The Stovebolt Site Forums The Shop Area Driveline Violent shaking at highway speed

I just got done installing and testing out my 3 speed overdrive in my 1958 Suburban. The trans works great.

The problem now is that I'm easily reaching speeds I've never gotten to before. Now when I get to 60mph I start to get a bad shaking on the front left side. I can't be positive, but that's where it feels like its coming from. At 65-70 it gets pretty violent to the point I'm afraid a wheel might break off or something.

Before I installed the new trans, I had taken the tuck up to 65 or so without any real issue. The only thing that has changes is the trans itself. I put in new u-joints also. Before I took the truck out on the road I ran it through the gears on the jack stands and didn't feel anything out of the ordinary. I'm pretty sure the issue is speed based and not engine/trans rpm based.

During the trans install I did jack the truck up and down several times. I'm wondering if I screwed up something in the front suspension. Based on the amount of caked on grease, it looks like the parts are either original equipment or very old. They look okay to me but I don't know any better. I'm like a pig staring at a wristwatch when it comes to suspension parts.

I thought about the wheels needing to be balanced but wouldn't that issue have presented itself earlier?

Any thoughts on the subject would be greatly appreciated.

Seems like if it wasn't there before you installed the overdrive at 65 mph, that it has something to do with the overdrive. I don't suppose it could be an out of balance driveshaft??

John

I would think an out of balance driveshaft would show up more as a high speed vibration than violent shaking. But can't hurt to check it. Maybe the drive shaft is bent.

If it feels like it's coming from the left side of the vehicle, check the tires for possibly a lead weight from balancing the tire being thrown off, or maybe a knot on a tire has developed.

"Based on the amount of caked on grease, it looks like the parts are either original equipment or very old."

so you're pushing a 55 year old truck to 70 without a complete front end evaluation and refurbishment? did you bend the tie rod jacking the truck? have you had an alignment? wheel balance? checked the front wheel bearings? what condition are the front brakes in, ever open them up? how old are the tires? did you get all those U-joint needles back in?

Bill

Bill, all good points. One thing worth mentioning, after you put a big vibration on the suspension, such as "death wobble", everything needs to be checked on the suspension/running gear, because it could of loosened or broke something that otherwise wasn't broke before.
Steve

The drive shaft is original. All I did was take it off, disconnect the trans yoke, installed new U-joints and put it back on the truck. I didn't bang it around or drop it so I don't think its bent. The trans yoke looked solid and not bent or deformed at all. I did get all the needle bearings back in the u-joints to. My gut tells me its not the drive shaft.

I have not had an alignment done on the truck. I've always been very impressed with the driveability. The steering is pretty tight; no sawing the wheel back and forth on the road. It does not pull or wander on the road. The truck stops quite well; straight and true.

All that being said, I must admit I've never had the wheels off the truck. The tires appear relatively new and don't show any signs of uneven wear. When I got the truck it drove and stopped so well I never bothered to pull the wheels.

I'll pull the front wheels off and look for obviously missing tire weights, and check the breaks and bearings. I can identify issues with those.

My biggest concern is that I don't know what bad looks like when it comes to suspension parts. I was looking for some helpful advice to arm myself with for when I take the truck in for an alignment. I'm trying to avoid some guy glancing under my truck and saying "Oh year, your whole front suspension is shot. For just $950 I can fix that for you." I need to get with a trusted friend/fellow bolter in the area that know's their stuff to take a look at if for me.

one thing to look for under the front is a bent tie rod, common on these trucks from a number of things, including jacking the truck up with it .... clean everything well, like a power washer on all the joints to remove the caked on junk - have someone work the wheel back and forth 'forcefully' without causing the wheels to turn, while you look at what moves and what doesn't, see if every joint is as tight as you think

Bill

The driveshaft was just a thought, I figured maybe you had replaced it or needed to have it shortened with the overdrive.
I'm assuming the front end is a straight axle?? Jack up the axle under the spring mount, grip the tire top and bottom and see if it moves in and out ant the top and bottom. This would show wear in the king pins.
John

I think all points made above are great valid things one must consider. Your asking a truck that was designed to travel 50 mph to travel 28% faster than designed also using old likely worn out parts. If you want your truck to perform like a modern car, it needs updating. Just to new well working stock parts are fine, but you need a fresh start.

My truck travels those speeds all day long. But it also has all new modern tie rod ends or safer parts, (still drum brakes) but it is all new and in good working order. I inspect all part at least annually.

I'd consider yourself lucky that something didn't fail and harm you or someone else on the road.

most likely it is. you might not know what bad looks like but with new youll know what that looks like.

