[MrSweet1991]

Hi All,

So it's time that I replace the rear subframe, a while back in the snow I hit the rear passenger wheel off a kurb and not long ago I reversed at an angle to come off the dropped kurb but instead missed and came off the kurb and into the gutter which destroyed the shock and I think made the rear subframe worse.. Either way I wanted to replace it before as the car wouldn't align even after new Eibach springs, wheel knuckle and all arms replaced so..

Any recommendations or tips? I'm going to drop the rear subframe as a whole with differential and arms still attached. From my understanding all I need to do is remove the exhaust, the brake lines, height sensor, handbrake cable, wheel speed sensor and propshaft from diff?

I can't do anything yet as I need to order a 50mm spanner and may need to angle grind it thinner judging from the design of a specific differential spanner. But yeah if anyone has done this before I'd appreciate any tips or suggestions.

[Tambohamilton]

My e91 330d has a giubo at the diff, rather than the big nut.

You'll also need to faff with heat shields etc.

Definitely take the opportunity to install M3 or aftermarket rear subframe bushings while the subframe is out. Diff bushings too....and any other bit that might need or want to be replaced or upgraded.

[MrSweet1991]

Originally Posted by Tambohamilton

My e91 330d has a giubo at the diff, rather than the big nut.

You'll also need to faff with heat shields etc.

Definitely take the opportunity to install M3 or aftermarket rear subframe bushings while the subframe is out. Diff bushings too....and any other bit that might need or want to be replaced or upgraded.

That's interesting mate, was yours an automatic? If so I'll have to put it on axle stands tomorrow as that's the only reason I never made a start. And while I would jump at all that I just can't at the moment. I purchased a rear subframe and because I completely blew the shock and mounts I need to purchase some rear bilstein with all mounts for around £168 plus odd things like brake and differential fluid and my insurance is due for renewal next month which for me is £500 and something just for the deposit FML so I'll have to settle for this for now, but to me the car should be exceptionally good as for a long time I've been driving with a slightly unaligned rear passenger wheel and shock absorber was shite and I can't say for sure but I think I knackered the subframe bushing so given my situation I think the car will feel 100 times better than what I'm used to lol

[MrSweet1991]

Originally Posted by Tambohamilton

My e91 330d has a giubo at the diff, rather than the big nut.

You'll also need to faff with heat shields etc.

Definitely take the opportunity to install M3 or aftermarket rear subframe bushings while the subframe is out. Diff bushings too....and any other bit that might need or want to be replaced or upgraded.

Wow, so after you wrote that I remembered I did a video of the rear subframe and I pushed the phone down by the differential to see that 50mm nut. Well I forgot to watch that video back and I don't even think I have the 50mm nut lmao, that's me occupied for tomorrow

[MrSweet1991]

Originally Posted by Tambohamilton

My e91 330d has a giubo at the diff, rather than the big nut.

You'll also need to faff with heat shields etc.

Definitely take the opportunity to install M3 or aftermarket rear subframe bushings while the subframe is out. Diff bushings too....and any other bit that might need or want to be replaced or upgraded.

Nightmare this is! Anyway, I've got the exhaust off finally but the propshaft donut is cracked so that will need replacing. But, which 3 bolts do I remove? The bolts or the 3 E-torx bolts.. Or all of them? And if I'm not mistaken, can the propshaft be removed from the differential side and then it can slide out or do I need to disconnect the propshaft at the transmission side as well?

[Tambohamilton]

All of the bolts into the donut. I need to do mine too, but putting it off as long as possible. Expensive bit of rubber!

Not sure if you can remove the shaft after the diff is out...I rather suspect you need to unbolt it from the transmission too

[MrSweet1991]

Originally Posted by Tambohamilton

All of the bolts into the donut. I need to do mine too, but putting it off as long as possible. Expensive bit of rubber!

Not sure if you can remove the shaft after the diff is out...I rather suspect you need to unbolt it from the transmission too

I mean just to drop the rear subframe, did you just remove the 6 bolts from the donut and lower the subframe or?.. I'm just a little confused whether the differential pulls away from the propshaft while dropping the subframe or whether the propshaft slides towards transmission with the 6 bolts undone . Or whether both sides of the propshaft need removing before the subframe can be dropped?

[Tambohamilton]

If you unbolt the 3 bolts on either side of the donut, it comes apart. So only 3 bolts (from either side) need to be removed from the donut to drop the subframe fully. I'd recommend loosening all 6 (because you need to remove the donut itself) while it's still attached though - they'll be tight!

[MrSweet1991]

Originally Posted by Tambohamilton

If you unbolt the 3 bolts on either side of the donut, it comes apart. So only 3 bolts (from either side) need to be removed from the donut to drop the subframe fully. I'd recommend loosening all 6 (because you need to remove the donut itself) while it's still attached though - they'll be tight!

Got you mate! Thankfully I've got that beasty Milwaukee m18onefhiwf12-0 with 1898nm of reversible torque which makes like so much easier.. I nearly had an accident though, you know the donut bolts with a nut on the other side, well I wasn't holding the spanner properly and when I used the impact the spanner flew straight past my head

Hopefully things go to plan tomorrow that exhaust was a nightmare, kwik fit rounded off the exhaust bolt a bit (the bolt on the C clamp just after the flex pipe) and, because they tightened it as much as possibly the nut sank into the bracket so a socket wouldn't fit on and a spanner barely did, I had to angle grind the nut off.

