VW 412 Steering Wobble

[raygreenwood]

Greg...let me know when you get to to the clutch slave. Is this the late 44.5mm FAG slave or the early smaller slave?

About 5 months ago I was about to rebuild 10 of them. I have a source for a serviceable EPDM seal....just have to order too many. I was about to nickel plate the 10 I have back to factory spec after honing clean (which would make them last forever)...and cast a new high temp silicone boot....and sell them off at cost just so I have spares.

However....I have too many other parts that REALLY need electroless nickel to waste on these. They would still be roughly the same cylinder so not ideal by any means.

I have found that the slave cylinder from my 2012 Golf....would work no problem with a simple adapter plate and a modified pushrod. These run about $65 to $95-ish and ran on mk 4 through probably the current mk7. I got 120k miles from mine on my Golf. You can get them anywhere.

I have to calibrate the throw of the stock cylinder and set the shim for these. Its one of my back burner projects but if you need the data I can move it up front. I figure $10 worth of metal and studs and about an hour on a drill press ...and you can have an easily replaceable slave cylinder with a modern bayonet style fitting. Let me know if you need the info and pattern for the adapter plate.

The smaller slave diameter would also REALLY improve pedal feel. Ray

I missed this from you, Ray. I've already got the cylinder. It's an NOS large unit, which I know will be hit or miss because of the age of the seals.

If it doesn't work or last, I'd love that adapter plate info for the later Golf one.

Working on it. The plate plan is done. What I am trying to do over the next 10 days...among other projects...is to get thickness and spacing of the cylinder right so all anyone has to to is but a cylinder...make the plate and hook it up.

The gist is that the slave cylinder diameter is roughly....and I will measure mine...but its listed in most places as 19.05mm. That will give quite a bit more normal pedal feel. The stock early 411 clutch slave was 22.25 with the same 19mm X 30mm master cylinder....but a different pivot point ratio. I have heard it feels better.

The late 411 and all 412 used the 44.5mm slave with the same 19mm 30mm strke master cylinder. While super light...no pedal effort....its also hard to get used to. No break point is able to be felt.
This slave will be a bit harder to push....but can also "over reach" or over lift. That can be fixed with spacing.....or if you want a very short throw pedal....you can put a stop on the pedal.
I have to do a basic rebuild on my clutch master cylinder....then pull the spare trans with a case and fly wheel attached out next to the car and run a metal tube so I can experiment for an hour or two with a stack of shims.

Ray

[gearheadgreg]

An update on a couple things. I installed the NOS clutch slave cylinder. While bench testing and bench bleeding the new unit, the cylinder was stuck. Not surprising being machined, then sitting on the shelf for decades, likely. I put synthetic brake fluid in the fluid feed, and pulled the rubber boot and put some around the cylinder, the using a piece of wood and a light hammer, tapped and the cylinder started moving right away. Feeling at least there was a chance it would work, I installed it, greasing the ends of the pushrod.

Backing up a bit to removing the old slave cylinder - I removed the two retaining nuts, and the hydraulic hard line, as well as the clip that holds the hard line to the body at a soft line junction. This allows the hard line to move away from the cylinder by using the flexibility of the soft hose. When I tried to remove the slave cylinder, it wouldn't budge. I got it to wiggle a little bit, but could not get it to start coming out of the bellhousing. I tried several things, but in the end, I realized the slave itself would be the best way to push it out. I hooked the hydraulic line back up and pumped the clutch pedal. I heard a click/pop and looked - the slave had pushed itself out about an inch. At that point, I could lever under the mounting ears near the studs and gently pry it out. Just an FYI for anyone doing the job.

Once the NOS one was installed and plumbed, I started bleeding it. I didn't have a helper, so used a Mityvac vacuum bleeder to flush through a bit, then did a pump and hold bleed. Voila - firm pedal and good clutch action. Again, being an NOS unit, it may not last forever. I hope I can use some of Ray's information to rebuild the old unit to have it as a spare. Thanks to him for the huge amount of info he's posted over the years.