WITNESS chris didnt you mean all day long and then some. drum brakes i didnt know you had brakes period, all i ever watched you do was glue the gas pedal to the floor as we prepared for take off


in having the fun we have when we all get together is always a pleasure. with a no fear factor in the back of at least my mind of going that fast and feel like your riding in a limo is a testament to the work done in order to go that fast.

Gentlemen;

Thanks for the additional feedback. That is exactly what I was looking for. There are some great tips there.

I'll post a follow up once I do a little exploration.

Hooah!!

New u-joints?
Were they installed using a press? 1 or 2 slipped needles will cause violent shaking at highway speed. The engine rpms may be reduced in od, but the driveshaft will still be spinning over 3000 rpm at 70 mph.

When I was a kid, I had my 57 3100 up to 100 mph many times, it never had any sort of shaking. I would cruise 70 on the freeway .
Anytime I had an old vehicle that would do the shake deal, it was usually initiated by a nice bump in the road. Any kind of looseness in the steering system will be the reason it exists, an outa balance wheel-tire will cause it, especially dynamic balance. I've not known of a drive line imbalance causing it, though not saying it couldn't.
Small tricycle landing gear aircraft all have what is called a shimmy dampner, its like a shock absorber of sorts, the front wheel is a very loose setup and will shimmy, also some VW bugs used the same type of deal. Ive seen them added on older straight axle vehicles too, but I don't like how the after market units mount to the axle, I'd use the spring to axle U bolts and a special bracket if going that route. The old straight axle setup works good and should if it good shape not shimmy, just look at all the over the road trucks out there using that system. I'd suspect all the pivot points in that steering system, from king pins on. Also steering gear back lash.
How tight are the wheel bearings? If they are ball type they need to be slightly preloaded, and roller type have about .001 of slop. If you have to stock ball type follow the shop manual for adjustment. Loose wheel bearings can cause it too.
Also check toe in, and tire wear condition.

Just a side thought. Bent front wheel? Easy check, jack it up a spin the wheel while watching a reference point.

Mike that day in Macungie is still talked about. What fun indeed.

Please let us know what you uncover under the grease. Mine sure was interesting...

After work tonight I pulled the Burb out into the driveway and jacked it up one wheel at a time to look at the suspension. See the pictures at the following link.

http://s1053.photobucket.com/user/biglarry3/library/


I pulled the drivers front wheel first. There was some grease/sludge coming out around the wheel bearing washer. There is a closeup picture of that side. There was also a little bit of play in the bearing. Not much, maybe a 16th/8th of an inch. I posted a video of me moving the wheel back and forth. You can hear a distinct knocking sound as I rocked it back and forth. I assume the bearings are supposed to be tight without free play. The passenger side was the same. Just a little bit of knocking back and forth.

I looked at the rest of the steering parts. I didn't have anyone to play with the wheel for me, so I just looked over the parts. All the joints were tight. I tried my best to move the parts/joints around but there were solid. I posted some pictures of the parts as well.

As you can see there is lots of old caked on grease/mud/who knows what on the parts. The last picture is of the pile of stuff I pried off the passenger side back of the spindle.

So, my first impression is that the wheel bearings probably need to be replaced.

As far as the drive shaft goes, the u-joints were installed with a press. I did it by hand. That being said, once I discovered the secret of putting the bearing caps on the freezer for a little while, they went right in. I got all the clips in place no problems. I'll crawl back under and take another look to be sure.

As always, any observations or suggestions are appreciated.

yeah, the first thing is to pull the hubs and check those bearings, might be OK but will need a good clean out, regreasing, and proper tightening ... all that crap on the joints is probably what makes them appear 'solid', may well find some zerks that won't even take grease [once you find them!] ... also note those tires aren't great, and the pitman end of the drag link has been rubbing on turns, will eventually rub the cap thin enough it'll come apart, hopefully not when you're at speed on a rough road - the tire might have a bad spot on the inner sidewall because of it as well, narrower, taller tires would improve things .... seeing the condition of things under there it's no surprise there's shaking at speed

Bill

Larry

My truck looked very similar to that when I started. I'd replace the tie rod ends with safer modern ones, rebuild the pitman arm and evaluate the condition of your kingpins.

Bill;

Ok. I'll pull the hubs off on Friday and have a good look at the bearings. I'll probably just buy new ones and have them ready to go. One of the things I noticed was that there was a little play in the washer behind the castle nut. It would spin free and had some in/out side/side play. At first I was just going to pull the cotter pin and tighten the nuts. I decided not to and to wait till I had the time to take them apart for a look.

I'll have one of my boys sit in the cab and work the wheel back and forth while I look for lose joints. I pushed and pulled and twisted them as hard as I could and they seemed to be real solid. I'll also move the steering wheel lock to lock and look for interference from the tire. I'll check the back side of the tire too. Another issue I forgot to mention is that when I back up and turn the wheel hard to one side or the other I hear a rubbing/grinding noise. I thought it might be the bad bearings, but now I'm thinking it may be a rubbing tire.

