How to fit a Powerflex A frame bush (live axle)

[dalongbloke]

Jack up back of car (placing jack uinder A frame bush)

 

Place supports under tyres - I place car ramps under... there is very little room to work if you use axle stands. MAKE SURE YOUR STANDS ARE SECURE and the the car cannot fall.

 

Drop jack down, undo bolt and nyloc (3/4 socket inch on live axle). You should replace the nyloc with a new one when refitting. Withdraw, retaining the washers outside he mounting flanges. Bolt nay need to be tapped out of the old bushes.

 

Gently lever down A frame - I use an old screwdriver beteween the bush and the axle case. The axle will then twist backwards (towards petrol tank) a coupe of inches as it loses its bottom mounting point. The nose of the diff will drop a few cm as the axle rotates.

 

Pull/drift the old bushes out (or watch them disintegrate and crumble to dust).

 

Push the two pieces of the new poly bush into the A frame housing. Mine came with stainless steel ends which makes the next part much easier.

 

Take an M6 (or imperial equivalent) bolt long enought to pass through both halves of the bush, NO larger, and 4 suitable washers.

 

With the bush in place in the A frame, place 2 washers on each side of the bolt hole, bolt through, place 2 washers and a nut on the other end (10mm nut if using M6). The washers will just be big enough to "plug" the bolt hole in the bush, but still allow you to push the bush into the A frame carrier.

 

Tighten the M6 bolt until the bush is compressed enough to slide into the carrier. I did not lubricate the steel ends of the bushes. You may decide it is a wise idea!

 

The clamped bush in the A frame now needs to be popped into the carrier frame in the axle. The carrier on the axle however, seems miles out of place.

 

Get your jck under your seven again, this time under the nose of the diff. Gently jacking up the nose untilaxle it rotates back to its original poisition, with the bearing mounting flanges directly above the compressed bush.

 

The edges of the bush will then pop into the flanges... tighten further if necessary, you may need to jiggle the position of the M6 bolt to allow lcearence... you'll see what I mean.

 

When 2 or 3mm of the bush has lifted within the flanges, remove the M6 bolt, and gently "ease" the bush into the carrier. Don't hammer/mallet/force the bush too high. If you do, you will need to lever it down again. Use the large bolt you originally removed to ensure the holes ar aligned in the mounting cradle.

 

If you need to move the axle back or forward slightly... raise or lower the jack which will gently twist the axle forard or back.

 

When the bush is fully home, reinsert the large bolt NOT FORGETTING the washers either side of the cradle. I used coppaslip on the bolt, up to you. Torque up... I can't rememberwhat the figure is!!! I used 25ft/lb, but need to look it up.

 

Thats it! Good luck

 

Please feel free to add comments, corrections and improvements.

 

 

 

Edited by - dalongbloke on 18 May 2011 12:57:57

[davedlr]

Nothing to add - but thanks for the write up. After recently replacing my a-frame bush for the 2nd time in a year, I vowed the next time would be for a powerflex / poly bush.

 

I've not researched extensively - but is this the part required [PF8 901]:

http://www.part-box.com/product_info.php?products_id=41568

 

cheers

Dave

[dalongbloke]

Hi Dave... I had had been meaning to do it for ages. Dunsfold Dads Day out finally killed mine! Rubber boshes last me about 3K miles.

 

Drove 20 miles on the new bush today... no noticable deterioration in ride quality.

 

Got mine from EBay here

 

Edited by - dalongbloke on 19 May 2011 22:42:07

[Steve C]

3K miles ! That's not even trying Andy :-)

 

More like every 600 miles :

Sh*gged bushes

 

...Or every race as was Colin Chapman's expected rate of attrition.Sunrise Sevens

 

 

 

 

[dalongbloke]

See you tomorrow. I cannot resist.... A