Replacement rubber strut donut bushings for late 1973-74 412's

[raygreenwood]

I am making this as a separate document for those who are replacing JUST the rubber bushings in their strut mounts. This only applies to the late 412 (mid 1973 through 1974-75) and Super-beetle strut mounts with the asymmetrical bolt pattern.

The symmetrical bolt pattern strut mounts from the 411 and early 412 do not have a separate rubber bushing. They are of all bonded construction.

This is NOT a “how-to”. All of that is covered in these two links to the Audi strut modification and rebuild for early and late 411/412.

VW 411 and 412 Audi Strut Rod document (test)
http://www.thesamba.com/vw/forum/viewtopic.php?t=624354&highlight=

Audi Strut Modification part 2- 1974-75 412 specific
https://www.thesamba.com/vw/forum/viewtopic.php?t=764509

This is just for those whose rubber strut mount bushings are bad. This is MAINLY about finding/buying good rubber bushings and making the choice between what you can get.

I will also give my opinion as to what I think you “should” buy from what is currently available. Most of this information is also in the two links above but unless you are doing a complete rebuild and/or the Audi strut modification, that’s a lot of information to wade through.

For quick background on why this is a decision problem you can look at this link:

“Gap on top of strut cap? Wth?”
https://www.thesamba.com/vw/forum/viewtopic.php?t=798710

How do you know your rubber strut bushings are bad?
You will usually have poor/noisy handling and the tops of the struts will look like this:

This one is from my right hand strut. You can see by the yellow boxes that the stepped/dished black cap under the nut is not parallel with the white nylon glide ring on the top of the mount and the gap is about 3X what it should be.
At rest, the gap should be about 5mm maximum and about 2.0mm minimum. So not only have my mount bushings “squished” vertically, they have slipped sideways. Very common.

This is from tim3’s post. His are pretty straight but the gap looks to be about 1/2" which is very excessive.

Your situation/scenario:

Let’s say your struts are just fine, either original stock or aftermarket replacement cartridges or new modified with Audi strut cartridge and the only thing wrong is either you have a bad strut bearing or a bad strut donut bushing. All you want to do is replace the rubber donut and/or bearing.

Your current choices:

Choice A:
Buying a completely new strut mount assembly with metal plate, threaded studs, bearing cartridge, glide ring and rubber donut.

This is the easiest one but it has issues these days.
You can buy the complete strut mount assembly from Cip1 or Topline or several other places. It comes with the steel mounting shell, the rubber donut, the nylon glide ring and the bearing cartridge. You will have to reuse your old steel center bearing tube bushing.

NOTE: all of these are listings for the late super beetle. It’s all the same mount and this is what you should look for. Its easier to find than searching for one for 411/412.

J-Bugs
https://www.jbugs.com/product/133412329B.html?utm_...rLEALw_wcB

AutoHaus AZ
https://www.autohausaz.com/pn/14236513-JP-13341234...1uEALw_wcB

Socal imports
https://socalautoparts.com/product/strut-pivot-sup...c6EALw_wcB

Cip1
https://www2.cip1.com/acc-c10-4023/?srsltid=AfmBOorF22Wu92_4SnrK4yOQqngQGJM-F5jtRZC_BfY9NNdw-RGzuMIv

Top Line:
These guys list the mount being made in China and the ball bearing being made in Germany. I suspect most of the stampings are like this even if they say Dansk.
https://www.toplineparts.com/product/strut-top-bearing-mount-74-to-79-super-beetle-87-0261-2/

Pros of choice A:
1. These are all the same part likely made by the same company. Almost any of these (and there are others) will be about the same quality so buy them where you get the best deal.

2. While Cip1 lists them under their “Five Star” house brand, a few people that list the manufacturer list them as Dansk. The quality of the metal mount, studs and bearing cartridge are excellent.

3. Going with this method is the least fuss because it means you get brand new steel mount, threaded studs, rubber bushing and ball bearing. Everything is new and nicely painted and ready to install.
However, it’s not any easier work-wise because it takes no more or less effort to replace the whole mount as it does to take out the old one and slip in just the bearing and/or bushing. The mount has to come out either way.

Cons of choice A:

1. the main negative is....It’s a gamble as to whether the rubber donut is molded correctly or is the right hardness/compound.

The rubber bushings installed in the picture of my strut above are those from Cip1 complete assemblies. I bought a pair and used the bearing and cartridge only and they installed perfectly. But, within 6 months of sitting still in the garage, my bushings sagged like you see in the picture.
They have “0” miles on them.

2. This is the most expensive method. Just 6-7 years ago, these mounts were about $25-30 each. The best prices right now are $55-$60 each and some as high as $85 each. Don't spend that much because the $85 part is "probably" no different than the $55-$60 part.
While I may be wrong on that, one could spend a lot of $$$ just finding out. The only part of any of these that could or should be better is the rubber.

Conclusion: So, if you need the steel mount and your threaded studs are damaged and/or the bearing is rusty, it is worthwhile to just buy the whole strut mount from one of these places and take your chances on the quality of the rubber.

