Help!!! taking out rear end and have the for pesky bolt issues.

[MartinJ]

Hi all,
Currently in the process of taking rear end off Z3 1997 1.9. Taken a week of work to do this.

Have read up on how to do this and having gone to a doner car am versed in taking out rear trailing arms.

However, only really got started today. Now have exhaust off , taken out the brake cable retaining nuts from handbrake, but not pulled cable s out yet...

I have hit a wall with the four hex headed bolts holding the plate in at the rear. The dreaded four. I cleaned off as much rust around the nuts themselves with a wire brush. I used both WD silicone specialist rust penetrating spray and Aeroknoil. I sized the hex up with a 6 hex which did not fit. Tried a five and it appeared to be a tight fit , possibly due to rust in the head of the nut. it appeared to turn but it looks as if I have slightly rounded the hex itself. it still looks hex in shape so some hope. Now I am trying to get a 5.5 mm hex to se if that will do it. It the only thing holding me up at present.
Is there anyone out there e who can help with undoing these nuts. i live in the Bristol area an would apricate any help physical or through the web or text , phone anything really . Thanks all, as Captain Bob; said tomorrow will be a better day, Here's hoping....

 

[MartinJ]

lots of spelling errors , but hit a wall

 

[andyglym]

@Mazza @Lee are the guru's

 

[Lee]

Hi all,
Currently in the process of taking rear end off Z3 1997 1.9. Taken a week of work to do this.

Have read up on how to do this and having gone to a doner car am versed in taking out rear trailing arms.

However, only really got started today. Now have exhaust off , taken out the brake cable retaining nuts from handbrake, but not pulled cable s out yet...

I have hit a wall with the four hex headed bolts holding the plate in at the rear. The dreaded four. I cleaned off as much rust around the nuts themselves with a wire brush. I used both WD silicone specialist rust penetrating spray and Aeroknoil. I sized the hex up with a 6 hex which did not fit. Tried a five and it appeared to be a tight fit , possibly due to rust in the head of the nut. it appeared to turn but it looks as if I have slightly rounded the hex itself. it still looks hex in shape so some hope. Now I am trying to get a 5.5 mm hex to se if that will do it. It the only thing holding me up at present.
Is there anyone out there e who can help with undoing these nuts. i live in the Bristol area an would apricate any help physical or through the web or text , phone anything really . Thanks all, as Captain Bob; said tomorrow will be a better day, Here's hoping....

Those dreaded cap heads are 6mm head size, most likely full of crud and rust. I tap the socket in making sure its fully seated home.

If any of these round at this stage I opt for a hammer and chisel, after that power tools but bare in mind the plastic fuel tank is inch's away.

 

[Mazza]

I had problems in getting mine out, so bought these from screwfix ( about £12.00 )
Erbauer nut / bolt removers.
Work really well.

Cant upload a picture at the moment

 

[Mazza]

Had a problem with mine so bought these from Screwfix ( about £12.00 )
Selected the one that was close to the head size , used an extension and tapped it onto the head of the bolt and used a breaker bar to give more torque . Got all four undone.

These were mine....and the extractor just bit into them and they undid.....

Just to let you know that BMW no longer supply these ( obsolete) I replaced mine with a Hex head flanged bolt M8 x 25

 

[Lee]

I had problems in getting mine out, so bought these from screwfix ( about £12.00 )

Your teasing him

 

[Mazza]

I think there has been a hiccup on the system...???......it kept kicking me off the forum....
..or have I outstayed my welcome

 

[Lee]

Yeah I think it did. @GazHyde worth tidying the thread me old mucca.

 

[mrscalex]

I had problems in getting mine out, so bought these from screwfix ( about £12.00 )
Erbauer nut / bolt removers.
Work really well.

Cant upload a picture at the moment

+1 except mine are Irwin. One of my favourite get out of jail tools.

 

[Althulas]

I just cleaned up and tap the 6mm hex in but had my version of sockets similar to Malcs not need in my case but I’ve used them elsewhere. Well worth owning a set as they have been invaluable with some corroded exhaust nuts.

 

[MartinJ]

Thanks all; Erbauer it is then. Them nuts are out tomorrow.

 

[MartinJ]

OK progress today. Captain Bob was right; today was a better day.
so today: thanks to Lee and Althulas. the tapping in the 6mm socket with a hammer worked. with a little prayer and lots of juice including 3-in 1 oil they came out. . Mazza I did get the Erbuaer kit and think they may come in handy in the future. .

So today at the stage I should have been at Tuesday midday.
So far the exhaust is off, the pesky nuts are off and the prop shaft nuts are off. I took the cross member and protective shield off to get better view of exhaust bolts. Probably need new Cross member. See pic.

An ooops issues. Forgot to undo the 30mm nuts in hub whilst car on ground , will play with that tomorrow along with the removal of the brake callipers and taking out of the speed sensor and brake sensors. Are there any tips about this ...

I am hoping that tomorrow I will have the rear end off the car. A day later than anticipated.

and finally... do the outer handbrake cables really just pull out of the rear trailing arm...

