I've got the shakes! - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Suspension - Brakes - Steering
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 06-15-2004, 11:29 AM
Member
 
Join Date: Nov 2002
Location: Beverly Hills
Posts: 442
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
I've got the shakes!

Alright, here is a new one. My 37 Plymouth street rod has a SBC 307/350 combo with a 10 bolt GM 2.73:1 rear end. Front suspension is a Fatman IFS w/ power R&P. The rear is hung on the original springs w/ standard gas shocks. Wheels are 15x7 smoothees w/ P215/70R/15 BF Goodrich boots. I have a nagging shake above 55 mph. The engine has been externally balanced, the drive shaft has been balanced too. The wheels and tires were balanced only hours before my trip to Indy. Yet the car shakes. At the steering wheel and into the body. One rodder said it might be a rotor. Mine are less than 2 years old w/ less than 5,000 mile on them. All the shocks are new and tested OK when off the vehicle earlier this spring. Any suggestions where I should look for an imbalance? Short of puting the car on a chassis dyno, I don't know what to do. Any suggestions?

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 06-15-2004, 12:46 PM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Last photo:
Join Date: Jul 2002
Location: Columbia, Mo
Age: 37
Posts: 4,078
Wiki Edits: 0

Thanks: 0
Thanked 9 Times in 9 Posts
rotor out of round, Drive line out of round or bound. Bent wheel or bent axle, anything along the drive line basically.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 06-15-2004, 01:36 PM
Member
 
Join Date: Nov 2002
Location: Beverly Hills
Posts: 442
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
That's the frustrating thing about the problem. I have checked the car and all the components for out of round, out of alignment, binding and flat spots or bent rims and can find nothing unusual.

When you say "rotor out of round" are you suggesting the rotor could be egg shaped or are you suggesting the rotor is warped along the plane of the rotor. If it was warped, the brakes would pulse and the brakes are very smooth and even.

Is it possible the front end setup could cause some sort of shaking to occur?
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 06-15-2004, 09:24 PM
Member
 
Last photo:
Join Date: Aug 2002
Location: Alabama
Posts: 606
Wiki Edits: 0

Thanks: 0
Thanked 4 Times in 4 Posts
Take the front tires off and put them on the back, and the back on the front and see if the vibration changes in any way. If it does one or more of the tires need to be replaced. When I worked at Firestone I have seen tires that were both trued and balanced, shake. They call it radial vibration and I have seen it on brand new tires also. There is nothing visibly wrong with the tire. I assume you have already checked for tight front end parts and bearings.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 06-15-2004, 10:28 PM
Member
 
Join Date: Aug 2003
Location: California
Posts: 903
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
jpd37,

Has the car always done this or did something change?
I would check tire balance but on the car. You will have to go to a bigger tire shop and have then spin the front tires one at a time and using a strobe light find out which tire it is. I don't think it is a back one but if the fronts check out then do the back. I do not know how much this costs but sometimes you have to pay the piper.
Another place to check is the drive shaft where it attaches to the rear end. Sometimes when, we get in a hurry, we can put these in but slightly off center. Everything seems to look ok but look very closely. This will cause the driveshaft to "whip" and anything could shake.

Good Luck
Scholman
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 06-16-2004, 06:15 AM
Member
 
Join Date: Nov 2002
Location: Beverly Hills
Posts: 442
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
I free spun the front wheels last night and both wheels have a slight wobble. Run-out is about 3/16" on each wheel. That may be part of the problem.

I will loosen and reset the rear U-joint to be sure it is centered.

I'm going to put a stiffer set of shocks on the rear too. I may be getting some wheel hop because the stock springs may not be stiff enough to keep the wheels on the pavement above 60 mph.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 06-16-2004, 10:01 AM
Bluejackets67's Avatar
Member
 
Last photo:
Join Date: Oct 2003
Location: Central Ohio
Age: 47
Posts: 47
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Is the vibration/shake in the steering wheel? If so, you may have a caster shake. Add a little more caster (1 degree at a time) and see if that takes care of it.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 06-16-2004, 10:19 AM
Member
 
Join Date: Nov 2002
Location: Beverly Hills
Posts: 442
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
CASTER SHAKE!

Now we are talking about something new. You may have something there! I have set the caster to the recommended setting per the instructions from Fatman. It never occurred to me that a shake could result from that. I will make the adjistment and test drive it to see if that is the problem. I have a feeling that could be the answer. I'll let you know. THANKS!
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 06-16-2004, 10:36 AM
4 Jaw Chuck's Avatar
Hotrodders.com Moderator
 
Last photo:
Join Date: Mar 2002
Location: Manitoba, Canada
Age: 46
Posts: 4,900
Wiki Edits: 0

Thanks: 0
Thanked 72 Times in 60 Posts
Quote:
Originally posted by jpd37
I free spun the front wheels last night and both wheels have a slight wobble. Run-out is about 3/16" on each wheel. That may be part of the problem.

I will loosen and reset the rear U-joint to be sure it is centered.

I'm going to put a stiffer set of shocks on the rear too. I may be getting some wheel hop because the stock springs may not be stiff enough to keep the wheels on the pavement above 60 mph.


