Weird Front End Vibration

[roger350]

My truck has recently developed a weird vibration in the front end, and I'm hoping someone can give me insight into what needs replacement. The alignment has been out for about 4 months now, it trys to pull right, enough that I can do a lane change on the highway by just letting go of the wheel. (Yeah I know I should have got it fixed, but the tires are on their last 10K anyway, so I was waiting) Because of the alignment issue, when I'm traveling straight, the steering wheel is cranked left about 30-40 degrees. About 2 weeks ago I started noticing a hum and vibration when I'm going down the road straight or turning left. It sounds and feels like normal road noise from a really aggressive mud tire. When I turn right the vibration and noise go completely away. It vibrates until the steering wheel gets just past center on a right hand turn, and then it abruptly stops vibrating like someone just flipped a switch. I have looked at the left suspension, around the tire, etc., and I don't see anything visually cluing me to what is wrong.

My only stab in the dark is that it is the left outer CV joint, that for some reason operates fine within a certain range of angles (turning right), but developes a vibration at the angles required to go straight or turn left?

Does this sound possible? Has anyone had this type of problem before? Of course I am way past warranty time, and I don't know of any shops in my area that I trust enough to take it to. I figure most shops will just start replacing stuff until it goes away, and I really don't want to pay for that!

If anyone has any insight I'd appreciate it. I have no idea if this is at all related, but during slow speed turns it squeals like a pig. I had previously been told that this is probably a sign I need the steering shaft lube/new bearing kit.

Sounds like I need a total front end rebuild. I was trying to wait until Moog had their beefed up pittman arm, idler arm, and tie rod ends out, so I could do all this just once, but I think the time is now to fix this before something breaks when I'm going down the road at 70. If I can get away with just replacing one bad part now I sure would prefer that.

Thanks for the help.

[JimWilson]

Since I can't actually hear the noise I don't have a lot of insight, but here's one idea: maybe it's your tires. Old, worn out tires can make noise to begin with. Ones that are on the front of a truck with really bad alignment will wear funny. If their feathered or cupped you will definitely feel and hear something from them. Perhaps that's all it is.

Maybe it's time to get those new tires after all... smile.gif

[roger350]

The tires don't look any worse than normal, i.e. there is a little feathering/cupping on the fronts, but not excessive. If they had another rotation left in them I'd rotate them. I'll probably put the spare on this weekend and see if anything changes, but because of the way the hum/vibration goes away when the tires are pointed right, I figured it probably isn't a tire problem? Thanks for replying.

[cruzer]

You should check things out for wear.
1.jack up frt end rotate (spin)tires to see if you have a bent rim. also see if there is much resistence in turning the tire. (caliper or axle)You may want to turn strng wheel and ck that way too. There will be more resistence though. Right & left should be about the same. If more resistence than the other then, I'd lean toward C-joint. While it is in the air grab the tire at 12:00 & 6:00 and push top/pull bottom and viceversa to see if there is play. If so then wheel bearing or a really worn out ball joint,
which you should be able to see at the knuckle.

2. Put truck on ground, have someone shake or slightly turn the steering wheel back and fourth,
say from 10:00 to 2:00 O clock or slightly less repeatedly. The truck does'nt have to be running. Have someone look at each individual steering
joint(tie rod ends and idler arm) Tie rods should rotate(twist)slightly from back and fourth movement of Strg wheel but not have movement at their axis(side to side) where they are attached. Idler arm should have no movement other than pivoting w/the pitman arm..

3. Ball joints are more difficult to describe
the check. Jack frt end up, using a pry bar wedge between steering knuckle and A-arm next to the ball joint so as to pry knuckle away from truck. You don't need too much pressure, you are looking for similar movement as checking for a bad tie rod. Side movement from axis.

I hope this helps some. It is very difficult to describe these checks w/out actually showing someone how to do it.

If you get a frt end alignment, they HAVE to do these checks B4 it can be aligned. From what you describe I would be leaning toward worn frt end steering parts. It could be 1 wheel dragging more than the other.(axle or caliper) An axle rotates in the center of the tire and should not usually cause a pulling condition.

Oh yeah, After you check for a bent rim also put the palm of your hand across the tread and slide your hand around the circumfence of the tire and feel for bluges or raised areas on the tire tread. If there are some it indicates a belt inside the tread has slipped and the tire is shot.
This would create a vibration.

[ 01-21-2004, 11:33 AM: Message edited by: cruzer ]

[GSXRTURBO1]

Sounds like a bad wheel bearing to me. :(

[roger350]

Thanks for all the suggestions, and keep 'em coming. I plan on taking a detailed look at it this weekend, and trying to inspect these things. A guy my friend knows said this is a symptom of a bad pittman arm? I had already planned on having to replace that when I got new tires and tried to have it aligned, so maybe I'm in luck. If so, I'll replace it now before it takes the steering box with it.

[cruzer]

I wouldn't replace or buy anything until I checked out every part and found what was specifcally wrong. Your going to have to get your hands dirty. There's no way to tell just by the way it drives or the noise it makes. It could be low tire. Who knows.

[roger350]

Yeah, I'm not going to jump to conclusions about what it is. I plan on trying the inspections you suggested this weekend. If I can't find anything from that I'll probably take it to an alignment place and let them see if they can align it. If it is a pitman arm they won't be able to align it in specs. I figure in the end I may have to pay a front end shop to find the problem, but may be able to save some money by replacing the stuff myself. Thnaks for the help.

[mark45678]

how many mile are on it? do you do your own front end lub? I had problems with the firestone steeltex for day 1 till the day I took them off and put michelins on it! out of ballance ,out of round ,cord shift (lumps in the tread/side walls)

[Lone Eagle]

Good post CRUZER. Sounds like you have done some front end work also. Cupped tires didn't come from the pitman arm. Tire balance, warn ball joints or shocks. Maybe all the above. Take it to a good front end shop. Some one in every town will have a good rep. Ask around. Later! Frank

[jbplock]

Originally posted by mark45678:
... I had problems with the firestone steeltex for day 1 till the day I took them off and put michelins on it! Dittos! I took off the Steeltex at 10k and replaced them with Michelin XRadial LT's. Night and Day difference.
smile.gif

[roger350]

Well I finally got around to jacking up the truck and looking at the suggested items/tests. It appears to be a wheel bearing, as when I grab it at 12:00 and 6:00 there is a large amount of play. It is also harder to spin than the other side. I noticed a little grease coming out from the back of the hub also.

Does this sound conclusive as a wheel bearing, or might it be a CV joint also?

I was going to disassemble it to try and isolate it for sure to the wheel bearing, but I didn't have any sockets big enough to get the caliper off? Does anyone know how big the bolts are to remove the caliper? The ones that hold the claiper to the "caliper cage" are 19mm, but the ones that hold that cage on to the spindle are at least 20 or 21mm? A 13/16 almost fit them, but was tight. So I assume it is a 21mm. From the feel of them, I'm going to need air tools to get these off...

Any tricks I should be aware of to change out the beraing/hub assembly?

Thanks for all the help.

[BassinRVer]

If it is the wheel bearing, you will see very small metal flakes on the inside of the hub.