Hi all,
So quick backstory; had a vibe with throttle only after I installed my lift. It would come around 40-50 strongest and most reliably but sometimes it would happen much lighter at lower speeds, usually starting as an oscillating "wub-wub-wub" sound that would steady out. Only with throttle; would cut out the second you let off. Figured it to be bad u-joint(s), so I replaced my driveshaft which helped but didn't solve the problem - come to find one of the u-joints they used was crap and had very obvious play in it, to the point where the driveshaft would clunk if pushed just right. The bad joint in question was in the rear, at the slip yoke/third member.
I put up with it for a while until recently tackling it again, and replacing the joint with a brand new one from Spicer; now I still have the vibration, but it's even worse than before. Doesn't oscillate so much, but definitely louder than before - still same symptoms as before, happening worst at ~50mph and ONLY with gas, seemingly around 1500RPM and over. Happens in both 2WD and 4WD. Feels and looks like I'm driving a subwoofer when I look in the mirror. I have attached a video of it happening though it might be hard to hear without headphones on. (Before anyone says so, I was on my way to the gas station while recording this!)
After replacing the joint the play I noticed was gone but pushing on the driveshaft the clunk was still there, just greatly diminished. I have a feeling at least one of the u-joints in the double cardan is probably also faulty (and if they used 3 from the same batch like it seems, it's probably a safe assumption)
With all that said, I'd love to hear anyone's input on this. I'm fairly confident it's either a bad pinion angle or u-joint, but I've never experienced a bad pinion angle before so I'm not sure what to look for in that regard; if that's where I should start looking, how does one check their angle, and is there a good number to shoot for? I tried looking for a missing balancing weight on the prop shaft and didn't see anything missing. To add to this my third member has been replaced before and the oil looked fine when draining it last year so I highly doubt it's the pinion bearing/diff itself wearing out; and the fact that the sound has changed/altered as I messed with the driveline leads me to believe I'm on the right track. Regardless a second or third opinion would still be appreciated here. Buddy of mine is adamant it's the trans, but it doesn't seem that way to me - I would imagine it to be much more constant with much worse symptoms if so. I tried to include anything I thought would be handy, but if I missed any information let me know.
For 4wd pinion angle you want the rear diff pointing slightly below the transfer case output. The best way I can think of to measure it is with a magnetic digital angle finder. Put it on your rear pinion flange and zero it out/ then put it pn your driveshaft. You should have something close to 90 degrees. Probably 89/91 degrees. You don't want a perfect 90 degrees because the u joints will wear prematurely.
I was thinking of doing this but wasn't sure if that would put strain or not on my front end, going 50mph and whatnot. Might give it a shot when I check my angles
I was thinking of doing this but wasn't sure if that would put strain or not on my front end, going 50mph and whatnot. Might give it a shot when I check my angles
Well, don't go doing burnouts... but there should be no problem with a normal test. (think of the stress that 4LO puts on the drivetrain - you'll just be driving on the street)
-Charlie
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'99 4Runner SR5 Auto - 4WD swapped
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You did put alignment marks on the DS before you took it off?
If no ref marks, try unbolting and reattach the DS 180°. It could make a difference in the vibs.
You did put alignment marks on the DS before you took it off?
If no ref marks, try unbolting and reattach the DS 180°. It could make a difference in the vibs.
I believe that's only relevant when pulling the slip yoke, which can't be done on my a/m shaft
welp I went and bought one of these little guys and took some measurements. Trans was just under 90*, rear was 95*. Guess I'll be sending Opt Offroad a check
welp I went and bought one of these little guys and took some measurements. Trans was just under 90*, rear was 95*. Guess I'll be sending Opt Offroad a check
If you have a 4wd then your driveshaft angles will be different at the transfer case and rear differential. Your rear pinion should be pointing at your transfer case flange.
Well, don't go doing burnouts... but there should be no problem with a normal test. (think of the stress that 4LO puts on the drivetrain - you'll just be driving on the street)
-Charlie
I’m having a similar problem with vibrations and squeaking coming from (i think) the rear driveshaft.
I still have to drive (on 40mph roads) to class every day while I figure this all out. There shouldn’t be a problem driving like this on slow roads for a week or two, right?
From what I hear, driving with 4wd on pavement is only a bad idea because the front and rear wheels travel different distances. If the rear is disconnected, it doesn’t matter, right?
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1997 4x4 SR5 3" Lift @254,000 miles
I welded my own bumper!
I’m having a similar problem with vibrations and squeaking coming from (i think) the rear driveshaft.
I still have to drive (on 40mph roads) to class every day while I figure this all out. There shouldn’t be a problem driving like this on slow roads for a week or two, right?
From what I hear, driving with 4wd on pavement is only a bad idea because the front and rear wheels travel different distances. If the rear is disconnected, it doesn’t matter, right?
There will be no transfer case bind with the driveshaft removed. With the rear driveshaft removed you have to put it in 4wd to move anywhere.
There will also be no park if you remove the rear driveshaft and leave it in 2wd
If you have a 4wd then your driveshaft angles will be different at the transfer case and rear differential. Your rear pinion should be pointing at your transfer case flange.
Yeah I saw that after I took my measurements, thank you. Which made a lot more sense, I was under the impression I needed to reduce my angle which seemed completely unlikely and the opposite of literally everyone else on here. Even just glancing at it you can see it's not totally aligned to the transfer case so that's probably my issue