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Robbo

A Guide to beam mount bush fitting

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Fitted the beam mounts to the 525i today so I though i'd do a little guide as to how a BM technician does them :D

1. you will need the following tools

22mm Impact Socket

13mm Impact socket

Compressor and impact gun (preferably)

Hammer and cold chisel

Centre Punch

Breaker bar

Blowlamp

Idealy a ramp!

or Trolley jack and some tall axle stands

A pry bar or similar.

To make a Puller you will need:

length of 12 or 14mm threaded rod

Nuts to suit above

A 2 leg puller to butcher

Steel Disc (1/2 inch at least) with an od of 67mm

Steel ring 75mm (approx) in height 67mm id

Some heavy (inch at least) steel bar I suggest

When you jack up the car, I suggest you put the front stands under the chassis legs and the rear stands on the sills or rear jacking points.

If you're worried about your tender underside, use some 4x2 on top of the axle stands to spread the load.

Don't put the stands under the rear beam as you need to be able to drop the beam down to remove and refit the bushes

Step one: loosen the two 13mm bolts on the dog bone, using impact gun or ratchet.

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Step two: Loosen the 22mm nut on the bottom of the beam mount, using impact gun or breaker bar.

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Step 3: Lift the rear seat

Step 4: with the beam bush nut still in place, but loosened, hit it upwards with a big hammer!

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Step 5: When you cannot move the bolt any further up through the bush, remove the nut and strike the bolt with a centre punch and hammer until it is free of the bush.

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and remove bolt (under back seat)

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Step 6: Using the hammer and cold chisel, knock the bottom of the bush lip inwards on opposite sides so the puller can seat on the beam mount carrier.

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Step 7: Assemble your puller, you may need to lever the beam downwards slightly using a bar to gain access to the top of the bush

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Step 8: begin winding the puller, when the outer rubber of the bush has moved slightly away from the bottom edge of the beam mount carrier stop.

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Step 9: Now heat the metal outer with a blowlamp.

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I strongly suggest you cover your arms hands and face for this as the rubber can (and did) spit and molten rubber on your skin isn't very nice!

Heat for 2-3 mins (approx) to soften the rubber.

Step 9: Working quickly, start winding the puller until the bush is about halfway out of the metal carrier, then stop and re-heat with blowlamp. (as above)

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Step 10: You should then be able to wind the bush all the way out no problem.

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Step 11: with the bush removed, you need to clean the debris from the inside of the metal outer. We used an electric power file but a wire brush in an electric drill would suffice or good old sand paper.

Take your time and get it as clean as you can removing the old rubber and any corroded bits it will make fitting the new on 100% easier

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Step 12: Now you're ready to fit the new bushes, lube the bush slightly with the BM technicians lubricant of choice, fairy liquid.

step 13: you'll need to change the set up of your puller, for this use a piece of the threaded bar with the 67mm ring on the top of the bush mount, the flat bar on top and a nut, again you may need to pry the beam down a little to get access.

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Ensuring the assembly of your puller is 100% square on the top and the bush is lined up straight and the groove in the bush is lined up with the nobbles in the carrier.

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You can get it started by hand.

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Put another piece of bar on the bottom of your threaded rod and another nut.

Wind the nut on the bottom of your threaded rod to push the bush into the carrier.

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If it starts to go off square stop, back it off and start again

Step 14: Once the bush is full home in the mount, drop the bolt back in from under the back seat, you may need to wiggle the beam to get it to drop in.

Step 15: Once the bolt is in place, using a trolley jack, jack the beam up into position and re-attatch the dog bone to the beam mount with the 22mm nut using a breaker bar

Step 16: Re-attatch the two 13mm bolts at the other end using a ratchet.

Jobs a good un, started at 1pm finished at 3.30pm.

This job ain't that hard of you fashion some pullers, which is very easy.

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An old two legged puller, some threaded bar, some nuts, a gear from a micra gearbox et voila!

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Same threaded bar, an old wheel bearing shell, amd two bits of inch steel with a hole through the middle.

Any questions, please ask and thanks to Duncan all round legendary mechanic and BMW trained technician :wink:

And I hope this guide is of some help guys :D

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and thanks to Duncan all round legendary mechanic and BMW trained technician

No problem :lol::lol:

obviously that wasn't me :roll:

nice write up - i have powerflex bushes for my rear beam which i have shied away from fitting - puller looks fairly straight forward though.

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Looks a good write up, however in a Haynes star stylee, I'd rate that as a twenty star nightmare - there's even a possibility of injury!!

Not as hard as it looks tbh, mind you, watching somebody do it who's probably done 100's helps!

As does having the right gear, and knowing which order to do things.

Stu, multimeter is all packed up, just need to get to the post office!

Duncan, next time you're in Norfolk visiting the inlaws, maybe we could persuade duncan to do yours for the price of a curry and a few chilly ones....

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A friend and I recently changed these on my car. We did some head scratching as to how to support the rear of the car as I was not comfortable using the sills. We found that axle stands placed each side under the driveshafts, where they bolt to the drive flanges, would support the car and still allow the beam to be pulled down enough to remove the bushes. We did also place stands loosely under the sills for added safety.

I would also recommend replacing the bushes with the Powerflex type mentioned by Duncan, these are fitted by hand and make the job much easier.

BTW, I thought the 'dog bone' was the Pitman Arm that bolts between the trailing arm and the beam? To the right of the pic in Step 4.

