Is There A Reason You Can't Use A Solid Spacer To Replace Rag Joint?

2000xp8

SN Certified Technician
Aug 8, 2003
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Just curious, I've been around here a while, not sure I've ever seen it spoken about.

I'm making a few suspension changes and soon I will need an alignment, so I want to get in all work and parts in before hand, obviously.

The MM shaft is like $211. Not that I think that number is out of line, i'm just curious to why a solid machined spacer isn't as good.
I know they say they use needle bearing u joints for smoothness, but I use a 12:1 agr road race rack and i'd bet the majority of you guys here would think my steering shaft wasn't even connected to anything, yes it's that light and extremely smooth with the stock shaft in place.

By no means am I knocking MM or their pricing, I love their parts, i'd really just like to know why I can't buy a replacement rag joint (which I think do exist), take it to a machine shop friend I have and just have him make me a spacer out of steel or aluminum.

Has it been tried or am I missing something obvious?
Is there another flaw in the stock shaft that's a big deal?
 
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Just curious, I've been around here a while, not sure I've ever seen it spoken about.

I'm making a few suspension changes and soon I will need an alignment, so I want to get in all work and parts in before hand, obviously.

The MM shaft is like $211. Not that I think that number is out of line, i'm just curious to why a solid machined spacer isn't as good.
I know they say they use needle bearing u joints for smoothness, but I use a 12:1 agr road race rack and i'd bet the majority of you guys here would think my steering shaft wasn't even connected to anything, yes it's that light and extremely smooth with the stock shaft in place.

By no means am I knocking MM or their pricing, I love their parts, i'd really just like to know why I can't buy a replacement rag joint (which I think do exist), take it to a machine shop friend I have and just have him make me a spacer out of steel or aluminum.

Has it been tried or am I missing something obvious?
Is there another flaw in the stock shaft that's a big deal?

The rag joint does two things: dampens vibration, and flexes for misalignment. The mm unit replaces the rag joint with a u joint and that handles misalignment. A solid disc would not, and would lend itself to binding and early wear due to misalignment.
 
I welded a U joint on to a stock shaft to replace the rag joint and the interwebz told me I would die in a fire and be sent to the seventh circle of hell for all eternity.

And that's only a slight embellishment.
 
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I welded a U joint on to a stock shaft to replace the rag joint and the interwebz told me I would die in a fire and be sent to the seventh circle of hell for all eternity.

And that's only a slight embellishment.

I know I've told you this, but I did the same thing in my 79 back in about 91... Before there was a mm or flaming river part like that... Sold the car to another racer who frequented the strip leaving his hood open, and then they started showing up in the aftermarket. I shoulda got a patent!!:fuss:
 
image.jpeg
Back in teh day... 90 or 91 i think. One of the only photos I have of that car. Dude I sold it to put an aero nose on it and painted it blue. Looked like every other fox on the road after that.
 
I knew it was there to help prevent vibrations, wasn't aware it was also there to prevent bind, that would explain why aftermarket shafts exist, thanks.
 
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