I did dig out all the grease fittings I could find. I want to say there where 4 on each side for the spindle assembly. One more on each of the joints for the steering components. All took grease. I had to pump it pretty hard into the two fittings on the spindle where the king pins are but it went in.

Sweet;

Hooah. The more I think about it, it's probably time to just take the whole thing apart and reassemble it with new parts.

Interpretation of "Violent Shaking" may come into play here. My idea of "violent shaking" is what i also call the "death wobble".

What speed do you get to before the "shaking starts"?

Agree, irresponsible to consider driving down the block w/o a complete overhaul of brakes and suspension.

Roy;

I don't think I'd call it the death wobble. It starts at about 60mph and gains in intensity from there. I didn't push it over 70mph. At that point the shimmy/shaking is disturbing but not what I would consider destructive or bordering on failure.

I'm going to take Bills advice and inspect/replace the wheel bearings and look for tire interference. I'll test drive after that. If the issue persists I'll have to take the whole thing apart and replace all the older parts. Classic Parts offers a suspension rebuild kit, but it's a bit pricey. I don't have the $650 to spend on it right now. I'll have to look at all the components and see if I need all the parts or not.

I just had a thought. When you did your driveline job, did you remove your tires and wheels? If so, did they go back on in the same positions that you took them off of?

Mark;

No. As a matter of fact the first time I ever had the front wheels off was yesterday to take the suspension part pictures.

I've always been very impressed with the driveability of the truck and never had reason to suspect anything was amiss in the steering/suspension until this shaking started.

Sounds to me like a tire out of balance or maybe separating. And depending on the tire you may not see it. Had you been up to 60mph or more before the trans swap?

Maybe take the drive shaft back out and check over the u joints, make sure they are not bound up or off center?? You said it always drove good before??

That's why I thought of the tire swap-a-roo. A separating tire on the back axle might not be felt but put it on the front axle and it's a whole new ball game.


The way to inspect front end components is, after a visual inspection, and while up on jacks, grab a hold of the different components and give a good tug. See what you can shake back and forth and feel for loose stuff. This includes the wheel assemblies. Tug them left to right ( like you're trying to turn the vehicle ) and up and down ( while grabbing the top and bottom of the wheel, push the top and pull back. Like you're trying to twist it off.) This will help you find loose king pins and bearings. Feel and listen for big or little "clunks". Look for loose ubolts. Put your hand on them and see if you can move them. Look where the springs attach to the frame for shiny metal or fresh rust. Give a good shake or tug. Put a hand on all your components.

Roy;

Yes. I had taken it up to about 65 in the past. The engine wound up like crazy but I don't remember any shaking. I didn't stay at speed for very long though so maybe I just didn't pick up on it.

Don;

I really don't want to take the drive shaft back out. It was such a monumental pain in the butt to get in. I fought with the u-joints for hours. I actually went through 3 brand new u-joints before I got one successfuly installed. I'll give it a real good visual inspection and see if anything looks odd. If I can't solve the shaking any other way, I'll save the drive shaft task as a last resort.

Mark;

I like your approach. I did that to a cerain extent the other day and didn't find anything lose other than the wheel bearings I mentioned. There was a distinct knocking sound with about 1/16th to 1/8th an inch of play. Not real bad, but I could see it starting to wobble at highway speed. Both sides were about the same. I'll put the truck up on jack stands this weekend and really heave hoe on the parts to see if anything shakes loose.

I need to dig into the shop manual this evening and see what it says about installing/tightning the wheel bearings. If I can't find clear guidance, I'll post a question. I can already hear Bill (Red58)getting ready to chastise me for not reading the manual first. :-)

one of the reason it never happen before is because you never drove it that fast to find out..

I dont know anything about those old over drives and this might be a stupid question, can you drive it at a good speed with out using the over drive, if so that might answer your problem

Joker;

Good point/idea. Yes you can deactivate the overdrive by pulling the lockout cable. I'll try that as well. I'll run it up to speed in regular 3rd gear and see if the shaking starts.



On a related note, and this may be a stupid question, I assume that the tapered roller bearings are better than the old ball bearings?? Is there an installation procedure difference between the two. I've seen that classic parts offers both the rollers and the ball bearings. Just wondering which set to buy.

stick with the ball bearings, they work fine as designed and are available at any parts store [outer B67 or B01 - inner B52 or B40], which is worth keeping in mind if you do any traveling, the roller bearings are a specialty item not readily available and useful only if you change to disc brakes

Bill

Bill;

Excellent. Good thing I asked. I'll swing by NAPA and pick up an original set.