Then at muffle end the E torx bolts rounded off so rsther than sit there again trying pointless things I had to remove the bumper and then remove the metal bumper.carrier which oddly enough is what holds the rear muffler.

It could be coincidence as well, but most subframe I see online for sale including the one I purchased seem to have the brake lines cut.. I have a feeling they can be a pig to get off so I'm not looking forward to that.

[Tambohamilton]

Haha, I tried to rotate my exhaust a little recently. The but loosened just fine, somehow, even though it was super rusty (thankyou duck oil!), but I couldn't get the damn thing to move! Tightened it back up and I'll just have to live with a crooked tail pipe, until it annoys me enough to fix it (again).

Yep, I had to break then remake the hard lines on the subframe when I did mine. Pain in the ass!

[MrSweet1991]

Originally Posted by Tambohamilton

Haha, I tried to rotate my exhaust a little recently. The but loosened just fine, somehow, even though it was super rusty (thankyou duck oil!), but I couldn't get the damn thing to move! Tightened it back up and I'll just have to live with a crooked tail pipe, until it annoys me enough to fix it (again).

Yep, I had to break then remake the hard lines on the subframe when I did mine. Pain in the ass!

Well today was a surprise, I removed all the subframe bolts (very nerve racking) and I slowly dropped the rear subframe double checking if anything was still connected but all is well. So then, I tried to move the subframe away from the Propshaft and that thing ain't moving!

Now, when I went out today I was going to do what you suggested which was removed the other bolts from the transmission side but to do that you would need to remove a sort of brace which also has same transmission mounts so I looked at the center of the Propshaft and noticed that there's a knuckle so I just went ahead and lowered the subframe as is..

I've managed to create a gap between the donut and Differential mounting piece but it just won't pop out, I've knocked a screwdriver and spanner but it don't seem to make much difference so I decided to post here and give it a try tomorrow just on the off chance there is something I'm missing

[Tambohamilton]

As far as I know, it's just a close-fitting spigot down the middle. Should just pull out (with a bunch of penetrating lube, swearing, twisting, more swearing, levering, etc)

Edit: I'm talking through a hole in my head/ass...seek advice/check the diagrams on realoem. Or look it up on newtis.info

[MrSweet1991]

Originally Posted by Tambohamilton

As far as I know, it's just a close-fitting spigot down the middle. Should just pull out (with a bunch of penetrating lube, swearing, twisting, more swearing, levering, etc)

Edit: I'm talking through a hole in my head/ass...seek advice/check the diagrams on realoem. Or look it up on newtis.info

Right so I finally managed to do it a couple of days ago. Just behind the propshaft bearing (towards the transmission) there's a rubber gator, by removing the two bearing bolts you can then push the propshaft towards the transmission.

It still didn't slide out the differential though, there's a piece of metal at the end of the Propshaft that I think is used to center the propshaft into the differential and I had to pry with a spanner to get it to pop out.

I had both subframes laid on the floor and the and the wishbone mount was very slightly bent (the arm next to the top control arm)

Just waiting on a Propshaft donut to arrive and tomorrow I'm popping to a shop who should hopefully be able to make me another brake line.

[MrSweet1991]

I couldn't believe the amount of rust under the subframe, and the heat shield nuts and washers crumbled off revealing more deep rust

I haven't done a perfect job but I used a 40 grit flapper disc on an angle grinder and a wire brush and then coated on some Hammeright Underseal with added Waxoyl and it looks a lot better, hopefully it should slow the rust down.

Done the same to the differential which looks a lot better

[Tambohamilton]

Ugh! I hate rust!! Watch out for that hammerite shit - I've found it washes off after a bit. If you really want to slow down the rust, get some rocol cold galvanising spray (69515)...the price is wild though!

[MrSweet1991]

Originally Posted by Tambohamilton

Ugh! I hate rust!! Watch out for that hammerite shit - I've found it washes off after a bit. If you really want to slow down the rust, get some rocol cold galvanising spray (69515)...the price is wild though!

Now that you mention it, I actually had a tin of "ZG-90 Cold Zinc Galvanise" in the cupboard that I was going to spray onto the chassis ground when I installed the subwoofer.

Because of where the Hammeright is I'm hoping it won't really get too much abuse as the heat shield, subframe and Differential will cover a lot of it and the arch also has the arch lining. I have to say I was really surprised at how easy it was to coat the Hammeright and it looks a lot better under there now.

I put the order in for the Bilstein B4 shocks, top mounts, lower mounts, dust and bump stops yesterday on AutoDoc.. I have a feeling ill end up putting some more Hammeright on out of boredom waiting for AutoDoc

[Tambohamilton]

Yeah, hammerite stuff is lovely in summer! Awesome gooey slop. Pain in the ass in winter though - it doesn't want to go on. I've put it in a spray bottle, then dunked that in boiling water and sprayed it on, previously