Changing top mounts on a cab - IT DID GO WRONG!

Tue Jul 01, 2008 8:21 pm

Done a few searches but can't find a cab-specific guide.

Looks bloody easy! With the roof tipped fowards and hatch open I can remove the covers and see the tops. Infact I can move the tops around with my fingers which can't be a good thing.

What I don't want to do is take things appart then get stuck. The bolts look pretty rusty. Any chance of a step by step?

Ta

Tue Jul 01, 2008 8:30 pm

Can't help you there mate, but just bought a cab myself and the back of the hood doesn't seem to sit right on the boot as u can see from pics. have you ever seen this? also what sites were looking at as I think I might change my hood, its a bit faded and had the top repaired.

Tue Jul 01, 2008 8:32 pm

Chris - very little to go wrong. Once you have the nut off the top of the damper rod free, you're away.

gar81 - could you remove / reduce the size of your avatar please?

Tue Jul 01, 2008 8:38 pm

very very easy to change on the cab i would suggest jacking car up until the wheel just leaves the floor then undo the bottom shocker bolt and the top 2 smaller nuts (under the horseshoe underneath a rubber grommit thing) and drop the shock out along with top mount still attached then just undo the top nut on the shock to remove 10 minute job at the most

Tue Jul 01, 2008 8:40 pm

Wow that easy???? I've got to do mine once i managed to track down some of the illusive E46 cab top mounts that everyone goes on about being a good upgrade.

Thanks for the write up!

Wed Jul 02, 2008 7:24 am

NatDJ wrote:Wow that easy???? I've got to do mine once i managed to track down some of the illusive E46 cab top mounts that everyone goes on about being a good upgrade.

Thanks for the write up!

There is a write up for this on the uucmotorwerks.com site in the techtips section that lists all the parts with p/nos. All parts available at main dealer or AFAIK through the zone.

Wed Jul 02, 2008 7:58 am

dhfs wrote:There is a write up for this on the uucmotorwerks.com site in the techtips section that lists all the parts with p/nos. All parts available at main dealer or AFAIK through the zone.

Thanks for that! What a great find! All in all probably looking at £35 for the E46 top mounts including the Z3 reinforcement plates.

Thanks for the info.

Wed Jul 02, 2008 9:04 am

You don't even have to jack the car up, although it is easier if you do, especially on the exhaust side.
We have our own main dealer on here. Zimmerbimmer1 in his genuine parts section.

Wed Jul 02, 2008 1:54 pm

Zimmer has the part number at his fingertips for the E46 type top mounts,do not forget the gasket thingys for them..the top nut on the damper is best removed with the damper held in a vice,ring spanner on the big nut and a little one on the square thingy at the top of the damper to stop the whole lot spinning round.

Wed Jul 02, 2008 7:44 pm

what are the Z3 plates? Why do I need them?

Mon Jul 21, 2008 4:17 pm

I've ordered bits form zimmerbimmer only it wasn't him, he was on another line. All I've ordered is top mounts (E46 M3 cab) and nuts and bolts. Do I need anything else?

Mon Jul 21, 2008 4:40 pm

New gaskets, although I imagine you'll get them with the mounts.

Mon Jul 21, 2008 5:42 pm

I wouldn't recomend jacking the car up until at least the top or bottom has been unbolted.
If you have the correct shock for the spring it should just hold the spring under tension when fully extended, so when you try to unbolt it it can strip the last couple of turns on the thread as the spring unloads.
Best jack it up from under the trailing arm with a trolly jack first to get the bottom bolt out while the weight of the car is holding the spring compressed.
Then do the top two nuts and it should just drop out.

Mon Jul 21, 2008 6:54 pm

so following on from this, on a Hardtop i presume the top mounts are behind the carpet? and to chnage the springs at the same time are they secured in with a locking plate?

Mon Jul 21, 2008 7:19 pm

Top mounts accessed from inside the boot in a saloon, springs are not secured with anything.

Thu Jul 24, 2008 12:05 pm

Cheers guys. Job done. Really was as easy as described!

Fri Jul 25, 2008 7:41 pm

After less than 90 miles the (genuine BMW E46 convertable) top mount on one side has failed. The damper is free to wobble around and does a very good job of bashing against the mount on bumps. Haven't had chance to investigate but I can only think of 2 causes

1) top mount was duff from the factory
2) there is something wrong with the damper - maybe it has limited movement - and that causes the mount to fail.

I can push the damper down easily from above and when relaesed it gently sighs back into position. Interestingly the dampers were odd (as in not a pair) so must have had a cheap skate owner in the past. I'm assuming next stage is to remove the damper, can I test it in some way? What would you recomend as a next step?

Fri Jul 25, 2008 8:10 pm

The last breaker I bought had fairly new aftermarket dampers and totaly knackered almost new top mounts.
The total lack of any steel washer under the mount probably had something to do with it!

Fri Jul 25, 2008 8:12 pm

ChrisBarns wrote:After less than 90 miles the (genuine BMW E46 convertable) top mount on one side has failed. The damper is free to wobble around and does a very good job of bashing against the mount on bumps. Haven't had chance to investigate but I can only think of 2 causes

1) top mount was duff from the factory
2) there is something wrong with the damper - maybe it has limited movement - and that causes the mount to fail.

I can push the damper down easily from above and when relaesed it gently sighs back into position. Interestingly the dampers were odd (as in not a pair) so must have had a cheap skate owner in the past. I'm assuming next stage is to remove the damper, can I test it in some way? What would you recomend as a next step?

For a start put a matching pair of dampers on it, that cant possibly help the handling. as for the failed top mount take it out and have a look. mite give you some clues as too why it failed?

Fri Jul 25, 2008 9:03 pm

Brianmoooore wrote:The last breaker I bought had fairly new aftermarket dampers and totaly knackered almost new top mounts.
The total lack of any steel washer under the mount probably had something to do with it!

Is this cupped washer, about an inch across?

Sat Jul 26, 2008 12:36 pm

OK, got new mounts and exploded diagram from dealer. Bit confused as I'm not sure what is exploded top mount, what is top of damper and what is washer. It appears that my car was missing some bits already! The diagram seems to show 2 nuts on the top and 2 cup shaped large washers, I've only got one nut and one washer per side.

Sat Jul 26, 2008 12:44 pm

http://www.realoem.com/bmw/showparts.do ... g=33&fg=45

I'm confused by 6 and 12, 11 and 13

Sat Jul 26, 2008 9:07 pm

I reckon that 6 and 12 are one and the same,but you need 11 and 13 as well. I fitted E46 cabbie top mounts to the touring and reused the existing dampers with no issues,on the saloon I was upgrading the suspension and fitted the improved top mounts with gas dampers and M-tec springs.Once I had tightened all the bolts and got the bits in the correct place

I have had no problems. Seems that you may have received a dodgy top mount.

Sun Jul 27, 2008 5:36 pm

My car only had 1 washer per side and it was on upside down. I just replaces like with like. Current plan: I'll go to the dealer tommorow and order everything on the exploded diagram and hope I can work out which one is which.