Nasty Vibration
 

The Monte has developed a very bad vibration in high gear. Changed driveshafts and the problem seemed to lessen temporarily, but it's back as bad as before. The driveshaft is straight. Dad can barely hold the shifter back in 4th as he crosses the finish line. We are taking the tranny apart to see if the mainshaft is bent or ???. Can a ring gear be out of balance? We are sending the clutch and disk away to get balanced. Axles ???.

Any help would be appreciated as we're really scratching our heads on this one.

Many thanks in advance!!

Re: Nasty Vibration
 

Just random thoughts, but 1, Make sure rear hasn't moved (string-measure both sides, center of front whl. to center of back whl.) 2, Pinion bearing going bad, or something moved inside rear? Good luck....WJ

Re: Nasty Vibration
 

Might have lost a wheel weight or two???????

Re: Nasty Vibration
 

Several years ago, I had a front wheel/tire out of balance at Scribner that caused my vision to blur so bad that I could not see the scoreboards.
It shook everything in the car.
I had Joe Archer re-balance and cleared it up.

Re: Nasty Vibration
 

Rear bushing in tranny or main shaft bearing.

Re: Nasty Vibration
 

Had a similar problem years ago. I had the drive shaft rebalanced, changed the bushing in the trans tail shaft housing, and also had the front and rear wheels rebalanced. Problem was still there, bad vibration about the last 300' of the track. Ended up breaking the trans case across the bell housing. I put a new Dedenbear trans case in the car and the problems was still there. By this time the rear tires needed replacing and bingo the problem went away. Smooth as glass with the new tires. Before this problem started the car had sat in the garage for two months while freshing the engine. I had neglected to put the car up on jack stands and I guess the rear tires got flat spots. Won't make that mistake again.

Re: Nasty Vibration
 

I had the same issue on my 5speed mustang, it would vibrate so bad that it would jump out of gear as soon as i pulled into gear. It was my mainshaft that was bent. I took it to work and put it on jig and realize it was bent!!! I junked it and put a new one in, and never had the problem again.

Re: Nasty Vibration
 

Mike I had the same thing last year. I could not hold the shifter in high gear. Pilot bearing came out in pieces when we dropped the can. Ed

Re: Nasty Vibration
 

I had a similar situation when a couple of bell housing bolts had backed out earlier this year, sounds simple but it can happen.

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Housing is centered. Pinion bearing feels good and rotates smooth, but 3rd member is coming out tonight, so we'll see. Thanks

Re: Nasty Vibration
 

New tires last weekend at Denver. Balanced with no change. Thanks

Re: Nasty Vibration
 

That's where we're going tonight, along with 3rd member. Thanks, Adger.

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Yeah, that's the reason the tires where changed before we made any runs at Denver. Thanks, Darrin.

Re: Nasty Vibration
 

Got the tranny out last night. After it's apart tonight, we'll set the main shaft up on "V" blocks just to see if there is an obvious bend. If not, it's going in to get checked tomorrow. Thanks, Adger.

Re: Nasty Vibration
 

Another good suggestion. We'll find out tonight. Thanks, Ed. Coming up to Tulsa this weekend?

Re: Nasty Vibration
 

Hey mike when we first got the cavalier done we had a terrible vibration in the steering from the 1000 ft on ,we checked everything, to make a long story short we had a bad set of front tires how we found this out jason took them to a tire shop in north kcmo that balances big tires like for FWD trucks it is different than conventional spin balancers it has wheel of some sort that spins on the outside of the tire and thats how we found out the tire wasn't round from now on we always take them there to get mounted and balanced . this might not be your problem but keep that in mind for the future ,don't trust the track balancers were you buy your tires we had both front and rears checked and they told us they were ok ! good luck chris

Re: Nasty Vibration
 

Thanks, Chris. Even on stands, the vibration is horrible. On visual inspection, the rears don't seem to be out of balance, ie. not hopping or bouncing. I think it has to be in the driveline somewhere, but I also think we need to balance the tires once, as you mentioned. It definately wouldn't hurt and might make the ride more smooth.

Thanks again for the suggestion. Why weren't you guys at Denver?

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Mike find out anything yet? No im not coming to Tulsa. Considering going to the 3 races in 3 days S/SS combo at Belle Rose next month. Ed

Re: Nasty Vibration
 

Got the clutch and pressure plate back yesterday. The pressure plate was out of balance by 38 grams!! We all know that these cintered iron setups warp from all the sliding, but does that usually make them out of balance?? Nothing was missing from the pressure plate, and the disc is still in one piece. Anyone ever have this issue?? The tranmission is still coming apart, hopefully tonight, but 38 grams is a TON spinning at 9000 RPM

Any other thoughts??

Re: Nasty Vibration
 

Mike,
I'm sure thay told you 38 grams, but to really tell how much out it is the actual correction radius needs to be known... 38 G. 2 in from center is not nearly as much as 38 g. 8 in from center..... Still 38 G is a big number for any correction radius.
That could have knocked a little extra clearance in a few other vital parts. Rear bushing and Pilot bearing as well as all bearings in the tranny come to mind..
good luck

Re: Nasty Vibration
 

The "lug" was welded just past center, more towards the outside of the hat than the inside. There was a small one on the opposite side that was cut off to balance properly. Something doesn't add up...without breaking a finger, etc., how can a pressure plate be that far out of balance?

The mainshaft appears straight, but we'll know later today for sure when we get it back from the machine shop.

