Chasing a frontend vibration, Mostly fixed 06-16

[TomRhere]

EDIT: 06-07

 

Seems I swapped a worn rack in when I swapped racks a few weeks ago. This one has up/down play in it on the PS end. Pulled the old one off the shelf, and sure enough, it has about the same amount of play.

 

I feel like big dummy now for not really checking things out further when I swapped the racks. But when yo're in a rush to get it going again.

STUFF OCCURS!!!!

 

Now, I get to find me another rack.. Be a bit though, money tight for a bit right now.

 

 

 

Since last November, I've had a vibration in the steering wheel of the '86 BRAT. It started out softly, but got more violent before I got the chance to actually work on it mid December.

 

List of things done in hopes of fixing it are;

New tires mounted on H-style rims. Lessened the vibration, but it was still there.

 

Re-torque of axle nuts and wheel lugs didn't improve it any.

 

In January, it started to make noise during righthand curves. AHA, bad wheel bearing(s). New bearings on both sides, no help with vibration, but noise during righthanders is gone.

 

Noticed worn ball-joint during bearing job. New ball-joints both sides. No help.

 

Had the rag joint on the steering rack go bad. Replaced rack along with new inner/outer tie-rods. Bushings for the rack are in good shape. No help.

 

Had it up on the hoist at a friends garage, inspecting everything under the front. Found no slop in control arm bushings, nor in the strut rod bushings.

 

In the past few weeks, the vibration has gotten way worse. I can't drive faster than 55 on any road. And now, it really shakes the steering wheel going thru lefthand curves. No noise, just severe shaking of the steering wheel.

 

I've flipped the tires front to rear, side to side. No help.

 

Swapped the knuckles out including fresh bearings/seals. No help.

 

Swapped axles out with known good ones. No help.

 

What am I not seeing here? I've done everything I can think of and I'm not gaining anything.

Edited June 16, 2009 by TomRhere

[zyewdall]

You've already tried everything I was going to suggest and it sounds like you've replaced the entire front of the car, pretty much. I've had vibrations from flat tires (even at full psi they had a flat spot, from sitting at low psi in one place for too long) and from bad CV's (didn't click, just vibrated under power). But you've swapped those out it sounds like.

 

Can you feel the vibration anywhere else besides the steering wheel? In the shifter (especially high/low range shifter) If so, then it could be related to motor mounts, transmission mounts, or bearings/u-joints of the driveshaft. That usually shows up more in other places than the steering... but it's my last guess.

[aba4430]

When you say shaking of the wheel, do you mean oscillation from side to side, or severe front end shaking. If it is just oscillation from side to side, I think your front end components should be OK. I recommend that you check whether your calipers are sticking. Not just severe sticking, but not retracting easily. Plus also check whether your rotors are warped. Sticking calipers and warped rotors will lead to vibration (oscillation) of the steering wheel. If this is the case, you might also notice that high speeds, such vibrations are minimized or non-existent, but you feel it at low to moderate speeds.

 

Edit to fix spelling.

[GeneralDisorder]

Check the driveline u-joints and all four drivetrain rubber mounts.

 

Just for giggles - put a dial indicator on each rotor. Probably won't find anything but it would still be nice to know.

 

GD

[TomRhere]

Ok, by vibration in, or shaking of, the steering wheel,, I guess oscilation would better describe it.

Actually acts like a broken belt in one of the front tires, but tires are good, and I've had each one of them on different corners. Again, no help.

 

No oscilation below say 45 nor up to roughly 53. 55 and faster, steering wheel oscilates. Driving straight, it moves maybe 1/4" back-n-forth. Get into a curve, or get up over 55, and it will increase to an inch or better of motion. If there is noise from one of the front corners, I can't hear it over the noise from the whole vehicle shaking, it's that bad....

 

Tranny mounts are new as of last October, and are still intact. Motor mounts have some give to them, but aren't broken. I can lay under the BRAT, push up on the motor on either side and lift the BRAT.

Just so you all know, I can still benchpress a Chevy Turbo 400 tranny up into place, and recently did the same with a Ford C6 tranny. Those be a couple damned heavy transmitions. I have good arm strength, believe you me...

 

The trans shifter does bounce around some when this happens. But, just putting my hand on it stops it from moving. No force applied in any direction, just holding it. Nothing really felt thru it either..

 

Can't really see a bad u-joint on the driveshaft, or a bad joint in one of the rear axles causing the oscilation in the steering wheel, but I'll check those.

