Ultimate Rear Diff Bushings DIY

[Samf82m4]

My Notes:
-There are some oddball bolt sizes so make sure you have:
T30, T60, E18, 6mm Allen, 16mm, 21mm
-Get Etorx sockets in ½” because the subframe bolts are incredibly hard to remove
-This tutorial will show you how to remove the front mount without removing the driveshaft from the diff. After some research, the process of removing and reinstalling the driveshaft to the diff is too much work in comparison to sliding the mount over the driveshaft. User's have reported noises and vibration after trying to reinstall the driveshaft to the diff let alone the tools required and that's something I didn't want to deal with.

New Bushings:
I went with purple powerflex bushings (slightly stiffer than stock). The car feels fantastic and there's no added vibration or noise from the diff. There are many options out there and BMW has a new OEM poly bushing to replace the crappy rear bushing. They started using a poly rear bushing in 2017+ models. I didn't have a press to insert this newer style bushing so I went with powerflex because the 2 piece style makes them incredibly easy to install.


Issues I had that WERE RESOLVED:
Clunking when changing gears (really annoying)
Shifting never felt precise
Shifter would move (6mt) back and forth when letting on and off the throttle
Power didn't feel like it was being delivered smoothly

BMW tells you to replace the following bolts:
All 4 subframe bolts ( I highly recommend )
All 4 bolts on the front subframe mount ( I highly recommend )
Rear diff mount bolt
All bolts on both V braces

Torque Specs:
-4 bolts on front diff mount - 120nm / 80 ft lbs
-Rear diff bolt - 210nm / 15f ft lbs.
-Vibration damper on rear bolt - 19nm / 14 ft lbs
-Rear diff bracket - 120nm / 88 ft lbs
-4 subframe bolts - 108nm / 80 ft lbs
-6 guibo bolts - 55nm / 40 ft lbs (+ 90 degree)

Part Numbers:
-4x BMW Repair bolts: 07147426660
-4x BMW Repair bolt washer: 31336776760
-4x Replacement subframe bolts: 33302284642
-Guibo bolts: 26117527475
-Guibo but: 26127536563

Tools:
Bushing Removal kit- https://www.ecstuning.com/b-schwaben.../024979sch01a/

Instructions:
-If you are using a Quick Jack, lift each side of the car with a standard low profile jack and remove the outer T60 bolt for both V braces. You will not be able to access this when the car is lifted using the quickjack. Also remove any plastic fasteners holding the plastic shields that cover the V brace.

-Remove both rear wheels
-Lift the car and remove both outer V braces.


-Remove the exhaust
-Remove the 3 heat shields covering the drive shaft and transmission
-Remove the heat shield that is above the muffler
-Disconnect the ground strap from the body (near rear bushing)


-Lower the subframe onto the repair bolts with washers (Important - part number for bolt and washer above). Easiest way to do this: Remove the driver side rear subframe bolt and replace with the repair bolt, support the rear driver side with a jack (circled below) and replace the front driver side bolt with a repair bolt. Lower the jack so that the drivers side of the subframe lowers onto the repair bolts. Repeat for the passenger side



-Remove the vibration damper and loosen the rear diff bolt but don’t remove just yet.


-Now we need to lower the subframe on the drivers side more in order to access the outer driver side bolt on the front mount (blocked by the gas tank). Remove the 3 bolts for the driver side shock. Remove the driver side caliper and place on top of control arms.
-Open the black door to the right of the driver side shock and pull the connectors out of the water shield box (you don’t need to disconnect them). This will give you enough slack while you drop the subframe lower.


-Support the driver side of the rear subframe with a jack and remove the repair bolts on the drivers side.
-Lower the drivers side of the subframe until you can clearly access all of the bolts on the front mount.


-Place a second jack under the diff and remove the 4 bolts holding on the front brace to the diff/subframe


-Head to the front of the car and support the transmission. Once supported, remove the transmission mount, rubber mounts, and metal brace from the transmission itself.
-Remove the 6 bolts holding the guibo to the driveshaft / transmission.
-Slide the front diff brace over the driveshaft and out of the car.


-Replace all 4 bushings and slide the brace back over the driveshaft and to the diff.


-Install the 2 inner bolts connecting the mount to the diff. (Don’t install the outer bolts to the subframe just yet)


-Re-install guibo bolts and transmission mount. Remove transmission support
-Wiggle the diff out of the way and remove the rear diff bushing and install new (this is why we haven't installed the front outer bolts yet). The Schwaben kit won't work on this bushing so I got a piece of 3" ID steel to use as a sleeve. I ended up removing the middle of the mount somehow and still had to cut out the outer metal section of the old mount using a saw and chisel




-Move diff into place and install rear bolt and two outer front bolts so diff is connected to subframe



-Lift drivers side of the subframe slowly and guide the drivers side shock and spring into place. Keep lifting until you can reinstall repair bolts.
-Reinstall caliper and electrical connectors.
-Lift both side of the subframe one at a time and reinstall new stock subframe bolts
--Reinstall heatshields
-Reinstall Exhaust
-Reinstall V brace
-Lower car and enjoy the amazing feeling of a diff that doen't bounce around while you're shifting

Happy wrenching!!!

