vibration problem - 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> Transmission - Rearend
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 12-28-2005, 07:57 AM
wildfire78's Avatar
wildfire78
 
Join Date: Jul 2005
Location: Louisiana
Age: 70
Posts: 21
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
vibration problem

I have a 78 Dodge D100 with a modified 318. I recently changed the rear end gears from 3.2? to 4.11's. Since that time when I get to around 4500 RPM I begin getting a severe vibration. I can't pinpoint where it is since it is felt through out the truck. I have checked pinion angle, drive shaft balance, tire/wheel balance, etc.. All of which is good. I'm now wondering if it is being caused by the rear end gear swap or if it was there already and I never pushed it to the 4500 RPM with the lower numerically gears. Am I overlooking something?? Any help would be appreciated. Thanks

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 12-28-2005, 08:19 AM
Member
 

Last journal entry: More propane stuff
Last photo:
Join Date: Jun 2003
Location: -
Posts: 277
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Is it more noticable at certain speeds or rpm? Does it vibrate at 4500 in all gears? Or is only in high gear at highway speed? Does it vibrate in neutral at that speed or do you have to throttle it up to get it to vibrate?

Let us know

John
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 12-28-2005, 11:47 AM
wildfire78's Avatar
wildfire78
 
Join Date: Jul 2005
Location: Louisiana
Age: 70
Posts: 21
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by propaniac
Is it more noticable at certain speeds or rpm? Does it vibrate at 4500 in all gears? Or is only in high gear at highway speed? Does it vibrate in neutral at that speed or do you have to throttle it up to get it to vibrate?

Let us know

John
It starts to vibrate at about 4300 RPM on the highway and gets worse the higher the RPM/speed goes. I'm running the 727 automatic and there is no vibration in 1st or 2nd even when I am on it hard and RPM reaches 4000. I haven't tried shifting to neutral at that speed, the next time I am on the road will try this. I was wondering if maybe I needed a new harmonic balancer since this is the original from 78. I figured I would feel vibration even at lower speeds if this was it though. Thanks for the thought on trying it in neutal, that completely slipped my mind.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 12-28-2005, 12:33 PM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Last photo:
Join Date: Jul 2002
Location: Columbia, Mo
Age: 38
Posts: 4,080
Wiki Edits: 0

Thanks: 0
Thanked 10 Times in 10 Posts
Drive shaft balance problem or u joint problem. Bad tire wear problem.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 12-30-2005, 09:47 AM
Member
 

Last journal entry: More propane stuff
Last photo:
Join Date: Jun 2003
Location: -
Posts: 277
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I agree with Johnsongrass. The lower gears have sped up your driveline, ( thats why you didnt notice it before) See if you can find a good driveline shop and get them to balance it.(replace the ujoints when you have it out) I have a friend here that has a balance machine and it is interesting process to straighten and balance a shaft.

Also check the slip yoke and bushing in the trans.

Keep us informed. Nothing more frustrating than never hearing if we helped or not.

John

Last edited by propaniac; 12-30-2005 at 10:11 AM.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 12-30-2005, 10:00 AM
poncho62's Avatar
Out of the Loop Moderator
 
Last wiki edit: Streetbeasts links
Last journal entry: at car show
Last photo:
Join Date: Oct 2003
Location: Hanover, Ontario, Canada
Age: 62
Posts: 16,899
Wiki Edits: 5

Thanks: 20
Thanked 261 Times in 213 Posts
Im thinking "U" joints also.......they can still be tight, but dried out which will cause vibration. Replace them both....they are cheap enough, and a simple fix.
__________________
Ontario Rodders

Budget RVs
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 12-30-2005, 10:14 AM
wildfire78's Avatar
wildfire78
 
Join Date: Jul 2005
Location: Louisiana
Age: 70
Posts: 21
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I tried putting it in neutral today while on the highway and the vibration was still there. Both U-Joints have been replaced. I believe you'll may be on to something with the drive shaft since it still vibrates in neutral and as propaniac stated the speed of the driveline has increased compared with before. As soon as I get the chance I will pull the drive shaft and find someone to check for straightness and balance. I'll let you'll know what I find out. Thanks again for all the suggestions.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 12-30-2005, 10:32 AM
poncho62's Avatar
Out of the Loop Moderator
 
Last wiki edit: Streetbeasts links
Last journal entry: at car show
Last photo:
Join Date: Oct 2003
Location: Hanover, Ontario, Canada
Age: 62
Posts: 16,899
Wiki Edits: 5

Thanks: 20
Thanked 261 Times in 213 Posts
Turning the "U" ,joint 180 degrees in the rear yoke may also make a difference.
__________________
Ontario Rodders

Budget RVs
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 12-30-2005, 11:30 AM
1931 steve's Avatar
Hotrodders.com Moderator
 
Last wiki edit: How to rebuild an engine Last photo:
Join Date: Nov 2004
Location: Michigan
Age: 43
Posts: 1,207
Wiki Edits: 4

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by poncho62
Turning the "U" ,joint 180 degrees in the rear yoke may also make a difference.
I always mark them before I take the shaft out so to install it back in the same position. And yes I have had them vibrate by being 180 out.

Steve
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 12-30-2005, 12:29 PM
1982 SS's Avatar
Flamethrower
 

Last journal entry: More Cooling fan pictures.
Last photo:
Join Date: Mar 2005
Location: Utah
Age: 27
Posts: 340
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Just a thought, nobody has said motor or transmission mounts. I replaced all of mine and it made a huge difference. I would imagine it could be the rubber mounts just given the age of the vehicle unless the have been replaced.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 12-30-2005, 04:34 PM
Member
 
Last photo:
Join Date: Aug 2005
Location: Yackandandah.Australia.
Age: 52
Posts: 641
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Check the diff yoke, I had one side worn on a 9 inch and it chopped out 2 rear unis in 2 weeks. Also consider driveshaft diameter, check the shaft from a factory 4.11 geared truck - they may differ. Is your pinion bearing preload ok? It all points to a problem between the g/box planetary set and the pinion as this part of the powertrain is the one that has seen the increase in rpm.
Reply With Quote Quick reply to this message

Recent Transmission - Rearend 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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Ignition Problem malibuman66 Electrical 17 01-24-2006 01:05 AM
Driveline Vibration-Cause-Engine Problem, HELP 71gtx Engine 12 01-19-2006 09:00 PM
Found low oil pressure problem.... kc_ksom Engine 2 09-06-2005 07:01 PM
Vibration Problem missconduct Transmission - Rearend 2 07-20-2004 10:12 AM
Vehicle Vibration Smittyd55 Transmission - Rearend 3 03-01-2004 05:31 AM


All times are GMT -6. The time now is 01:42 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.