Death Wobble - FJ80 Axles Swap on LR Disco 1 - Pirate4x4.Com : 4x4 and Off-Road Forum
 
Pirate4x4.Com : 4x4 and Off-Road Forum  

Go Back   Pirate4x4.Com : 4x4 and Off-Road Forum > Brand Specific Tech > Toyota - Land Cruiser
Notices

Reply
 
Share LinkBack Thread Tools Display Modes
Old 05-07-2019, 12:06 AM   #1 (permalink)
Registered User
 
Join Date: May 2019
Member # 867952
Posts: 3
Death Wobble - FJ80 Axles Swap on LR Disco 1

Hello everyone,

My name is Jon, I am "new" to Pirate 4x4 but have used this site many times for research, entertainment, learning, etc.

I have a problem though. I bought a Land Rover Discovery 1 that has a set of FJ80 axles underneath it. When I bought it, I was informed it had a "death wobble". I have experienced it for myself once and it is pretty violent, and it happens around the 50mph+ mark. I was tinkering around with trying to find out what cause it to wobble so violently. This was last August.

That August my wife and I were in a really bad car accident while in her Honda (we were stopped and got rear-ended at 65+mph) that left me with a traumatic brain injury and MANY physical issues (my wife came out relatively unscathed and is almost recovered).

Anyway, I am not capable of spending the time, energy, or brain processing needed to figure out what is causing the wobble and although I have searched this site and many others, I am having trouble finding a good explanation for what might be wrong (which may be more down to my lack of ability to process things which is causing the problems).

Lets just say this. Any ideas what could be causing the death wobble with the FJ80 axles? They were supposedly completely rebuilt 25K miles ago, and do have ARB lockers front and rear. Otherwise, they are pretty much stock.

Could it be upper and lower ball joints? Our Dodge 2500 had a death wobble and it turned out to be the ball joints...not sure if that translates over the the Toyota style axle though.

The link from the pitman arm to the axle is very slightly bent, but all the linkages feel tight. No play in the steering wheel really. The previous owner made his own suspension arms by modifying the OEM Rover arms. Could it be the Caster angle causing the wobble?

I am not sure. I have only ever owned the truck with the wobble. So I am not sure of how everything is supposed to feel while in good operating order. I do know the previous owner put the 25k miles on it so it can't have had the wobble the whole time. But it got side lined and in fact got sold to me because the previous owner couldn't figure out the wobble?

Any ideas would be sincerely appreciated! Sorry for grammar, spelling, not making sense and rambling. I just need to sell the vehicle to pay medical bills and it would be worth more if I could get it fixed and drivable. Please any advice would be wonderful.

Thank you,
Jon
RRClassicBT550 is offline   Reply With Quote Quick reply to this message
Old 05-07-2019, 02:48 PM   #2 (permalink)
Registered User
 
Join Date: May 2012
Member # 217829
Location: Carlsbad, NM
Posts: 581
I would start with the caster angle. Ive never had death wobble with worn trunnion bearings (what you think are ball joints).
smracing is offline   Reply With Quote Quick reply to this message
Sponsored Links
Old 05-08-2019, 05:22 AM   #3 (permalink)
Registered User
 
surftaco's Avatar
 
Join Date: May 2005
Member # 47670
Location: Jersey Shore
Posts: 856
as some one pointed out that axle doesn't use ball joints, instead there are 2 bearings that the knuckle pivots on. There are shims under the top bearing cap to set preload. If the bearings arnt preloaded properly that would result in some play in the knuckle. You can check for this by jacking the truck up and wiggling the tire. Check for play in all the front end parts, have someone rock the wheel back and forth while you feel all the pivot points for play. If you can't find anything loose in the front end its probably your tires, try another set of tires and see if that helps.
__________________
"Whoso Speaketh Of What Concerneth Him Not Shall Hear What Pleaseth Him Not."
Sir Richard Francis Burton

Build Thread -
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
surftaco is offline   Reply With Quote Quick reply to this message
 
Old 05-08-2019, 07:59 AM   #4 (permalink)
Granite Guru
 
GLTHFJ60's Avatar
 
Join Date: Aug 2009
Member # 140040
Location: Durham, NC
Posts: 928
Quote:
Originally Posted by RRClassicBT550 View Post
...I am not capable of spending the time, energy, or brain processing needed to figure out what is causing the wobble...
But you want us to do the research for you, spoon feed you the answer, then supposedly you have the energy to fix the issue adequately? I'm skeptical.

The wobble can be caused by improper preload on the trunion bearings, but if the axles recently developed this issue, then that's most likely not the issue, as the trunions last much longer than 25k miles. Check your knuckle studs to see if there are any loose or broken, that's quick and easy.

Steering angle (relay rod to drag link), caster, and your custom suspension geometry are most likely to be causing this issue. Give us pictures of your suspension, then commit to spending some time, energy and brain power to this problem, and we can help you fix it.
__________________
1987 4BTJ60 - MoonShine - 4BT/NV4500/EcoBox/NP205/D60/14B
2004 F-550 - 6.0/ZF6 - full bulletproof
GLTHFJ60 is offline   Reply With Quote Quick reply to this message
Old 05-09-2019, 05:57 PM   #5 (permalink)
Registered User
 
Join Date: Dec 2003
Member # 24859
Location: Where ever my wife says
Posts: 5,624
Loose lug nuts, worn wheel bearings, worn trunion bearings, incorrect caster, worn link ends on suspension arms could exaggerate any issues.

Just have to check each item individually.
__________________
Mellonhead
peesalot is offline   Reply With Quote Quick reply to this message
Old 11-03-2019, 10:06 PM   #6 (permalink)
Registered User
 
Join Date: Oct 2018
Member # 858178
Posts: 1
Get a wheel alignment done, this will tell you if the castor is out.
Check preload on the swivel hubs, knuckle bearings as this can cause shakes, along with worn wheel bearings, worn panard rod bushes as others have posted.
Check rims and tyres, will be a process of elimination
Ozyota is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Pirate4x4.Com : 4x4 and Off-Road Forum 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.

** A VERIFICATION EMAIL IS SENT TO THIS ADDRESS TO COMPLETE REGISTRATION!! **

Email Address:
Insurance
Please select your insurance company (Optional)

Log-in


Thread Tools
Display Modes

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
Ultimate Wrangler Build Ups and Swaps thread gtxracer Jeep - Hardcore Tech 364 09-28-2017 05:54 AM
FJ40 Axles with FJ80 lockers jeep937 Toyota - Land Cruiser 8 10-15-2015 01:03 PM
Effing death wobble oneofakind97 Ford 32 10-16-2014 07:54 PM
K30 Death Wobble after king pin bushing replacement acesneights1 Chevy 15 08-22-2014 07:50 PM
Questioable Buyer Concern? Need help! Duffster Bad Sellers, Disputes, etc... 126 09-01-2006 07:05 AM


All times are GMT -7. The time now is 12:07 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.0 ©2011, Crawlability, Inc.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.