Rear Urethane Bushings?

[heeroyuy01195]

Hey everyone,

sorry if this has already been covered but I can't seem to find anything on this within the forum and on google. Anyone ever make urethane bushings for the rear torsion beam? Only thing I've found are these "Siberian Bushing" urethane bushings on Amazon. Saw mention of them on here in another thread but I haven't seen anything about anyone trying them out. Anyone have any info in regards to the Siberian Bushings or any leads on other rear urethane bushings? Have White Line bushings for the front, wouldn't mind having the rear match so to speak.

-Nick.

[tmontague]

Never heard about those "Siberian bushings" however afaik there are no poly bushing for the torion beam for a Yaris.

That said I'll be making my own using a product meant to be poured into the own bushings to make them solid poly bushings.

It's fairly cheap and I've just finished doing my torque mount (dogbone moint) and it was very easy to use.

It has a 7 day cure time for 100% strength so I plan on ordering the torsion beam bushings then filling them and after a week or so dropping the beam and pressing them in. They are very strong after 48 he's and could probably be installed then, but I'd rather they be fully cured.

I drilled/dremmeled out much of the oem rubber on my torque mount and then drilled grooves into the left over rubber, sanded with a wire wheel and then cleaned with rubbing alcohol before I poured the polyn. This gives it something to grab into so the poly doesn't start to slip out when under torque.

It makes it easier to do if you have a spare bushing or engine mount to do it on, but if your car can be down for a few days then it isnt necessary.

I'll post pics about it when I do my trans mount in a couple week as I'll be pulling the one from the car for a few days to do it

Here's the link to the producthttp://www.energysuspensionparts.com/diymmi

[heeroyuy01195]

Thanks for the tip, pics would definitely be appreciated! I think I might pick up the siberian bushings just to see if they really do fit. At $30 with free shipping, I figure it's worth investigating.

[tmontague]

I just google the siberian bushings, seem legit, although not sure how they compare to the like of Whiteline and what not.

It would actually be cheaper for me to just install the Siberian bushing than to buy stock bushings and then buy the poly to fill them.

Can you post up how stiff they are compared to oem as well as their fitment? Also where did you buy them?

EDIT* just read that you saw them on Amazon. They are rated at 65A harndness which should be pretty good, my enigne mounts I poured are 80A and are pretty darn solid with little to no movement so 65A is probably a good balance for a DD.

I can't find anywhere in the Amazon description if you get both the left and right bushing for the $35 or just one. If that's the price for both then it's a good price.

[heeroyuy01195]

I was on the siberian website last night and looked up my hatch, got the part number from their catalog and searched it in google. Amazon seems to carry them with prime shipping so that's a plus. In the process of getting the chassis and suspension overhauled and back to how it was 11 years ago (Wow! Now that I've said that out loud, can't believe I've had the little bugger for so long!). Plan is to swap in a 2ZR once I have a solid foundation again.

[tmontague]

do you mind posting that part # on here? The parts will be the same for the sedan or hatch so it'll help anyone else as well

[heeroyuy01195]

https://www.amazon.com/dp/B00VPPLJSQ/ref=wl_it_dp_o_pC_S_ttl?_encoding=UTF8&colid=1H7UVISFF4OO3&coliid=IR3AL99U6QIE9

that's the amazon link; PN: 1-06-1793

[malibuguy]

Someone proved that poly rear bushings induce too much bind and the stock bushings provided more consistent times


I recently urethaned my engine side mount. Going to throw a quick video together soon about it. Urethane is super easy to work with.

[heeroyuy01195]

Any chance you remember the the article or thread about the rear poly bushings binding? Wouldn't mind giving it a read to see what all was going on there.

[tmontague]

I second that, would like to read that as well.

The siberian bushings like fairly conservative in terms of stiffness and they still have a fair amount of voids in them so I can't imagine they would be worse than oem.

Now a solid poly mount I could see being a potential issue

[malibuguy]

It was YEARS ago when i read it unfortunately.

Considering the design of the rear axle id stick with stock or balls

[heeroyuy01195]

Haven't looked under the rear of my car in a while so I'm can't remember how the torsion beam back there is assembled. I would have thought that reducing lateral movement would improve the handling. Unless the urethane used was too stiff which would lead to a loss of traction. But then again, that can be corrected with correct spring rate and damping settings which should result in better handling due to the reduced "sway" under load. I'll see if I can do some simulations in SolidWorks when I get home.

[tmontague]

it's your typical "H" torsion beam type axle. Only points of connection to the frame is the 2 front bushing points and then in the rad of the torsion beam where the rear shocks (and springs) attach to.

The shocks/ spring control the rate of movement of the torsion beam but they pivot on the bushings. You are correct about soft rubber ones would lead to more "wiggle" of the whole torsion beam assembly on cornering over bumps (which I have experiences on on curvy on ramps)

What I am not clear about is - does the rotation of the torsion beams depend upon the flexion of the bushing, or does it rotate on the bolts and inner metal bushing sleeve?

If it's option number 2 then a stiffer bushing shouldn't affect the normal movement of the torsion beam, but it would correct the incorrect side to side movement.

If it's option number one then the stiffer bushing would stiffen the rear end in its normal movement, however I couldn't imagine the bushing works like this because it would put a ton of force and torque on the oem bushing and prematurely tear it