Ball bearing also don't like wide tires either, or if the rim are offset with a deeper dish, which puts more load toward the outer bearing..... But from what I've read on here, I think I'd stick to ball bearings too....

John

Something to think about concerning ball bearings vs tapered bearings, almost ALL modern cars and light trucks are using ball bearings, regardless of tire size, tire type, and brake type. The ball bearings will be just fine, just make sure to lube them thoroughly and set the preload properly.

Bill/John;

Roger. I went to look for replacements at NAPA and a couple of other places yesterday. Nobody had them in stock and the best price I could get for a full set for both sides was $190. My intent was to simply replace them and not have to worry about it.

Based on my experience at the FLAPS I decided to do an inspection of the ones I had. I pulled the hubs apart and looked at the bearings. The bearings themselves looked good. No broken pieces or worn/chipped balls. I was kind of surprised by the state of things. The grease was a little thin. I cleaned them out as best I could and packed a bunch of new grease in them. I reassembled the hubs and torqued the castle nuts to 33 pounds as instructed in the shop manual.

That solved my bearing wiggle/knock problem. They spin free and true and there is no play in the bearings anymore. The passenger side is solid all around. The drivers side still has a little play in it. From what I can tell it is in the king pin.

I'm going to classic truck parts this morning to pick up a king pin replacement set and a set of tie rod ends. I'll be back in the shop manual this afternoon trying to figure that process out.

As always, any helpful hints on king pin/tie rod replacement will be greatly appreciated.

I generally don't replace bearings unless they are discolored (from heat) or spalded (marked). I wash them up in gasoline and dry them, repack them and install.
I was thinking about that the other day, was it ball bearing they use to say use fibered wheel bearing grease in?? I don't think you can even buy fibered wheel bearing grease anymore? The new blends of grease are probably better anymore anyway.

John

I went over to Classic Truck Parts this morning and picked up a set of tie rod ends and a king pin replacement kit. I got a PM from Jerry (Hotrod Lincoln) suggesting I adjust the steering box worm gear "lash." I decided to do that and then take another test drive before jumping into the tie rod ends and king pins.

I made the adjustment and went out for a drive. It was better, but I still had a pretty significant shimmy. While out and about I decided to swing by my local family owned tire shop and have them balance the front wheels. After about 5 minutes in the shop, the technician came and got me and said "you really need to take a look at this." That is never a good sign!! He had the front left tire on the balance machine (the wheel that was causing the most problems).

When he spun the wheel on the balancer it looked like something out of the Flintstones. It had a very noticeable flat spot/bulge on the tire. The rim may have been bent slightly as well. It's the first time I've seen a tire go out of round. Perhaps the vehicle hit a curb real hard or the wheels sat on the flat tires for a long time. It's weird because the tires themselves look pretty good. Not to old and plenty of tread left.

I ended up having the shop balance all four wheels. There was one more that had some issues. We put the two best wheels/tires on the front and the other two in the back. I ran it out on the highway for a test drive on the way home. My front shimmy problem was solved. It ran straight and true with no vibration in the wheel. The problem is that the shake migrated to the rear wheels. With the rear axle being relatively fixed the shaking wasn't as bad as the it was in the front, but it was definitely there.

The tire guy recommended that I buy two wheels to replace the two that were beat up. He also suggested buying 4 new tires. Now I'll need to find two replacement wheels.

I'm going to hold onto the tie rod ends and king pins. I'll replace them next time I have some garage time.

In the mean time, I need some ideas for replacement wheels. I see that most of the GM trucks and SUVs have gone back to a 6 lug pattern. The tire guy measured my lug pattern and said it is a 6 x 4.75" Does anyone know if there are any modern vehicles that run that size bolt pattern? I see a lot of wheels/tires for sale on Craigslist. Sometime you get info on the vehicle the wheels came off, but no one ever lists the bolt pattern size.

I'm going to keep the truck on the local roads until I get this wheel situation sorted.

Good to hear you figured out what was going on. Tires can be a big deceiver. They can look good with lots of tread, but when they get older, or have been parked for a while, they may not be much good.

My pickup had a bent rim and I didn't know it until I had to put on a new tire. Truck didn't shake or shimmy, but you could see the tire moving ever so slightly in and out while on the tire machine.

Another rim solved that problem.

Your tire guy mis-measured the bolt pattern, it's 6 x 5.5" on the 6 lug trucks. Late model 6 lug wheels from full size trucks do have the same bolt pattern, but the backspace and offset will not allow them to be used on the older trucks without interference issues with the suspension/steering. Same problem occurs when using import truck 6 lug wheels. You'll want to find wheels that are a fitment for '87 and earlier 6 lug GM full size trucks, wheels for the '71-'87 1/2 ton 4x4 work perfectly.