411/412 Strut and Shock Replacement

[Denver412]

So sorry to start this topic all over again, but in searching the forums I am still not able to completely finish my strut replacement project.

As I understand, I can use strut cartridges from an Audi 4000, but is there a specific YEAR of 4000 that I stick to? A part number would be great. I think I understand how to space the cartridge up in the tube but am not completely clear on lengthening the attachement point at the top. Several posts indicate a machine shop is needed, but a couple do not.

What about replacement of the rear shocks? They seem like a pretty standard size. Any info on what model/brand/part number to use?

Thanks much.

[raygreenwood]

There should be rather long but complete threads on this. Search on my name. The rear shocks may look standard but are anything but. The valving is far beyond anything front engined. They are the exact crossmatch part for the front of a Ford econoline 1/2 ton. For a bit more pressure you can use the front shocks from an econline 3/4 ton. The only difference is the lower eye bushisng will need extra outer bushings or washers. Probably about 1979-82 on the Ford. The KYB gas-a-justs are great for the rear.

As for the front struts...the cartridges fom probably an 82-86 audi 4000s or a VW quantum. se only oil filled at worst...or KYB low pressure gas...GR-2 versions. DO NOT use the KYB gas-a-just high pressure gas or it will be undrivable and ruin your ball joints. You will need the plans for the stub at the top. I recommend using the later plans I made with the strengthening flange. Use a piece of stiff wall pipe with a pipe cap cut to length to bring the strut cartridge up to normal height under the cap on the strut housing. Using the later plans measn that you will dump the stock boot and bumop stop. use any late model golf bump stop or generic that fits available at Pepboys. Many of these come with their own boots. Many part #'s that work.
An afterkarket bump stop..I size for a very loose fit on the shaft and them contact cemnet it to the top plate so that it keeps the boot extended.
Send me a PM and Iwill e-mail the stub plans to you. Ray

[Denver412]

Thanks Ray!

For the rears, here are my options for the Ford Econoline, 1980:
E-100 ECONOLINE BASE
E-150 ECONOLINE
E-150 ECONOLINE CLUB WAGON
E-250 ECONOLINE
E-250 ECONOLINE CLUB WAGON
E-350 ECONOLINE
Which is the first one you recommended and the second, 3/4 ton?

Will

[raygreenwood]

I found one of my old posts with part #'s. http://www.shoptalkforums.com/viewtopic ... ock#p39298

I would suggest starting with the KYB 5410. The 5406 for 3/4 ton will have a tighter compression stroke and may not be exactly what you need if you have not replaced your rear trailing arm bushings. It may be too much in an unloadedwagon. Oh...and I am e-mailing you the plans for the stubs.

If memory serves the KYB strut cartridge is this one: KYB 365008

It fits:

AUDI 4000 (1980 - 1983)
AUDI 4000 QUATTRO CS (1986 - 1987)
AUDI 4000 QUATTRO S (1984 - 1985)
AUDI 4000 S (1984 - 1987)
AUDI 80 (1988 - 1992)
AUDI 80 QUATTRO (1991 - 1992)
AUDI 90 (1988 - 1995)
AUDI 90 CS (1993 - 1994)
AUDI 90 QUATTRO 1995
AUDI 90 QUATTRO CS (1993 - 1994)
AUDI 90 QUATTRO SPORT 1995
AUDI 90 S (1993 - 1994)
AUDI 90 SPORT 1995
AUDI CABRIOLET (1994 - 1995)
AUDI COUPE (1981 - 1982)
AUDI COUPE GT (1983 - 1987)
VOLKSWAGEN FOX (1987 - 1993)
VOLKSWAGEN FOX GL (1987 - 1993)
VOLKSWAGEN FOX GL SPORT (1989 - 1990)
VOLKSWAGEN QUANTUM (1985 - 1987)
VOLKSWAGEN QUANTUM CUSTOM (1982 - 1983)
VOLKSWAGEN QUANTUM DLX (1982 - 1983)
VOLKSWAGEN QUANTUM GL 1988
VOLKSWAGEN QUANTUM GL CUSTOM (1984 - 1987)
VOLKSWAGEN QUANTUM GL DELUXE 1984
VOLKSWAGEN QUANTUM SYNCRO (1986 - 1988)
VOLKSWAGEN QUANTUM WOLFSBURG EDITION 1984

I have also heard from somewhere that the Monroe sens-trac may also be an equivalent in gas pressure (low pressure gas) to the KYB GR-2

Ray

[bradey bunch]

Would it be possible to cut the strut rod off of an old/busted 412 strut and then shorten it to about 6" and drill and tap it so it threads on to the audi strut cartridge? Or am I missing something completley? Is the metal too hard to do that? I will try this eventually to find out, but have so much going on right now.

Braden

[Lahti411]

That's exactly what i did. This is possible only if you have the original shock absorbers to work with. The replacement cartridge's rods were much tihinner than the originals so there wouldn't be enough material for inner threads. Replacement cartride's rods are also made of much harder material than the original so they would be impossible to cut on a lathe with regular tools.

[raygreenwood]

That's exactly what i did. This is possible only if you have the original shock absorbers to work with. The replacement cartridge's rods were much tihinner than the originals so there wouldn't be enough material for inner threads. Replacement cartride's rods are also made of much harder material than the original so they would be impossible to cut on a lathe with regular tools.