Choice B:
Buying just the rubber donut bushing.
This is the same scenario as choice A but you just want to replace the rubber donut bushing and plan to reuse your bearing and steel mounts:

Cip1:
https://www2.cip1.com/VWC-823-412-355-2/?gad_sourc...8FEALw_wcB

This Cip1 part has been all over the place in quality. There seems to have more than one mold being used.

Gabriel part # 142251
https://www.finditparts.com/products/13601398/gabr...EffEd9mTMm

Gabriel used to have the best replacement parts for these. The last set I bought were nicely made but too thin (in height, not cross section). They will work but you need to adjust the height above with shims. Not ideal if you find this out when you pull them out of the box.

Pros of choice B:
1. This is the cheapest method. Same amount of work

2. If you have top quality, good condition original parts, this is the easiest way to make sure that the rubber part is good as well….if you can get good quality separate bushings

Cons of choice B:
1. It has gotten increasingly difficult to find just the rubber donut bushing at all.

2. About half of the donuts I do find are no longer made in the same place as they were or are of poor material


Choice C:
Buying a bonded rubber donut and bearing assembly (all one piece):

I used to dislike this choice. It will automatically add approximately 3/16” (0.1875”) to your front end height AFTER it gets bedded in. Right out of the box, before the bonded rubber bushing conforms its shape to the shape of the steel plate/shell it adds about 3/8” to the height of the front end. Once it beds in, it’s about half that at 3/16”.

This means that when you install the complete bonded bushing/bearing assembly you will need to add about 0.080” of shim washers between that stepped top plate under the nut, drive a couple of hundred miles and then remove the nut and most of the washers to set the final height of that stepped cap and the gap.

These strut bearing/bushing cartridges were used in the last few years of Super Beetle, used by dealers as replacement cartridges over the past few decades and were actually a VW Fox and Mk1 Rabbit strut mount.

They are higher quality, stiffer rubber. However, the shape of the rubber where it fits the stamped steel mount is slightly different so you need to install them and let them bed in before doing the final adjustment for that top gap.

Here are some pictures which are excerpts from my original strut document showing the difference in height and shape between the two-piece donut and bearing assembly and the one piece bonded rubber bearing and bushing assembly. The two piece is on the left in this picture:

This picture below show two bonded, one piece units next to each other. The one on the left was out of a 412. The one on the right is a new one that has not been installed, driven on and reshaped by pressure.

As I noted in my long document. I “think” at one time there was a bonded combo bushing that was made for just 412 and Super Beetle and it just went out of production and only the slightly different Fox bushing started being used.

So many places list the Super Beetle and Fox bushing by the same part #.
Either way, the bonded unit can be used with no problems in the 412 and super.
You just have to adjust it when you install it, drive it to break it in and shape the rubber to the steel mount and then pull the nut and upper dish loose and add shim washers if necessary. Here is an excerpt of that from the big document.

Here is what the new unit looks like vs after installed and broken in:

Why you have to adjust/shim and how you do it:

When you install a brand new bonded bushing/bearing unit like the Monroe #901941, once you put that dished cap on it, look through the hole and you will see this:

The dished cap will be resting on the lip of the metal mount (its not supposed to be) and you will see a visible gap between the underside of the dished cap and the top of the bearing race tube in the center (red arrow). This is not right.

So, you go to the hardware store and get metric washers or arbor bushings that fit the strut rod. Stack them up on top of the steel bushing in the bearing like this:

This is what we are doing. You can see that this one needs just a couple more shims but we are making up this distance and closing the gap.

When it is correct it will look like this from the side. You are looking for a minimum gap of ~2.5mm or a maximum gap of ~5.0mm noted by the yellow box/. Please ignore the bent strut mount.

Once you install this stack up and the weight of the car is on it, you may need to remove a washer or two.
Once you drive it for a while and the rubber bushing shapes itself to the steel mount, you will need to remove the nut and dished plate and remove one or two more washers and then you are done.

Pros of choice C:
1. These are available in a lot of places and are available in pretty good quality.

Cons of choice C:
1. As noted, they are a little higher. If you are doing the Audi mod and are carefully lowering your front end to level, you can grind the bottom of these on a belt sander to remove the excessive height. You need to adjust the lower spacer between strut top plate and the bearing cartridge to fit.

The bonded bushing in this picture is the Monroe “strut-mate” part # 901941.
https://www.summitracing.com/parts/mon-901941?
srsltid=AfmBOoozIYg7C1vz9mJd_7XnjTd53h-EfFORgigiyGqQhrHetfiS-Uru

Mevotech makes good ones as well.

Your best search words will be to look for VW fox strut bearing 1987-1993
https://www.partsplaceinc.com/vw-fox-strut-bearing...Z0y__awyr_

Conclusion:
As you can tell, I am favoring “choice C” these days mainly because I am tired of buying rubber donuts and either having them be thin pieces of crap out of the box or having them look normal and installing them and having them fail in very short order.

Ray

[superbeetle1302s]

Hi... I just saw Upper strut dampening ring, 1974-1979 Super Beetle, on the page:

https://www.wolfsburgwest.com/cart/DetailsList.cfm?ID=823412355

&

https://www.cip1.ca/vwc-823-412-355-2/

I hope it will be helpful for the future.