rear subframe drop 328xi E91

h3ll · 08-28-2023, 04:42 AM

K Ive been looking around & never see what Im looking at under my car..

OBJECTIVE: Drop rear subframe with differential.

The car already has its suspension, brakes, wheel hub removed. All that is left is the differential, & half shafts.
I've removed the 6 bolts form the guibo at the rear on the driveshaft where it mates up with the diff. Ive got a floor jack under the diff & removed all 6 bolts from the subframe & that all came apart fine but its still not letting go from the driveshaft guibo?!?!
All I see are vids of people who have the drive shaft attached withe 50mm nut... I have no visual of how the driveshaft might be still attached to the diff.. Is there something rusted in place? Do I need to drop the driveshaft from the center bearing?
I've been under the car # of hours working on disconnecting everything & even cutting my brake lines since that whole rear connector is rusted to sh!t & I have to rebuild my brake hard lines while I plan on working on the subframe bushings etc..
Guess I'm just tired now & huffed too much gas that my friend spilt so I'm losing my patience & just want simple guidance of what to do so I can just get that out asap lol..

Thx
included is picture showing the diff/driveshaft guibo in question from both sides

Brian86 · 08-28-2023, 10:16 AM

Get a crowbar and pry it apart.

It really is just rust holding it together. It's a pain because the rubber deflects and makes it hard to get a good bite.

Plan on buying a new guibo. The rears are smaller and wear out more quickly, but it's a good time to do the front as well.

h3ll · 08-28-2023, 01:25 PM

Quote:

Originally Posted by Brian86

Get a crowbar and pry it apart.

It really is just rust holding it together. It's a pain because the rubber deflects and makes it hard to get a good bite.

Plan on buying a new guibo. The rears are smaller and wear out more quickly, but it's a good time to do the front as well.

Perfect! If thats the case I already got new guibos.. just wanted to make sure before I break something else & just was not in the mood in case I forced something.. so I'm just gonna whack a crowbar in there & pry it apart..
As per the front & center bearing, planning on that next year when I drop the transmission to change the clutch.
Everyday I curse rust inthe North east

AWD Addict · 08-28-2023, 02:32 PM

My undercarriage looks really good after 15 years. I do the undercarriage wash every time I go through the touch free, particularly in the winter, and all the bolts and hangers underneath look great.

The subframes however, suck. I've already replaced both due to heavy rust and corrosion, and had the replacement treated with POR 15, which has held up amazingly.

My mechanic did my calipers with the POR too, which looks great and should help extend their life.

Peter Morrin · 10-03-2023, 11:42 PM

I feel your pain. I just replaced my rear sub-frame with a friend and we had about 60 man-hours into the job and still some bits left to do. We lowered the mid-bearing for the drive shaft which required removing the exhaust and heat shield. It took hours getting the 8 tunnel bolt Torx bolts off.

Getting the bushings out was a bear. We ended up using a large hole saw (4"), heated the bushings with a torch and extracted them with the threaded rod technique. I used Poly (Rev Shift) bushings which pressed in by hand once the sleeves were cleaned and greased.

When you reinstall the sub-frame you need to get all 4 sub frame bolts threaded into their wholes and then bring the sub-frame up evenly. The poly won't deflect like the original rubber. Our holes did not align perfectly, but we eventually got the sub-frame in. Aluminum bushings would not have worked. I am not sure why the sub frame was off with respect to my car. It looked like it came from the factory without any impact signs.

I also am in Eastern Canada and I believe the actual brake cylinder rusted through. Seals are fine, but spraying brake fluid from the cylinder. I am running out of time so ordered new. Another delay.

Also be aware that there are different wheel position sensors between years. Some are blue, some are grey. They are not interchangeable.

Parking brake cables were siezed into the existing hubs. NO way to reuse. $115 at the dealer.

In our case it was a much bigger job than I was led to believe from the write-ups.

Good luck.