 

Really can't see it being a warpped rotor either, as I feel no pulsation in the brake pedal at all during stops. And I've had to do a few "panic" stops due to idiot drivers and 4-legged animals.

 

I recently installed new loaded calipers and no indication of one hanging up. BRAT rolls easily, last documented tank of gas gave me 316 miles driven, 11 gallons to top of tank, roughly 28.7 mph. So I don't think it's brake related. I will borrow a dial indicator from work and check things out though.

 

I had thoughts of bad shock or strut causing this. But I can bounce any corner of the BRAT with my 230+#'s and she recovers in excelent time, like 1-1/2 moves. Seems good to me. She sits level from the side to side aspect, has the tailup stance of the BRATs, but she sits squarely.

 

It's definetly got me puzzled. Maybe I'm looking to hard and can't see the forest thru the trees. Don't know..... That's why I'm asking for ideas here. There's gotta be something I'm overlooking.

[GeneralDisorder]

I have noticed that the EA81's are VERY sensitive to wheel balance. So much that the normal wheel balance that schwab does doesn't seem to be good enough - either their machine isn't calibrated right or the monkeys don't know how to use it.

 

I would have them redone and have the weights put on the inside of the rim. If you are getting that much vibration at speed it is probably because the wheel balance is off and it's transmitting it through the steering rack directly to the wheel.

 

GD

[zyewdall]

I have noticed that the EA81's are VERY sensitive to wheel balance. So much that the normal wheel balance that schwab does doesn't seem to be good enough - either their machine isn't calibrated right or the monkeys don't know how to use it.

 

I would have them redone and have the weights put on the inside of the rim. If you are getting that much vibration at speed it is probably because the wheel balance is off and it's transmitting it through the steering rack directly to the wheel.

 

GD

 

Your description does sound exactly like the symptoms you'd get with a wheel out of balance. My subaru (all of them actually) do that if I get ice frozen onto part of the rim or mud on part of the rim, that makes the rim out of balance.

[4x4_Welder]

Try having the wheels balanced with a balancing compound like Equal (not the fake sugar stuff).

They pull the weights, but a bag of this stuff in, and air the tire back up. No spin balancing or anything, the wheel constantly rebalances itself as you drive down the road. This will correct any road force variation and even unbalanced wheel mount components. As proof, I have a 75 Jeep Wagoneer with 31s that drives down the road with no vibrations thanks to this system. It had a slow leak, my wife took it to Les Scwab, and they used a spin-balance on that wheel. Now it has a vibration on just that wheel.

[ihscout54]

Try having the wheels balanced with a balancing compound like Equal (not the fake sugar stuff).

Ive never used the powder, liquids, or balancing rings befor. But alot of commercial vehicle guys swear by these systems. The only thing I recall hearing that was a real problem with the powders & liquids was the air MUST be dry or it will clump up mix and stop balancing. Finding dry air might be a a little tougher for the average joe. But not as hard as nitrogen.

 

http://www.imiproducts.com/equal/Videos/equal_512k.wmv

[4x4_Welder]

Another option is to use heavyweight plastic BBs. Don't use the metal ones as they corrode and disappear.

[NorthWet]

My money would be on the strut rod bushings. Just because you can't measure or eyeball a problem doesn't mean that they are OK. They are an excellent source of oscillations, a "wear" part, and relatively cheap to replace.

[GeneralDisorder]

My money would be on the strut rod bushings. Just because you can't measure or eyeball a problem doesn't mean that they are OK. They are an excellent source of oscillations, a "wear" part, and relatively cheap to replace.

 

That's an interesting theory. Worth checking into.

 

Although if you can get the tire place that sold them to you to rebalance them for free I would try that first.

 

GD

[TomRhere]

I'll order me some strut rod bushings.

 

I can get the tires rebalanced with no problem.

[ShawnW]

Driveshaft id put $ on it my 86 Brat did those exact same shakes of steering at those speeds.

[Davidjlo]

I dunno dude, I had brand new CV's on my brat and like, 100 miles later they both broke. Why? Because my wheel bearings were shot. The shot bearings can damage your axles. I had the very same oscillation of my steering wheel and it was because on of my axles had broken. Grab the middle section of your axle and try sliding it back and forth and if you hear a tapping on either side, your axle is done. Even if the boot hasn't broken.

