Shimmy while coasting

Post Reply

Topic author
Cobra
ASV Supporter
ASV Supporter
Posts: 1750
Joined: Sat Jun 16, 2007 2:31 pm
Location: Toronto, Ontario
Has thanked: 1 time
Been thanked: 1 time

Shimmy while coasting

Post by Cobra »

so i'm not sure where to post this but i have a vibration that i have never been able to get rid of it's all most not noticeable when accelerating except you can see the review mirror shaking a little bit starting at about 80km/h 50mi/h. If i get up to say 150km/h 90mi/h and let off the gas i get a fairly violent vibration, if i'm just maintaining the speed though you won't feel the vibration only when decelerating. I had the pleasure of making a rather short stop today on the highway and you don't feel the vibration under braking conditions. U-joints and prop shaft have been done recently, tires were rebalanced only days ago. i was watching the other vibration threads for ideas but i didn't notice anything that i feel wound cause this (i may be wrong though) i'm sorrta leaning toward front cv's but not sure what symptoms they would cause and would have to take them out to really check them (i think that's what i was told)
1998 GMC Safari AWD, BFGoodrich AllTerrain T/A
Jet performance tuner 91 octane preset, Jet under-drive pulleys
Rancho 999000 series shock, on-board controller to be installed later
DHC rock rails and skid plate Add-A-Leaf
G3500 front calipers
Zexel Torsen Diff
11" drums
180 amp Alternator
Long tru-cool 4590 trans cooler

1997 gone

batmo
I sleep in my van
Posts: 264
Joined: Tue Apr 21, 2009 1:11 pm

Re: Shimmy while coasting

Post by batmo »

I had an old Javelin do that and it was the tie rod ends.

Kidhauler
I sleep in my van
Posts: 877
Joined: Wed Sep 13, 2006 5:46 pm
Location: Vancouver B.C.

Re: Shimmy while coasting

Post by Kidhauler »

I would look at the idler arms. Failing that try looking at the output shaft of the trans.
1999 Safari Touring edition.
trailer tow pack with a 3:73 posi
Bucket bench seats, Rear heat, Rear Airconditioning.
teal green
300 000 kms
AirRide air bags in the rear to fix soft stock suspension.
Onboard aircompressor to make it all work nice.
User avatar

Kabey's Van
I sleep in my van
Posts: 682
Joined: Mon Sep 29, 2008 8:35 am
Location: Victoria B.C.

Re: Shimmy while coasting

Post by Kabey's Van »

I agree that the steering components are at falt. Tie rods, draglink, pitman arm, jack up the van and check them all. Don't forget to check your wheel bearings too.

Peter

Topic author
Cobra
ASV Supporter
ASV Supporter
Posts: 1750
Joined: Sat Jun 16, 2007 2:31 pm
Location: Toronto, Ontario
Has thanked: 1 time
Been thanked: 1 time

Re: Shimmy while coasting

Post by Cobra »

wheel bearings were replaced 2 and a bit years Tie rods, draglink were replaced under a years ago idlers, ball joints were replaced just after i bought it 3 years ago (it been 3 years already...?) inspected 3? weeks ago and there was very little lateral motion. steering gear box is the only thing that hasn't been replaced yet but sure needs to be.

actually a couple weeks ago i had 30 24x24 paving stones in the back of my van and i was drifting back and forth on the highway like a real drunk. Especially after lane changes had to keep counter steering (actually a little scary) almost like a had a REALLY heavy trailer on me going down hill and it was pushing me around. not sure if that will help point to the answer or not but thought it might be relevant. i'll be up under there today or tomorrow so i'll take a peek at the idlers again since there are the oldest component in there. anymore suggestions are always welcome
1998 GMC Safari AWD, BFGoodrich AllTerrain T/A
Jet performance tuner 91 octane preset, Jet under-drive pulleys
Rancho 999000 series shock, on-board controller to be installed later
DHC rock rails and skid plate Add-A-Leaf
G3500 front calipers
Zexel Torsen Diff
11" drums
180 amp Alternator
Long tru-cool 4590 trans cooler

1997 gone

LiftedAWDAstro
I have my van tatooed on my cheeks
Posts: 4379
Joined: Sat Sep 09, 2006 3:35 pm
Location: New Haven, NY

Re: Shimmy while coasting

Post by LiftedAWDAstro »

Have you checked the diff pinions? You may have one that loosened up for some reason. The only way to really check them would be to remove the drive shafts from the diff's. If they check out, remove the front drive shaft completely and test drive.

Does it do if you put it into neutral at that speed?
Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy

Topic author
Cobra
ASV Supporter
ASV Supporter
Posts: 1750
Joined: Sat Jun 16, 2007 2:31 pm
Location: Toronto, Ontario
Has thanked: 1 time
Been thanked: 1 time

Re: Shimmy while coasting

Post by Cobra »

hmmm i haven't tried it in neutral

edit:so i tested it this morning and even in neutral it's there also cruising at 85mi/h the vibration is visible in the dash 90+ mi/h you can hear the dash shaking and the steering wheel is clearly vibrating.
1998 GMC Safari AWD, BFGoodrich AllTerrain T/A
Jet performance tuner 91 octane preset, Jet under-drive pulleys
Rancho 999000 series shock, on-board controller to be installed later
DHC rock rails and skid plate Add-A-Leaf
G3500 front calipers
Zexel Torsen Diff
11" drums
180 amp Alternator
Long tru-cool 4590 trans cooler

1997 gone
User avatar

dunedog
ASV Supporter
ASV Supporter
Posts: 686
Joined: Wed Feb 07, 2007 1:22 pm
Location: Pioneer Valley WMass

Re: Shimmy while coasting

Post by dunedog »

All the crap in your toolbox in the left rear corner of the van is throwing off the balance numbnut!!! :peep: Eh!
1999 LS AWD 3" Lift,4.10's,Snowplow,9500lb Ramsey winch

Topic author
Cobra
ASV Supporter
ASV Supporter
Posts: 1750
Joined: Sat Jun 16, 2007 2:31 pm
Location: Toronto, Ontario
Has thanked: 1 time
Been thanked: 1 time

Re: Shimmy while coasting

Post by Cobra »

you listen here my 300lbs of random stuff is evenly spread out back there
1998 GMC Safari AWD, BFGoodrich AllTerrain T/A
Jet performance tuner 91 octane preset, Jet under-drive pulleys
Rancho 999000 series shock, on-board controller to be installed later
DHC rock rails and skid plate Add-A-Leaf
G3500 front calipers
Zexel Torsen Diff
11" drums
180 amp Alternator
Long tru-cool 4590 trans cooler

1997 gone
Post Reply