Additionally, since I had the rear wheels off, when reinstalling them, I torque them by hand of course, and double checked the fronts since i had them off last week doing the fuel filler hose. I noticed that the front wheels do have some 'natural' front to rear movement, noticed when torquing the passenger side front wheel. Getting under the car and looking while putting pressure on the lug with a breaker bar, I could see the source of the movement was the radius rod rubber bushings. The amount of movement was really surprising to me, especially considering that the control arm bushings are delrin ones made by Bill K. Does anyone know of polyurethane radius rod bushings to replace these? I like rubber, but I think this needs to be a fair amount stiffer to maintain the wheel/alignment location under loading.

[raygreenwood]

An update on a couple things. I installed the NOS clutch slave cylinder. While bench testing and bench bleeding the new unit, the cylinder was stuck. Not surprising being machined, then sitting on the shelf for decades, likely. I put synthetic brake fluid in the fluid feed, and pulled the rubber boot and put some around the cylinder, the using a piece of wood and a light hammer, tapped and the cylinder started moving right away. Feeling at least there was a chance it would work, I installed it, greasing the ends of the pushrod.

Backing up a bit to removing the old slave cylinder - I removed the two retaining nuts, and the hydraulic hard line, as well as the clip that holds the hard line to the body at a soft line junction. This allows the hard line to move away from the cylinder by using the flexibility of the soft hose. When I tried to remove the slave cylinder, it wouldn't budge. I got it to wiggle a little bit, but could not get it to start coming out of the bellhousing. I tried several things, but in the end, I realized the slave itself would be the best way to push it out. I hooked the hydraulic line back up and pumped the clutch pedal. I heard a click/pop and looked - the slave had pushed itself out about an inch. At that point, I could lever under the mounting ears near the studs and gently pry it out. Just an FYI for anyone doing the job.

Once the NOS one was installed and plumbed, I started bleeding it. I didn't have a helper, so used a Mityvac vacuum bleeder to flush through a bit, then did a pump and hold bleed. Voila - firm pedal and good clutch action. Again, being an NOS unit, it may not last forever. I hope I can use some of Ray's information to rebuild the old unit to have it as a spare. Thanks to him for the huge amount of info he's posted over the years.

Additionally, since I had the rear wheels off, when reinstalling them, I torque them by hand of course, and double checked the fronts since i had them off last week doing the fuel filler hose. I noticed that the front wheels do have some 'natural' front to rear movement, noticed when torquing the passenger side front wheel. Getting under the car and looking while putting pressure on the lug with a breaker bar, I could see the source of the movement was the radius rod rubber bushings. The amount of movement was really surprising to me, especially considering that the control arm bushings are delrin ones made by Bill K. Does anyone know of polyurethane radius rod bushings to replace these? I like rubber, but I think this needs to be a fair amount stiffer to maintain the wheel/alignment location under loading.

Ah.

DO NOT...use polyurethane. It WILL break the mounting eye. Ask me how I know....and that is a very springy steel and not weldable. I can show you how to very cheaply make new donuts from Buna N sheet from mcmaster car with two hole saws. ...if you need them....but this is one of the few parts that even when 50 years old and a little cruddy looking...work fine.

What is causing the movement you are seeing is that there is a entering ring missing that goes between the donuts....in abut 99% of all type 4 cars I have worked on.

The factory material was really poor and they literally turn to dust and disappear. Decades ago, the only books available like Chilton, Clymer and Haynes....were so poorly printed that this part did not even appear. The originals were made of polyethylene. Far too soft. I have made them from delrin (almost too hard but work fine), UHMW (not bad), Nylon (excellent).

Not sure if this link will work




Its part #2 and its VW part # is 411 401 159

I can send you a sketch with dimensions of how to make them. The originals were literally a medium soft plastic...about like milk jug material. It was literally a grommet. You deform it and snap it into the hole so one flange is on each side and faces up against one of the track control donuts.

Without this centering ring....you will find that the hole in the metal eye of the subframe ....is roughly 2-3mm large than the diameter of the track control radius arm. This centering ring is "supposed" to be a STIFF, low friction plastic that keeps the radius arm from contacting the metal of the eye...wearing it...and rattling.

