Ohlins Road & Track noise

[FazerBoy]

Hi,

I recently had a set of Ohlins Road & Track suspension (with the Ohlins standard springs) fitted to my E92 M3.

Although I am happy with the handling I am getting creaking noises from the rear of the car when setting off from rest or taking tight corners quickly but not while steady state cruising or handling.

I think the noise is being caused by the springs shifting where they are in contact with the body of the car at the top and bottom of the spring. My shop told me that the Ohlins kit does not include the rubber isolating pieces that the stock suspension has and that they could not use the stock rubber isolators because they do not fit the Ohlins springs.

Can anybody advise whether they have experienced the same problem? Just looking at the stock rubber isolators I can't see why they can't be used with the Ohlins springs so is my shop correct? If they are is there another way to reduce the creaking noises?

Any help gratefully accepted.

Cheers

Jack

[M3SQRD]

I'm not sure what type of spring mounts/isolators the Ohlins R&T kit comes with, or which stock pieces should be reused, but the best way to quiet down rear springs is to install thrust sheets/Torrington bearings between the spring and chassis. These bearings allow the spring to twist freely as it compresses - improves ride quality and the linearity of the spring rate. Their inexpensive and easily installed.

[FazerBoy]

Originally Posted by M3SQRD

I'm not sure what type of spring mounts/isolators the Ohlins R&T kit comes with, or which stock pieces should be reused, but the best way to quiet down rear springs is to install thrust sheets/Torrington bearings between the spring and chassis. These bearings allow the spring to twist freely as it compresses - improves ride quality and the linearity of the spring rate. Their inexpensive and easily installed.

Hi,

Thanks for that.

Do you know of any specific thrust sheets / bearings that I should get that will fit the Ohlins springs and the E92 M3 or are they generic?

Jack

[Hujan]

Originally Posted by FazerBoy

Hi,

Thanks for that.

Do you know of any specific thrust sheets / bearings that I should get that will fit the Ohlins springs and the E92 M3 or are they generic?

Jack

+1

I have similar noises coming from the rear of my car that started when I installed the Ohlins R&T coilovers. I installed RD Sport sway bars and solid bushings in the diff and subframe at the same time as the Ohlins, though, so I wasn't sure where to place the blame for the noise. Sounds (pun not intended) like it might be the Ohlins. I would like to hear more about thrust sheets.

[FazerBoy]

Originally Posted by Hujan

+1

I have similar noises coming from the rear of my car that started when I installed the Ohlins R&T coilovers. I installed RD Sport sway bars and solid bushings in the diff and subframe at the same time as the Ohlins, though, so I wasn't sure where to place the blame for the noise. Sounds (pun not intended) like it might be the Ohlins. I would like to hear more about thrust sheets.

I've also got the solid rear subframe bushings and Delrin diff bushes but I had these fitted for a while before I had the Ohlins kit fitted. The Delrin diff bushings are a bit noisy but I had got used to that noise. It is more of a clunking and thumping noise and I'm not bothered about it..

Now that I fitted the Ohlins there is a distinctly new noise coming from the rear of the car that was not there before. It is a higher pitched creaking or clicking noise and I'm pretty sure it's being caused by the rear springs twisting and moving and their contact with the solid body of the car.

To be honest I'm more concerned about whether it will cause damage than the noise itself. If somebody knowledgeable tells me no damage is being caused to the contact points on the car and it's just a noise then I'm happy to put up with it...

[M3SQRD]

Here are a couple links to thrust sheets/Torrington bearings:

http://http://store.bimmerworld.com/torrington-bearing-kit-p1858.aspx

http://http://www.swiftsprings.net/products/universal/misc.html

[FazerBoy]

Originally Posted by M3SQRD

Here are a couple links to thrust sheets/Torrington bearings:

http://http://store.bimmerworld.com/torrington-bearing-kit-p1858.aspx

http://http://www.swiftsprings.net/products/universal/misc.html

Thanks.

Anybody know what size I would need to fit the rear Ohlins springs?

Also, looking at those links, it appears to me that the thrust sheets are for fitting to coilovers where the spring is sitting around the damper. This is the setup at the front but there is no noise from the front.

So I presume that for the rear springs on my car (which sit on their own next to the damper) I might need the Torrington bearings. Is that right? Will I need one for the top of each spring and one for the bottom?

Sorry to be asking these silly questions but I really don't understand much about suspension and I'm looking to find a solution and take it into a shop to be installed. (Yes, I know - the shop should be working this all out for themselves but they're too busy).

[M3SQRD]

Originally Posted by FazerBoy

Thanks.

Anybody know what size I would need to fit the rear Ohlins springs?

My guess is they're 60 mm-Dia springs (if it's a straight, not barrel, shaped spring) because the rates are in N/mm. However, you could use 2.5"-Dia sheets/bearings. 60 mm = 2.36"

[RickyBobby]

What keeps them in place?

[Groundpilot]

I have Ohlins R&T coils with standart springs and its nice and quite, did a few track events and am very happy with this system.
My guess is, something is not installed correctly. As far as i know, my shop did not use thrust sheets

[FazerBoy]

Originally Posted by Groundpilot

I have Ohlins R&T coils with standart springs and its nice and quite, did a few track events and am very happy with this system.
My guess is, something is not installed correctly. As far as i know, my shop did not use thrust sheets

Yes, that could be - that's what I am trying to find out.

When you next take a rear wheel off, could you please have a look and see what the top and bottom of the rear springs are sitting on?

