[vladskies]

Hello everyone,

Due to E92zilla I was able to snatch up a whole rear end swap. It was a steal, and zilla here is an amazing seller, I owe him one for linking me up with this piece. Photos/video of the rear end, with 34k miles on it so doesn't look like I have to do any suspension refresh or bushings. Should be an easy swap, except for the fact I'll be doing it on the floor.

It is due to arrive here in the next 12 hours or so, and I am preparing myself for the swap that is due to come. Got a few questions if some of yall might have answers for me as I can't seem to find good resources online to help.

Going to be using this guide to help me perform the swap, but most of it is fairly useless as I have a complete swap. That is where my question comes in, by the looks of it I will have to do the following: measure the N54 driveshaft, disconnect the emergency brakes, disconnect the brake sensor and the second one near it (speed sensor?), disconnect brake lines going to the calipers, disconnect the driveshaft from the transmission, unbolt 6 subframe mount bolts. Am I missing anything?

I will be needing mounting bolts, am I okay to reuse the ones from my N54 set up or is it recommended to get new ones?

Also looks like I'll need about 1500mL of diff fluid. Does anyone have recommendations for this?

Lastly, looks like the brakes on the rear end are fairly used and will be needing replacement. Will stock N54 rear rotors and pads fit onto the M3 rear end? My current rear brakes from the 335i are brand new, and it looks fairly similar in size from the photos.

P.S. If anyone has any good resource of a DIY write-up or video of a complete rear end swaps then please link em to me. Everything I have been finding is fairly wacky.

[jamaicaLemons]

Originally Posted by vladskies

Hello everyone,

Due to E92zilla I was able to snatch up a whole rear end swap. It was a steal, and zilla here is an amazing seller, I owe him one for linking me up with this piece. Photos/video of the rear end, with 34k miles on it so doesn't look like I have to do any suspension refresh or bushings. Should be an easy swap, except for the fact I'll be doing it on the floor.

It is due to arrive here in the next 12 hours or so, and I am preparing myself for the swap that is due to come. Got a few questions if some of yall might have answers for me as I can't seem to find good resources online to help.

Going to be using this guide to help me perform the swap, but most of it is fairly useless as I have a complete swap. That is where my question comes in, by the looks of it I will have to do the following: measure the N54 driveshaft, disconnect the emergency brakes, disconnect the brake sensor and the second one near it (speed sensor?), disconnect brake lines going to the calipers, disconnect the driveshaft from the transmission, unbolt 6 subframe mount bolts. Am I missing anything?

I will be needing mounting bolts, am I okay to reuse the ones from my N54 set up or is it recommended to get new ones?

Also looks like I'll need about 1500mL of diff fluid. Does anyone have recommendations for this?

Lastly, looks like the brakes on the rear end are fairly used and will be needing replacement. Will stock N54 rear rotors and pads fit onto the M3 rear end? My current rear brakes from the 335i are brand new, and it looks fairly similar in size from the photos.

P.S. If anyone has any good resource of a DIY write-up or video of a complete rear end swaps then please link em to me. Everything I have been finding is fairly wacky.

Just look up budget bimmers video

Edit: jk that guide you have is probably better than their video

[Koolsilver]

You have a very high threshold for pain if you think it's an easy swap. Your high level breakdown is about right but there's many smaller things that go into each step. The exhaust after down pipe will be dropped as well. Make sure you have the special tool for removing the driveshaft from the old diff. Diff fluid I believe is Castrol and you can get it cheaper using the AMG part instead of BMW. Remember rear struts are are not the same and will not fit. The rear brakes use the same calipers and pad size however I don't recall if rotor size is different and the m3 has two piece rotor instead of one, you could look up m3 rotor size and if it is in fact larger that is because of the caliper mounting bolt position. I did this swap many years ago so my memory is fading but I can try to answer any more questions.

[Vivek.]

The brake pad that's visible in the pic seems to be about 5-7mm. Reasonable life remaining, even if we assume that the inner one is thinner. I'd just run em as-is til they're done and replace with M3 parts. I'd err on the side of buying new bolts for the subframe. Peace of mind and I can't imagine they're crazy expensive.

[vladskies]

Originally Posted by Koolsilver

You have a very high threshold for pain if you think it's an easy swap. Your high level breakdown is about right but there's many smaller things that go into each step. The exhaust after down pipe will be dropped as well. Make sure you have the special tool for removing the driveshaft from the old diff. Diff fluid I believe is Castrol and you can get it cheaper using the AMG part instead of BMW. Remember rear struts are are not the same and will not fit. The rear brakes use the same calipers and pad size however I don't recall if rotor size is different and the m3 has two piece rotor instead of one, you could look up m3 rotor size and if it is in fact larger that is because of the caliper mounting bolt position. I did this swap many years ago so my memory is fading but I can try to answer any more questions.

Thank you for that, I appreciate the heads up.

I didn't mention the exhaust because it's understandable, already had that in mind, swapped exhausts twice before so it will be easy to do it again. I'm used to those bloody hangers by now.

One thing I did not consider is the rear struts...
Gonna have to figure that one out, I'm currently running B8(SP) with Eibach short springs. So looks like I'll need E90 M3 struts. If anyone has anything for sale then don't hesitate to hit me up.

Thanks again, you saved me from a headache with the struts.

Oh before I forget, are you referring to a thin 50mm wrench as the special tool to remove the driveshaft?

