Mechanically Inclined And Stumped - 92 SR5 V6 Rear End Vibration

[CaribooT4R]

Hey Everyone ,

Built a few honda's and acura's in my time , nos , turbo , all motor blah blah blah not new to mechanics , sold my projects and came across this 4 runner and I fell hard I love it pieces , She recently got all 5 new doors to remove the rusted ones , spark plugs , oil change , diff change , etc.. ,

i recently just put on 34 Inch tires on 18 inch wheels , get u the exact measurements , it rubbed abit so i cut the back bumper abit as well as the inner fender well and now no more rubbing, drove nice and smooth all through x-mas holidays

coming home from work i noticed at about 70-80 KM/h that the ass end was vibrating like crazy and the truck really didnt want to accelerate past that , i backed off and took it back to the tire shop , all 4 tires have been re-balanced , however , even after i got it back they told me the vibration is gone , and yet , I dunno its my truck its still there , at 80-90 km/h its there still but its not as pronounced , ive checked my diff fluid level , tire pressure s again etc , three shops tell me its normal , but i dont buy it , its my new toy and i know where theres something wrong with her , any suggestions would be greatly appreciated.
Thanks.

 

[CaribooT4R]

something else to add before i forget , there is absolutley , no noise coming from the rear end , just a vibration , no droneing , no squeaking , squeling nothing... and as soon as i left off the gas at 80-90 km/h the vibration stops and she glides , im thinking the driveshaft or possibly the rear end but what ?

 

[drmorbius]

something else to add before i forget , there is absolutley , no noise coming from the rear end , just a vibration , no droneing , no squeaking , squeling nothing... and as soon as i left off the gas at 80-90 km/h the vibration stops and she glides , im thinking the driveshaft or possibly the rear end but what ?

Check the U joints for slop.

 

[CJ3Flyr]

Check the U joints for slop.

:iagree:

 

[CaribooT4R]

Starting To Worry Here

Ok So ,

Spent the weekend kinda going over the haynes manual as well as my truck , not that its pertaining to my issue but all possible fluids have been checked and topped up in the truck ,

i checked the ujoints for slop , they look like they need replacing lol , but there isnt any slop and to top it all off get this

when the truck is moving and in gear it shakes like crazy , however , when i push the clutch in and just glide down the road , the vibration , shake , shimmy whatever u want to call it , completely disapears , so now im really stumped. someone not on here made reference my tranny could be shot :S *sigh* any other suggestions guys ?

thinking im going to replace the ujoints tommorow anyway , oh and i should have mentioned this at the start , my idler arm is totally fubard , it has approx 2 inches of play when the front diff is in the air. :S , someone said that might just be the problem , but IF it was , why when the clutch is pushed in does the truck just glide down the road ? :S

 

[fourwd1]

...found this little bearing in the clutch kit box, and not the throwout bearing...

That's the pilot bearing.

 

[drmorbius]

It goes inside the flywheel

It goes in the end of the crankshaft.