random vibration after 5100's

so i put a set of 5100's on my truck set at 1.75 with no tsb on the rear, got it aligned and i have something like a pulsing vibration at 30-40mph it comes and goes in pulses, it's barely noticable and nothing at higher speeds only at the posted ones, any ideas? doesn't seem like a real big deal but i just wanted to make sure i'm not missing something that could cause excessive wear miles down the road

 

First thing I'd check is to make sure everything is still torqued correctly after settling.

 

i did check that soon after the install but it's had some time to settle since then, i'll check everything again tomorrow when i'm doing the oil change, do you really think setting the 5100's at 1.75 would get you the vibs all the guys with 3in lifts get?

 

Are you feeling the vibs in the steering wheel or in the seat? Steering wheel would point to alignment, and feeling it in the seat would suggest driveline

 

i got the same thing going on! but i set mine at 2.5" but it's not exactly a vibration... it feels like something is barely touching something and sounds like a humming noise. i'll have toget a hold of a torque wrench to make sure everything is good. do you guys know what those numbers are???
thanks!

 

Sounds like it may be in the driveshaft. Not sure if you can get spacers to lower the center bearing to correct the angle

 

yeah thats what mines like, kind of like groan... 10sec pause groan....10 sec pause ect

 

it's hard saying, it kind of seems like i can feel it in the floor board, and possible the wheel, it's so faint no one else notices it but me, cause i drive it every day

 

i just noticed the same thing going on with mine the other day. i'm not an expert, but i wonder if it has something to do with it being colder. the temperature has really dropped in the past few days here. and i wonder if it has anything to do with everything getting warmed up and the fluids lubing everything up. i say that because it's happened since it has gotten colder and the buzzes/vibes are stronger when i start driving after it has sat overnight or for a few hours in the cold. once i have drove it for about 30min, the buzzes/vibes seem to fade completely away. the longer i drive, they disappear.

 

See my thread - Possibly your front differential if your 4x4

http://www.tacomaworld.com/forum/2n...on-30-40mph-after-5100s-installed-1-75-a.html

 

the different symptoms and experiences along with the different fixes don't really give a solid answer. i wouldn't want to spend a chunk to fix something that isn't broke. why hasn't toyota addressed this issue? are they just kind of overlooking it because it's "our" fault because we lifted our trucks? they are probably using that excuse to cover their mistake.

 

well i'm gonna take it for a spin in a few min and throw it into 4wd and see if the noise goes away, if it does i'm gonna try a diff drop kit and see if that helps/eliminates the vibes, i'll post back and let you guys know if the noise goes away in 4x4

 

Sounds like it may be driveshaft related. Have you tried to shim the carrier bearing? One of the vendors on here makes a carrier bearing drop that is supposed to help eliminate the vibs. Lifting changes the drive shaft angles which can cause those vibes.

 

yeah but would raising the front only change anything on the rear?

edit, when i first hit the road it was doing it, i threw it into 4wd and it went away but then i could barely tell the vib was there when i threw it back into 2wd? wtf

i took it for a drive to my parents (about 30miles) kinda weird cause i noticed it didn't do it once i was on the road for about 15min like someone else said, once the front dif fluid warmed up, idk what to do here, buy a diff drop kit and do it anyways, it's barely noticable but if a diff drop kit will prolong the life of everything up front i'll buy it

 

Ya by just lifting the front you raise the engine, which raises the tranny, which in turn changes the angle of the driveshaft.
It's that difference in the angle that can cause the vibs.

 

ok, well it's so minimal now i think i'll just shrug it, i may still buy the front diff drop kit since it's only $30, other than that i think i'll just see how it goes, mabye it's just a cold thing and it'll stop in the warmer months, only time will tell i guess

 

If you do buy the diff drip let me know if it gets better or worse. I had my front diff replaced under warranty and seemed to cure the vibe but I do feel like I have now the very slightest constant "vibe" in my accelerator pedal. They did the pedal recall though at the same time. I wanted to aal to give back a little rake (im set at 1.75 and the back sits about .5 lower. Barely noticable but I do notice and certain angles) but worried about more problems. I may just go down to .85 and say the heck with it. My intentions was to go to 2.5 but it sounds like a headache.

 

will do, i'll update the thread when i do so (it may be awhile) hard to get motivated with this cold freakin weather!

 

Just food for thought, but most people who have installed the diff drop kit, wound up creating more vibrations and later removing it. I'm a prerunner so I have not personally messed with the diff drop. Good luck figuring it out and getting rid of it.

 

Ok, I did some searching and came up with this. Hope I'm allowed to post this but sorry if i'm not, just trying to help.

http://www.trdparts4u.com/scripts/prodView.asp?idproduct=-8232