Suspension spherical or urethane upper control arm differential side bushings?

colehelm · Jul 3, 2024

wanting to redo my rear suspension as i added some more power to my car, my plans so far are extreme duty non adjustable mm lowers, then mm uppers aswell, but now im stuck on what axle end bushings do i get for the uppers? this will be a nice day city driver, but i also plan on taking it to the strip occasionally, and the occasional race at the red light, should i go with spherical bushings on the differential end of my uppers, the max motorsports urethane replacements they sell (Part # E4SZ-5A) or is there something else i should consider instead? im going to be reinforcing my torqueboxes aswell.

limp · Jul 3, 2024

Maximum Motorsport has a recommendation for rear upper control arms.... I suggest you go to the MM site and read it..... You might think differently on what your plans are...

Mustang5L5 · Jul 4, 2024

I would not do spherical upper bushings on a street car.

With the MM lowers, MM recommends stock rubber arms and bushings, otherwise you will have way too much bind in the axle.

I would do these

https://www.summitracing.com/parts/fms-m-4050-b

Bullitt347 · Jul 4, 2024

Mustang5L5 said:
I would not do spherical upper bushings on a street car.

With the MM lowers, MM recommends stock rubber arms and bushings, otherwise you will have way too much bind in the axle.

I would do these

https://www.summitracing.com/parts/fms-m-4050-b

Those stock bushings and arms are the definition of bind.
Remove one end or the other and try to articulate the arm through a range of motion. You pretty much can't because you are pushing/pulling against the bushing that does not rotate. That is why you don't tighten the control arm bolts until the vehicle is at ride height, otherwise you put the bushings in a bind.
For a stock or lightly modified vehicle, they work fine, because they eliminate NVH which the typical driver wants.
Any bushing that eliminates bind is going to compromise NVH to some extent, some more than others. The amount of NVH that a person is willing to live with will dictate their suspension choices.
A full articulating suspension by necessity will have the most NVH but at the same time offer the best performance.

colehelm · Jul 4, 2024

Bullitt347 said:
Those stock bushings and arms are the definition of bind.
Remove one end or the other and try to articulate the arm through a range of motion. You pretty much can't because you are pushing/pulling against the bushing that does not rotate. That is why you don't tighten the control arm bolts until the vehicle is at ride height, otherwise you put the bushings in a bind.
For a stock or lightly modified vehicle, they work fine, because they eliminate NVH which the typical driver wants.
Any bushing that eliminates bind is going to compromise NVH to some extent, some more than others. The amount of NVH that a person is willing to live with will dictate their suspension choices.
A full articulating suspension by necessity will have the most NVH but at the same time offer the best performance.

nvh isnt a huge deal for me, im driving the car to have fun, not be comfortable, i dont even have ac, if that tells you anything, i just want good performance that doesnt hinder street driving and cornering too badly

2000xp8 · Jul 5, 2024

Look, if you are worried about driving that hard and having a no bind situation, just do the panhard bar and torque arm and dump the uppers, period.
It's easily the superior setup for spirited street driving.
If not just run the rubber bushings and motorsport style uppers.

I'd be curious on how long the sphericals really last on the street. The NVH is one thing, rattling and squeaking is another.
As fair as i know, i don't remember seeing a set designed to retain the grease like a tie rod.

AeroCoupe · Jul 5, 2024

Been running Maximum Motorsports (spherical on both ends) LCA’s for about 20 years on the Coupe and zero issues.

Extreme-Duty Mustang Rear Lower Control Arms, 1979-1998

Ran them with the stock uppers for 5 years then added the panhard bar and torque arm. Have not serviced them other than inspecting them a couple of times for wear.

Cannot comment on UCA’s with sphericals on a Mustang but I do have them on the T-Bird. Hardly any miles on those as that car doesn’t get driven much.

Mustang5L5 · Jul 5, 2024

I’m answering this on the basis he states he wanted a nice city street cruiser.

I’d stick with the rubber bushings just for the sake of NVH. Just my opinion of course.

2000xp8 · Jul 5, 2024

AeroCoupe said:
Been running Maximum Motorsports (spherical on both ends) LCA’s for about 20 years on the Coupe and zero issues.

Extreme-Duty Mustang Rear Lower Control Arms, 1979-1998

Ran them with the stock uppers for 5 years then added the panhard bar and torque arm. Have not serviced them other than inspecting them a couple of times for wear.

Cannot comment on UCA’s with sphericals on a Mustang but I do have them on the T-Bird. Hardly any miles on those as that car doesn’t get driven much.

I run those too, but i didn't think that was the kind of spherical we were speaking of. I don't remember when i installed them, the spherical end wasn't all metal on metal were they? I could have sworn it was like a urethane ball on a shaft.

In this case, i figured they were talking about these:

https://lmr.com/item/JM-23910/mustang-spherical-upper-axle-bushings-j-m-79-04?utm_source=bing&utm_medium=cpc&utm_campaign=PLA&scid=scbplpJM-23910&sc_intid=JM-23910&msclkid=d46ec80af2781a057f68ae82bbcfe43f&utm_term=4585307093518325&utm_content=40-49.99

AeroCoupe · Jul 5, 2024

The MM extreme units are technically spherical but PTFE lined.

Large PTFE-lined spherical bearings at each end allows freedom of motion for both pivoting and angularity, preventing unwanted deflectionwhile still allowing the angularity required for proper articulation.

Mustang5L5 · Jul 6, 2024

2000xp8 said:
I run those too, but i didn't think that was the kind of spherical we were speaking of. I don't remember when i installed them, the spherical end wasn't all metal on metal were they? I could have sworn it was like a urethane ball on a shaft.

In this case, i figured they were talking about these:

https://lmr.com/item/JM-23910/mustang-spherical-upper-axle-bushings-j-m-79-04?utm_source=bing&utm_medium=cpc&utm_campaign=PLA&scid=scbplpJM-23910&sc_intid=JM-23910&msclkid=d46ec80af2781a057f68ae82bbcfe43f&utm_term=4585307093518325&utm_content=40-49.99

That’s actually what I was referring to as well since he specifically asked about the axle bushings

I have the MM arms with poly on one end and spherical on the other.

manicmechanic007 · Jul 6, 2024

I'd run the stock rubber ones and replace them once in a while

Suspension spherical or urethane upper control arm differential side bushings?

colehelm

Member

limp

wrap a little cheese around it and its a done

Mustang5L5

That is…until I whipped out my Bissell

Bullitt347

I have been doing it wrong this whole time

colehelm

Member

2000xp8

AeroCoupe

lube between the nut and the face. I know my lubes

Mustang5L5

That is…until I whipped out my Bissell

2000xp8

AeroCoupe

lube between the nut and the face. I know my lubes

Mustang5L5

That is…until I whipped out my Bissell

manicmechanic007

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Suspension spherical or urethane upper control arm differential side bushings?

Member

wrap a little cheese around it and its a done

That is…until I whipped out my Bissell

I have been doing it wrong this whole time

Member

lube between the nut and the face. I know my lubes

That is…until I whipped out my Bissell

lube between the nut and the face. I know my lubes

That is…until I whipped out my Bissell

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