After buying this kit..my rear end CRREEAAKKKS!
05-23-2011, 02:02 PM
#91
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Carl,
To do this right, you really need to insure that you drill the hole and then use a reamer to ensure a perfect hole dimension on the plate. Without that hole being a proper size, it will allow it to move too much which will then allow the outer bolt to be worked loose.
To do this right, you really need to insure that you drill the hole and then use a reamer to ensure a perfect hole dimension on the plate. Without that hole being a proper size, it will allow it to move too much which will then allow the outer bolt to be worked loose.
05-23-2011, 02:08 PM
#92
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If the plate were shorter so the pull centered on the pin that could be acceptable longterm. That would leave the droplink mount stock. Of course, this tie down plate is more fixed with two mount points, but the two mounts are the core of the problem. Designing a simple fix that retains both mount points without creating a new problem is where we are still puzzling right now.
05-23-2011, 02:16 PM
#93
Nordschleife Master
Sean,
This would mean that you are putting all the force of a pull down or tow strap on that one tiny (M8??) bolt.
Not going to happen.
Bill,
I am aware that will prevent it from being a fix that can be performed at home.
But if it is to be fixed right, this is in my opinion the only way to do the fix. Thankfully, I have a lathe and drill press, and have no problem buying a $200 tool to be able to do the job right.
This would mean that you are putting all the force of a pull down or tow strap on that one tiny (M8??) bolt.
Not going to happen.
Bill,
I am aware that will prevent it from being a fix that can be performed at home.
But if it is to be fixed right, this is in my opinion the only way to do the fix. Thankfully, I have a lathe and drill press, and have no problem buying a $200 tool to be able to do the job right.
05-23-2011, 02:22 PM
#94
Racer
Sean, question is if it holds.... depends on how much force is transferred by he drop link. Could even make things worse 
Also I don't like the idea of making a tight fit rotating metal sleeve. This will get stuck at some point, as water, salt, and dirt will hit it on a regular basis.
Also I don't like the idea of making a tight fit rotating metal sleeve. This will get stuck at some point, as water, salt, and dirt will hit it on a regular basis.
05-23-2011, 02:31 PM
#95
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Sean,
This would mean that you are putting all the force of a pull down or tow strap on that one tiny (M8??) bolt.
Not going to happen.
Bill,
I am aware that will prevent it from being a fix that can be performed at home. But if it is to be fixed right, this is in my opinion the only way to do the fix. Thankfully, I have a lathe and drill press, and have no problem buying a $200 tool to be able to do the job right.
This would mean that you are putting all the force of a pull down or tow strap on that one tiny (M8??) bolt.
Not going to happen.
Bill,
I am aware that will prevent it from being a fix that can be performed at home.
But if it is to be fixed right, this is in my opinion the only way to do the fix. Thankfully, I have a lathe and drill press, and have no problem buying a $200 tool to be able to do the job right.
05-23-2011, 02:35 PM
#96
Nordschleife Master
Sorry Bill, I misread SeanR's statement.
The only problem I see is that as the suspension is compressed and released, that plate will move up, altering the drop link geometry.
The only problem I see is that as the suspension is compressed and released, that plate will move up, altering the drop link geometry.
05-23-2011, 02:48 PM
#98
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What I'm describing is a new plate where droplink mount is left stock, and the plate only mounts to the pin. Obviously not a simple home fix either.
05-23-2011, 02:49 PM
#99
05-23-2011, 06:13 PM
#100
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I hope Carl can apply his creativity to all the input and come up with a workable longterm solution. I don't think we are there yet. A lubricated bushing/spacer sounds fine but it needs to be just the right length, adequately hard for 103 ft-lbs and requires rather precise redrilling of the hole in the plate. Maybe there is another totally different good solution, but until Jeff comes back over (looks like this Thursday) and we fiddle some more with it, I'm on hold. BTW, all I have is a hand drill and a hacksaw - no lathe.
05-24-2011, 12:33 PM
#101
Developer
We are working on it now. We have an entire rear lower suspension link on the workbench so we can load it (105 lb ft) and unload it and see how much deflection there is in those bushings.
It seems the 103 or 105 lb/ft (depending on where you read) is fairly specific because, too little and the tapered bushings are not held in place and load correctly, too much and the outer bushings are pulled in to where the pin now hits the back of the stock washer - effectively locking the pin and the bushing together.
