06-24-2021, 11:54 PM
#10
AudiWorld Member
