[EdmJunky]

I paid a lot of money for my 09 E90 and I refuse to sell it at the highly depreciated value it holds today. So I'll be driving that car until it won't drive anymore, and then I'll probably swap the engine and drive it some more lol. With that in mind I decided it's time to do a full suspension overhaul as the suspension is pretty much toast with 170k miles.

I purchased a level 3 suspension refresh kit from ECS which comes with just about everything I'll need. Also picked up a fresh set of Koni yellow's front and rear, and I'm currently in the market for a set of Eibach springs. That should complete the list of parts I'll need for the overhaul (let me know if I missed anything).

Anyway the reason for this post is I want to pick the brains of those of you that have done this before. Any challenges I'll be running into? Any tips or tricks I should know before hand? Any special tools I'll need to get? I know I'll have to drop the rear subframe so I'm aware that will probably be the hardest part of this job but other than that I'm entering unknown territory. Would be helpful to have documentation on torque specs for everything too, currently don't have that. I probably won't actually be tackling the job for another few weeks so right now I'm just gathering as much info as I can in preparation.

[stevesingo]

To save time, buy a used subframe off ebay. Replace all the mounting bushes and diff bushes (add in the hard brake lines if you like) and build it with the new arms etc off the car. Then it is a one for one swap without running in to problems with the car on ramps/stands.

[BSM n54iS]

Top nut on the front struts have caught some people off guard...

Most end up just using an impact, but if you're going for full correct torque specs may look into a pass-through wrench of some sort or I've heard the O2 sensor socket can work

[martinm0]

If you are lowering the car you'll need some adjustable (or differently sized) end links.

[EdmJunky]

Originally Posted by stevesingo

To save time, buy a used subframe off ebay. Replace all the mounting bushes and diff bushes (add in the hard brake lines if you like) and build it with the new arms etc off the car. Then it is a one for one swap without running in to problems with the car on ramps/stands.

Not a bad idea at all but I feel like it would be an unnecessary added cost. Although I will keep this in mind as I do more research on dropping the subframe and weigh out the better option.

Originally Posted by BdSM n54iS

Top nut on the front struts have caught some people off guard...

Most end up just using an impact, but if you're going for full correct torque specs may look into a pass-through wrench of some sort or I've heard the O2 sensor socket can work

I mean I could just hit them with an impact. And this goes for everything else I'll be bolting up as well. In theory I could just tighten everything really tight and use thread locker as opposed to trying to torque everything to spec. If this will be fine I have no problem doing that. I was just worried about over tightening things. I'd like to make this entire thing a one and done job so anything that would avoid me having to re do anything would be good.

Originally Posted by martinm0

If you are lowering the car you'll need some adjustable (or differently sized) end links.

How accurate is this? This is the first time I have hears this. Currently my car is on stock end links and already sits pretty low due to the shot suspension. Plus I will be installing Eibach springs which from what I read is not an aggressive drop.

[gjm120]

Originally Posted by EdmJunky

How accurate is this? This is the first time I have hears this. Currently my car is on stock end links and already sits pretty low due to the shot suspension. Plus I will be installing Eibach springs which from what I read is not an aggressive drop.

I looked into this and found out most just live with the stock endlinks but it isn't optimal. Somewhere on here is a thread that shows the geometry of a dropped car with and without the right length endlinks.

I put adjustable endlinks up front quite a while after driving my car after lowering and the stock links. It made a noticeable difference - not huge but it was an improvement.

[mweisdorfer]

Originally Posted by EdmJunky

I paid a lot of money for my 09 E90 and I refuse to sell it at the highly depreciated value it holds today. So I'll be driving that car until it won't drive anymore, and then I'll probably swap the engine and drive it some more lol. With that in mind I decided it's time to do a full suspension overhaul as the suspension is pretty much toast with 170k miles.

I purchased a level 3 suspension refresh kit from ECS which comes with just about everything I'll need. Also picked up a fresh set of Koni yellow's front and rear, and I'm currently in the market for a set of Eibach springs. That should complete the list of parts I'll need for the overhaul (let me know if I missed anything).

Anyway the reason for this post is I want to pick the brains of those of you that have done this before. Any challenges I'll be running into? Any tips or tricks I should know before hand? Any special tools I'll need to get? I know I'll have to drop the rear subframe so I'm aware that will probably be the hardest part of this job but other than that I'm entering unknown territory. Would be helpful to have documentation on torque specs for everything too, currently don't have that. I probably won't actually be tackling the job for another few weeks so right now I'm just gathering as much info as I can in preparation.

Buy a special schwaben strut socket.

