Convertible Rear Beam (Done) - Diff refitting issues....

[FinalD]

Trying to drop the rear beam/subframe on the convertible so I can change the bushes and brake lines. Unfortunately they appear to be stuck fast. I have had the burner on one of them and that has freed it up somewhat but not enough to drop it properly.

On the touring I can remove the rear seats and see/access the top of the bolts that go through the bushes. This means I can give it a good clout with a hammer to remove but on the convertible I can't seem to find the top of the bolts. Are they accessible and can I beat them from below to push them out from the bushes?

[capri_rob]

It will be the alloy inner of the bush that has corroded itself to the steel body of the car that is stuck.

The bolt needs to come out completely and if its really stuuk you will need to drill the alloy inner bush out.

Never had a cab so cant comment on the rear seats but there will be a way to access the top of the bolt - it is splined so when the nut is off you will need to hit it from underneath to pop it up into the car

its a good idea to put a rag or something over the bolt so if you have to whack it hard it doesnt come flying up into the car

[FinalD]

Yeah, that's how it was on the touring when I put the beam back on that but I can't see/find where the top of the bolts should be on the convertible so don't want to whack them in case I break the bodywork.

[Brianmoooore]

There's an oval shaped hole in the side structure of the back of a cab each side, near where the rear seatbelt ends are bolted. The top of the subframe pins are accessed through these holes.
Rear seat cushion and side trim panels have to come out.

[FinalD]

Ah ok, that's fine then. I have no seats etc. in the car at the moment. So basically I can give the bolts a good old hammering (with rubber mallet / block of wood to avoid knackering the bolts) to get them up and out of the bushes.

Cheers for that.

[FinalD]

Ok so I've been beating it senseless with a hefty rummer mallet and it is going nowhere! The bolts refuse to move at all. I can lean on a bar on the beam/frame and it will move but the inner race of the bush is seized to the bolt it would seem.

On the driver side I put some penetrating fluid into the bolt well and waited for it to drip through...which it didn't. I then hit the bolt from below which seemed to dislodge the bolt enough to let the fluid flow through...but not enough to allow the bolt to go up into the body out of the way.

On the passenger side I did the same but even with beating it refuses to let the fluid drain through! I don't know if the fact I had a mate round yesterday helping and he thought it'd be a good idea to get a butane flame on the bush to 'burn it out' has made things better or worse on this side (only did it on the passenger side).

Any more help would be appreciated although I fear that the best information anyone can provide is already supplied above really.



Couple pics of the offending bolts from below.

Driver Side


Passenger Side

[BenHar]

Put the nut back on part of the way and it it harder.

You will probably have to get new nuts. Fnarh fnarh.

Ben

[Grrrmachine]

You really need to get that bolt out first; use a proper hammer, not a mallet, and screw a sacrificial nut on the end to protect it.

Also, is the beam "bare" or does it still have the diff and trailing arms attached? If it's loaded, it'll be trying to twist, meaning it won't drop down square.

I had a nightmare removing mine, and in the end I used various drill bits on a cordless drill, plus a knife heated with a blowtorch, to slice through the rubber of the bush. That allowed the beam and outer steel collar of the bush to fall, leaving the aluminium core still in place, to be smashed and drilled out afterwards:





Then you batter out the steel collar from the rear beam:

[FinalD]

I put the nuts back on, gave the bolts a couple of sharp taps with a solid plastic ended hammer (it is heavier and harder than the mallet I had been using but still won't destroy stuff) and the bolts proceeded to go inside the car, result.

Nearly lost the bolts inside the wings mind, the convertible doesn't make things easy.

Passenger rear inside wing area:



Subframe bolt hole:




Driver rear inside wing area:



Subframe bolt hole...behind fuel filler pipe:






I now 'just' have to get it free of the underside of the car. I still have the diff, arms etc. on as the reason for dropping it is not for rebushing (will have to rebush the beam now anyway) but to replace the flexi brake lines from rubber to braided. Such a huge amount more hassle than I'd hoped (was hoping to just replace the lines with it all in place).

Having looked at the state of the bushes on the arms though...I might as well rebush them too which means I'm going to want to drop the whole rear drive assembly. The bit of that I'm not looking forward to is the diff as I know it isn't light having hauled the one on the touring around.

[FinalD]

Dropped the diff last night, along with the nearside wishbone and hub. Can't get the offside wishbone and hub off though because BMW in their infinite wisdom put the fuel filler pipe in the way of a bolt on the wishbone.... http://i.imgur.com/na5sT.jpg

Beam still won't come down. Guess I need to get the drill out and some spare/junk bits and drill through the bugger to drop it and then beat the hell out of the inner race to remove it from the chassis.

[bmw9818]

that trailing arm is a bitch! i managed to get it off after struggling, think what i did was tilt the bolt and just wound it out with a spanner,

to reassemble it though you need to remove that filler pipe! preferably drain the tank!

i didnt realise how much was in the tank ended up holding 40 kilos above my head with petrol dripping on my chest trying to manhandle the bolt in whilst it was raining in the cold on the concrete floor!

one of the worst jobs ive done!

[FinalD]

I plan on putting it back on the way I did on the touring...put the trailing arms back onto the beam and he-man it into position. Not the nicest of ways to do it given the weight etc. but saves covering myself in fuel. I'll have to support the arm and drill out the bushes I guess...fun weekend ahead.