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hmm that could be a plan.

At the moment they're low on the list as a had new ones fitted just after i got the car 3 years ago but i will be doing it when i get the time!

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ok i've been looking at the puller - how does the 12mm section of threaded rod fix to the fatter threaded rod of the puller?

as i see it the cog spreads the load over the top of the bush and you wind the puller up (the legs 'bracing' it against the chassis)

are the two bits welded or threaded or what?

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The larger section of rod is M16 and came with the puller which duncan threaded on a lathe to take the M12 rod as M16 rod won't fit through the bush.

M12 rod would be fine, thats the size we used to pull the new bushes back in, and will take the strain no problem.

Most large pullers have seem to have 12mm rod.

Yes powerflex bushes are easier to fit but I believe it makes the ride much more harsh, perhaps less noticable though on a m-tech equipped car than my 525.

And you've still got to get the old ones out which is 3/4 of the job, getting the new ones in is fairly easy tbh.

@ Duncan Correct, thats how is works, but the legs brace against the rim of the bush holder on the end of the beam.

who said architects were all idiots with no practical sense :lol: (no offence m8 :wink: )

@ Jonah I'd never heard that bit called the dog bone either! Correct term is push rod iirc.

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Stu, multimeter is all packed up, just need to get to the post office!

Cheers! I'm more at home with one of them than fabricating tools on a lathe! It makes the £80 a corner charged by my indie to change these bushes seem a total bargain!

Stewart

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who said architects were all idiots with no practical sense (no offence m8 )

:shock::lol:

None taken, i much prefer being hands on - i striped my old house back to a shell and re-built that on my own and i prefer (when i can) to do all my own work on the cars.

Obviously at somepoint i need access to fancy machinary (lathes, presses, welders etc) and then i carefully select who meets my fussy standards!

infact i'd love just to be able to potter around a garage like jimmy's!

That said many of my conteporaries didn't know their @rses from their elbows for many years after we left college!

I was basically brought up on building sites & I always listen to the old boys on site (or workshops) - they know more about any particular aspect of their trade than i ever will but i know enough about them all to pull them together! - thats the trick

The architecst your thinking about are the ones who think they know it all! and there are many.... :wink:

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I'm in the building trade, i've heard so many times "now the architect would like us to do this"

and the reply from the knowledgeable old guys you mention comes "well maybe he'd like to come and show us how the fuck we are meant to do that" :wink:

My sister is a trained architect but is now a commercial manager for a facilities management company? (waste of 7 years @ uni but there is no telling her!)

She said the same as you when at uni, some of the students came up such with pie in the sky ideas, offering no concideration whether it was actually buildable or practical for the people who would build it.

I was only jesting you know that.

We've strayed from the subject...

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With regard to the suport of the car during work on the rear end i always place a pair of ramps under the body and the axle stands on the sills.

These were the only pionts available as i removed the diff and axle carrier, a doner axle carrier was was bought prior to removal and just as well as the left hand bush was seized onto the bolt which extends from the body, and i had to cut the axle carrier through with a grinder to get it off. take a look at the state of these 23 year old bushes anyone beat that.

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Just to add, if you put the new bushes to be fittted in the freezer for a good 24 hours, they go in SO much easier. :wink:

Did mine recently (on the manual) with the proper tool and it wasnt that bad a job.

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Seen the 'official' procedure posted before. Just undo the nut and hit it with a big hammer. Remove the bolt then cut the bushes out with a jig saw. No, dont cut the subframe. Clean the inside of the bores with a drill and a fan grinder. Put a bit of wood between the subframe and the body (mind the brake pipes!) and use the weight of the car to force the new ones in. Put a bit of fairy liquid on the new bushes before you fit them. Make sure you have the lug lined up! And the most important bit: put the new bushes in the freezer for at least 24 hours before fitting and dont hang about. An hour a side and no special tools.

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and thanks to Duncan all round legendary mechanic and BMW trained technician

No problem :lol::lol:

obviously that wasn't me :roll:

nice write up - i have powerflex bushes for my rear beam which i have shied away from fitting - puller looks fairly straight forward though.

Did you get round to fitting the Powerflex bushes? What colour are they & what are your thoughts on the ride or extra noise etc :?:

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I have purple ones but not yet fitted - i had new ones fitted at great expense after i bought the car so its not high on the list really.

Ok. Mine are due to arrive in the next few days. I did read somewhere else that black ones should be fitted......

I will see how I get on with ones I get.

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In all sincerity, thank you so much for this guide: I followed it to the letter, having paid someone else to replace my subframe bushes last year, only to have them fail a few thousand miles later.

Only thing I'd add is that I had to make a couple of cutouts in the top part of the puller to clear the locating "nodules" inside the bush mounting, as per pic.

Total cost of tool: £0.

FItted Powerflex bushes, and so far brilliant. Post below about same and about trackday using new poly bushes, but thought it worthwhile to add to the guide itself.

Thank you again,

Rob

cutoutsinpuller.jpg

homemadepullerwithpulledbush.jpg

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After much messing around, source of clunking from rear identified as having taken slightly too much off stainless sleeves, so (I think) beam coming into contact with front edge of rear wheelarch on take off, or beam sitting slightly too high and causing exhaust to clang.

Sorted with improvised washer!

Must be 1,000 miles and it's nearly a year ago since last post, so definitely a thumbs up for Powerflex bushes from me.

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