How tight should front-end be?

I am trying to find the cause of a high speed vibration and I am starting with the front-end. Car is my Bucamino with 65 GS suspension. I can move the passenger side tire at least a quarter of an inch with my hands and the other side does not move. The center link goes up and down when I move the tire. I am suspecting the idler arm and one of the inner tie rod ends. Plan of attack is to change all the tie rod ends and the idler arm. Does this seem like too much play in the steering?

Thanks,

 

How much play in the pitman arm and centerlink connection is reasonable?

 

yep, it wanders on the road. centerlink to pitman arm is the only spot in the steering linkage that is loose. probably 1/16-1/8" of side-to-side play. Centerlink on a 66Riv is expensive to replace/refurbish!

thx!

 

High speed vibration is usually caused by one of the front tires being out of balance or out of round. You may have some other linkage issues, but they don't usually cause a vibration.

 

Isn't the centerlink for 66 and earlier different than the TRW DS785 (67-70 Riv)? Anyone know where to look-up the part number for a 66 Riv centerlink?

 

Intrested in what you find out though, may help point me in a direction.
Have done all new rims, tires and brakes [drums,rotors.calipers] all around and front wheel bearings. still got a slight vib around 50 in the left front it feels like.

Though before doing all that new stuff it was a death rattle around 50 that said go no faster or else. Just a slight vib now. I don't wander all over either.

 

like buickrat said its not a loose part problem its a balance issue your tie rods would have to be damn near falling off to vibrate the car and a 50mph vib that you can drive faster and get out of is a balance issue make sure the tire shop balances them to a 0 not "close enough" if you have modern custom wheels that the center hole doesn't fit the hub tightly you may need hubcentering rings to get the wheel to stay mounted centered on the hub

 

if that was meant for me ill have to do the balance again and I guess to be honest I should double check them at another shop. As the place didn't bother to check my rims run-out the first time around. So I made them re-do them for free since they goofed and didn't say they were bent when they put on new tires. Rims shouldn't be an issue, I got stock steel replacements.

 

just tell them that you have been having consistent balance issues and they will get em done right not just done ,well if its a good shop anyhow

 

I have had this car a little over a year, but I am just now able to look into what is causing this problem. I am checking out the front end and then I am going to compression check and tune the engine. It vibrates at 55+. Front-end shops have balanced the new tires and rims, drive shaft has been rebalanced. The tires run true and everything looks good, so those are most likely not the problem. I am really suspicious that the motor shaking is what I am feeling. It shakes up to around 2,000 rpm while sitting still, but starts to shake at around 3,000 rpm while driving down the highway. Motor mounts have age cracks, but look like they are not separated. After checking how the motor runs, I will consider looking at the flywheel to make certain it is installed correctly. BTW, this is a 65 GS 401 drivetrain that might have a mild cam installed. Transmission is stock 65 GS T-10.

 

Do you feel the vibration in the steering wheel, or is it the whole car?
Can you feel it when you put on the brakes or through the brake pedal?
Does the car drive straight?

What about the rear axle bearings?


ElectraJim

 

Jim, I guess I will have to drive the car down the highway and see how it behaves, taking your questions into account. It drives straight, I know that much without driving it. It is definitely a "don't go faster than this" type of shake.

 

I hate that feeling. Be safe.

One thing I just thought of. If there is a chassis dyno in your area, you can run it on that, and see if it is front end related, or driveline.

Dyno testing is a lot of fun, and cool to bring your local car club too when the track is closed.

just a thought,

ElectraJim

 

I almost want to say possible u-joint? There will be a vibration, at higher speeds, but it will feel more like rumble, mostly in the seat, sometimes in the wheel (remember, the driveshaft turns 3 times for each tire revolution). If the vibration is consistent with rpms,(try it in 1st, 2nd and 3rd) then it is engine/torque converter related.
If it is a vibration from the front end and changes at times, (usually felt only in the steering wheel) it is a balance/runout issue. If you also feel it in the floor, look at the back tires also. If possible, find a shop that does "on the car" balancing. That should fix you right up. You may have a wheel/ seating issue that will only show up on an on the car balance.

 

This is definitely a vehicle speed issue. I would say it starts around 55 mph, but the speedo is probably way off, so I would have to say highway speeds. PO said driveshaft was rebalanced (it is repainted), so I assume it is not u-joints. The PO thought it was worn-out bushings in the rear-end, but I didn't see anything that looked that bad back there. He was assuming it was the angle of the differential. I like the balance the wheel on the car idea. I will have to see if anyone around here does that. (I do live in a remote part of northern California.) I also have another set of rims and tires I could try, but they are really old and I wouldn't want to leave them on the car. With my new Bend Pak lift :grin: it wouldn't be difficult to change the tires. Yes, I am enjoying my new lift, it is so cool. (Lift stuff is under the Bench on this site.)

 

how old are our tires? it could be possible that a belt in the tire is going away and causing a vibration. but would still balance true. maybe rotate the tires to see if the vibration moves.

are the engine mounts ok?

nate