Rear arms polyurethane bushings

[inquirer]

I am about to install new shock absorbers to my Lancer in the near future and I was thinking of also testing poly bushes.

Will replacing the small bushings of the rear axle:

• no. 121880 of the camber arms
• no. 121881 of the toe arms
• no. 121882 of the lower arms

make any difference in the feeling and handling of the car, without changing the big bushing of the trailing arms which by the way is not available by Stronglflex.

Furthermore would there be any difference between 80 Sha and 90 Sha for these small bushings?

 

[IndyIan]

That looks a lot like the rear suspension on the Focus wagon which usually needs none of the rubber bushings replaced, ever.
TBH I wouldn't bother replacing anything in the back with polyurethane unless you are competing with the car and maybe not even then.
I had a lot of fun autocrossing with my Focus wagon, and just a simple slotting of the front strut upper mounts gave some nice camber and caster gains for free while maintaining factory NVH. Improved front grip a bit and gave a bit more feedback in the steering.

 

[Kalle.J]

Could make you feel a difference, doubt it will make a significant difference other then in the wallet
Meyle HD in the front trailing arm. And some sticky tyres is what I would do.

 

[Rust_Belt_Pete]

replace ALL bushings with poly or stick with OEM rubber.

 

[inquirer]

That looks a lot like the rear suspension on the Focus wagon which usually needs none of the rubber bushings replaced, ever.
TBH I wouldn't bother replacing anything in the back with polyurethane unless you are competing with the car and maybe not even then.
I had a lot of fun autocrossing with my Focus wagon, and just a simple slotting of the front strut upper mounts gave some nice camber and caster gains for free while maintaining factory NVH. Improved front grip a bit and gave a bit more feedback in the steering.

The Lancer's bushing are still good too. At least no one has cracked, I guess though that ageing and miles may have altered the rubber properties somewhat.

I would like to change them as an experiment, but I'm wondering if changing these small bushings of the smaller arms will have any felt effect.

For some car's like the Audi A3 Strongflex uses the stiffer bushings in both the sport kit and standard kit for the rear axle of the car for the smaller bushes and the only one the change is the one of the trailing arm.

I wonder if I should follow a similar approach for the Lancer. Strongflex though uses all reds for their standard kit and all yellows for their sport kit for the Lancer, it doesn't mix colors as it does for the Audi A3 and maybe there is a reason for that.

Could make you feel a difference, doubt it will make a significant difference other then in the wallet
Meyle HD in the front trailing arm. And some sticky tyres is what I would do.

Are Meyle HD bushings considered upgrade parts? Do they use hardened rubber?

replace ALL bushings with poly or stick with OEM rubber.

That's my plan. Stronglflex does not offer a bushing for the rear trailing arms though. Also read my question I wrote above about mixing red and yellow bushings in the rear as Strongflex does for the Audi.

 

[KevinMalone]

I only use polyurethane on bushings that don't see a lot of deflection, or only deflect in one dimension

 

[inquirer]

I only use polyurethane on bushings that don't see a lot of deflection, or only deflect in one dimension

What's your judgement about these specific arms I mentioned (rear camber, toe and lower arm)? Would these small bushings have any felt effect performance wise and comfort wise or only the big trailing arm bushings would?

 

[oldcodger]

Don't the poly bushings need to be lubricated regularly or they will squeak?

 

[inquirer]

Don't the poly bushings need to be lubricated regularly or they will squeak?

I think that depends. I have read many reviews by people who have installed poly bushings and not everyone had squeaking or NVH issues.

I guess at some point they will need regreasing, but that's not something that will necessarily will happen soon. I guess also the climate and the conditions where a car drives play a role too.

 

[Exhaustgases]

I never liked poly bushings, can ride and sound like a 1930's truck.

 

[IndyIan]

I think that depends. I have read many reviews by people who have installed poly bushings and not everyone had squeaking or NVH issues.

I guess at some point they will need regreasing, but that's not something that will necessarily will happen soon. I guess also the climate and the conditions where a car drives play a role too.

