Outer Limits 4x4 Board

When i hit 80km/h my 89 runner starts vibrating like crazy but only when power down. any one got any ideas

RunnerMitch wrote:When i hit 80km/h my 89 runner starts vibrating like crazy but only when power down. any one got any ideas

By "power down" do you mean when you back off the accelerator? Sounds like tailshaft unis to me (and/or tailshaft centre bearing if your runner has a 2 piece shaft like a hilux).

Check the ball joints in your steering . I had a couple of cruisers do the same thing , start shuddering between 75 and 80 and wouldn't stop untill you slow back down. Replaced the steering ball joints and they're as good as new.

RAY185 wrote:

RunnerMitch wrote:When i hit 80km/h my 89 runner starts vibrating like crazy but only when power down. any one got any ideas

By "power down" do you mean when you back off the accelerator? Sounds like tailshaft unis to me (and/or tailshaft centre bearing if your runner has a 2 piece shaft like a hilux).

Or the tail shaft bolts might be loose

Is it a Constant Noise or a on off noise/shudder
You been doing any burn outs, Sounds like spidergear Vibration

sorry should have been more clear by power down i mean when i have my foot on the accelerator. Also should of said that the unis are fine as just replaced tailshaft as i blew it the shudder only started afterwards. It is a one piece tailshaft. there is no play in the unis and they have been greased.

hammer down wrote:Check the ball joints in your steering . I had a couple of cruisers do the same thing , start shuddering between 75 and 80 and wouldn't stop untill you slow back down. Replaced the steering ball joints and they're as good as new.

Ball Joints are all near new.

RunnerMitch wrote:sorry should have been more clear by power down i mean when i have my foot on the accelerator. Also should of said that the unis are fine as just replaced tailshaft as i blew it the shudder only started afterwards. It is a one piece tailshaft. there is no play in the unis and they have been greased.

bent shaft? out of balance maybe

Hmmm, I've got a 4runner and have just replaced the shaft as the uni's and slip were buggered. I did the shaft myself as I work for Hardy spicer, and am actually having balancing problems with it. Funnily enough, it sounds almost exactly like the same problem you're having... that being, at around 80 kph when backing off there is a vibration. Its just like a resonance in the shaft or something like that, I'll try to rebalance it next week and let you know if I find anything that might help you.

Just out of interest, was your tailshaft rebuilt using standard toyota parts or aftermarket parts? I used aftermarket as thats what we carry at work, just seeing if there might be an issue with one of the parts...

Did you both make sure to put the shaft in "phase" when you put it back together? ie transfer end and diff end flanges aligned with each other?

Does it sound like a small plane taking off,
Could be a Pinion shaft Bearing,Mine did that from about 80 -100kmh

it is a second hand tail shaft looks good. How do you check it is in phase. Will check pinion today if it stops raining. I am not sure about spider gears as that would be something critical and i have been driving it with the shudder for nearly 3 weeks with out it gettin worse

RunnerMitch wrote:it is a second hand tail shaft looks good. How do you check it is in phase. Will check pinion today if it stops raining. I am not sure about spider gears as that would be something critical and i have been driving it with the shudder for nearly 3 weeks with out it gettin worse

This pic is an example of a tailshaft that is in phase. Basically the ears on the shaft are aligned (in this pic you can see the grease nipples on the ears are in line with each other). If it's out just one tooth it can be nough to give vibrations. You should be able to check yours just by sight.



You are 100% sure the unis are ok being a second hand shaft?

RAY185 wrote:Did you both make sure to put the shaft in "phase" when you put it back together? ie transfer end and diff end flanges aligned with each other?

I know for a fact that mine are as I built it from scratch, but maybe it could be the pinion bearing... will check one day when I get a chance... actually I wouldn't have a clue how to check it

Thanks for that i will check that. there is also play at the transfer end so i assume the bearing is shot. how is this bearing replaced is it difficult.