Rear Suspension Movement

[CrankyOldMan]

Originally Posted by Viperoni

The only replacement I see working properly is a spherical bearing in place of the rubber bushing.

I'm curious about how you would propose to go about this. Calculating the loads to select an appropriate bearing would be beyond my skills as a Junior in engineering school, and the cost of said bearing that could resist road grit (and possibly salt) would be astronomical compared to a delrin/poly bushing. Not knocking/hating, just curious.

[Viperoni]

Originally Posted by CrankyOldMan

I'm curious about how you would propose to go about this. Calculating the loads to select an appropriate bearing would be beyond my skills as a Junior in engineering school, and the cost of said bearing that could resist road grit (and possibly salt) would be astronomical compared to a delrin/poly bushing. Not knocking/hating, just curious.

I've made some rod-end suspension links that have held up quite well in the past... I make sure I'm at least a few multiples of the maximum g-load that the car would ever really be able to produce (so in a Yaris/Echo, let's say 1.5g) multiplied by the car's weight.
So for a Yaris, figure 2400lbs x 1.5 = 3600lbs, and I'd shoot for at least 10k, ESPECIALLY in the rear axle situation where you'd only have the two bushings supporting all of the load.

Here's an example of some ball joint swivel bearings on McMasterCarr:
http://www.mcmaster.com/#rod-end-bearings/=lkzyc8


Even a small bearing with a 1/2" ID and 1" OD has a 19,875lb rating and costs $7.78.
I'd go bigger than this personally: there's a 1" ID and 1.75" OD bearing with a 82k lb rating that's $20.


On top of that, you'd want to get rod end boots or shields to keep the grit out... there's a few manufacturers for these.

[xnamerxx]

Rod Ends don't like side loads which this axle has quite a bit of, so it doesn't really solve any problems. A rod end would work if you have something that can control lateral movement but you don't need a rod end to do that in the first place.

As for rod ends that can survive salt and such, look at what the dirt track racers run, its usually a good idea as to what works.