[Rani]

Hi!
Is it normal to ride on bump stops in f30? Because i feel a floaty ride in my used car (Bmw 328d xdrive 2014) .Front or rear of the car when going on highway, feel too floaty like no shocks are there. Car bounces 2-3 times....This feel is only when road have any bumps, and some road imperfections. I removed front shock dust cover by hand today and it seems that bump stop is sitting on the shock with no free play between them. Is this normal? I will post a photo of bump stop. Any idea could help me very much! Thank you!

[FaRKle!]

It's normal to only have 0.5-0.75" of damper travel before bump stop engagement. If you're on lowering springs and haven't changed bump stops, you're likely already riding on them at static ride height.

[Rani]

Originally Posted by FaRKle!

It's normal to only have 0.5-0.75" of damper travel before bump stop engagement. If you're on lowering springs and haven't changed bump stops, you're likely already riding on them at static ride height.

Thank you for your reply!
I don't know what kind of springs my car have, or if it is lowered. I think the shocks are stock and seems at standard height(3 finger gap from wheel), but i don't know why bump stops are touching the shocks. The ride is really bad. I feel only springs, not shocks to do their job.

[cfm56d7b]

OP, how many miles does your car have?

[Rani]

Originally Posted by cfm56d7b

OP, how many miles does your car have?

Hi!
89k miles but i think this have nothing to do with bump stop free play rate.
I doubt that the car is lowered and the bump stops are stock.
I need to know the exact bump stops free play before engagement both ,front and rear for my model 328d xdrive 2014, then i will replace bump stops with shorter ones.

[Foriegnmonkey1]

Originally Posted by Rani

Hi!
89k miles but i think this have nothing to do with bump stop free play rate.
I doubt that the car is lowered and the bump stops are stock.
I need to know the exact bump stops free play before engagement both ,front and rear for my model 328d xdrive 2014, then i will replace bump stops with shorter ones.

Generally X drive models, with non m sport suspension are very floaty and bouncy.

I had a rwd sport line and it was very bouncy, I lowered it with dinans and it was still bad.
F30's generally don't have the best sport suspension compared to others in the market, so you need to replace them with better shocks/add thicker sway bars/ etc

[Rani]

Originally Posted by Foriegnmonkey1

Generally X drive models, with non m sport suspension are very floaty and bouncy.

I had a rwd sport line and it was very bouncy, I lowered it with dinans and it was still bad.
F30's generally don't have the best sport suspension compared to others in the market, so you need to replace them with better shocks/add thicker sway bars/ etc

Thank you for your reply !
You are right ,but I still thinking in my head that all is about bump stops are all time engaging over shocks and overall suspension goes bad from this point.
I will trim they very little today just to make some free play to help the shocks to absorb any small road bumps and will show the result.

[damack]

I'd be more concerned with why the springs are sagging to the bumpstops

[Rani]

Originally Posted by damack

I'd be more concerned with why the springs are sagging to the bumpstops

Factory wrong design of the springs or bump stops i think ,because i have seen many factory problems with theese models.

[FaRKle!]

Originally Posted by damack

I'd be more concerned with why the springs are sagging to the bumpstops

I'd want to verify if this is actually the case. The bump stop is sort of press fit into the top hat, but can come out. If Rani is unable to press the bump stop into the top hat at all, then it's probably resting on it, but he might be able to, thus showing there's room.

[Rani]

Update!
The car was totally stock. No lower springs or any other mod.So i decided to cut the bottom ring of both bumpstops ,front and rear just to verify if bounce comes from bumpstops that engaging too early without enough free play over the shocks. After cutting the rings, i tested the car on same bad road . The result was amazing. No more bounce , floating or wobble come from the car. I'm very comfortable with the soft like silk suspension of my car now. Only thing that i don't liked, was a small steering loose feeling but it was cured by increasing front tyres from 32 to 35 psi. No more bounce exist on my car and i'm very happy with this small modification. I think this is bad factory design of bump stops to make the car tighter in corners , or to save money by making thinner sway bar and put low cost polyurethane to reduce body roll ( thick sway bar's job) ,but this sacrifices the ride comfort as it produce too much bounce and the shocks are not able to do their job as they should. I like classic suspension where the job is done from shocks and springs and bumpstops only to protect the shocks from any damage... I know better would be to replace the bump stops with any shorter or softer one, not to trimming them. Please i need any advice about right bump stops (shorter or softer) that i should buy .

[natesi]

Sorry to revive an old thread but I'm highly interested in this and have a question for the OP, or anyone else who might know:

How would he have cut the the "bottom ring" of the rear bump stop -- as it is attached to (part of) the bell-housing - isn't it? The rear bump stop doesn't detach from the bell housing, does it?

The only thing I can think of would be to cut the top of the rear bump stop, but the only thing holding it in place is friction, as it is jammed into the "top mount" -- and since the top of the bump stop is wider than the rest of the bump stop (below it) how would it stay up there?

I'm a little lost.

Thanks,

[jltiii]

I have the same issue with our 2014 F30 328D. I replaced the rear stock shocks with the BILSTEIN B6. The rear bump stops were torn apart so I replaced them with the stock replacement ones & dust cover. After I got everything back together I noticed there was only .5-.75" of play with the car setting empty.
There was no way to shorten because if you cut the top it won't stay in the shock mount, and the bottom is connected to the dust cover.
There is a previous thread that discusses this and at the end the gentlemen recommended using the F8x Bump Stops on an F31. I think I'll go with these as well. We get a very noisy ride on a bumpy road.
These were the part numbers provided...
Front 31336859768
Rear 31337847662

[natesi]

Awesome; thanks.

I tried cutting the rear bumpstops yesterday -- I shimmed the top portion so they stay put. Unfortunately, this change didn't give me the ride I was looking for, although I did notice a little bit more suspension travel over larger bumps, which didn't hurt things.. I don't like the shim idea long term though -- kinda ghetto. So I'll probably get the F80 ones. Thanks for the part numbers!

[jltiii]

This is very good stuff about bump stops...

https://f30.bimmerpost.com/forums/sh...o_threadrating

I'm just wondering if the F30 front dust cover will adapt to the F80 bump stop?

[natesi]

Originally Posted by jltiii

This is very good stuff about bump stops...

https://f30.bimmerpost.com/forums/sh...o_threadrating

I'm just wondering if the F30 front dust cover will adapt to the F80 bump stop?

Thanks for the link; same thread I was looking at too.

I don't think we have to worry about changing the dust cover for the front struts if we switch to the F80 bump stops.

[jltiii]

I'm replacing the struts and the old ones are torn....

[natesi]

Ah, OK.

Sidenote: If you're replacing struts, check out the Koni Special Actives -- they are supposed to be better than OEM in every way.