924Board.org

markmazour

Well I have finally gotten around to installing new Weltmesiter control arm bushings on my 1982 924. http://www.weltmeister.com/ProductDetails.aspx?productID=402 PB-1019 (along with new ball joints and wheel bearings)

After loosely assembling everything I got out my Haynes manual to check the torques. As I began torquing the front pivot bolt it dawned on as I saw the bushings begin to bulge that I was not going to get to the recommended 50 ft-lbs.

So my question here is how tight should these pivot bolts be with the Weltmeister bushings? Is there an alternate tightening method?

In retrospect I am beginning to wonder if i should have gone with the OEM bushings that have the steel sleeve.
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Mark
1982 Porsche 924 Indiana Red Metallic SOLD
2001 BMW 325i Silver SOLD
2011 BMW335is Space Gray 6mt

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

Those Weltie bushings suck grande for the reason you have identified.

Search online for ProThane bushngs for Golf/Rabbit Mark I. Steel sleeve and all. . .should be sub $30.
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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

Part # is 22-201
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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

fiat22turbo · Joined: 18 Jan 2006 Posts: 4040 Location: Portland, OR

Plus, the red is just stylish

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Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

markmazour

I will use those the next time around but for now I'd like to use what I have already paid for. You are right the red bushings look pretty sweet in there. I am half tempted to have the calipers powder coated red.

Has anybody used these?

I suppose I could machine some sleeves using the dimensions from the old ones and then bore out

the Welts to accept the sleeve.

This brings a question to mind just for discussion purposes.
What part of this assembly should rotate and what should be fixed?
There exists three scenarios:
1. In the OEM version, a bolt, a steel sleeve molded into a rubber bushing, a steel control arm

and the steel cross member. In this case as the bolt is torqued to 50 ft-lbs the crossmember

flexes inward against the steel sleeve pinching it thus creating a fixed assembly. In which case

we have a scenario where the rubber bushing flexes around the steel sleeve, or the control arm

rotates around the rubber bushing.

2. A bolt, a sleeve, a poly bushing, a steel control arm and the steel cross member. Here again

as the bolt is torqued to 50 ft-lbs the crossmember flexes inward against the steel sleeve

pinching it thus creating a fixed assembly. In which case we have a scenario where the bushing

rotates around the steel sleeve.

3. A bolt, a poly bushing, a steel control arm and the steel cross member. In this case the bolt

cannot be torqued to 50 ft-lbs. It, in my best guess, should be tightened to the point that the

crossmember flexes inward and makes contact with the bushing. In which case we have a scenario

where the bushing rotates around the bolt or depending upon the fit the bolt in the bushing the

bolt rotates in the holes of the crossmember.

Or...am I missing the whole point here? Should the steel crossmember not flex at all under the

force of the 50 ft-lb torque. And should the fit of the steel sleeve between the torqued cross

member flanges be such that the sleeve rotates freely on the bolt?
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Mark
1982 Porsche 924 Indiana Red Metallic SOLD
2001 BMW 325i Silver SOLD
2011 BMW335is Space Gray 6mt

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

The poly bushings rotate around the sleeve, which is trapped by the squeezing member (heh).

You're gonna machine sleeves, and then machine the Welt bushings just to make them work? To save $25?

Damn.
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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

fiat22turbo · Joined: 18 Jan 2006 Posts: 4040 Location: Portland, OR

Well, this is the 924board.

(goes back to work on the statue of Joe....)
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Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

markmazour · Posted: Wed Apr 06, 2011 12:08 pm Post subject:

I have a background in Engineering and IT, not that IT has anything to do with this. But I have access to very talented tool machinists who are willing to trade machining services for drafting, engineering and IT services. And because of where I work I have access to a wide variety of materials that can be had at scrap rates of cents/lb, so... Anyway I have already spent too much money on the existing bushings to not use sleeved or sleeveless.

Rasta your response regarding the solid member, hehe, does make sense. But I wonder still wonder about the OEM? Any thoughts on that?

Not to be rude but now that we've had suggestions on alternate solutions does any body have an answer to the original question?

Ultimately I believe I will just use them as is and tighten both sides to a random, but equal, distance between the cross member flanges, where the clearance between the bushings and the cross member flanges would be zero. Basically start on one side and while shining a flashlight from behind my line of sight tighten the bolt until I cannot see light between the bushings and the cross member flanges. Measure with calipers and tighten the other side to that dimension.

This car is a Sunday driver/garage queen so I think I will be fine.
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Mark
1982 Porsche 924 Indiana Red Metallic SOLD
2001 BMW 325i Silver SOLD
2011 BMW335is Space Gray 6mt

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

markmazour · Posted: Wed Apr 06, 2011 11:26 pm Post subject:

Rasta: Per FSM? What is FSM? So Porsche relied on the flexibility of the rubber for rotation eh? Interesting.

Has anyone used the Welmesiter bushings that I have? If so, when installing them how tight did you torque the pivot bolts be with the Weltmeister bushings? Was an alternate tightening method?
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Mark
1982 Porsche 924 Indiana Red Metallic SOLD
2001 BMW 325i Silver SOLD
2011 BMW335is Space Gray 6mt

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

FSM = Factory Service Manual.

Ditch the welties, get the prothanes, and be done with it!
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erstwhile owner of just about every 924 variant ever made

jazz guy · Joined: 26 Nov 2002 Posts: 434 Location: Colorado

markmazour · Posted: Thu Apr 07, 2011 12:46 am Post subject:

And Mr. Rasta's advice is appreciated, seriously and will be followed. Either by purchasing the recommended parts or machining sleeves and boring the existing bushings.

I am only asking the original question now out of curiosity, what can I say I am an odd sort when something gets in my head....

I sent Weltmesiter an email I'll let you know their response if I receive one.
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Mark
1982 Porsche 924 Indiana Red Metallic SOLD
2001 BMW 325i Silver SOLD
2011 BMW335is Space Gray 6mt

jazz guy · Joined: 26 Nov 2002 Posts: 434 Location: Colorado