[Samf82m4]

Huge thanks to hC1001 and marauder1 for all of their super helpful pics and links!!

[Kilabyte]

Saving for future reference. Mine are still looking OK but I know that I'll be changing them at one point.


Let me borrow your quickjack

[FrankMstein]

You can post most any YT video.

[jmciver]

Big thanks to Samf82m4 for putting this together. I have this one bookmarked for a future upgrade project if my rear diff bushings need replacement (still good after 52k+miles). But I had a few clarification questions…

1. Repair Bolts. Since you ultimately removed the the subframe repair bolts on the drivers side to gain additional clearance, what is the purpose of installing them in the first place? Are they long enough so that the subframe can rest on them and still have the clearance needed to do the job? If they are still needed, how far do you lower the subframe on them since they are pretty long? 1", 2", etc?

2. Disconnecting CF Drive Shaft. How did you actually disconnect (or "wiggle" off) the drive shaft at the transmission, with it still connected at the diff? I recently did a SSK install and wanted to disconnect the drive shaft at the transmission for better access. I removed the 3 bolts connecting the guibo to the transmission (keeping the guibo connected to the drive shaft), but still could not "wiggle" the drive shaft loose from the transmission - and I was too scared to wiggle too hard for fear of breaking something. You removed the guibo as well in order to get the diff bracket off, but is there some trick to get the drive shaft to break free from the transmission after the bolts have been removed?

3. Lowering Subframe. When you lowered the subframe for further access, you only lowered the driver side. Why not lower both sides evenly to prevent any extra stress on the chassis when lowering one side further than the other?

Thanks!

[GuyLedouche]

Originally Posted by Samf82m4

My Notes:
-There are some oddball bolt sizes so make sure you have:
T30, T60, E18, 6mm Allen, 16mm, 21mm
-Get Etorx sockets in ½" because the subframe bolts are incredibly hard to remove
-This tutorial will show you how to remove the front mount without removing the driveshaft from the diff. After some research, the process of removing and reinstalling the driveshaft to the diff is too much work in comparison to sliding the mount over the driveshaft. User's have reported noises and vibration after trying to reinstall the driveshaft to the diff let alone the tools required and that's something I didn't want to deal with.

New Bushings:
I went with purple powerflex bushings (slightly stiffer than stock). The car feels fantastic and there's no added vibration or noise from the diff. There are many options out there and BMW has a new OEM poly bushing to replace the crappy rear bushing. They started using a poly rear bushing in 2017+ models. I didn't have a press to insert this newer style bushing so I went with powerflex because the 2 piece style makes them incredibly easy to install.
Attachment 2950226

Issues I had that WERE RESOLVED:
Clunking when changing gears (really annoying)
Shifting never felt precise
Shifter would move (6mt) back and forth when letting on and off the throttle
Power didn't feel like it was being delivered smoothly

BMW tells you to replace the following bolts:
All 4 subframe bolts ( I highly recommend )
All 4 bolts on the front subframe mount ( I highly recommend )
Rear diff mount bolt
All bolts on both V braces

Torque Specs:
-4 bolts on front diff mount - 120nm / 80 ft lbs
-Rear diff bolt - 210nm / 15f ft lbs.
-Vibration damper on rear bolt - 19nm / 14 ft lbs
-Rear diff bracket - 120nm / 88 ft lbs
-4 subframe bolts - 108nm / 80 ft lbs
-6 guibo bolts - 55nm / 40 ft lbs (+ 90 degree)

Part Numbers:
-4x BMW Repair bolts: 07147426660
-4x BMW Repair bolt washer: 31336776760
-4x Replacement subframe bolts: 33302284642
-Guibo bolts: 26117527475
-Guibo but: 26127536563

Tools:
Bushing Removal kit- https://www.ecstuning.com/b-schwaben.../024979sch01a/

Instructions:
-If you are using a Quick Jack, lift each side of the car with a standard low profile jack and remove the outer T60 bolt for both V braces. You will not be able to access this when the car is lifted using the quickjack. Also remove any plastic fasteners holding the plastic shields that cover the V brace.

