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Discussion Starter #1 (Edited)
Disclaimer: This is not a Honda designed part, it is a off-the-shelf poly bushing with closest to perfect length and diameter to the stock the factory rear trailing arm bushing. Due to the change of stiffness, the poly bushings may or may not change the handling characteristics of the car at the limit, you may or may not encounter "lift off/snap oversteer".

What's the happens if you encounter lift off/snap oversteer? Steer it where you want to go and put your foot in the gas. More info towards the bottom on this post.

This post is to show you what you need to buy and what machining needs to be done to the bushings to make them work for your 00-06 Honda Insight as rear beam axle bushings. I have nothing to sell.

Total cost, $60 for bushings. $4 for grease. $15 for shipping. $40 for machining. Total of $119.

Step 1, buy http://www.ruffstuffspecialties.com/catalog/BUSHDOM.html?gclid=Cj0KEQjw-ezKBRCGwqyK0rHzmvkBEiQAu-_-LKFasxgh_DyNEimWWLfPS3BvShEr_EL2GiBgLvdqY1waAnTQ8P8HAQ with the following dimension: tube size, 2" x .250" Wall DOM, 1/2" Sleeve I.D., NO zerk grease fitting, and over all width of CUSTOM, put 3 5/8" in the custom width box, and select quantity of 2.

15% off coupon!

Use coupon code:
WELCOMEBACK
To instantly save 15%

Step 2, buy poly grease from here . Wheel bearing grease/petroleum base grease/graphite/etc are NOT the correct lubricant to use with poly!!!

Step 3, remove the stock bushings (I took subframe off first, then use a brass hammer and an axle socket to get the stock bushing out) axle socket on stock bushing

Step 4, ask/pay a machinist with a lathe to machine the outer metal sleeve while using the stock bushings as guide. 2 inch diameter is the metal sleeve, stock bushing has a slight taper to it, is about 1.980 to 1.970 in diameter. See stock bushing vs new poly bushing and below link.

Step 5, We used a hydraulic press to press in the metal sleeve to into the subframe and install bushings with grease, then re-install everything else.

Skip to the useful pictures and link.
Machined metal sleeve of the new bushings, pressed in, greased, and installed.


No, I do not machine parts nor do I have any service/parts to offer.




Original post.

Any body interested in poly rear beam axle bushings?

The ONLY replacement right now is thru Honda dealer, and you have to buy the entire rear beam axle, cost near $900.

I sent my rear beam axle bushings to a poly bushings maker and he expressed concern about not being able to get his mold investment back due to possible low sale number due to low volume of the car.

Price range is probably $150-$200 for the set of bushings.

So, if you're interested, now is the time to speak up! Also, I will need an volunteer near Coos Bay , Oregon so the poly bushing maker can put a car on his lift. Please PM me for your contact info!

Thanks!

PS, no I have no financial gain in this, I just want a set for my Insight!






LIFT OFF/SNAP oversteer info

https://en.wikipedia.org/wiki/Lift-off_oversteer
 

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i can take a look on my parts car how they are designed and see about turning something out.
 

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Mold would be a dumb idea. Insights are so rare that CNC would be the best way to do it, or a lathe.
 

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At minimum you'd want to make a prototype set and then test them thoroughly. The standard ones aren't just dumb bushes; they're designed to deflect in cornering to provide appropriate toe changes.
 

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poly bushings would be too stiff and don't require any of that fancy stuff. hence i'm not sure why this company is trying to mimic the way these bushing are designed. if so, polyurethane isn't what they should be using if so.

all i'd need to do is knock out the old bushing, measure the ID and turn out some poly material on the lathe and get a center bushing.

rear steer steer is probably a little bit of overkill anyhow. my other car is rear wheel drive and has a similar system and i hate how mushy it feels when cornering hard.
 

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Deflecting bushes are pretty well a requirement of torsion beam axles. Without them, I'd expect that you'd get quite major rear steer. But as I said, test one set to find out.
 

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If someone can come up with a viable replacement for a decent price, I'm in. My bushings are starting to tear and eventually will need replacing.
 

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Discussion Starter #9 (Edited)
Deflecting bushes are pretty well a requirement of torsion beam axles. Without them, I'd expect that you'd get quite major rear steer. But as I said, test one set to find out.
I doubt "major rear steer" is going to happen with only poly bushing.

I have the same type of rear beam axle with poly bushings and a big rear sway bar on my Dodge GLH and I don't get any oversteer at all.



Trust me, I tried hard to get it to oversteer.


Due to the heat, both bushings on my Insight are done. When the metal sleeve separate from the rubber, I will have a HUGE hazard. Since my Insight is down without those rear beam axle bushings, and there is little interest shown, this project is cancelled. See page 2 for update.
 