By the way....these parts missing are one of the MAJOR causes of the "wobble" and for wearing out other parts. When you make these out of a harder plastic...you make them with only one flange....so its basically a snap in bushing...that looks roughly similar to those plastic bushings you snp into a desk top for your computer cables to run through. I install them with the flange toward the front.

Here is a side view sketch. I will get dimensions later tonight.


By the way....I THINK I may have found a seal for the stock 44.5mm slave piston that will fit and is made of the correct EPDM material. I will be speaking to the company in a day or so. After that...I can easily cast new outer boots from silicone.
Ray

[gearheadgreg]

Wow. Thanks Ray. Yes on needing the dimensional drawing.

[Hulken]

What is causing the movement you are seeing is that there is a entering ring missing that goes between the donuts....in abut 99% of all type 4 cars I have worked on.

The factory material was really poor and they literally turn to dust and disappear. Decades ago, the only books available like Chilton, Clymer and Haynes....were so poorly printed that this part did not even appear. The originals were made of polyethylene. Far too soft. I have made them from delrin (almost too hard but work fine), UHMW (not bad), Nylon (excellent).

Not sure if this link will work

Its part #2 and its VW part # is 411 401 159

I can send you a sketch with dimensions of how to make them. The originals were literally a medium soft plastic...about like milk jug material. It was literally a grommet. You deform it and snap it into the hole so one flange is on each side and faces up against one of the track control donuts.

Without this centering ring....you will find that the hole in the metal eye of the subframe ....is roughly 2-3mm large than the diameter of the track control radius arm. This centering ring is "supposed" to be a STIFF, low friction plastic that keeps the radius arm from contacting the metal of the eye...wearing it...and rattling.

By the way....these parts missing are one of the MAJOR causes of the "wobble" and for wearing out other parts. When you make these out of a harder plastic...you make them with only one flange....so its basically a snap in bushing...that looks roughly similar to those plastic bushings you snp into a desk top for your computer cables to run through. I install them with the flange toward the front.

Here is a side view sketch. I will get dimensions later tonight.


By the way....I THINK I may have found a seal for the stock 44.5mm slave piston that will fit and is made of the correct EPDM material. I will be speaking to the company in a day or so. After that...I can easily cast new outer boots from silicone.
Ray

Wonder if this could be a part that 3D print would work fine for? I'm not familiar with 3D printing,but have friends who are. Does any of you know what material would be best suited for 3D printing?

[gearheadgreg]

Hey Ray, just checking in to see if you had a chance to locate those drawings. My step son works as a drafter at a tech company, so getting it made shouldn't be too difficult I hope.

[gearheadgreg]

Just checking in again to see if you have those dimensions, Ray - hope you are OK

[Hulken]

He replied over at thesamba;


Hawker wrote:
Ray!
Have you managed to update your suspension book?
BR, Rob

Not yet. Work has actually been fairly busy through all of this pandemic.
Lots of projects outside of work as well.
That being said, though it is harder to scroll and read in its current format.....there are no errors in the book as it is.
While it is a project that is in the works.....its also a LOT of work to bring it into the samba. Possibly by mid june. Ray

[gearheadgreg]

[

Here is a side view sketch. I will get dimensions later tonight.


By the way....I THINK I may have found a seal for the stock 44.5mm slave piston that will fit and is made of the correct EPDM material. I will be speaking to the company in a day or so. After that...I can easily cast new outer boots from silicone.
Ray

Just checking in again. I'd like to try 3d printed one to see. Better than nothing at least.

[raygreenwood]

Man...sorry!....its been busy. I have pictures taken of the parts and an outline of slight mods needed. I will try to get them into a post this weekend. Ray

[gearheadgreg]

Awesome. Thanks Ray

[raygreenwood]

Here is the how-to with dimensions. Sorry it took so long!

https://www.thesamba.com/vw/forum/viewt ... 02#9384202
Ray

[gearheadgreg]

OK, so I had some made (2 sets, actually) so will be installing them sometime in the near future. Will update. Thanks for the help, Ray.

[Hulken]

Would you offer the other set up for sale Greg?

[gearheadgreg]

Would you offer the other set up for sale Greg?

Possibly. Let me make sure this set installs correctly, first.