BMW M5 Forum and M6 Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
1,014 Posts
Discussion Starter #1
My thrust arm bushings are shot, I've got new thrust arms with OE bushings installed but I'm considering purchasing G.A.S. Monoball bushings and pressing them in my thrust arms before installing them.

What I'm looking to achieve by installing monoballs is more direct and precise steering response without a large increase in NVH. I drive my car daily but also drive hard on the mountains and twisty roads near me.

Should I purchase and install them? Will they make a big difference in steering feel, justifying the cost and added time of pressing out the old bushings and pressing in monoballs?
 

·
Registered
Joined
·
25 Posts
I just got the GAS monoballs. they feel amazing on open road but I feel an increase NVH in city driving (granted the streets in my city are VERY bad) so the increase in NVH is proportional to road conditions, specifically square edge bumps. The performance and reliability increase is wonderful but be realistic about your driving conditions when it comes to NVH
 

·
Registered
Joined
·
221 Posts
With stock suspension it's a no-brainer significant improvement, with stiffer set ups it will really depends on the roads you are driving every day. I have a PSS9 and put Turner bushings in - steering feel is just great and front end feels very tight, having said that, my daily commute on the NE roads is not very pleasant now.

I might go back to the solid rubber bushings instead of monoballs.
 

·
Registered
Joined
·
341 Posts
If you are sensitive to NVH, then just stick with the rubber bushings. It is really too subjective of a criteria to give feedback on.

For example, I have seen plenty of posts saying that monoballs have too high NVH in the city. I live in New England and the roads are horrible. For me, I will take the sharper and more precise handling. I have not noticed any increase in NVH or I am simply use to it by now when I switched to monoballs. I only thing I do know with certainty is that I really enjoy driving my car even in the city.

If you are going from worn bushings to new ones or monoballs, the difference in handling will be stark.
 

·
Registered
Joined
·
7,519 Posts
With stock suspension it's a no-brainer significant improvement, with stiffer set ups it will really depends on the roads you are driving every day. I have a PSS9 and put Turner bushings in - steering feel is just great and front end feels very tight, having said that, my daily commute on the NE roads is not very pleasant now.

I might go back to the solid rubber bushings instead of monoballs.
This is the key point. It does come down to what other suspension modifications have been done.

I had Dinan springs/Konis/sway bar setup plus Ground Control camber plates. The combination of the GC plates and the Dinan monoballs is what, in my case I believe, created a significant increase in NVH. It was essentially only over high frequency inputs (sharp pavement edges/Botts lane markers, etc). The car would transmit a sharp crack in both feel (in steering wheel) and noise. The increase in steering sharpness and accuracy, especially under very heavy trail-braking into corners, kept me using the monoballs for many years (2007-2015).

When I decided to take them out (replacing the arms with OE new ones) since I wasn't using the M5 for aggressive driving any longer, the transformation was astounding. The touring M5 was back. All that sharp noise and harshness was gone (along with the precise feel too). It was quiet and enjoyable on the highway now, etc.

I'm guessing that if I didn't have the GC camber plates with their decreased NVH absorption compared to the stock bearing/spring hat, the issue would not have been nearly as pronounced.
 

·
Registered
Joined
·
12,784 Posts
Consider the X5 thrust bushings as a middle ground. They are more robust and I think retain the stock M5 feel.

I have used 2 sets over my time of ownership (over 100k miles). You do install them 180 degrees out of phase (they were designed for the X5). There is an old thread, something like "Crevier sucks". A ton of info.

Regards,
Jerry
 

·
Registered
Joined
·
471 Posts
I am very pleased with the GAS monoballs, after the last set of stock bushings on my car failed in under 20k miles. I really noticed no difference in NVH, so it's a win-win in my opinion.
 

·
Registered
Joined
·
1,494 Posts
After going through few bushings including powerflex, monoball upgrades are one of best upgrades you can add to your E39 M5. Search up moosehead engineering thread I created few years ago and you can see my review on there.
 
1 - 9 of 9 Posts
Top