Frankie the Fink

OK then - here are some thoughts on vibration troubleshooting from some pros (attached).

Tracy64

Thanks for the check list Frankie. Here's my update from the previous discussion. I went to the shop today to let the guys re-balance my tires with the road force balancer. That really didn't help. It's actually worse now. Doesn't make any sense though. While it was on the lift the tech checked the u-joints. There is a little play in the drive shaft u-joints but not much. Maybe enough to cause a vibration but don't know. The half shaft u-joints seemed ok. One other tech says that the right upper a-arm is worn out. I didn't see it but he says he could see movement around the front bushing casing. Maybe, but again I didn't see any movement. So now I'm back to where I was before I got the decent balance job done. The car pretty much bounces around before hitting 50mph so I have to correct that crap before testing for the other vibration I was feeling. I'm still leaning towards a bad tire. One of the tires had a 56 RF. My buddy at the tire shop where I bought the tires says that we can start swapping out tires to see if that helps.

So there's my follow-up. No steps forward, two steps back and it's finally summer time in South Georgia! LOL

/Tracy

Bluestripe67

FWIW Since you have discovered some worn/worn out parts that are directly related to motion, chasing the tire issue (assuming there really is an issue) may not make a difference. The working parts of the driveline and suspension need to be brought up to a safe standard. U-joints should not have any play in them! Control arm bushings that are bad need to be replaced (all 8) and so do the u-joints. This can only get worse without corrective action. Dennis

Tracy64

Thanks Dennis. The u-joints are on my to-do list anyway. They're not flopping but there is very slight play. I'm not so sure on the upper a-arm. I didn't see what he was seeing and the tech just walked by, moved the tire and made that comment. He wasn't the one doing the tire service. I will inspect that closer and if the a-arm is bad then I'll do the full job.

Back to the tire question, I moved the fronts to the back and vice-versa so now I'm back to where I was prior to yesterday. Slight vibration/bounce in the 50-55mph range but after you push on past that it's fine up to 70 or so. So I'll let that ride until I go through Frankie's check list and replace the u-joints.

Thanks for the input!

/Tracy

blubu

Make sure rear axles castle nut which is keyed are torqued. 50 ft lbs then keyed . And check out ctr mount for rear end it torques at 70 lbs check make sure it is good. I checked my wheels and tires for years even bought another set. To no avail those last two fixed it

dennis6605

Do you have a buddy that would loan you his tires and wheels for an afternoon? Just to at least eliminate that possible problem and expense.

Dennis

sub006

Just take a ride in his car first to make sure it rides perfectly smooth.

Tracy64

Thanks for the input. I'll be sure to check those additional items as well. I checked the upper right control arm myself and I can now see the play. I couldn't see it at the shop because we were looking from the fender well, over his shoulder and with limited light but looking at it from the top, engine compartment, I can see it. Also I can hear a slight metal on metal tinking sound. It's quieter out here in the country compared to the noisy shop. So... at least one control arm but I'm thinking just do the whole set. Also I'll do the u-joints as well. One other thing, I was going to drop my exhaust manifolds to replace the gaskets because I could here a small exhaust leak. What I found while under the car last night while changing the oil was the clean air tube, lower choke tube that plugs into the exhaust manifold, is broke right where it plugs in. So those three pieces will get replaced. While I'm at it I might as well do the tie-rod ends. What the hell, brake job too! Looks like project creep just bit my in the butt!

I'm still not convinced on the tires or after market wheels but I won't focus on them any longer until I correct the other items that's been identified.

It's all good though. I needed something to do anyway!

/Tracy

Tracy64

Hey guys,

I finally got around to installing the control arms that I ordered. Well, at least the uppers. The right side upper seems to have been to culprit, for the most part. If I had to give a percentage I would say that it's 93-95% better. I still have the lowers to install along with the tie rod ends, idler arm and steering stabilizer then get an alignment. I can still feel a little bump in the seats in the 55mph range but nothing like before. Once I had the upper right off you could really see the play in the bushings. So, thanks for the input!

/Tracy

blubu

I have a 63 coupe I fought the same problem for 20 yrs . I tried everything had shafts balanced tires spun up wheel checked Bought new tires had all brgs replaced including P trac Every time you kicked and picked the front end up it woul shudder in the rear. Everything I done helped a little. I even replaced the brgs in the motor. To make a long story short recently I changed rear ends. When I found the front snubber bushing on the nose of front was wore out. I replaced all of it helped immensely as I was putting it back. I noticed the rear stubs axles were pinned with a cotter pin My left one was loos but could not go anywhere. So I torqued it up replaced the cotter pin since I don't drive it much. It had not moved the axle . That finally fixed it. I was so glad to see it fixed.