Knocking rear - Lemforder?

S

Secondtothird

Member
Hello all,

Had my coupe for a couple of months now, it's a fantastic car, been very well cared for and I fully intend to carry that on!

In the last few weeks it's developed a knocking at the rear though.

The car has been fully polybushed, and had the rear suspension taken apart and put back together in the last two years. That's included new rear drop links and bushes, and also new rear top mounts (though the previous owner couldn't remember which type they were, he doesn't think a named brand). It's had the standard suspension replaced with AP coilovers in the past, and sits lower, probably by around an inch or so I'd have thought.

The knocking noise seems to be coming from the upper rear, so I'm thinking top mount, but I did notice the shock on the opposite side is misting a bit so I'll be replacing these at the same time, likely with Bilstein B4s. (I know from reading there's a little confusion around whether they're compatible with lowered suspension - it seems they are up to a drop of 40mm - and I'd like the rear to be more compliant than the current AP shocks).

The issue I have is I can't seem to find Lemforder top mounts anywhere for the coupe? Looking online, many sites selling them claim they don't fit the coupe, despite the description of the parts suggesting they do.

Could someone shed some light? I've heard people have been unhappy with Meyle HD ones knocking, so I'd rather go Lemforder, but can't find any?

Help!

Thanks you good, good people.

Owen
 
I had Meyle ones and they knocked. Took them off again and discovered that the bottom of the rubber mount does not have the raised knobs on it like the Lemforder ones do. In addition, the metal sleeve protrudes past the rubber. So the sleeve impacts directly onto the metal cup washer.
Lemforder definitely cured my problem.
Sorry, couldn't tell you if they are the same as the E85 though.
 
Thanks yeah, that's what I'd heard. Has anyone any experience with fitting these?

https://m.autodoc.co.uk/febi-bilstein/1878884

Febi/Bilstein obviously a good reputation for OE+, but not sure of their top mounts?

The site which claimed the Lemforder rear ones I'd found wouldn't fit the E86, but the part numbers listed were:

Use number: LEMFÖRDER 25853 01
EAN: LEMFÖRDER 4047437084254

Could anyone who's fitted Lemforder rear top mounts do me a favour and check if the part number you fitted matches this?

Thanks so much,
Owen
 
Okay bit the bullet on a pair from C3BMW, he wasn't sure if the E86 Coupe had different top mounts from the E85, but checked and seemed to think they'd fit okay. Would anyone be able to clarify if there's a difference in the rear top mounts from the roadster to the coupe?

Thanks all
Owen
 
I’ll be very curious to hear if the mounts fix your problem. I’ve been dealing with a knocking sound in the rear for the past year, replaced shocks, mounts, drop links, etc. but it’s still there. At this point I’m wondering if it’s something with the brakes (from an old post about a z3) or dust covers for the shocks.
 
horseless_carriage said:
I’ll be very curious to hear if the mounts fix your problem. I’ve been dealing with a knocking sound in the rear for the past year, replaced shocks, mounts, drop links, etc. but it’s still there. At this point I’m wondering if it’s something with the brakes (from an old post about a z3) or dust covers for the shocks.
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What make were the top mounts?
 
Would anyone know if the rear bump stops on coupes with the sport suspension are different than those with the SE?

I was thinking of buying a couple of these when I do the rear shocks but there's no indication of whether I'd need different ones for a sport model...

https://www.ebay.co.uk/itm/363537108281?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=9RtuYQ4-SxO&sssrc=2349624&ssuid=-YYlFYYbQ-G&var=&widget_ver=artemis&media=EMAIL

Thanks
Owen
 
horseless_carriage said:
enuff_zed said:
What make were the top mounts?
Click to expand...

The top mounts currently on the car are lemforder (2585301). Replaced the rubber washers an associated hardware with new OEM parts as well. My car is a 2008 E85 3.0i convertible.
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Well assuming it's all together in the correct order then it is much less likely to be the top mounts.
Was everything torqued up with the weight on the wheels?
 