My only experience with poly is in the torque engine mount for my Focus and it had very little rotational forces on the poly and it still wore in a few years, so I don't really understand how they could possibly work in suspension in the long term in a daily driver?
But maybe it works somehow? My car gets a few months of sandy wet roads which would seem to wear poly fast if it doesn't work like a rubber bushing with internal flex so no chance for sand to enter the rotational area and wear the bushing like it would with poly?

 

[alcyon]

My advice, replace to poly if you are unable to get OEM rubbers. If you go for poly, go for the softer shore.
And when you get the bushings, measure the inner tube inner and outer diameter. Get some Stainless steel shims 0.5 and 1mm thick, inner diameter must be same, and outer diameter slightly smaller like 1 to 2mm smaller.
When assembling the poly, use a few shims to make sure the inner shaft is longer than the bushings, to prevent the poly bushing faces from binding on the subframe.

 

[inquirer]

My only experience with poly is in the torque engine mount for my Focus and it had very little rotational forces on the poly and it still wore in a few years, so I don't really understand how they could possibly work in suspension in the long term in a daily driver?
But maybe it works somehow? My car gets a few months of sandy wet roads which would seem to wear poly fast if it doesn't work like a rubber bushing with internal flex so no chance for sand to enter the rotational area and wear the bushing like it would with poly?

There are cars that have OE rubber bushings that fail relatively soon and others that have bushings that last "forever". I guess that has to do with the quality of the rubber they use and probably the same is true for poly bushings. They also come in different qualities.

Undoubtedly the driving environment plays a role too (also for rubber bushings, but I guess they are less affected by environmental conditions).

My advice, replace to poly if you are unable to get OEM rubbers. If you go for poly, go for the softer shore.
And when you get the bushings, measure the inner tube inner and outer diameter. Get some Stainless steel shims 0.5 and 1mm thick, inner diameter must be same, and outer diameter slightly smaller like 1 to 2mm smaller.
When assembling the poly, use a few shims to make sure the inner shaft is longer than the bushings, to prevent the poly bushing faces from binding on the subframe.

That's my intention to go for the softer ones. I have my doubts though, because as I mentioned for some cars Strongflex in both their standard and sport kits uses only the stiff bushings for the smaller ones (mostly only for the rear axle, rarely they do it for front arms too) and they only difference of the kits has to do with the big bushings of the trailing arms.

For the Lancer though for which they don't offer a trailing arms bushing upgrade, they don't mix colors. They use only soft or only stiff bushings if you buy them as a kit.

Maybe after all they have tested their bushings on the cars they are intended to be installed on and have concluded that these combinations work better for the specific cars. I hope that's the case.

Thanks about mentioning the use of shims. I have read a lot regarding bushings and its the first time I hear about using shims. I definitely look into it.

 

[alcyon]

There are cars that have OE rubber bushings that fail relatively soon and others that have bushings that last "forever". I guess that has to do with the quality of the rubber they use and probably the same is true for poly bushings. They also come in different qualities.

Undoubtedly the driving environment plays a role too (also for rubber bushings, but I guess they are less affected by environmental conditions).



That's my intention to go for the softer ones. I have my doubts though, because as I mentioned for some cars Strongflex in both their standard and sport kits uses only the stiff bushings for the smaller ones (mostly only for the rear axle, rarely they do it for front arms too) and they only difference of the kits has to do with the big bushings of the trailing arms.

For the Lancer though for which they don't offer a trailing arms bushing upgrade, they don't mix colors. They use only soft or only stiff bushings if you buy them as a kit.

Maybe after all they have tested their bushings on the cars they are intended to be installed on and have concluded that these combinations work better for the specific cars. I hope that's the case.

Thanks about mentioning the use of shims. I have read a lot regarding bushings and its the first time I hear about using shims. I definitely look into it.

I used Super Pro poly bushings, they have knurling inside to keep grease in, but they also have issues with the inner tube being shorter than the bushing. I noticed on a lot of videos on poly U ushings squeaking, its always the faces of the bushings get stuck on the subframe faces, and because of that, they stick to the subframe, and the arm moves while the bsuhong stays, thats what is causing the squeaks.



