[Tobz_au]

Hey!

So am considering dropping the rear subframe to swap the rear bushings.

Also now related I also need to change my rear bearings as they have worn out.

Decided to start a new thread to allow some collaboration on the forum. Particularly with my partner in crime Pussiwillow

Step one. Which bushings to buy? Based on a quick search have found these but interested in other options available:

https://www.akgmotorsport.com/produc...m-f30-f80-f22/

This will also likely look at doing the diff bushings and all the rear arms. Would not expect this thread to move quickly, but should show steady progress

[Tobz_au]

So I do have a question if anyone happens to be reading.

Changing the bushings, either to solid or a poly bush from whiteline looks to be a crazy amount of work. What sort of difference is likely between the solid bush vs the powerflex inserts?

Are we taking a small or large difference?

I ran subframe inserts on my old r34 skyline and they really took away a lot of the rear looseness.

Be interested in thoughts, I want to know if the juice is worth the squeeze on this!

Inserts would take maybe 30-60 mins of work. Changing the subframe bushings would be considerably more time

[Jvac]

Originally Posted by Tobz_au

So I do have a question if anyone happens to be reading.

Changing the bushings, either to solid or a poly bush from whiteline looks to be a crazy amount of work. What sort of difference is likely between the solid bush vs the powerflex inserts?

Are we taking a small or large difference?

I ran subframe inserts on my old r34 skyline and they really took away a lot of the rear looseness.

Be interested in thoughts, I want to know if the juice is worth the squeeze on this!

Inserts would take maybe 30-60 mins of work. Changing the subframe bushings would be considerably more time

From what I remember reading here, the subframe inserts didn't make much meaningful difference. The real improvement came with the full subframe bushing swap to aluminum or delrin. I thought about doing it at one time but the labor cost was prohibitively high and I don't have a spare vehicle to use while I take my time doing it myself.
The big question is how hard it will be to remove your old bushings because it's possible they get properly stuck in the subframe over time. The whole thing really needs to be pulled off the car so that it's safe to take a blowtorch or chisel to them if they don't want to come out. I read a thread where a guy spent more time fighting to get his out than he spent removing and replacing the subframe, for example. It's been a few years, but there are some threads on it if you search.
The diff bushings added harshness and driveline noise but not as much handling improvement if I remember correctly.

[WDE82]

I put inserts in my E82 and it made a small difference. I put in Powerflex poly bushings a couple years later and it was THE best thing I EVER did for that car. Now, the F30's RSF isn't nearly as bad as the E82, but the lesson is, the inserts aren't really worth it.

Yes pressing bushings in and out sucks. But when you buy the new ones, take a bunch of measurements and put together your strategy for removal and installation with some homemade presses.

[Pussiwillow]

Inserts are going to be meh, you won't get much from them in comparison.

My plans are, AKG Motorsport aluminum subframe bushing but considering 75d which is around hard hat and bowling ball density, and 95a poly differential bushings. This is the exact set up my old e36 had, it was perfect.
I may do 75 d in both locations however and lock it down as this car makes considerably more power, I already have the BMS differential lock down plate

[Watsey]

I've been running these for several months in my F31 330d and I am very happy with them :

https://ukwhitelineperformance.com/p...17-bushing-kit

Rear subframe has been really tightened-up; less chassis/subframe differential movement; much better feel.

Although the rear of the car feels much tighter I wouldn't describe it as significantly increased NVH. I was cautious/hesitatnt about the upgrade, mainly due to the risk of NVH, but these bushes have met my expectations and the reassurances from Whiteline when I 'phoned them to discuss.

[Tobz_au]

Originally Posted by Pussiwillow

Inserts are going to be meh, you won't get much from them in comparison.

My plans are, AKG Motorsport aluminum subframe bushing but considering 75d which is around hard hat and bowling ball density, and 95a poly differential bushings. This is the exact set up my old e36 had, it was perfect.
I may do 75 d in both locations however and lock it down as this car makes considerably more power, I already have the BMS differential lock down plate

Yer ok based on the above I may skip the inserts. So any good diy on how to remove the rear subframe? Or is it as simple as:

Disconnect the rear control arms
Remove the rear driveshafts to the wheels
Undo the massive bolt for the driveshaft going from the engine to the diff
Remove the exhaust
Remove the diff
Remove the subframe?