We have confirmed, tho, that the compressive load is supposed to be on the stack of bushings, and not on the pin alone.
What we are making now is a part that will replicate the stock function exactly. It will behave exactly like the stock washer and you will be able to load at 105 lb ft of torque and whatever the Porsche engineers designed to happen with their flat washer will happen again.
I will post pics when I have them, hopefully later today or certainly tomorrow.
I think it will be a nice improvement to this part.
It seems the 103 or 105 lb/ft (depending on where you read) is fairly specific because, too little and the tapered bushings are not held in place and load correctly, too much and the outer bushings are pulled in to where the pin now hits the back of the stock washer - effectively locking the pin and the bushing together.
We have confirmed, tho, that the compressive load is supposed to be on the stack of bushings, and not on the pin alone.
What we are making now is a part that will replicate the stock function exactly. It will behave exactly like the stock washer and you will be able to load at 105 lb ft of torque and whatever the Porsche engineers designed to happen with their flat washer will happen again.
I will post pics when I have them, hopefully later today or certainly tomorrow.
I think it will be a nice improvement to this part.
Last edited by Carl Fausett; 05-24-2011 at 12:48 PM.
05-24-2011, 12:35 PM
#102
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We are working on it now. We have an entire rear lower suspension link on the workbench so we can load it (105 lb ft) and unload it and see how much deflection there is in those bushings.
It seems the 103 or 105 lb/ft (depending on where you read) is fairly specific because, too little and the tapered bushings are not held in place and load correctly, too much and the outer bushings are pulled in to where the pin now hits the back of the stock washer - effectively locking the pin and the bushing together.
We have confirmed, tho, that the compressive load is supposed to be on the stack of bushings, and not on the pin alone.
What we are making now is a part that will replicate the stock function exactly.It will behave exactly like the stock washer and you will be able to load at 105 lb ft of torque and whatever the Porsche engineers designed to happen with their flat washer will happen again.
I will post pics when I have them, hopefully later today or certainly tomorrow.
I think it will be a nice improvement to this part.
It seems the 103 or 105 lb/ft (depending on where you read) is fairly specific because, too little and the tapered bushings are not held in place and load correctly, too much and the outer bushings are pulled in to where the pin now hits the back of the stock washer - effectively locking the pin and the bushing together.
We have confirmed, tho, that the compressive load is supposed to be on the stack of bushings, and not on the pin alone.
What we are making now is a part that will replicate the stock function exactly.It will behave exactly like the stock washer and you will be able to load at 105 lb ft of torque and whatever the Porsche engineers designed to happen with their flat washer will happen again.
I will post pics when I have them, hopefully later today or certainly tomorrow.
I think it will be a nice improvement to this part.
Wow..glad I brought this up.
05-24-2011, 03:50 PM
#105
Developer
Ok, here is a finished prototype.
We took note of the fact that the stock washer is flat, and engages both the bearing surface of the bushing and (maybe) the pin.
We think that when the nut is torqued correctly, it puts the proper pre-load on the stack of tapered and non-tapered bushings, but does not compress them so far as to clamp the pin, so the pin can turn. When we over-torqued the nuts on our test-bench, we could clamp the pin so it was not able to turn as freely.
So - we wanted to emulate the factory design so it would still behave in the factory way.
In this prototype note that the hat washer is made from aluminum. It was just fast to turn a mock-up part. The "real deal" would be steel.
The hat washer is flat on the backside, just like the OEM washer, so it will behave the same way.
What I need to do now is make a pair of these in steel, mount them to a car or two and drive them for a month.
We took note of the fact that the stock washer is flat, and engages both the bearing surface of the bushing and (maybe) the pin.
We think that when the nut is torqued correctly, it puts the proper pre-load on the stack of tapered and non-tapered bushings, but does not compress them so far as to clamp the pin, so the pin can turn. When we over-torqued the nuts on our test-bench, we could clamp the pin so it was not able to turn as freely.
So - we wanted to emulate the factory design so it would still behave in the factory way.
In this prototype note that the hat washer is made from aluminum. It was just fast to turn a mock-up part. The "real deal" would be steel.
The hat washer is flat on the backside, just like the OEM washer, so it will behave the same way.
What I need to do now is make a pair of these in steel, mount them to a car or two and drive them for a month.