[vladskies]

Originally Posted by Vivek.

The brake pad that's visible in the pic seems to be about 5-7mm. Reasonable life remaining, even if we assume that the inner one is thinner. I'd just run em as-is til they're done and replace with M3 parts. I'd err on the side of buying new bolts for the subframe. Peace of mind and I can't imagine they're crazy expensive.

Yeah you're absolutely right, that's what I was thinking as well, but I was also thinking in case I don't find them in stock locally then I don't want to halt my swap process.

But looks like I'll be held up by the need for struts, so I should have time for fcp to deliver

[vladskies]

And of course, just my luck, fcp has the M3 B8's on back order

Im guessing my current springs wont work, I'll do a little more homework to make sure

I'm not the greatest when it comes to suspension. When converting my rear, what more will I need other then a strut and spring? Will I need upper and lower spring pad? Bump stop?

I'm guessing since I already had B8(SP) on the rear that I can reuse the upper mounting hardware, so I just need the strut and spring. Is that correct?

I hate suspension with a passion, so this just made the project questionable. Might take it to a shop at this point. Well I have to decide by tomorrow.

https://www.fcpeuro.com/products/bmw...r-m3-24-143318

[autoart]

I would look on the M3 forum for springs and shocks if you have not done so.

[cruizinmax]

Another option would be to keep your stock lower control arm. That would allow you to keep your current shock. The M3 arm doesn't really offer any other benefits.

If this were my car I would just swap the differential, axles, and sway bar. Possibly a couple of control arms that have spherical bearings instead of rubber bushings. Beyond that I don't see other benefits to using the m3 subframe and brakes.

[Koolsilver]

Originally Posted by vladskies

Thank you for that, I appreciate the heads up.

I didn't mention the exhaust because it's understandable, already had that in mind, swapped exhausts twice before so it will be easy to do it again. I'm used to those bloody hangers by now.

One thing I did not consider is the rear struts...
Gonna have to figure that one out, I'm currently running B8(SP) with Eibach short springs. So looks like I'll need E90 M3 struts. If anyone has anything for sale then don't hesitate to hit me up.

Thanks again, you saved me from a headache with the struts.

Oh before I forget, are you referring to a thin 50mm wrench as the special tool to remove the driveshaft?

I don't remember the exact wrench but sounds about right. You don't need the super expensive exact tool but you need some type or special tool one way or another. I believe rear springs can be reused and upper portion of strut is the same but the bottom is definitely different.

[haaken675]

Originally Posted by Koolsilver

I don't remember the exact wrench but sounds about right. You don't need the super expensive exact tool but you need some type or special tool one way or another. I believe rear springs can be reused and upper portion of strut is the same but the bottom is definitely different.

The set from harbor freight that comes with that wrench will work. Now i have a gigantic wrench set i can't foresee using for anything else ever, lol

[vladskies]

The dealership I work at is doing the swap, and I'm glad because that rear subframe is heavy af

I need to get rear struts, but do I need rear springs or will my current ones work? If anyone knows that would be great

Currently running Eibach lowered springs for a 335i

[Tyc0]

Originally Posted by Koolsilver

You have a very high threshold for pain if you think it's an easy swap. Your high level breakdown is about right but there's many smaller things that go into each step. The exhaust after down pipe will be dropped as well. Make sure you have the special tool for removing the driveshaft from the old diff. Diff fluid I believe is Castrol and you can get it cheaper using the AMG part instead of BMW. Remember rear struts are are not the same and will not fit. The rear brakes use the same calipers and pad size however I don't recall if rotor size is different and the m3 has two piece rotor instead of one, you could look up m3 rotor size and if it is in fact larger that is because of the caliper mounting bolt position. I did this swap many years ago so my memory is fading but I can try to answer any more questions.

You do not need a special tool for the driveshaft as long as you have big enough pliers.

[Pinscher]

Originally Posted by vladskies

Hello everyone,

Due to E92zilla I was able to snatch up a whole rear end swap. It was a steal, and zilla here is an amazing seller, I owe him one for linking me up with this piece. Photos/video of the rear end, with 34k miles on it so doesn't look like I have to do any suspension refresh or bushings. Should be an easy swap, except for the fact I'll be doing it on the floor.

It is due to arrive here in the next 12 hours or so, and I am preparing myself for the swap that is due to come. Got a few questions if some of yall might have answers for me as I can't seem to find good resources online to help.

Going to be using this guide to help me perform the swap, but most of it is fairly useless as I have a complete swap. That is where my question comes in, by the looks of it I will have to do the following: measure the N54 driveshaft, disconnect the emergency brakes, disconnect the brake sensor and the second one near it (speed sensor?), disconnect brake lines going to the calipers, disconnect the driveshaft from the transmission, unbolt 6 subframe mount bolts. Am I missing anything?

I will be needing mounting bolts, am I okay to reuse the ones from my N54 set up or is it recommended to get new ones?

Also looks like I'll need about 1500mL of diff fluid. Does anyone have recommendations for this?

Lastly, looks like the brakes on the rear end are fairly used and will be needing replacement. Will stock N54 rear rotors and pads fit onto the M3 rear end? My current rear brakes from the 335i are brand new, and it looks fairly similar in size from the photos.

P.S. If anyone has any good resource of a DIY write-up or video of a complete rear end swaps then please link em to me. Everything I have been finding is fairly wacky.

Budget bimmer YouTube channel covers a lot of m3 to a 335 swap.