Hello enuff_zed, having searched your posts you seem to have gone through the rear bump stop replacement yourself - could I ask if you know whether the rear bump stops on a sport coupe are a different length to those on an SE?

I would presume so, but I'm not seeing much indication online as to Febi part numbers? You've previously mentioned 103828s, but the link above I found suggested 103790s.

If you could help clarify I'd be much appreciative.

Owen
 
Secondtothird said:
Hello enuff_zed, having searched your posts you seem to have gone through the rear bump stop replacement yourself - could I ask if you know whether the rear bump stops on a sport coupe are a different length to those on an SE?

I would presume so, but I'm not seeing much indication online as to Febi part numbers? If you could help clarify I'd be much appreciative.

Owen
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Hi Owen,
Yes I always replace the bump stops as a matter of course as they seem to be made of cheese and crumble away.
I'm afraid I have never worked on a coupe though, so I can only tell you the roadster has slightly shorter bump stops for Sport than for SE.
I would take a guess that the coupe is the same.
Have you tried looking for the part number by putting your car details into realoem?
What I would say is that on the roadster the difference in length is only about an inch.
Given that the bump stop only comes into play right at the very end of travel and is basically designed to stop the damper bottoming out (at which point your suspension becomes a metal bar), I would not get too hung up on the exact length. But if there are two options then go for the slightly shorter one.

I've just looked at Autodoc, filtered by rear axle and Febi Bilstein (purely because I've used them before) and it gives two options, one for Sport Suspension and one without. It also tells you which OE number the parts relate to.
Hopefully this will help?
https://www.autodoc.co.uk/car-parts/shock-absorber-dust-cover-and-bump-stops-10472/bmw/z4/z4-coupe-e86/19300-3-0-si?supplier%5B0%5D=101&criteria%5B100%5D%5B1%5D=HA
 
Thank you both for the recommendation of RealOEM.

One Febi option is 221mm long, one is 216mm long, so I'd presume the shorter of the two, though both state they're not compatible with sports suspension. There's also a Febest one which is 50mm shorter and doesn't mention it's not incompatible with sports suspension, but then doesn't say it's specifically for it either.

Of the two Febis, both listed say they'll fit an 'Si', but not one with 'sports suspension'. Am I incorrect in thinking that's the same thing?

Thanks again
Owen
 
Secondtothird said:
Thank you both for the recommendation of RealOEM.

One Febi option is 221mm long, one is 216mm long, so I'd presume the shorter of the two, though both state they're not compatible with sports suspension. There's also a Febest one which is 50mm shorter and doesn't mention it's not incompatible with sports suspension, but then doesn't say it's specifically for it either.

Of the two Febis, both listed say they'll fit an 'Si', but not one with 'sports suspension'. Am I incorrect in thinking that's the same thing?

Thanks again
Owen
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You're right! I misread that, sorry.
Unless you intend to drive around bends on the door handles I don't think you'll actually be employing the bump stops very much, so either would do. I have fitted the slightly shorter ones on the 2.5si I'm selling and have had no issues at all.
If it helps at all, when I changed the rear shocks on the 2.2i I did up last year, one was a longer one and one was a shorter one. Never noticed any impact on handling at all. needless to say I fitted a matching pair.
 
Thanks chap that's great to know, I'll pick up a pair of the shorter Febis then if you've had them on a sport suspension model and not had any troubles yourself. It's just I have the coilovers so wanted to make sure they would be compatible.

Best
Owen
 
Secondtothird said:
Thanks chap that's great to know, I'll pick up a pair of the shorter Febis then if you've had them on a sport suspension model and not had any troubles yourself. It's just I have the coilovers so wanted to make sure they would be compatible.

Best
Owen
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They just sit there at the top of the strut doing bugger all except giving something for the dust cover to hang on 99% of the time. :D
 
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