Re: Nasty Vibration
 

Mike,
It could have something in the clutch failing and the plate be way off center.
I'm not familar with your clutch, but the old Long style and Borg & Beck I used back in the 70's would shift the pressure plate off center if a stirup or a hat hold down bolt would/was failing.

Good Luck

Re: Nasty Vibration
 

I really can't explain the driveshaft change and temporary vibration reduction having anything to do with what you have going on in the pressure plate but pay attention to Adger. If it's a failing eyebolt the plate will shift and cause what you found. (assuming the balance has changed) Definitely double check your finger height at whatever compressed thickness your disc is before reusing the pressure plate. I'm also assuming there is no centrifugal weight malfunction going on. Good luck....

Re: Nasty Vibration
 

I went through a vibration problem with my car and it ended up being the universals that the drive shaft company installed were .040 too short in the sleeve that they sat in. Another words, if you messure the end to end of the universal, they might not fit exactly the way they are supposed to. I found it by going under the car, when getting myself back out, I grabbed the drive shaft and it went clunk. It was only .030 to .040 too short, but I went crazy looking for the vibration. The manufacterer was I believe Splicer and they were the 1350 solid joints.

Casey Miles
248H

Re: Nasty Vibration
 

I have heard of clutch surfaces being machined (improperly) at an angle and accounting for such out of balance numbers as you are reporting. You won't be able to see the problem either. It will also make your runs horribly inconsistent and a vibration. Measure all of your friction surfaces from side to side across 4 corners.
If you find your pilot bearing (I hope you use a bearing and not a bushing) is bad, I wouldn't jump to the conclusion that was the initial problem until I measured the clutch parts.
While on the subject, I've also heard of heat shields being ground but the back side remains warped from excessive heat. That will also cause problems because the friction side has inconsistent depths of material.
And while your at it, make sure your bellhousing to trans mounting surface is still parallel. Years of bolting down a trans can take it's toll on this. And re-dial indicate the run out of everything too.

Re: Nasty Vibration
 

I bought an aluminum driveshaft with the trans yoke still attached and put it in my car. It came out of another Jerico equipped AMX and we both had Dana 60 rears so I figured it would be an easy swap.
The new shaft / trans yoke did not engage as far as my old driveshaft. I thought it wasn't a big deal, maybe 1/4" shorter than before.
That thing shook the car so bad when I pulled it out of my driveway I couldn't believe it. Then I tried to load the car on the trailer. I never got above 5 MPH and it sounded like the car was going to fall apart. I changed back to the MW CM driveshaft in the street as I didn't want to put it in gear and move it again. Took care of the problem.
Something to think about...

Re: Nasty Vibration
 

Had a rifle drilled axle bent in housing. It was twisted and curved half way down axle. Low speed was noticable but top end it was bad.

Re: Nasty Vibration
 

Two things:

1. Found out that the pressure plate was balanced without the disc in place. In doing so, the floater can move around causing this inbalance and also, adding weight to the pressure plate where it was added is a no-no. Clutch is going back to Hyatt to get fixed.

2. Took the rears to get high speed balanced, and the results were not good! We have egg shaped slicks that were produced in 2001, and we just bought them!!

As John Force would say..."Bottom line is..." we may not have found the problem yet. The search continues...

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Where did you buy "new" 9 year old tires? Send them back. Dyno

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Shelf life on slicks is 3 years...may vary by manufacturer but that's approximate. I always make sure I'm getting the freshest sets available.
Find out what your mfg says about shelf life and demand a new set from the vendor you bought them from.

And do get that clutch fixed by Hyatt!

Re: Nasty Vibration
 

After reseaching and a phone call to the Akron, OH Goodyear facility, they have not made the tire we run for a long, long time and won't for sometime either. They said they are 3,000 sets behind in production. We use the 1823's 14x31.5 D4A compound. We bought them from the distributor in OKC and took them to Denver. No one has these anymore and the compound on this part is junk. We have a set of Hoosiers that we couldn't ever get to work on our car, but they might be going back on for the time being.

Anyone ever make the radials work for a stick car ?????????

Re: Nasty Vibration
 

Mike -

My dad has a set of Mickey Thompson tires that were recommended by them to use on his stick E/SM. I know there were several comp cars this weekend at Tulsa running Mickey Thompson radials. The tires he has are the 3074R 32.0/14.0R15. We have not ran them yet to give you an idea of if they work or not, but we will definitely be running them in the future.

Re: Nasty Vibration
 

I bought a set of 1823's from Goodyear tire distributor Carol Shelby here in Phoenix, AZ just this year (probably February?). Although they are at the shop 75 miles away and I can't give you a date code, they were fresh or at least fresh enough.
It was Goodyear that told me a 3 year shelf life was acceptable.
Rob Youngblood talked me into these 1823's as he loves them on his SS/J 'Vette. He tells me they will match 60' times with anything but will excel in the 330' and beyond. It's a lot bigger tire than anything I'm used to but I can't help but think they'll work for me.
But nothing will help an old slick so I guess it's cha-ching time!

And I'm not aware of radial tire success with a stick. If there is, guess it's a big secrete!

Re: Nasty Vibration
 

Vibration gone! Bell housing was twisted. After many futal attempts to straighten with no luck, purchased a new bell housing and now, smooth sailing once again. Thanks for all the tips and suggestions. Glad this saga is finally over. We went through 2 QuickData's, loose motor mount bolts, loose 3rd member bolts, metering rod hanger pin suck through the carb and many other "gremlins" due to the vibration. On to the next adventure!

Re: Nasty Vibration
 

Wow never heard of that one before. Glad you found it and good luck. Joe