Tire balancing - Page 4 - Nissan : Datsun ZCar forum :Nissan Z Forum: 240Z to 370Z
User Tag List

Reply
 
LinkBack Thread Tools
post #31 of 43 (permalink) Old 02-08-2019, 03:20 PM
Senior Member
 
bificus's Avatar
 
Join Date: Sep 2010
Location: SC
Posts: 1,046
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 53 Post(s)
Garage
Quote:
Originally Posted by chaseincats View Post
I don't, it's only at highway speed.

I jacked the car up and free spun both wheels - the driver one spins well, the passenger one is noticeably slower to free spin. Could that be an indication of anything shake-related?
Not normal. May be wheel bearings or brake caliper issue. Does the slower wheel have any play in it? Check for grease.

1975 280Z F54/N47 MSA 6-1 Header 2.5 Exhaust
bificus is offline  
Sponsored Links
Advertisement
 
post #32 of 43 (permalink) Old 02-08-2019, 03:22 PM Thread Starter
Senior Member
 
Join Date: Jun 2016
Posts: 512
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 107 Post(s)
(Thread Starter)
Quote:
Originally Posted by bificus View Post
Not normal. May be wheel bearings or brake caliper issue. Does the slower wheel have any play in it? Check for grease.
it doesnt have any left/right play - that was fixed with new tie rod ends. check for grease under the wheel bearing cap, right?

1978 280z - stock L28 engine - Dallas, TX
chaseincats is offline  
post #33 of 43 (permalink) Old 02-08-2019, 03:23 PM
Senior Member
 
Join Date: Sep 2006
Posts: 5,079
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 149 Post(s)
Could be worn shocks. The shocks act as a dampener to the spring action and mass of the tires, springs and suspension items. Usually there will be a "sour spot" at a certain speed where you'll hit a resonance between the shock and the mass where a small vibration will occur but disappear as your speed goes beyond that point. Always for some reason found this on most cars to be around 60mph.

Changing to different weight tires/rims can change the dynamics of vibration.
https://auto.howstuffworks.com/car-suspension1.htm

zippityzda
dumbestone is offline  
Sponsored Links
Advertisement
 
post #34 of 43 (permalink) Old 02-08-2019, 03:25 PM Thread Starter
Senior Member
 
Join Date: Jun 2016
Posts: 512
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 107 Post(s)
(Thread Starter)
Quote:
Originally Posted by dumbestone View Post
Could be worn shocks. The shocks act as a dampener to the spring action and mass of the tires, springs and suspension items. Usually there will be a "sour spot" at a certain speed where you'll hit a resonance between the shock and the mass where a small vibration will occur but disappear as your speed goes beyond that point. Always for some reason found this on most cars to be around 60mph.

Changing to different weight tires/rims can change the dynamics of vibration.
https://auto.howstuffworks.com/car-suspension1.htm
So I went from these 50lb each monstrosities that the car came with to the ZX 6 spoke. the car drove WAY better after the change but the shake continued

1978 280z - stock L28 engine - Dallas, TX
chaseincats is offline  
post #35 of 43 (permalink) Old 02-08-2019, 11:10 PM Thread Starter
Senior Member
 
Join Date: Jun 2016
Posts: 512
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 107 Post(s)
(Thread Starter)
Quote:
Originally Posted by bificus View Post
Not normal. May be wheel bearings or brake caliper issue. Does the slower wheel have any play in it? Check for grease.
I actually just confirmed they both spin properly. I am in the middle of this mess and it seems the brakes didnt fully disengage when I spun it: https://forums.hybridz.org/topic/127...g-disc-brakes/

have you had to do this before?

1978 280z - stock L28 engine - Dallas, TX
chaseincats is offline  
post #36 of 43 (permalink) Old 02-09-2019, 02:53 AM
Senior Member
 
Join Date: Sep 2006
Posts: 5,079
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 149 Post(s)
That would change the dynamics/influence of the shocks with less unsprung weight, but not eliminate "all" the vibration.

You would think that if the rotors are dragging (and the brake pistons only return as far as the rotors push them back) and you had a problem with the MC return hole not letting fluid back, the drag would heat the pistons and the fluid behind them and expand the fluid with no way to relieve the pressure back to the MC. Result more drag, and that could cause vibration if the rotor is not true and it grabs intermittently as the "high spots" on the rotor grab with each revolution. But you would notice the drag holding you back and the brakes would grab as soon as you touched the pedal.

zippityzda
dumbestone is offline  
post #37 of 43 (permalink) Old 02-09-2019, 08:53 AM
Member
 
Join Date: Jun 2017
Posts: 64
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 16 Post(s)
Just read through this thread for the first time. A few things:

1) I don't see where you mention whether the shaking is a new phenomenon or if the car has done this from day one of your ownership. If it's "always" been there, then the possibility exists that it's more than a tire/wheel/brake/suspension issue, in which case some careful measurements of the body and frame are probably in order.