Exactly. The rods of most replacement cartridges are induction hardened. Very, very, very hard. Cutting and then grinding square is not really the problem. Drilling and tapping is virtually impossible. The stock strut rod appears to be similar to a tool steel that is chrome plated.
It really is fairly simple and shoul be pretty cheap to have a pair of tool steel stubs made. Mine cost about $100 back in 2000-2001. It may sound expensive, but the cartridges you put on them are cheap compared to NOS 411/412 cartridges and you come out cheaper and far far better in the long run...and you only have to make them once. Ray

[Hulken]

I've been thinking of adapting an adjustable coilover suspension from a different car to my 412. If we start with a pair of adj coilovers and welds on a triangular plate that match up to the steering knuckle. I guess I would need an sleeve to fill up the gap between the damper shaft and the round hole in the steering knuckle. Some sort of sleeve would also be needed on the top mount. In the rear one should look up an adjustable coilover with similar mounting as the original damper for 412.

What do you think, is my plan possible? Is it possible to weld on a triangular plate on the damper? I could buy the kit in the picture for a small amount of money, it's original is a Audi A3 1998.


http://images.thesamba.com/vw/gallery/pix/652872.jpg

[ubercrap]

Yes, I think somebody did something similar to what you are suggesting- I can't quite remember who, I think it was a '69 411 coupe, off white, centerline type wheels... who's car was this?

[Hulken]

I've been in contact with the swedish company named Öhlins today, and the can supply adjustable front struts for our beloveds. Price for a pair is around 1600 usd. Complete height adjustable strut with damper and spring.

http://www.khmotorsport.se/index.htm

[ubercrap]

If that is the same Öhlins I'm thinking of, their reputation preceeds them. I'm sure the quality would be superb- and the price reflects this. Not that I don't think it would be worth it, just that if I had the money it strays outside "wife approved" territory...

[raygreenwood]

You will have to be very selective with that company as to what initial coil spring strength you select. This is a very peculiar front end.
The control arms generate lots of leverage....yet the weight loading is light. The trunk sizing is such that you could also incur heavy loads. It creates an issue that you need a very progressive coil spring....whose initial and maximum rate spring rate does not get to high to quickly.
This is a very odd combination if you want to maintain drivability.

I keep saying...VW did a superb job on the coil spring rate design. They did a less than satisfactory design on the strut valving (especially rebound)....but its hard to say whether that was simply a longevity issue on struts of the day.

You can do a very superb job simply by keeping the original springs and working to put a better cartridge into it.

You can get the same custom type of products as you can get from Phlins...from Bilstein and from Foxx. But...in order to get the progressiveness required of our front end....you will need to use dual spring rates with dual spring perches.....both adjustable. It will have to have FULLY adjustable rebound and compression valving. What this entails is a short harder (but slower) load carrying spring on the lower perch ...a middle perch above that....a lighter comfort spring above that with fast reaction and then the top plate.
The issue is that most of these are not struts. They are shock assemblies...and will require significant fabbing to install in our cars.

The cost range....from Bilstein and Foxx....is about the same price range as the company you listed. I very nearly spent monet on a system from Bilstein back in about 2001. Ray

[bradey bunch]

I removed the struts that I got off of the parts car, and pulled out one kyb and one gabriel. I wanted to compare them to the NOS tokico ones I bought. Here are the pics that show the differences. The blue one is the kyb, and the black is the tokico. The parts car was a '71. It appears the space between the tip of the rod and where it widens is shorter on the tokicos. What is going on here? Are the struts I purchased for '74's? They were advertised as 73 and earlier. Here are the pics.






TIA, Braden

[Bill K.]

Correct Braden. You'll need a '74 bump stop without the metal spacer or an aftermarket bump stop - both will fit over the shaft and allow the shaft step to seat against the spring plate.

[raygreenwood]

yes, the blue KYB is the universal part for 411 and early 412. See that "knurled" area near the step? Either the 411 or the early 412 .....both using symmetrical bolt pattern strut bushing...but with different type bearing.........one of these two required a 13mm difference in step position. Just can't remember which. Anyway....the KYB (and Sachs, and Boge and Gabriel and pretty much everyone else)....included this 13mm bushing in the kit along with a new top nut. In this way, the kit would fit both Early 411, late 411 and early 412.
As Bill mentioned, you will need the late (74) bumpstop internal steel spacer....with or without using the bumpstop (you could add an aftermarket one no issue)....and the late strut bushing.

Yes...you can use the early symmetrical strut mounts.....which you should get rid of...or simply replace them every two to three years like clockwork. But, you will need to mock this up with the new strut cartridge and early symmetrical bushing on the work bench to get it right.

The parts that should be assembled to check fit are: The black 74 strut cartridge that you have, the top strut plate/seat, the bump stop spacer.......... which if memory serves...and I will check.....does not have a spacer. I think the step in the rod sits right under the plate, the thrust washer stack that goes between the top plate and the bottom bearing face (the early style) bearing should be just a bit above the top strut plate...maybe .050", the bearing/bushing, the top thrust washer....and the nut. It needs to be assembled and checked for movement before installing it. It will change the front height and spring compression slightly (slightly lower I think). Ray