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79 Midget bushing replacement

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dave99

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Hi all, I have started rebuilding the front end of a 79 Midget 1500 I picked up in CA. All the rubber needs replaced so I am beginning from the front to the back.

The lower control arm inner bushes were still original and totally shot. I have replaced them with Poly bushes but have found no info on what the torque should be. The original rubber ones had a steel sleeve and the poly's don't, so I am not sure how 'tight' to set the new ones.

Thanks for any info.

Dave
 
I think I may have messed up. I installed the front poly bushing set from Moss Motors. Was I supposed to reuse the steel sleeves from the old rubber ones that I removed? Has anyone installed the Moss poly bushings?

Thanks
Dave
 
The original bushings had the sleeve bonded to the rubber. The sleeve was intended to be clamped between parts & the rubber to flex/twist as the parts rotated. The sleeve must be clamped tight before the rubber is completely compressed. There was no actual sliding movement between sleeve & rubber. A rubber torsion spring if you will. If the bushings get old & the sleeve to rubber bond breaks the sleeve is free to rotate in the rubber & squeek. This is the reason that suspension with the rubber bushings are supposed to be normalized before the sleeve is final clamped. To prevent over rotation which breaks the rubber to sleeve bond.

Since poly bushings do not flex very much, the bushing now turns on the pivot bolt like a bearing. Some people like this "changed" design, some don't. They do tend to squeek & wear if not frequently lubed, & there is no way to easily lube the poly bushing. Ok on a race car that has the suspension frequently disassembled & lubed. A nuisance on a street car.

If yoy reused the sleeve with the poly bushing, you would be back to a metal to poly bearing with no lube. same as a bonded rubber bushing that has the original bond broken. The pivot bolt on the poly bushing without sleeve must not be clamped so tightly that it binds. A slightly stiffer rubber with a bonded sleeve would stiffen things up without the other problems.

I personally prefer the original flex bushing as there is no actual rotation between the moving parts, just the rubber flex, & they do not wear or need lubrication. This original design provides many miles of smooth squeek free operation.

I guess the choice is street car or race car with it's increased maintenance & lubrication requirements.
D
 
I had the same question years ago. Eventually, I found (from the guys at Moss) that the poly bushings should be "just tight", which I took to be about 25 ft. lbs. It seems to be working for me.
Removing the rubber sleeve bushings can be a devil and I have often simply sawed the bolts off and replaced them too...they seem to rust to the sleel sleeves in the bushing (replacing old poly bushings is much easier, since they never get stuck).
I would agree that the poly bushings used on the street should be harsher in theory, but in practice, I have not found that to be the case. Maybe Midgets are so harsh anyway, it doesn't make a difference.....
Do not use the steel sleeves in poly bushings....the poly should ride directly on the pivot bolt.
Also, I would advise that you pose your future questions about your car at the "Spridgets" section of BCF, since this "MG" forum is really intended for "big" MGs.
Also, if you use the Search Function and look up "bushings" (limit to the Spridgets section), you'll find lots of info on this subject.
G'luck!
 
We have a search function??? How does that work, please? /ubbthreads/images/graemlins/computer.gif
 
Angus, at the top of the page, between the "Forums" and "Active Topics" buttons, is one marked "Search". Hit it, and it's pretty well self explanatory after that.
Jeff
 
Thanks very much. I feel better now because I tossed the old bushings. I did search this group for bushings, not aware that Spridgets is where I belong! I'm outta here;)

Dave
 
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