I'd rent the special subframe bushing tool from HP
Autoworks

https://www.hpashop.com/Bushing-Tool...g-tool-kit.htm

I'd also redo the rest of the bushings in the subframe while you have it out of the car. Get M3 Differential bushings & then you have about 9 more bushings I think.

https://www.ecstuning.com/b-genuine-...h/33312284019/

https://www.ecstuning.com/b-genuine-...33326763092kt/

The above kit has 8 of them. It doesn't have the single, large (front) Differential bushing.

https://www.ecstuning.com/b-genuine-...g/33176770866/

You will need a bushing tool for the small bushings too.

https://rover.ebay.com/rover/0/0/0?m...2F192899716941

[stevesingo]

Originally Posted by EdmJunky

Not a bad idea at all but I feel like it would be an unnecessary added cost. Although I will keep this in mind as I do more research on dropping the subframe and weigh out the better option.

I picked up a subframe from ebay for £60. Removed the bushes, shot blast and powder coat (£50). Installed new bushes.

The removal and install of bushes is at least a days work. I saved that time on the axle stands plus more when I fit all the new arms to the sub frame.

Not to mention de-risking the whole time on axle stands. Some of the bushes were tricky to remove and install requiring a break to make up new pullers etc.

I didn't want to strip it all out to find I couldn't complete the job in one go due to running in to issues.

[Antetokounmpo]

Originally Posted by martinm0

If you are lowering the car you'll need some adjustable (or differently sized) end links.

I don't think that's true. I've lowered 3 E90s and every one of them you adjust rotate the front bar to line up with the end links just fine

[gjm120]

Not too old good thread on endlinks:

https://www.e90post.com/forums/showthread.php?t=1523326

[martinm0]

Originally Posted by Antetokounmpo

I don't think that's true. I've lowered 3 E90s and every one of them you adjust rotate the front bar to line up with the end links just fine

This seems to be a point of contention for many. Admittedly, I have not lowered any of my cars, so I can't provide any personal experiences to this statement.

That said, many have had this discussion, and at some point, the geometry of the sway bar will be an issue if it rotates too much and is where the end links come in to help keep it in the intended position, either by providing too much force to the sides of the car due to positioning, or hitting other components if rotated very far (or installed upside down).

Anyway, just food for thought. Not stating this is mandatory, or that I'm 100% right, but just something to keep in mind when lowering.

[ducatiti]

So you don't have to do research as I did, here are some torque values for my 06 325i I recently worked on. Got these from the forum and ECS/Bavarian videos...

Rear

21 mm / 21 mm (to counter) Control arm rear for spring removal - 121.6 ft lbs
17 mm / 15mm Bottom (to counter) nut for shock - 28 ft lbs
16 mm / 6 mm (to counter) Top nut for shock - 20 ft lbs


Front

18 mm / 18 mm (to counter) Strut bottom spindle - 34 ft lbs.
13 mm top strut mounts 3- 25 ft lbs
Sturt nut 1 - 47 ft lbs
18 mm Control arm bushing 50 ft lbs + 90 degrees
18 mm Tension strut 50 ft lbs + 90 degrees
16 mm / 17 mm (to counter) Sway bar end link 43 ft lbs


https://www.e90post.com/forums/showt...1590447&page=2

[philgli]

I lowered my car with coilovers at around 40k miles. Within 5k miles, the OEM end links were totally shot. I swapped in Meyle HD end links (the stock length) and have been good for another 30k miles. go figure...

[tlow98]

Nice choice with the Koni Yellows. They’ve always been good performers for me.

[EdmJunky]

Another thought that popped into my head as I get closer to tackling this job. Does anything need to be greased during installation? Any of the sway bar bushings or other bushings and such?

[mweisdorfer]

Originally Posted by EdmJunky

I paid a lot of money for my 09 E90 and I refuse to sell it at the highly depreciated value it holds today. So I'll be driving that car until it won't drive anymore, and then I'll probably swap the engine and drive it some more lol. With that in mind I decided it's time to do a full suspension overhaul as the suspension is pretty much toast with 170k miles.

I purchased a level 3 suspension refresh kit from ECS which comes with just about everything I'll need. Also picked up a fresh set of Koni yellow's front and rear, and I'm currently in the market for a set of Eibach springs. That should complete the list of parts I'll need for the overhaul (let me know if I missed anything).

Anyway the reason for this post is I want to pick the brains of those of you that have done this before. Any challenges I'll be running into? Any tips or tricks I should know before hand? Any special tools I'll need to get? I know I'll have to drop the rear subframe so I'm aware that will probably be the hardest part of this job but other than that I'm entering unknown territory. Would be helpful to have documentation on torque specs for everything too, currently don't have that. I probably won't actually be tackling the job for another few weeks so right now I'm just gathering as much info as I can in preparation.

Buy a Bentley Repair Manuel

Upgrade your brake lines to SS while your are in there. The lines are very easy to get to once the rear subframe is out of the way.

Make sure you have the special strut sockets.

Go back in and retighten everything after about a month

Remember to torque the bolts at ride height