08-28-2023, 04:42 AM	#1
h3ll New Member 2 Rep 21 Posts Drives: e91 07 6mt xdrive Join Date: Mar 2013 Location: Canada iTrader: (0)	rear subframe drop 328xi E91 K Ive been looking around & never see what Im looking at under my car.. OBJECTIVE: Drop rear subframe with differential. The car already has its suspension, brakes, wheel hub removed. All that is left is the differential, & half shafts. I've removed the 6 bolts form the guibo at the rear on the driveshaft where it mates up with the diff. Ive got a floor jack under the diff & removed all 6 bolts from the subframe & that all came apart fine but its still not letting go from the driveshaft guibo?!?! All I see are vids of people who have the drive shaft attached withe 50mm nut... I have no visual of how the driveshaft might be still attached to the diff.. Is there something rusted in place? Do I need to drop the driveshaft from the center bearing? I've been under the car # of hours working on disconnecting everything & even cutting my brake lines since that whole rear connector is rusted to sh!t & I have to rebuild my brake hard lines while I plan on working on the subframe bushings etc.. Guess I'm just tired now & huffed too much gas that my friend spilt so I'm losing my patience & just want simple guidance of what to do so I can just get that out asap lol.. Thx included is picture showing the diff/driveshaft guibo in question from both sides Attached Images
	Appreciate 0 Tweet Quote

08-28-2023, 10:16 AM	#2
Brian86 Captain 662 Rep 786 Posts Drives: e36 M3, e91 325xi, N50 Xterra Join Date: Dec 2020 Location: Pittsburgh iTrader: (0)	Get a crowbar and pry it apart. It really is just rust holding it together. It's a pain because the rubber deflects and makes it hard to get a good bite. Plan on buying a new guibo. The rears are smaller and wear out more quickly, but it's a good time to do the front as well. __________________ Sometimes a bolt is just a bolt.
	Appreciate 0 Quote

08-28-2023, 02:32 PM	#4
AWD Addict Chief Executive 388 Rep 2,919 Posts Drives: 2008 335xi 6spd Coupe Join Date: Dec 2007 Location: Boston iTrader: (1) Garage List 2008 335xi [0.00]	My undercarriage looks really good after 15 years. I do the undercarriage wash every time I go through the touch free, particularly in the winter, and all the bolts and hangers underneath look great. The subframes however, suck. I've already replaced both due to heavy rust and corrosion, and had the replacement treated with POR 15, which has held up amazingly. My mechanic did my calipers with the POR too, which looks great and should help extend their life.
	Appreciate 0 Quote

10-03-2023, 11:42 PM	#5
Peter Morrin Private First Class 59 Rep 196 Posts Drives: 2007 E90(sedan) 328xi Join Date: Dec 2021 Location: Kingston, Ontario, Canada iTrader: (0)	I feel your pain. I just replaced my rear sub-frame with a friend and we had about 60 man-hours into the job and still some bits left to do. We lowered the mid-bearing for the drive shaft which required removing the exhaust and heat shield. It took hours getting the 8 tunnel bolt Torx bolts off. Getting the bushings out was a bear. We ended up using a large hole saw (4"), heated the bushings with a torch and extracted them with the threaded rod technique. I used Poly (Rev Shift) bushings which pressed in by hand once the sleeves were cleaned and greased. When you reinstall the sub-frame you need to get all 4 sub frame bolts threaded into their wholes and then bring the sub-frame up evenly. The poly won't deflect like the original rubber. Our holes did not align perfectly, but we eventually got the sub-frame in. Aluminum bushings would not have worked. I am not sure why the sub frame was off with respect to my car. It looked like it came from the factory without any impact signs. I also am in Eastern Canada and I believe the actual brake cylinder rusted through. Seals are fine, but spraying brake fluid from the cylinder. I am running out of time so ordered new. Another delay. Also be aware that there are different wheel position sensors between years. Some are blue, some are grey. They are not interchangeable. Parking brake cables were siezed into the existing hubs. NO way to reuse. $115 at the dealer. In our case it was a much bigger job than I was led to believe from the write-ups. Good luck.
	Appreciate 0 Quote