williscr3

I have a pretty good wobble going on with my truck when going down the highway. Was taking rear driveshaft off to eliminate it as a possibility and my output shaft has a good bit of movement to it. Looks like rock auto may have the bearing but is it pressed in? Looks like I can remove the extension housing pretty easy but not sure if the case needs split to do or what? I removed the shaft and still have the shake between 50-60mph though. Also if front hubs are unlocked that should indicate the front driveshaft and axleshafts can not be the problem? I did grease the spindle bushings and its still the same. Any thoughts?

millball

Try tightening the output flange before you condemn the bearing.
Take the nut off, degrease flange and splines, apply locktite, torque the nut to 90-95fp.
and restake the nut.
Sometimes they just loosen over time.

If the hubs are truly unlocked, the front driveshaft and front axles should'nt turn, and can be ruled out as the source of your vibration.

williscr3

Thanks, ill give that a shot. I hope that's all it is. I'm also thinking check the steering rack bushings. I repacked the bearings. Brakes and rotors are new. Maybe bad tires but not ready to commit to New ones yet till this is looking to be the problem. Thanks so far though.

millball

If you're talking about your '91 pickup, it does'nt have a steering rack, therefore no steering rack bushings.

oldblue

if it does it in 2wd with the hubs disengaged that should rule out the front axles. and if it does it with the rear drive shaft removed that would rule out that suspected loose bearing (which still may need attention). sounds like its a problem with the steering or even the wheels/tires themselves. jack up the front end and see if you have any steering or bearing play first. then check your tire pressures, low tire pressures can cause weird issues. then try having the balance on the tires checked, preferably at a tire shop that has a machine that can check road force.

williscr3

Yeah Im not sure why I was thinking it had a steering rack specially since I rebuilt the idler arm few months ago. Any way... Wasn't able to crawl under it today, its raining. Jacked up front already, checked ball joints, they are good. Checked bearings and repacked them, they are good, also packed spindle bushings with grease. Tie rod ends are nice and tight. My steering wheel shaft seems to flop around a bit right before it goes through firewall inside the truck. Maybe a bushing or something inside steering column? Truck shakes in 2wd hubs unlocked, shakes in 4wd hubs locked and no rear drive shaft. It shakes pretty good between 50-60mph but sometimes its worse, to the point I can only go 50mph. That kinda makes me think it can't be the tires if its worse on some days.

oldblue

i think it would still be a good idea to have the balance checked on those wheels and tires. shouldn't cost more than $40 at most places, and its good maintenance as well to help the tires wear better. not uncommon for tires to get a "hop" to them, and not uncommon to bend a wheel and not know it.

williscr3

Now that you mention it, it does feel like it has a hop to it at slower speeds like 30-40ish. That would mean its out of balance? I have steel rims 15x10 after market ones. Wagon wheel looking kind think they would bend? I'll get them balanced for the hell of it.

peabody

iTrader: (1)

I put myself through hell and back with all of the tests to isolate a hop/clunk. No luck, worked on other repairs. Months later bought new (used but better) tires to replace the junk temporary tires and for the life of me I can't get the hop/clunk back, fortunately. Just couldn't believe shot tires could cause that.

williscr3

pulled the rear drive shaft off, turned out your right the nut was loose on the flange. i did what you said hopefully it stays tight for a while but atleast now i know. greased the shaft and u-joints while i was under there. didnt get a chance to balance tires yet. my back 2 tires are newer with full tread but looks like the one wheels weights fell off. thanks for the help.