[milescook]

Depending on how much fuel you have left, I just asked about this here from your picture:

http://www.e30zone.net/modules.php?name ... 6&start=50

[blondboy84]

You really need to get that bolt out first; use a proper hammer, not a mallet, and screw a sacrificial nut on the end to protect it.

Also, is the beam "bare" or does it still have the diff and trailing arms attached? If it's loaded, it'll be trying to twist, meaning it won't drop down square.

I had a nightmare removing mine, and in the end I used various drill bits on a cordless drill, plus a knife heated with a blowtorch, to slice through the rubber of the bush. That allowed the beam and outer steel collar of the bush to fall, leaving the aluminium core still in place, to be smashed and drilled out afterwards:





Then you batter out the steel collar from the rear beam:

oh, yeah - I did the same Yesterday night till 3am

but I had a hydraulic press without it - it's impossible

[FinalD]

Got the beam off eventually. I'm now stuck as to how to remove the bushes. I've attacked the bushes with a drill, blowtorth etc. previously when trying to remove them from the car.
Now though they appear to be stuck fast in the beam and I can't think of an easy way to remove them.
The drill just skips about now, so I can't drill out the cores really. Hammering doesn't seem to make any difference and I can't see how I can use the bench vice to help me.

Any thoughts?



Steel collar is now removed.


Steel collar is now removed.

[DanThe]

Get the end of the beam hot and they will push out by hand

[FinalD]

Yeah. I gave up, phoned a few local garages, one pointed me in the direction of a tractor mechanic. Took it there, used a proper oxy lamp to heat the beam, knocked the bushes out easily and then pressed the new ones in. All sorted and only cost £20. Saved me faffing around for hours with various tools and a small blowlamp.

[capnmchl]

Oxyacetelyn and an air hammer/chisel works wonders for future reference

[FinalD]

I also replaced the wishbone bushes, did this myself:





Hammer + impact socket sorted those out. Pushed the new ones in using the vice, large socket and some lube spray stuff. Rear end is now freshly bushed I just need to fit the diff...which has posed a problem as the prop appears to have grown in length since I removed the diff.

[Brianmoooore]

and some lube spray stuff.

Care needed in choice of lubricant. It must be of the type that ceases to lubricate after the bushes are fitted, which for most of us will be washing up liquid.

[FinalD]

Not 100% sure what stuff it was as I don't have the can with me. I wanted some proper rubber lube as was used by the agricultural guys on the beam bushes (tub of red grease) but my mate couldn't find any on Sunday so picked up the stuff we used. It's safe on rubber which was our main concern as I didn't want anything that would eat into the rubber and destroy the bushes.

I'll be under the car again tonight so will have a check to see if they are wet at all but the bushes appeared to go in, seat and be solid in place. I have a spare set of them if there are any problems with how they've seated (appeared to be fine).

[daimlerman]

Slacken the collar nut by the prop centre bearing and slide the two halfs back together.Birmingham spanner can be used if nesessary

[FinalD]

I figured it was probably the intermediate bearing area where it has grown. I did drop the heat shield and could see many splines which I didn't think looked right. It still locks when put into gear so wasn't sure.

I take it a Birmingham spanner is in fact a hammer?

[FinalD]

The intermediate bearing shaft looks like so:



It doesn't move either way (into or away from the bearing).


The diff when connected to the prop is miles off from going into the carrier bracket:






I thought I'd try with the drive shafts connected to keep the diff closer to the correct position:




The diff/prop connection does appear to be too far back (ie to close to the rear of the car):





So yeah...I'm probably being highly retarded, but any ideas?

[bss325i]

Tyre soap is the best thing for lubing up rubber bushes during installation. It completely dries soon enough as well which is what you want.

[e30topless]

The intermediate bearing shaft looks like so:



So yeah...I'm probably being highly retarded, but any ideas?

the splines are on the front part of the prop and they need to go further into the rear part to align it all up, (up to the rust line) a little WD40 and slacken off the nut next to them

your going to have a very difficult job getting the four bolts back into the top of the diff with everything attached

[FinalD]

I can/will just drop the diff off again, I haven't fully attached the shafts, just did a couple of the bolts up finger tight to see if it'd help with lining it up.

Looks like tomorrow I'll take the diff back off, slacken off the prop nut and apply WD40 to bring it back to the rust line.

Oddly, the diff only appears to be out by just over an inch yet the size of the clean section is quite a bit more.

Cheers for clearing up what I need to do on this though.

[bmw9818]

pair of stilsons on the centre prop nut does the job perfectly! dont bother with a spanner etc

[blondboy84]

your going to have a very difficult job getting the four bolts back into the top of the diff with everything attached

It wasn't so bad to get those 4 bolts in - easy peasy. at least for me

[FinalD]

I'll give it a go with everything as it is (obviously adjusting the proper to fit being the first thing) and see how I get along...most likely, much swearing and crushing myself/parts of myself with the car.

[FinalD]

Sorted this tonight. Took the diff off again, adjusted the prop, put the diff etc. back on.

Cheers for the advice in this thread.

[parkin10]

did the beam bushes my self at home pig of a job
lubed up the new bushes with washing up liquid a block of wood and a smack with a hammer popped em home easy