Thanks

[Hujan]

Originally Posted by FazerBoy

I've also got the solid rear subframe bushings and Delrin diff bushes but I had these fitted for a while before I had the Ohlins kit fitted. The Delrin diff bushings are a bit noisy but I had got used to that noise. It is more of a clunking and thumping noise and I'm not bothered about it..

Now that I fitted the Ohlins there is a distinctly new noise coming from the rear of the car that was not there before. It is a higher pitched creaking or clicking noise and I'm pretty sure it's being caused by the rear springs twisting and moving and their contact with the solid body of the car.

To be honest I'm more concerned about whether it will cause damage than the noise itself. If somebody knowledgeable tells me no damage is being caused to the contact points on the car and it's just a noise then I'm happy to put up with it...

Interesting. I was mostly referring to the clunks and thumps that I now hear when ascending/descending steep inclines at slow speeds. I don't recall hearing any high-pitched creaking noises, but I will try to pay attention and report back.

[V1.47fan]

Originally Posted by Groundpilot

I have Ohlins R&T coils with standart springs and its nice and quite, did a few track events and am very happy with this system.
My guess is, something is not installed correctly. As far as i know, my shop did not use thrust sheets

+1 thrust sheets are needed on the front springs because of the steering causing the springs to twist, not really needed on the rear.

The same reason the front stock spring upper mounts twist and the rear springs mounts dont...

[M3SQRD]

Originally Posted by V1.47fan

+1 thrust sheets are needed on the front springs because of the steering causing the springs to twist, not really needed on the rear.

The same reason the front stock spring upper mounts twist and the rear springs mounts dont...

When a spring, front or rear mounted, is compressed it also twists so they actually are useful on the rear.

[M3SQRD]

Originally Posted by RickyBobby

What keeps them in place?

You can install them between the spring and height adjuster.

[V1.47fan]

Originally Posted by M3SQRD

When a spring, front or rear mounted, is compressed it also twists so they actually are useful on the rear.

You use them in the front so does BMW because when you turn the steering wheel left or right, the shocks rotate left or right, no such thing in the back and the rear springs arent sitting on the shocks.

The spring doesnt twist when compressed otherwise every stock BMW, SUV etc. Will have bearings on the rear as well.

How come the stock springs without the thrust sheets dont make the noise the op is describing?


If you look at the rear rubber mounts where the springs sit they actually have lil tabs at the bottom that go on the A arm, also there's a stop in the rubber mount since the spring doesnt twist so the spring sits perfectly.

Like another member pointed out, probably an install error...

[E90M3velocity]

Originally Posted by Hujan

Interesting. I was mostly referring to the clunks and thumps that I now hear when ascending/descending steep inclines at slow speeds. I don't recall hearing any high-pitched creaking noises, but I will try to pay attention and report back.

Check if there is any play where the rear shocks are mounted on the bottom. I had those same thumps and clunks in the same circumstances as you. If you can wiggle it side to side then install some washers to get them snug.

[FazerBoy]

Well, thanks for all the helpful replies but now I am almost as confused as when I started the thread as I'm not sure whether my shop has installed the rears correctly in the first place (since there are people that have the Ohlins with no fancy washers and have no noise!).

Here is a pic of the installation instructions from the Ohlins manual. My shop tell me they followed these instructions. The bottom of the spring rests on a 'lower plastic seat' supplied by Ohlins. I think the noise is coming from this area (although I am not sure of this).

[E90M3velocity]

There should be metal spacers where the shock attaches to the bottom supplied by ohlins. I got mine used and i had to resort buying washers. Its not visible until you start looking at the parts list. Anyways, best to take it back to the shop so they can take a look at it or you can put the car in the air and start poking around. Good luck, i hope it is a quick fix

[m3aviator]

You must find the source of the problem before you add anything into the mix. My money is something is loose. Check the sway bar bolts.

[FazerBoy]

Originally Posted by E90M3velocity

There should be metal spacers where the shock attaches to the bottom supplied by ohlins. I got mine used and i had to resort buying washers. Its not visible until you start looking at the parts list. Anyways, best to take it back to the shop so they can take a look at it or you can put the car in the air and start poking around. Good luck, i hope it is a quick fix

Yeah, I hear what you are saying but I bought mine new and I posted above a diagram of the setup of the rear springs from the Ohlins manual and there is no metal spacer shown where the shock attaches to the bottom.

Originally Posted by m3aviator

You must find the source of the problem before you add anything into the mix. My money is something is loose. Check the sway bar bolts.

I agree, but I have been back once to the shop and everything is definitely tight. I think the problem is something to do with the spring and where it attaches to the car but there's nothing loose.

[W Cole]

There are definitely two metal spacers for each shock in the rear (4 total). I got my coilovers new and they were missing these pieces I had to PAY $100 to get them from ohlins. Are you saying you don't have these parts? If the rear shocks are just loose in the lower A-arm thats your problem but thats an insanely rookie mistake and unsafe of a shop to let you drive it like that.

I have ohlins and installed them myself. I have no noises from the rear. I have a couple of ideas of what it could be:

- My best guess: The rear shock isnt seated correctly in the top mount and/or the bolt isnt tightened enough (its hard to tighten - best to use an impact gun for this bolt and the front strut top nut. These are the two most common areas for mistakes).

- Did you lower the rear of the car significantly? If so make sure they shortened the shock length in unison. If not, the spring can "float" and this can make noise (although this probably wouldnt cause the types of noises you describe.. only over large bumps or going up driveways when the suspension is completely unloaded).