Thats is a lot of wobble, looks like you found your problem.
__________________
Outlawed tunes from outlawed pipes
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 06-16-2004, 08:38 PM
Member
 

Last journal entry: JB's 37 Pickup
Last photo:
Join Date: Oct 2002
Location: Smoky Mountains
Age: 76
Posts: 2,358
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
What brand tire do you have on the front? We just ran into a problem with some Brand X tires made in some third world company that proved to be very difficult to balance and required lots of weights. Turns out the sidewall thickness is so uneven as you go around the tire. We have not put the car on the road yet, but suspect we will be returning the junk and go with better tires. These are wide whitewall radials to go on a restored 56 Tbird. This uneven thickness produces unusual runout results, which caused us to run the calipers around the sidewalls, something we have never done before. One other thing I have found to cause vibrations transmitted thru the steering wheel is loose wheel bearings. You may want to recheck them while you are in the hunt.

Trees
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 06-16-2004, 09:39 PM
Rob Keller's Avatar
AKA:"SLOWRIDE66"take it easy!
 
Last wiki edit: How to post pictures on a forum
Last journal entry: 85 Suburban
Last photo:
Join Date: May 2004
Location: Central Florida U.S.A.
Age: 48
Posts: 4,297
Wiki Edits: 38

Thanks: 0
Thanked 1 Time in 1 Post
shake

Ive heard of wheel bearing not torqued to spec to cause a vibration
also a caliper sicking and warping a rotor
personally its probably a tire i went round and round trying to get round tires for my 85 3/4 ton suburban geess good year wranglers good for a tire fire 45 miles an hour and my soda is flat in five miles and who knows where my cell phone is it was on the seat

try to find an old timer who has a strobe balancer and have him turn each wheel individually if he has that hell probably have a tire shaver too
how attached are you to your sneakers?
start at the tire and move inward

good luck
slowride66
__________________
"SlowRide66"

"Illegitimis non carborundum"
Don't let the bastards grind you down!

Crankshaft Coalition Master List of Hotrodding Forums
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 06-17-2004, 02:21 PM
Member
 
Join Date: Nov 2002
Location: Beverly Hills
Posts: 442
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
I have asked two very reputable chassis shops that work on all types of cars and hot rods and they both said they have never heard of Camber Shake or any theory that considers camber a contributing factor to vehicle shake.
I have checked the wheel bearings. I do not torque my bearings any more than 1 lb. while the wheel is spinning. The wheels spin very freelyand the bearings are in good shape and well greased.
I'm running BF Goodrich boots. P205/70R/15 on all four.
I'm not sure if a 3/16" wobble in the wheel is enough to give me the shakes. It might be. I'm tempted to put the car on a chassis dyno to see if the problem can be isolated that way.
I'm fairly new at this automotive engineering thing so I do a lot of guessing and trial and error learning. The process is slow but at least I'm learning as I go.
I seem to recall seeing a strobe balancer a long time ago. That might be harder to find than my shaking problem.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 06-17-2004, 10:14 PM
Rob Keller's Avatar
AKA:"SLOWRIDE66"take it easy!
 
Last wiki edit: How to post pictures on a forum
Last journal entry: 85 Suburban
Last photo:
Join Date: May 2004
Location: Central Florida U.S.A.
Age: 48
Posts: 4,297
Wiki Edits: 38

Thanks: 0
Thanked 1 Time in 1 Post
stupid question

Beverly hills California? is where you are?
because there is a small town about 30 miles from where i am
point I know where there is one and the old timer who knows how to use it

use your common sense and you will be fine

good luck
slowride66
__________________
"SlowRide66"

"Illegitimis non carborundum"
Don't let the bastards grind you down!

Crankshaft Coalition Master List of Hotrodding Forums
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 06-17-2004, 10:33 PM
abstruse dutch uncle
 
Last photo:
Join Date: Feb 2004
Location: East Coast USA
Age: 44
Posts: 393
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I have heard of caster (not camber) shake. Look at a wobbly shopping cart wheel, and you will see a classic example. It is caused by too much positive caster, and is primarily a problem on cars with steering arms behind the wheels, and caster in excess of 4* positive. (and on shopping carts) If the front end is tight, it is usually not a problem.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 06-18-2004, 09:06 AM
Member
 
Join Date: Nov 2002
Location: Beverly Hills
Posts: 442
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
I'm taking the car in for a wheel alignment as soon as possible. Caster shake sounds more like the problem. I will talk to my tech about it before we do the settings. I have a new power assist R&P, so I assume the R&P is not the problem. We will check it for any unusual play.

I live in Beverly Hills MICHIGAN. It's a lot nicer than the west coast version and a lot less expensive. A lot of people get us confused with the west coast local.

To rule out wheel wobble, I have transfered the wobble to the rear to see if it makes a difference. I am also having the wheels rechecked for balance, roundness and trueness.

I have checked the rear "U" joint. Loosened the bolts, checked the seat, spun the cups and reset the joint and torqued the bolts to 4 lbs.

Hope the caster setting does the trick.
Reply With Quote Quick reply to this message

Recent Suspension - Brakes - Steering posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -6. The time now is 01:57 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.