I did this more than 8 months ago, and my front arms are still silent. Yes the arms will move forwards and backwards by a tiny amount while you drive, the movement will ensure while one of the bushing faces will contact the subframe surface, the other wont, so even if it binds for a while, having that little extra space will let the arms move away from the binding side, hence eliminating squeaks.

 

[Cujet]

I've been using poly bushings for 40 years. One universal truth, they do fail, and generally sooner than I'd like. Either by wear or through deterioration and crumbling into dusty goo. Use the wrong grease and they are certain to come apart.

In general I like the way sports cars feel with really tight flex-free but compliant suspension, including the proper use of poly bushings. However, it is not likely I will use them again. A better choice might be high durometer rubber. And/or rubber with lower possible deflection.

It is often a lot of work to install them. And if not competitively racing, to what end?

 

[KevinMalone]

What's your judgement about these specific arms I mentioned (rear camber, toe and lower arm)? Would these small bushings have any felt effect performance wise and comfort wise or only the big trailing arm bushings would?

Every car is different. I generally don't think they're worth the hassle and upkeep on a street car. If you do go with them, Mike Kojima (suspension guru of Moto IQ) shared a trick years ago to keep them quiet: wrap everything in teflon tape!

 

[inquirer]

@alcyon
I will certainly check the inner tube's length. I'm not sure if that's the only source of squeaking, but even if it isn't, eliminating one cause is still important.

@Cujet
Using the wrong grease obviously will damage poly bushings. But rubber is susceptible to damage by chemical products too. For example oil leaks destroy rubber bushings.
You are right, hardened rubber would be a better solution (at least for those who don't plan to use extremely hard bushings), but I don't think there are many options for this kind of bushings in the market. Poly bushings have a wider range by far compared to hardened rubber ones.
As for what's the purpose of using them on a road car, for me is experimenting. I have already upgraded the car's dampers and both the front and rear sway bars, I also have installed stiffer rear springs and I want to see what gains can the poly bushings offer, performance wise as well as regarding the feeling of the car and the road feedback.

@KevinMalone
Yes, I have heard about using teflon tape for the sway bar bushings. I haven't tried that myself though. The upgrade sway bars I have on my car came with hard bushings which were described as "self lubricating". I never heard any noise from them.
I don't know how long would teflon tape last though. Would it be effective longer than just greasing the bushings? Anyway, at some point it will fail and it should be replaced.
By the way, @alcyon's advice about the inner tube's length is something I plan to take into account too.

 

[Rust_Belt_Pete]

Don't forget that forces travel in a wave outward in a car. You can add poly bushings in the ear and it wil when worse. You can yeak something up front and add different bushings up front and suddenly it's night and day.
Just sit down draw it out and think what you want absorbed and which way do you want the forces to go.

 

[inquirer]

Don't forget that forces travel in a wave outward in a car. You can add poly bushings in the ear and it wil when worse. You can yeak something up front and add different bushings up front and suddenly it's night and day.
Just sit down draw it out and think what you want absorbed and which way do you want the forces to go.

As you had earlier suggested, I plan to change all the bushings, front and rear.

As I have already written, I'm not 100% sure though if I should use the stiffer ones for the small bushings of the rear axle.

Strongflex sells their bushings as a kit too, offering a standard and a sport version. For the Mitsubishi the standard version comes with only the softer ones and the sport version with only the stiffer ones.
For other cars though Strongflex uses the stiffer bushings in both kits for the small bushes of the rear axle and what differentiates the standard and the sport kit is that for the first one the big trail arm bushing is the soft one and for the later the stiff one.

I was wondering if I should too mix the colors, using the stiffer bushings for the small rear arms, but in the end maybe there is a reason Strongflex follows that approach for some cars and not for every single vehicle.

 

[Cujet]

I'd go with all one brand and what every combo they suggest. The brand likely to last the longest is my choice

I mentioned I probably would not do it now, mostly because I don't need any extra performance from my F-Type. Despite being a performance driver and HP junkie, I'm older, so I don't want to spend a week changing bushings.

But I do like the feel of a car with a well configured set of poly bushings. Tight and responsive.