 

[MartinJ]

I have posted an update but it has disappeared.

so nuts are off Hoo rah. thanks to Lee and Althulas and Mazza. The hammer and 6 mm socket trick worked, with a lot of prayer WD, Kano and 3 in 1...
exhaust is off. Prop shaft bolts off.

Way behind schedule.

Oops moment: forgot to undo the 30mm hub / driveshaft nut whilst car on ground. Will play with that tomorrow.

Have calipers, speed and brake sensors to remove. Will clamp flexible brake hose off the trailing arm side.

Have a few q's : does the handbrake outer cable really just pull out of the trailing arm end? Hoe do you remove the prop shaft from the diff end before removing the rear end and finally... with a different trailing arm and hub you cannot paint dots on hub and drive shaft, so how do you know where the drive shafts go in the 'new' hub?

Thanks for all the help....

 

[Mazza]

Glad you got the ‘screws of doom’ out ok . Probably the most nerve racking job when dropping the rear wheel end.
If you need 4 replacements, drop me a PM with your address as I have 4 spares that I can send you.

 

[Althulas]

If your on about the sensors on the hub just one torx bolt to undo and should pull out easily enough. If they are stuck once you have the hubs out a bit of penetrating fluid and gently tap out with a wood dowel but mine gave no dramas.

 

[mrscalex]

Oops moment: forgot to undo the 30mm hub / driveshaft nut whilst car on ground. Will play with that tomorrow.

Get a compressor and gun. No issue then There is a lock ring hidden amongst the crud you will need to remove.

Have calipers, speed and brake sensors to remove. Will clamp flexible brake hose off the trailing arm side.

Better to wedge brake pedal down with a rod. This will stop fluid flow from reservoir. If you're going to the time and expense of doing the rear end you should be renewing the hard and flexi brake lines.

Have a few q's : does the handbrake outer cable really just pull out of the trailing arm end?

Pull is an interesting word. It's certainly not held in by anything. But they can get well stuck with crud. Again the handbrake cables are candidates for replacement. So you can always cut near the hub and remove the 2 bolts that hold the guide mounted to the backplate/trailing arm. Then you can hit it out in a vice. Again, that guide should come off anyway so you can do a full refresh.

Hoe do you remove the prop shaft from the diff end before removing the rear end

No need to remove prop/centre joint. Turn so the joint is articulated in a way it will allow the axle to drop down. Remove nuts. Prop will part company with some encouragement as the beam/diff goes down.

and finally... with a different trailing arm and hub you cannot paint dots on hub and drive shaft, so how do you know where the drive shafts go in the 'new' hub?

Not important for the driveshafts as far as I'm concerned. I'm just reassembling mine and they are going back on different sides and different trailing arms. Relevant for the propshaft to diff. It will have markings but add your own if it makes it clearer.


Not much point saying you're behind schedule. Mine is in the last few hours of reassembly after approx 125 hours work. But then I have painted and/or renewed pretty much everything.

You should read all the ZedShed threads on this job as they are the experts having done several dozen now.

 

[MartinJ]

I have posted an update but it has disappeared.

so nuts are off Hoo rah. thanks to Lee and Althulas and Mazza. The hammer and 6 mm socket trick worked, with a lot of prayer WD, Kano and 3 in 1...
exhaust is off. Prop shaft bolts off.

Way behind schedule.

Oops moment: forgot to undo the 30mm hub / driveshaft nut whilst car on ground. Will play with that tomorrow.

Have calipers, speed and brake sensors to remove. Will clamp flexible brake hose off the trailing arm side.

Have a few q's : does the handbrake outer cable really just pull out of the trailing arm end? Hoe do you remove the prop shaft from the diff end before removing the rear end and finally... with a different trailing arm and hub you cannot paint dot?

 

[MartinJ]

Thanks for the info mrscalex, really helpful.and very thorough. I take the point about timing. I want my Z3 to be the best it can be so am on a similar journey regards new items as I to are trying to renew everything as I go. Parts list growing. As I have not been on the spanner’s for forty years s the return has been both daunting and a steep learning curve. I have read the manual, zroadster items ,bimmer and whatever info I can get. Going again is like jumping into a really cold pool, you psych yourself up, and just as you are in mid air wonder what the hell you were thinking. Appreciate the tips and experience.and pics. Rain stopped play so far today. Really appreciate the advice

 

[mrscalex]

Thanks for the info mrscalex, really helpful.and very thorough. I take the point about timing. I want my Z3 to be the best it can be so am on a similar journey regards new items as I to are trying to renew everything as I go. Parts list growing. As I have not been on the spanner’s for forty years s the return has been both daunting and a steep learning curve. I have read the manual, zroadster items ,bimmer and whatever info I can get. Going again is like jumping into a really cold pool, you psych yourself up, and just as you are in mid air wonder what the hell you were thinking. Appreciate the tips and experience.and pics. Rain stopped play so far today. Really appreciate the advice

I had a break of around 25 years. Mk 1/2 Escorts to the Z3s.