E36 suspension top mounts
E36 suspension top mounts
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sniff diesel

Original Poster:

13,124 posts

235 months

Monday 29th September 2008
quotequote all
I'm putting some Gaz Gold coilovers on my 325i track car, now the top ends of the coilovers look like this, with 40mm meant to come through the top mount:



But the top mounts are 40mm deep themselves, like this:



Which wasn't a problem with the old suspension struts as the tops of them looked like this, with 60mm there was plenty of protrusion to get the nut on the end:



I'm guessing I'm going to need some new top mounts that are only 30mm deep at most, any ideas on what I could do?

sniff diesel

Original Poster:

13,124 posts

235 months

Monday 29th September 2008
quotequote all
anonymous said:
[redacted]
Mine's a Feb 1992 car so it may be different to the later ones?

I'm thinking of going for some of these :

http://www.automac.co.uk/product/Adj%20top%20mount...

(if they fit) as I could get a bit of camber on the front then too.

They don't look any different to these although they are half the price for some reason:

http://www.automac.co.uk/product/Top%20mount

sniff diesel

Original Poster:

13,124 posts

235 months

Saturday 4th October 2008
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Anybody got any other ideas before I order some of those Automac ones?

Kerry540

55 posts

214 months

Sunday 5th October 2008
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Looking at the top pic, it would appear you are attempting to fit the top mount without compressing the coil spring. You need to clamp the spring so that the top mount slides down the strut and then you can fit the top nut.

If you want to increase camber, just fit camber adjusting top mounts, come complete and fit directly as a replacement for the old top mount.

Kerry, xxx

sniff diesel

Original Poster:

13,124 posts

235 months

Sunday 5th October 2008
quotequote all
Yep, the springs are adjusted to their highest ride height position so don't need compressing. Not sure if you can see what I mean here:


Kerry540

55 posts

214 months

Sunday 5th October 2008
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But that blue top collar is not touching the shoulder of the piston, and the only thing holding it off as far as I can see is the spring. As it is a coil-over, then I assume that there has to be some compression, however small on the spring when set at its lowest ride height setting or the spring would be loose on full extension which is an MOT failure as well as risky for spring displacement.
To get more piston through that top collar, the blue top spring seat needs to slide further down the piston, and as I say again, unless that blue collar is already on the shoulder of the piston, its the spring that needs compressing or the lower adjustment collar adjusting to its lowest setting to remove/reduce the pre-load on the spring.

Kerry, xxx

sniff diesel

Original Poster:

13,124 posts

235 months

Sunday 5th October 2008
quotequote all
Kerry540 said:
But that blue top collar is not touching the shoulder of the piston, and the only thing holding it off as far as I can see is the spring. As it is a coil-over, then I assume that there has to be some compression, however small on the spring when set at its lowest ride height setting or the spring would be loose on full extension which is an MOT failure as well as risky for spring displacement.
To get more piston through that top collar, the blue top spring seat needs to slide further down the piston, and as I say again, unless that blue collar is already on the shoulder of the piston, its the spring that needs compressing or the lower adjustment collar adjusting to its lowest setting to remove/reduce the pre-load on the spring.

Kerry, xxx
Kerry, even with the piston at full extension there is still the lip on the top to prevent the blue top bit from moving down, as seen here at the end of the tape measure.



Once the weight of the car is on the springs it will prevent them from being loose.

sniff diesel

Original Poster:

13,124 posts

235 months

Sunday 5th October 2008
quotequote all
As long as you didn't present it for an MOT with the springs loose I can't see how they could fail it.

Kerry540

55 posts

214 months

Sunday 5th October 2008
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Okey dokey,

Now I have seen the top of the strut with the collar off, I can see it is the shoulder on the piston stopping that collar going down far enough and not the spring.

I would therefore backtrack to the beginning with this new info, especially the excellent new pic and suggest the following,

1, I have seen that top mount fitted with both metal washers only and washers with a thick rubber underneath as yours has, would it all fit ok with just the washer? (I know your washer is bonded to the rubber)
2. Its the wrong piston fitted for your car, the shoulder is too high,
3. Should that top collar be relieved to fit over and down the piston a short way?

I would also recommend fitting some cheap, light helper springs from somewhere like Demon Tweeks just to keep those springs located.

Kerry, xxx.

sniff diesel

Original Poster:

13,124 posts

235 months

Saturday 18th October 2008
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Right, so I've got some top mounts but unfortunately the threaded top nuts are a fraction too small a diameter to fit my Gaz coilovers. Don't know how easy it is to get some new nuts to size as they have to be a round smooth surface to go in the rose joint of the top mount, or I could try getting an engineering shop to drill and tap them to size.








8Tech

2,179 posts

221 months

Saturday 18th October 2008
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If the nut has enough material in it I would just re-tap it, however if it is "just" too small then you might not get a full thread depth cut in it and that is not good for a structural part. I would, in that case, get new sleeve nuts made.

sniff diesel

Original Poster:

13,124 posts

235 months

Saturday 18th October 2008
quotequote all
8Tech said:
If the nut has enough material in it I would just re-tap it, however if it is "just" too small then you might not get a full thread depth cut in it and that is not good for a structural part. I would, in that case, get new sleeve nuts made.
Suppose it needs an expert to measure the two different threads to compare and see if there is enough meat to cut a new thread in there.

Kerry540

55 posts

214 months

Sunday 19th October 2008
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Post the nut and the sleeve to engineers like PhoenixMotorsport who could measure and check for you, do the thread if possible but also make the parts you need if not enough meat on the sleeve.

With solid top mounts and no shock absorbing rubber on the mount, there will be a lot of load on those parts. Best not to bodge it.

8Tech.

pegusus85

1 posts

200 months

Tuesday 7th July 2009
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Looking at the Nyloc you have there in the picture i would say that you are looking at a metric m12, or a metric fine thread. either way any1 with access to a vice, drill and tap and die kit should be able to drill and tap your nut to the correct size. Between the internal diameter and the external diameter it apears you have more than enough material to modify.

sniff diesel

Original Poster:

13,124 posts

235 months

Tuesday 7th July 2009
quotequote all
I got the nuts drilled and tapped months ago, thanks anyway.

TheEnd

15,370 posts

211 months

Tuesday 7th July 2009
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Hmm, this one was from the archives...

The e36 (in 6 cyl format) had 3 major suspension designs, very early (i think til 9/91) saloons had the dome mount and long droplinks that attached to the shock body similar to the M3s.
9/91- 6/92 used the short droplinks to the control arms, but still used the dome topmounts.

after 9/92 (alomg with the addition of vanos) the top mount design was changed, and it used a different shock.

You can convert pre 9/92 to the later type by buying a handful of parts from BMW, and this is often needed if you change the shocks, and pre 9./92 style are hard to come by in any sporty types.

Pre 91 long link suspension is trickier, some people say they have converted with a later roll bar (due to a lack of shocks with the needed long droplink bracket) but i've also seen people state they've had problems still. The subframe was redesigned around the time too, so that may have an effect.