Is there anything special to disconnect the driveshaft from the engine to the diff?

In terms of removing the old bushings, I’ll just burn them out.

[Tobz_au]

Originally Posted by Watsey

I've been running these for several months in my F31 330d and I am very happy with them :

https://ukwhitelineperformance.com/p...17-bushing-kit

Rear subframe has been really tightened-up; less chassis/subframe differential movement; much better feel.

Although the rear of the car feels much tighter I wouldn't describe it as significantly increased NVH. I was cautious/hesitatnt about the upgrade, mainly due to the risk of NVH, but these bushes have met my expectations and the reassurances from Whiteline when I 'phoned them to discuss.

Ooo nice to hear, I’m tempted to go the whiteline bushings

[Pussiwillow]

Originally Posted by Tobz_au

Yer ok based on the above I may skip the inserts. So any good diy on how to remove the rear subframe? Or is it as simple as:

Disconnect the rear control arms
Remove the rear driveshafts to the wheels
Undo the massive bolt for the driveshaft going from the engine to the diff
Remove the exhaust
Remove the diff
Remove the subframe?

Is there anything special to disconnect the driveshaft from the engine to the diff?

In terms of removing the old bushings, I’ll just burn them out.

Honestly I'm going to do what I did with my front subframe lol, remove the whole thing, probably remove calipers and hang them out of the way, remove parking brake, remove driveshaft which I hear is a pain in the ass, and then drop it out completely.

I'm going to put all new arms and upgrade what can be, hoping to do a limited slip diff as well, probably powder coat the rear subframe like I did on my e36.

I don't have a diy, pretty much just going to send it.

[Tobz_au]

Do we need any special tools for the driveshaft?

[Pussiwillow]

Originally Posted by Tobz_au

Do we need any special tools for the driveshaft?

I believe so, I can't recall, if I remember correctly it's a reverse thread with some sort of thread lock and it's very very tight, don't quote me I only catch this stuff in passing and could be off on my info, I'm sort of a "I'll tackle this blind and invent a new language during" which leaves the car down for twice as long lol.

I know the axles need a special tool if you're removing them at all, however there is a work around, some have popped them with large screw drivers I think, or similar but we know how that goes lol. 10 min turns to 5 hours

Edit: just make sure you break the axle nut free while car is still on the ground lol

[Tobz_au]

Good tip on the axle nut!!! And also thank god for stupid big Milwaukee impact wrenches….

I’ve ordered the whiteline subframe and diff bushings this morning. Managed to get them 50% off… which is a plus!

Now trying to find all the rear arms

And yer I think the driveshaft is a 50mm reverse thread

[Pussiwillow]

Originally Posted by Tobz_au

Good tip on the axle nut!!! And also thank god for stupid big Milwaukee impact wrenches….

I've ordered the whiteline subframe and diff bushings this morning. Managed to get them 50% off… which is a plus!

Now trying to find all the rear arms

And yer I think the driveshaft is a 50mm reverse thread

My man heck yes!
That's a great deal. You going with specific brand on arms? I'm looking at turner lower traction rods and spl upper rear control arms, AKG 75d bushings in subframe and diff most likely, this is the plan as of now but it's gonna be several months.

Edit: AKG has both upper arms for 210$ cheaper than spl, I'm a big AKG fan, maybe I'll run those
They have all of them, I did not add the lower toe rods, they're 330$ not sure if I'll need them or not, I will order when the rear is out officially,

[Tobz_au]

Orrrr replace them without dropping the subframe

[Pussiwillow]

Originally Posted by Tobz_au

Orrrr replace them without dropping the subframe

I do know the diff bushings are very challenging with subframe up, tho, the subframe bushings can be done just by lowering enough, I'll check that video out

[Tobz_au]

Also I’m thinking about getting the hardrace arms. I’m pretty sure they are just rebranded Megan racing arms. I used to have them in my r34 and they worked really well

https://www.hardracesuspension.com.a...ontrol-arm~923

[Tobz_au]

Originally Posted by Pussiwillow

My man heck yes!
That's a great deal. You going with specific brand on arms? I'm looking at turner lower traction rods and spl upper rear control arms, AKG 75d bushings in subframe and diff most likely, this is the plan as of now but it's gonna be several months.