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I don't want to be dogmatic in my argument about the Insight when neither of us actually knows, but....

The roll steer of a torsion bar rear axle will actually be reduced with a large rear anti-roll bar, because there will be less roll, that is one wheel extending a spring as the other compresses a spring. This is what causes roll steer in a torsion beam rear axle, as during these movements, one wheel moves forward and one wheel moves backwards.

The propensity to oversteer of a car will increase with greater rear roll stiffness.

The Insight is a car where major rear roll steer can become quite pronounced with changes in ride height, thus I'd also be cautious about rear bush changes.

I am not saying don't do it; I am saying - be careful, especially when you are talking about producing them for general sale.
 

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Discussion Starter #11 (Edited)
Over all length of the Honda bushing is about 92mm / 3.62 inch.
Over all diameter of the Honda bushing is about 50mm / 1.9685 inch.

Bushed DOM Sleeve - RuffStuff Specialties

This looks very promising. They do custom length-cut with two different bolt size.

I have to re-measure the Honda bushing but what this company offer is real close to what we need.
 

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Discussion Starter #12
I bought my parts to my friend who has a more precise caliper and measured my parts. Total of the stock bushings length is 3.645", diameter of where the bushings go into the slevee is 1.990 to 1.970, bolt diameter is .476 inch.

I chatted with a rep from the company, they only do imperial measurement.

So, I order a pair of 3 5/8" length bushings, with 1/2" Sleeve I.D., with zerk grease fitting. Also found a 17% off coupon on their facebook page.

All the parts should be within .030-.010 inch of fitment, making them work should be real easy. :)
 

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Discussion Starter #13 (Edited)
New bushings are here!

Other than needing to machine off the 2 inch diameter metal sleeve to 1.970-1.990, all other aspect of the bushings seem to be perfect. :)
Note, NOT perfect as a Honda design bushings, but as "closest to perfect" off-the-shelf bushings found, length and diameter wise.





 

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New bushings are here!

Other than needing to machine off the 2 inch diameter metal sleeve to 1.970-1.990, all other aspect of the bushings seem to be perfect.






You *do* realise that the original bush is designed to progressively stiffen with lateral force in one direction - that's what the shaped metal achieves? I know from your previous posts that this doesn't seem to interest you but to say that "all other aspects of the bushings seem to be perfect" in simply not true.
 

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You *do* realise that the original bush is designed to progressively stiffen with lateral force in one direction - that's what the shaped metal achieves? I know from your previous posts that this doesn't seem to interest you but to say that "all other aspects of the bushings seem to be perfect" in simply not true.
Agreed 100%. There is a reason the stock bushings are not just giant cylinders.
 

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Discussion Starter #17 (Edited)
Perhaps JulianEdgar and ADDvanced can open their own threads and find a solution they deem acceptable? Your concerns are noted, but beating a dead horse isn't going to help anyone.

DISCLAIMER:

My solution is obviously not a factory Honda designed part, my bushings solution may or may not change the handling characteristics of the car.

However, other companies, Dodge for exampled, made and sold millions of 80's FWD K-car with round/cylinder trailing arm bushings and their cars handle just fine.





People replaced their VW Golf gen II\III stock bushings to the round/cylinder polybushings with no ill effect.

VWVortex.com - POWERFLEX REAR AXLE Bushing DIY





We also have couple of people and made custom sleeve and made the VW GOLF gen II bushings to work with their insights.

1 year later.
http://www.insightcentral.net/forums/modifications-technical-issues/17742-rear-axle-poly-bushes-9.html#post238277

http://www.insightcentral.net/forums/honda-insight-forum-1st-gen-discussion/97306-first-time-insight-owner-build-thread-5.html#post1185994

Excellent how much did all this cost you?
Less than $60 so far.
 

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I am not saying it won't work or will even have negative issues, I am just saying "100% perfect fit if I mill a little off" is... uh... well. I mean. Bullshit?

Again, end result might be fine, I just think your statement was questionable.
 

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Discussion Starter #19
I am not saying it won't work or will even have negative issues, I am just saying "100% perfect fit if I mill a little off" is... uh... well. I mean. Bullshit?

Again, end result might be fine, I just think your statement was questionable.
Added this to the above post.

Note, NOT perfect as a Honda design bushings, but as "closest to perfect" off-the-shelf bushings found, length and diameter wise.
 

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Gentlemen,

If you need any polyurethane parts, let me know.
I can mould a perfect copy if you have an original.

Of course I have to say that this is my business and it will be financially feasible only with some kind of MOQ. I don't have time to work for hobby, even though I would enjoy it.
 
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