Rubber vs poly bushing (2 Viewers)

[Zjohnsonua]

Did a search for "rubber bushings" and didn't return much for the 60s.

So here goes.. I'm fighting some increasingly bad death wobble that hits around 50mph and is especially excited by slight to moderate steering inputs (pucker factor of 10 when it hits on a corner in a rainstorm). The only bits I haven't replaced/adjusted are springs and bushings. I got under the truck and started poking around at the various bushings and they're all rubber. However, none seem to be cracking out or exhibiting any other signs of disrepair. I've got some poly bushings here to pop in, but I'm curious what driveability changes were seen by those that did the swap.

 

[cps432]

They'll be stiffer than rubber. If the bushings you have now are original I doubt you'll just be popping some new ones in there. That's what I thought last weekend. I'm still trying to get pins out of old rubber and have decided to just cut everything off and install a new suspension package.

 

[OSS]

Rubber spring bushings give a nicer ride and are silent. Poly bushings are harder and will squeek eventually if they aren't used with greasable pins. I've had thrashed rubber bushings before but zero wobble. I doubt replacing bushings will help that.

The wobbling can often be caused by out of true tires & wheels. That's what I'd check first. There's an ocillation going on that increases with speed until it shakes the whole car. Make sure the tie rod ends and wheel bearings are tight.

 

[Seth S]

Poly bushings will be stiffer than the stock rubber. The poly bushings are often easier to put in because they are usually a split design with two halves that have a center metal bolt sleeve running down the middle. The drawback to poly bushings is that they dont last that long...maybe 3-5 years depending on how they are used and what environment they are in. The stock rubber bushings are often a real pain in the ass to get the old ones out and the new ones in and they will be a little softer than poly....but they will last for another 20-30 years.

I've run poly alternator bushings, shock bushings, suspension bushings and they all wear out after 3-5 years on different vehicles.

 

[lcwizard]

age old debate. I prefer poly but I change the bushings before they're gone. Rubber , if left too long will glue themselves to the pins and
frame tube. I honestly don't know how someone could ever set up a scientific study on the matter. There's good rubber and bad rubber and
there's good poly and bad poly. If you've ever bought a motor mount made in India you'll know how bad rubber can be

 

[g-man]

I put poly bushing in my spring eyes and spring shackles. Rode a little better. But shortly after I noticed one side was sagging in the rear. I replace my suspension with an OME suspension. The ride was MUCH better after replacing the entire suspension. I suggest waiting and replacing it all a once.

As mentioned getting the old bushings out takes some effort. I ended up burning the old ones with a hand held map gas torch. Even then it takes a while to burn the old ones until they let loose of the pin. Cutting the pins isn't a bad idea because there is a good chance the pins are rusty and pitted and need replacing. If you put new bushings on rusty pitted pins they will eat up the new bushings. Pins are not available but shackles w/pins are available from Toyota.

I can't imagine worn bushings causing a "death wobble". Put your truck on a lift and spin your wheels. See if there is play from side to side or up and down. Maybe the large 54mm hub nut came loose? Have you done a knuckle rebuild?

 

[Seth S]

for the wobble you should check your tire balance, shock condition, and possibly your front wheel bearings.

 

[Zjohnsonua]

The truck got lots of attention when I first put it on the road. New rod ends, knuckle rebuild, stabilizer, and shocks all around. Tires are used but don't show an obvious irrugularity.

I'll swap the rears to the front and see how she goes.

 

[cps432]

Yeah check everything else first. You don't want to deal with this and have to wait in replacement suspension parts while the truck on stands. Not the most fun I've had with this truck.

 

[Zjohnsonua]

Just got the 1st bout of full-on, unabashed death wobble... lovely. Got back to the office and noticed that the passenger side tire is sticking out of the wheel well farther than the driver side by half an inch or so.

Now, I realize that leaf springs dont hold center as well as track bars do, but, c'mon! This seems outside of what is reasonable. Or no?

Passenger side

• Zjohnsonua
• Sep 10, 2018

Drivers side

• Zjohnsonua
• Sep 10, 2018

 

[cps432]

That pin that I showed in the pics above was bound up because the leaf springs are sitting at an angle. My rear shackles are bent and completely rust pitted. If the bushings are toast the axle can wander. I'm not sure if it's enough to cause death wobble but your tires probably shouldn't be protruding like that.

 

[Zjohnsonua]

Now that the DW has shown itself I'll say that the tires may be exciting the system, but they're playing second fiddle to the real problem.

Tonight I'll commence the battle to disassemble the front suspension and determine what went wrong....

 

[Zjohnsonua]

Whoa! Was not expecting to find a broken pin.

I went to back the nut off to check the pin and the thing just kept spinning. Bad parts, PO overtorqued... who knows. I'll be replacing all 4 pins and the u-bolts...

 

[cps432]

Glad you found it while you're OUT of the drivers seat... are they rusted and pitted?

 

[Zjohnsonua]

Not at all. They looked reasonably new and are greasable. The springs and shackles got replaced some time relatively recently - still have their zinc coatings. I'm betting it failed at the grease hole mid-length. I wonder how often folks see this kind of failure on the greasable pins?

 

[cps432]

Not at all. They looked reasonably new and are greasable. The springs and shackles got replaced some time relatively recently - still have their zinc coatings. I'm betting it failed at the grease hole mid-length. I wonder how often folks see this kind of failure on the breakable pins?

That's a good question.

 

[DevonBen60]

Used rubber bushing from Toyota in my OME set up. They came in 2 halves like the poly bushes supplied with the kit. Not cheap at £10 each x 24 but very happy with them.

 

[cps432]

Rockauto sells acdelco bushings that are made in Japan. They're well made and fit perfectly. I think I paid $25 bucks for all of them.

 

[SteveH]

I didn't have a death wobble, but I have a 45 mph shimmy that was worse in light turns. Turns out to be wheel balance. After just a few miles, 3 of my 4 tires were off by almost an ounce. I have no explanation why, but it sure drove better after a rebalance job.

 

[Spook50]

Did a search for "rubber bushings" and didn't return much for the 60s.

So here goes.. I'm fighting some increasingly bad death wobble that hits around 50mph and is especially excited by slight to moderate steering inputs (pucker factor of 10 when it hits on a corner in a rainstorm). The only bits I haven't replaced/adjusted are springs and bushings. I got under the truck and started poking around at the various bushings and they're all rubber. However, none seem to be cracking out or exhibiting any other signs of disrepair. I've got some poly bushings here to pop in, but I'm curious what driveability changes were seen by those that did the swap.

I highly doubt your suspension bushings are causing your death wobble. If they're worn out, still, go ahead and replace them. I have polygraphite (self lubing) bushings from P-S-T, but it would seem they're not available anymore. Your death wobble symptoms sound very similar to what I was having. Light to no steering input at the 40MPH range was where it was happening for me. In the end it turned out to be the trunnion bearings. A complete steering knuckle rebuild fixed it.