Edit: AKG has both upper arms for 210$ cheaper than spl, I'm a big AKG fan, maybe I'll run those
They have all of them, I did not add the lower toe rods, they're 330$ not sure if I'll need them or not, I will order when the rear is out officially,

I hate you. Cancelled the whiteline bushings and now have an order for the 75D subframe and diff bushings. Also ordered their rear adjustable swaybar links.

In your screenshot you have 75D subframe bushings and 95A diff bushings. Shouldn’t you go 75D for both?

Will decide on what arms to go later on

Also worth watching this

[Watsey]

Originally Posted by Tobz_au

Ooo nice to hear, I’m tempted to go the whiteline bushings

I forgot to mention…I also had the diff bushes replaced at the same time. Also Whiteline items.

The 'tightness' in the rear of the car is noticeable but I wouldn't describe it as harsh. As the guy at Whiteline said "don't worry, the subframe bushes aren't going to turn your BMW into a rally car" and he's right.

[Tobz_au]

Originally Posted by Watsey

I forgot to mention…I also had the diff bushes replaced at the same time. Also Whiteline items.

The 'tightness' in the rear of the car is noticeable but I wouldn't describe it as harsh. As the guy at Whiteline said "don't worry, the subframe bushes aren't going to turn your BMW into a rally car" and he's right.

If only it was that easy to create a rally car!

So having a look under the car. I reckon I’ll do the diff bushings first. Plan of attach is to disconnect the rear exhaust hanger so the exhaust can drop a little. Then get access to the drive shaft bearing and take that off. That will give me slack in the drivetrain. Then unbolt the diff (while I have it supported) and lower it enough to get to the diff bushings.

Use a bushing removal tool to take the old ones out. Press the new ones in and voila all done. Bolt diff back on.

Then after support the rear subframe. Unbolt it, let it sag, press out the old bushings, press the new ones in.

Only tool I need to buy is the press tool kit

Then follow the fcp euro video to change the arms.

I think I have a plan now… so watch it fail miserably

[mike082802]

Originally Posted by Tobz_au

Orrrr replace them without dropping the subframe

thats exactly how i did mine in July, same way as i did it in my e82. just have 2 good jacks and take your time. took me about 4 hours and really had to cook the rubber bushings to get them out. dont know why you would want to take the whole subframe out if you don't have to. i used whiteline bushings i got off a one series facebook group for like $90, same part i used in my 135i.

[Pussiwillow]

Originally Posted by Tobz_au

I hate you. Cancelled the whiteline bushings and now have an order for the 75D subframe and diff bushings. Also ordered their rear adjustable swaybar links.

In your screenshot you have 75D subframe bushings and 95A diff bushings. Shouldn't you go 75D for both?

Will decide on what arms to go later on

Also worth watching this

Lol
And yes you're supposed to match diff bushings to the subframe bushings, however I had this debate 5 years ago when I was wrapping up a debate about my e36 build where I didn't want to hear the diff whine so harshly lol, I went solid aluminum with 95a, AKG reached out to me and said it won't cause harm; it's just not ideal for performance etc.

Car felt great, my car still hits the road for 4-6 hour road trips still. However this car isn't gutted and does have a solid diff brace attached, I doubt the noise will be so bad, I'll likely do 75d in both locations but I'm a bit behind for this project lol

As for arms I'll likely wait off so I can see the impact the bushings made; however I'll be doing traction rods right away with them, the arm it replaces is a toothpick and seen several break from load alone.

[Tobz_au]

The standard arms on the rear are really crap on this car. Looks like they will snap in a small breeze!

Also I wasn’t even going to do subframe bushes… now I have parts arriving :P I blame you!