[Caboobaroo]

So a quick question. DId you put new CVs in the front of it before it started doing it, like pretty recently prior to the vibration?

 

Reason why I'm asking and I'm sure Turbone might chime in as well. Done new axles in a couple of 5-lug conversions (mine and Rob's) and the "new" axles caused a nasty vibration. Even though the axles were causing the vibration, his symptoms were different then mine. Mine had a new axle on the LF and would cause a vibration starting at 35mph and go till 70mph and under right hand curves. His would do it starting at 25mph under accel and decel.

[TomRhere]

Haven't had the time to work on it any this week, but plan to over the weekend.

 

I still have a few extra parts here that I can swap out, and do some more checking of things suggested here.

 

Axles have been swapped a couple times here in the last 3 months or so.

 

Been driving the '85 BRAT this week. It's in need of some serious wrenching itself.... :-\

[lostbrat]

i think strut rod bushings, i had similar shimmy. replaced bushings and rods. shimmy fixed. as a side note, just took apart brothers 295,000 mile brat to junk. steering shaft u joint had one beairing totally blown and rag joint all tore up.

[Yo'J]

I had the same symptoms when my rack went out. As it started out, it was fine at 55 but would shake at 60. As it got worse I could only go 35 then 30. The rack was only giving slop on one wheel or so it seemed. It was almost visible when driving, like a bubbling tire. I never did ask the shop what happened on the inside of it. I started out doing all the things you did. Ball joints, bearings, strut rod bushings ect. till it was the last step, the rack.

[TomRhere]

I edited the 1st post yesterday, telling of what I found wrong.

 

Really don't know the cause/effect relation here,

but with the bad tires, bent rims that was on it before the new tires/rims, then the bad wheel bearing and worn ball-joint,

having a worn inner tie-rod,

bolt shearing off on the rag-joint connection (changed rack then).

 

It seems I had been fixing possible causes for the vibration, but didn't know that both of the steering racks were worn out.

 

Looks like the one under the '82 is in good shape, so I'll be dropping that one out tonight and swapping it into the '86.

[TomRhere]

Well,,,,, maybe not after all.

Or,,,,,,,,,

I have 4 worn out EA-81 manual steering racks here.

 

Rack in '82; has vertical movement on PS end of the rack/housing area.

Ditto both '86 racks,

Ditto rack in '85.

 

Been digging around for info, haven't found anything to say good/bad/indifferent. Yet.

[GeneralDisorder]

The rack shouldn't matter. That is only the steering link - it cannot cause a vibration like that as it does not rotate or change speeds with increased MPH. Maybe if the inner tie-rods or the tie-rod ends were worn.... but movement in the rack itself will only cause jinky steering (loose maybe).

 

I haven't read all the posts - did you have them rebalance the wheels? Have you tried putting the rear wheels in the front and maybe also switching them side-to-side?

 

GD

[TomRhere]

Thanks for that insight GD. My knowledge of R&P steering issues is limited, and was mostly from just swapping leaky power assisted ones out for the owner(s) of those vehicles.

 

The rack in it now has new inner/outer tie-rods on both sides. Mount bushings are in great shape, as is the rag joint.

 

I have rotated the tires around, but have not been able to get to the tire shop for rebalance yet. Work schedule is culprit there, but they just put me back to an 8 hour day as of yesterday, been working 9+, so maybe I can get there this week.

 

Still, swapping the tires around hasn't changed anything.

 

I don't know... Maybe I buggered a bearing when I swapped them out, I drifted them in via punch and hammer. I have another knuckle and more bearings/seals here. Thinking I'll take it all to work and use the press to install the bearings, then swap knuckle out. See what that gets me.

[ShawnW]

Did you try the driveshaft yet? I bet you could have it swapped in under 30 minutes.

[TomRhere]

Swapped the PS knuckle out again with one that I "pressed" some new bearings in. Installed another new outer tie-rod end, as I didn't want to attempt removing the one that was on the "old" knuckle.

 

Seems for the most part the oscillations of the steering wheel have gone away. It's still there on some roads, but it's not always present. Seems to make a difference as to where I have the BRAT in the lane, centered, close to the center line, close to the edge of the road.

 

I did have the tire/wheels rebalanced, and the tire guru said he saw nothing wrong with tires or rims. I have an appointment to have the front alignment checked.

 

I did do a quick run up to 65 for a bit. Didn't shake the crap out of the steering wheel like it did before.