4 jackstands = chassis flex

NotFast · 09-12-2003, 01:46 PM

This happened a few weeks ago, and I thought I'd finally share this with the S&M group here.

I had my car up on 4 jack stands, on a level surface (my garage). I was bleeding my brakes and changing my tranny lube. I went into the passenger front door to grab my owner’s manual to triple check how much MTL to use (3.7Q), and when I closed the door, it made a funny "clunk". I opened the door again, closed it and heard it again. After trying it a few times, I realized that the lower portion of the door was now rubbing/clunking against the bottom of the doorframe! I'd never noticed this before, so I got little freaked out when I realized that it was probably related to the car being up on stands, and I thought I had bent the door frame somehow.

After I got finished with the lube change, I lowered the car and tested the door again. Now that it was down on all 4 wheels, the door closed normally. Whew!

I'm not sure there's much else to say about this. I don't plan on opening the passenger door again with the car up on stands, but I do need to open at least the driver’s side door (because I remove all 4 wheels when I bleed my brakes, and need to get into the car to get to the brake pedal). I assume this happens because the car is suspended from a point more "inbound" than the wheels and there's some flex, although I also thought the Impreza chassis was extremely rigid, etc.

Anyone notice this before?

* Registered users of the site do not see these ads.

NicGordon · 09-13-2003, 12:00 AM

I've noticed the same. When trying to close my passenger side door, the window doesn't fit right. It doesn't fit underneath that little tab along the window trim.

dknc · 09-15-2003, 04:09 AM

Just today I jacked up my car on 2 jack stand in the front. Passenger side door opened and closed and that side window wheather strip tip thing blocking the glass from closing!

gypsymoth · 09-15-2003, 08:39 PM

You can easily see that the chassis flexes if you put a jack stand on any corner of the car. Look down the seam where the front door and rear door meets.

Those who thinks that our chassis are rigid enough that it doesn't need any bracing should think otherwise. No matter how rigid a chassis is, it will still flex.

Strut tower braces will help side-to-side. A cage will help in all directions.

Chieh

G-shock · 09-16-2003, 11:18 PM

Hmmm...if the flex is relatively that much than it could be possible to set a reference on a jackstand and measure the flex, then install a strut bar and remeasure...see if it makes a noticable difference on the stand. If it does it likely helps on the road as well.

09-12-2003, 01:46 PM	#1
NotFast Scooby Newbie Member#: 10119 Join Date: Sep 2001 Location: Schaumburg, IL	4 jackstands = chassis flex This happened a few weeks ago, and I thought I'd finally share this with the S&M group here. I had my car up on 4 jack stands, on a level surface (my garage). I was bleeding my brakes and changing my tranny lube. I went into the passenger front door to grab my owner’s manual to triple check how much MTL to use (3.7Q), and when I closed the door, it made a funny "clunk". I opened the door again, closed it and heard it again. After trying it a few times, I realized that the lower portion of the door was now rubbing/clunking against the bottom of the doorframe! I'd never noticed this before, so I got little freaked out when I realized that it was probably related to the car being up on stands, and I thought I had bent the door frame somehow. After I got finished with the lube change, I lowered the car and tested the door again. Now that it was down on all 4 wheels, the door closed normally. Whew! I'm not sure there's much else to say about this. I don't plan on opening the passenger door again with the car up on stands, but I do need to open at least the driver’s side door (because I remove all 4 wheels when I bleed my brakes, and need to get into the car to get to the brake pedal). I assume this happens because the car is suspended from a point more "inbound" than the wheels and there's some flex, although I also thought the Impreza chassis was extremely rigid, etc. Anyone notice this before? * Registered users of the site do not see these ads.

09-15-2003, 04:09 AM	#3
dknc Scooby Newbie Member#: 8165 Join Date: Jul 2001 Location: San Diego Vehicle: 2001 RS 2.5 Asspen White	same Just today I jacked up my car on 2 jack stand in the front. Passenger side door opened and closed and that side window wheather strip tip thing blocking the glass from closing!

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Got Chassis Flex?	fastcb	Texas Impreza Club Forum -- TXIC	23	04-27-2009 11:52 PM
front/rear sti rep strut bars cusco h brace 4 pt chassis	ted@mb	Suspension/Brakes/Handling	6	08-26-2007 12:22 PM
Car flex under jacking/jackstands	Senorpablo	Service & Maintenance	3	05-17-2006 09:50 PM
Matt K and how he broke 4 jackstands.	Fish	New England Impreza Club Forum -- NESIC	69	08-30-2005 02:43 PM
for GC8 Chassis.... Tein Flex or Cusco Zero 2 coilovers???	AzNStiImpreza	Brakes, Steering & Suspension	2	03-30-2004 11:44 PM

09-13-2003, 12:00 AM	#2
NicGordon Scooby Specialist Member#: 24827 Join Date: Sep 2002 Chapter/Region: MWSOC Location: Michigan Vehicle: 2005 GMC 2500HD 2008 Kia Spectra	I've noticed the same. When trying to close my passenger side door, the window doesn't fit right. It doesn't fit underneath that little tab along the window trim.

09-15-2003, 08:39 PM	#4
gypsymoth Scooby Specialist Member#: 6072 Join Date: Apr 2001 Chapter/Region: SCIC Location: Torrance or Redlands, CA Vehicle: 01 Silver 2.5 RS 04 Silver WRX STi	You can easily see that the chassis flexes if you put a jack stand on any corner of the car. Look down the seam where the front door and rear door meets. Those who thinks that our chassis are rigid enough that it doesn't need any bracing should think otherwise. No matter how rigid a chassis is, it will still flex. Strut tower braces will help side-to-side. A cage will help in all directions. Chieh

09-16-2003, 11:18 PM	#5
G-shock Scooby Newbie Member#: 36545 Join Date: May 2003 Location: Square One	Hmmm...if the flex is relatively that much than it could be possible to set a reference on a jackstand and measure the flex, then install a strut bar and remeasure...see if it makes a noticable difference on the stand. If it does it likely helps on the road as well.