2) Given the number of tire/wheel combos you say you've tried you can can set aside - if you haven't already - the idea that the tires and wheels are the culprit and focus on the suspension (depending on the answer to No.1 above, of course).

3) In an earlier post you noted that one front wheel rotates easily, while the other is harder to spin. Chances are, unless the one that's hanging up is more than just a little harder to turn, this is nothing more than a slight over-tightening of the spindle nut. I wouldn't expect this to cause any sort of shimmy, however, but rather to perhaps make the car pull slightly to one side.

3a) If on the other hand, the wheel you think is too tight is actually tightened properly (the front wheel shouldn't spin absolutely freely) then it's possible the one you think is fine is actually too loose, a condition that could certainly manifest itself by way of a shimmy, shudder or shake.

4) Front suspensions aren't terribly complicated, but they do require that the various components work together in some reasonable level of harmony. Shock absorbers, for example, were mentioned earlier. While shocks might not come first to mind as the likely cause of a front end shimmy they, like any front suspension part, should not be dismissed out-of-hand ... particularly after other, more commonly expected culprits, have been eliminated.

Finally, along with being not all that complicated (dirty, grimy, gorilla-type work, to be sure, but not complicated), the cost to rebuild a suspension is pretty tame when compared with some other major, or fairly major projects (I'm assuming here that you're a DIY kinda guy who won't be forking over $60-$80/hr for labor) so you might consider eliminating the problem by eliminating every worn out part (again, depending on your answer to No.1).



_

Last edited by nkowi; 02-09-2019 at 08:59 AM. Reason: typo
nkowi is offline  
post #38 of 43 (permalink) Old 02-09-2019, 11:54 AM
Senior Member
 
bificus's Avatar
 
Join Date: Sep 2010
Location: SC
Posts: 1,046
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 53 Post(s)
Garage
Quote:
Originally Posted by chaseincats View Post
I actually just confirmed they both spin properly. I am in the middle of this mess and it seems the brakes didnt fully disengage when I spun it: https://forums.hybridz.org/topic/127...g-disc-brakes/

have you had to do this before?

I had a poorly machined brake pad give me issues before. It didn't slide on the pins properly and would stick. If you haven't checked your brakes, probably a good idea. While your are in there look at tie rods and boots ball joints etc.

1975 280Z F54/N47 MSA 6-1 Header 2.5 Exhaust
bificus is offline  
post #39 of 43 (permalink) Old 02-09-2019, 11:57 AM
Senior Member
 
bificus's Avatar
 
Join Date: Sep 2010
Location: SC
Posts: 1,046
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 53 Post(s)
Garage
Quote:
Originally Posted by chaseincats View Post
it doesnt have any left/right play - that was fixed with new tie rod ends. check for grease under the wheel bearing cap, right?

Yeah, pretty easy. Did you get an alignment afterwards?

1975 280Z F54/N47 MSA 6-1 Header 2.5 Exhaust
bificus is offline  
post #40 of 43 (permalink) Old 02-09-2019, 11:50 PM
Senior Member
 
Join Date: Sep 2006
Posts: 5,079
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 149 Post(s)
Quote:
Originally Posted by bificus View Post
I had a poorly machined brake pad give me issues before. It didn't slide on the pins properly and would stick. If you haven't checked your brakes, probably a good idea. While your are in there look at tie rods and boots ball joints etc.
True that. And the "paint" they generously apply can "fill" the groove that slides on the pin.

zippityzda
dumbestone is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Nissan : Datsun ZCar forum :Nissan Z Forum: 240Z to 370Z forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
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:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



  Similar Threads
Thread Thread Starter Forum Replies Last Post
internal tire balancing media 74Adam 70-83 Tech Discussion Forum 22 11-30-2004 06:08 PM
Balancing Unknown User 70-83 Tech Discussion Forum 2 10-31-2004 08:42 PM
Anyone have trouble with tire balancing for SO-3's? z-boss 90-96 Tech Discussion Forum 12 03-16-2004 03:53 PM
Stroker balancing ??? Evan Purple240 70-83 Tech Discussion Forum 2 11-07-1999 11:59 PM
Equipment for balancing carbs? Unknown User 70-83 Tech Discussion Forum 5 01-23-1999 02:31 PM

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

 
For the best viewing experience please update your browser to Google Chrome
 


Content Relevant URLs by vBSEO 3.6.1