Mopar Muscle Association UK

Damn squeak is back again on the passenger side of the Challenger - really embarrassing driving down the road now! Pretty sure its the LCA bush on the K frame pin that's come adrift again for the second time. Everything was only tightened up once it was all back on the ground under its own weight so why should this happen again.....

I've always felt the LCA bush should freely rotate on the K pin otherwise you are asking the rubber bush to take a fair amount of torsional stress - hence it keeps failing? However the last time we renewed the LCA Bananarama! was installed with the K pin in place and once the bush was fully pressed home it was impossible to rotate the K pin - so I guess thats how it should be, but it seems a bad design waiting to fail ??

I've now found these greasable K pins with polyurethane bushes
http://www.classicindustries.com/produc ... h3006.html
which supports my view that the LCA bush should be able to freely rotate on the K pins? Anyone used these ?

Or what are we doing wrong?

I think there is the merest hint of Bull-s41t in the advert.
The only reason you grease Urethane bushes is to stop them squeaking.

I am personally not convinced on Urethane bushes. This means there is no positive location of the LCA which can shunt backwards and forwards. I am sure they are hard wearing.

Incidentally, I have mostly been changing LCA bushes on a Challenger tonight..I feel your pain.....

If you go for the greaseable pins, don't torque them up to 120 pounds as advised in the FSM, they snap! I tested a spare one in a vice after they sent a replacement set and they snap at about 90 pounds.
Consensus of opinion was that due to them being hollow you can't torque them to original spec, mine are currently at 80 pounds per foot

Mmm I did wonder about the strength of those 'hollow' pins...thanks.

The question is really about the original sleeved rubber bushings - should they be a tight fit on the pins which then puts immense strain on the rubber

The Rubber bond is the only thing that stops the bush and pin separation.

They are very robust and last a number of years but are a very cheap but serviceable part. The same bushes go in full weight "C" bodies so I would not worry.

Big fat front tyres and piling into bends and roundabouts are not their best friends.

raven68 wrote:should they be a tight fit on the pins

Yes they should. Did you make sure you did not torque them up until the car was resting on the ground at ride height? Otherwise you are putting them at that shear state when at rest. Otherwise they should last a long time. I agree as well about using rubber on the LCA rather than poly

Watching this thread with interest - front of my Chally squeaks like the Swedish Mouse Rafia ! Ordering a full poly-bush set which, one fitted will put things at peace.
Old cars eh ' ?

Make sure when you do change the bushings for the LCA, check the K frame for any cracks, especially where the LCA connects to the K frame, that area is prone to cracking, mine cracked and sounded like a an old bed ,and drove like a tractor, be sure to check

MrNorm wrote:

raven68 wrote:should they be a tight fit on the pins

Did you make sure you did not torque them up until the car was resting on the ground at ride height?

Yes as that was our mistake first time round when the bushes only lasted about 2 weeks !! So yes we renewed them again and only torqued all the various nuts up when it was back on the ground under its own weight.... I guess they've lasted about 2yrs this time but even then its probably less than about 300 miles....

drewcrane wrote:Make sure when you do change the bushings for the LCA, check the K frame for any cracks, especially where the LCA connects to the K frame, that area is prone to cracking, mine cracked and sounded like a an old bed ,and drove like a tractor, be sure to check

Good point - thanks..... We'll check that out

raven68 wrote:

MrNorm wrote:

raven68 wrote:should they be a tight fit on the pins

Did you make sure you did not torque them up until the car was resting on the ground at ride height?

Yes as that was our mistake first time round when the bushes only lasted about 2 weeks !! So yes we renewed them again and only torqued all the various nuts up when it was back on the ground under its own weight.... I guess they've lasted about 2yrs this time but even then its probably less than about 300 miles....

Well something def does not sound right - 300 miles is pretty crazy. I wonder if a misaligned strut rod could cause this - it could certainly put the bush in unintended stress. But I would have thought the cars handling would be off if there was a strut rod problem, and also (since the originals are non-adjustable) unlikely that both rods would be bent (for example) the same amount.
Is the suspension aligned properly?

have you got the fat washer for the lower bush pins?

it goes under the nut

if you sandwich it between lower control arm and K frame, stuff will be at the wrong position

the pins won't lock properly into K frame
the lower arm is 1/16 -1/8 inch too far back at the inner end and be pulled at an angle by the strut rod

the torsion bars will still fit as the clips fit into a groove well back in the housing.

Not been here for a while as been enjoying the charger this summer. We 'cured' this squeak by jacking up the front and drooping the suspension and squirting a can of WD40 all round the lower joints whilst working the suspension up and down with a trolley jack. Since when its been fine all summer so a simple fix, if not a recommended one !

I wonder if the plastic balljoint boots were the cause..

Dave