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Author Topic: Car lower on left side  (Read 4965 times)

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december2008

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Car lower on left side
« on: January 11, 2009, 12:41:47 PM »
My '71 B is slightly lower on the left side. Is this a problem in the rear springs and do I replace them ? Is this something a shade tree mechanic can do ?

Howard Bruce

Art

  • chfwrench
  • AMGBA Club Tech Staff
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  • MG information: '73 red B roadster
Re: Car lower on left side
« Reply #1 on: January 23, 2009, 02:30:51 PM »
Hi Bruce,

Unless there is chassis damage from rust or accident, yes, this is generally is a rear spring issue.  To check, with the car on its wheels (or wheels-off supported by stands under the rear axle as you need the body weight on the spring for this to work), measure the distance from the front "eye" or connection point of the spring to the chassis (you can use the bolt as a center point) to the edge of the lower rear shackle in a straight line, not under the spring or the measurements will just match from left to right. 

If the distances vary, the longer one is a weak spring, usually found to be on the left side.

Replacement is definitely a shade tree mechanics' job, with minimal and no specialty tools or skills  necessary, beyond a basic mechanical ability.  It's about an afternoon or work unless problems are encountered.

You'll need a couple of jack stands, a good, stable hydraulic or screw jack and an assortment of open/box end wrenches and deep-well sockets.  6-point box-ends and/or 1/2" drive deep-well sockets with a long breaker bar are very good to have for the axle u-bolts.  You should also have the springs you want and new bushings and at least the front spring attachment bolts on-hand before you start, one of the few times I think it wise to do this first.  I strongly reccommend the "Energy" urethane bushing set.  They tighten the ride and last longer than the original rubbers.  Youy should also inspect the shock absorber arms, stop bumpers and rebound straps - the rubber bands that run from the axle to the chassis - to see their condition and order replacements as necessary. 

Raise the body up on stands and remove the rear wheels.  Do this the night before you start so you can douse the shackles, u-bolts and all other bolts and threads with liquid wrench or WD-40 and them allow to sit overnight.  You support the body to keep the springs free and will use the jack to support and locate the axle to remove the weight from the springs later.  You might want to first take the shock absorber arm off the bottom spring plate, but that is not always necessary.  Once the U-bolts are off, the plate generally can be moved out of the way with the arm still in place.  Sometime, using another jack to lift the spring slightly moves this easily as well.  Your choice.

Next, loosen and remove the (4) nuts to the u-bolts that hold the axle to the spring on one side of the car only.  This could be the first problem point.  If the nuts are frozen or the threads damaged, the u-bolts might break.  If this happens, the "Help!" rack of universal parts at most Pep Boys, Advance or NAPA shop has replacements.  I found that this often required drilling-out the bolt holes on the bottom spring plate a bit for a larger diameter bolt, but the "U" size and length were otherwise correct and the parts were stronger (and less expensive) than the OEM replacements.  You can also find them at a truck spring repair shop, where they might be able to bend them to order in the original diameter for a bit more.

Using the jack, now raise the axle to take strain off the spring.  The u-bolts should follow it, dropping the plate off the bottom and leaving the spring loose, suspended btween the rear shackle and chassis connection point at the front of the spring.  Remove the rear shackle and drop the spring to the ground.  Then go after the front bolt.  This is generally the next area for concern as this bolt can be frozen.  If this happens, a little heat (if you have a torch) or a nut splitter can be used to get the nut off, but the bent sheet metal of the housing on the chassis some times makes the latter difficult.  A sawzall or small diameter cut-off wheel makes quick work of it.  More muscle intensive and time consuming would be to use a hack saw blade (free end style).  Whatever you do, be sure to make your cut between the spring and the inside of the sheetmetal support.  Cut into the rubber bushing to avoid damaging the chassis, as that would be more difficult to repair.  DO NOT use a chisel.  Also, as said earlier, regardless its condition, have a replacement bolt on hand or get one from a local shop.  With this bolt removed, the spring is now out and ready for replacement. 

Installation is the reverse procedure.  Install the new bushings on the new springs.  Remember to remove and replace the spring cushion (top of the spring to axle and bottom of spring to lower plate) and the rear upper shackle bushings (2 each side, 1 from outer side/1 from inner side of the chassis) before reinstalling. 

This should give an idea of what is involved.  I may well have missed something, so please make sure to have a manual and a catlog (for the pictures and part identifications) if you do decide to go ahead with the work yourself.

I hope that helps you.  Good luck.

Art
Art Isaacs
AMGBA Tech Staff
chfwrench@aol.com


 

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