-Remove both rear wheels
-Lift the car and remove both outer V braces.
Attachment 2950191

-Remove the exhaust
-Remove the 3 heat shields covering the drive shaft and transmission
-Remove the heat shield that is above the muffler
-Disconnect the ground strap from the body (near rear bushing)
Attachment 2950192

-Lower the subframe onto the repair bolts. Easiest way to do this: Remove the driver side rear subframe bolt and replace with the repair bolt, support the rear driver side with a jack (circled below) and replace the front driver side bolt with a repair bolt. Lower the jack so that the drivers side of the subframe lowers onto the repair bolts. Repeat for the passenger side
Attachment 2950194
Attachment 2950193

-Remove the vibration damper and loosen the rear diff bolt but don't remove just yet.
Attachment 2950199

-Now we need to lower the subframe on the drivers side more in order to access the outer driver side bolt on the front mount (blocked by the gas tank). Remove the 3 bolts for the driver side shock. Remove the driver side caliper and place on top of control arms.
-Open the black door to the right of the driver side shock and pull the connectors out of the water shield box (you don't need to disconnect them). This will give you enough slack while you drop the subframe lower.
Attachment 2950200

-Support the driver side of the rear subframe with a jack and remove the repair bolts on the drivers side.
-Lower the drivers side of the subframe until you can clearly access all of the bolts on the front mount.
Attachment 2950201

-Place a second jack under the diff and remove the 4 bolts holding on the front brace to the diff/subframe
Attachment 2950202

-Head to the front of the car and support the transmission. Once supported, remove the transmission mount, rubber mounts, and metal brace from the transmission itself.
-Remove the 6 bolts holding the guibo to the driveshaft / transmission.
-Slide the front diff brace over the driveshaft and out of the car.
Attachment 2950203

-Replace all 4 bushings and slide the brace back over the driveshaft and to the diff.
Attachment 2950204

-Install the 2 inner bolts connecting the mount to the diff. (Don't install the outer bolts to the subframe just yet)
Attachment 2950205

-Re-install guibo bolts and transmission mount. Remove transmission support
-Wiggle the diff out of the way and remove the rear diff bushing and install new (this is why we haven't installed the front outer bolts yet). The Schwaben kit won't work on this bushing so I got a piece of 3" ID steel to use as a sleeve. I ended up removing the middle of the mount somehow and still had to cut out the outer metal section of the old mount using a saw and chisel
Attachment 2950206
Attachment 2950207
Attachment 2950208

-Move diff into place and install rear bolt and two outer front bolts so diff is connected to subframe
Attachment 2950211
Attachment 2950209

-Lift drivers side of the subframe slowly and guide the drivers side shock and spring into place. Keep lifting until you can reinstall repair bolts.
-Reinstall caliper and electrical connectors.
-Lift both side of the subframe one at a time and reinstall new stock subframe bolts
--Reinstall heatshields
-Reinstall Exhaust
-Reinstall V brace
-Lower car and enjoy the amazing feeling of a diff that doen't bounce around while you're shifting


I'm working on a video time lapse now but idk what the rules are here about sharing your own Youtube content.

Happy wrenching!!!

Let's see that video!

[GuyLedouche]

Originally Posted by jmciver

Big thanks to Samf82m4 for putting this together. I have this one bookmarked for a future upgrade project if my rear diff bushings need replacement (still good after 52k+miles). But I had a few clarification questions…

1. Repair Bolts. Since you ultimately removed the the subframe repair bolts on the drivers side to gain additional clearance, what is the purpose of installing them in the first place? Are they long enough so that the subframe can rest on them and still have the clearance needed to do the job? If they are still needed, how far do you lower the subframe on them since they are pretty long? 1", 2", etc?

2. Disconnecting CF Drive Shaft. How did you actually disconnect (or "wiggle" off) the drive shaft at the transmission, with it still connected at the diff? I recently did a SSK install and wanted to disconnect the drive shaft at the transmission for better access. I removed the 3 bolts connecting the guibo to the transmission (keeping the guibo connected to the drive shaft), but still could not "wiggle" the drive shaft loose from the transmission - and I was too scared to wiggle too hard for fear of breaking something. You removed the guibo as well in order to get the diff bracket off, but is there some trick to get the drive shaft to break free from the transmission after the bolts have been removed?

3. Lowering Subframe. When you lowered the subframe for further access, you only lowered the driver side. Why not lower both sides evenly to prevent any extra stress on the chassis when lowering one side further than the other?

Thanks!

If you remove the drive shaft from the guibo it is very easy to remove the shaft and you don't need to remove the transmission mount either.

[Samf82m4]

Originally Posted by jmciver

Big thanks to Samf82m4 for putting this together. I have this one bookmarked for a future upgrade project if my rear diff bushings need replacement (still good after 52k+miles). But I had a few clarification questions…

1. Repair Bolts. Since you ultimately removed the the subframe repair bolts on the drivers side to gain additional clearance, what is the purpose of installing them in the first place? Are they long enough so that the subframe can rest on them and still have the clearance needed to do the job? If they are still needed, how far do you lower the subframe on them since they are pretty long? 1", 2", etc?

2. Disconnecting CF Drive Shaft. How did you actually disconnect (or "wiggle" off) the drive shaft at the transmission, with it still connected at the diff? I recently did a SSK install and wanted to disconnect the drive shaft at the transmission for better access. I removed the 3 bolts connecting the guibo to the transmission (keeping the guibo connected to the drive shaft), but still could not "wiggle" the drive shaft loose from the transmission - and I was too scared to wiggle too hard for fear of breaking something. You removed the guibo as well in order to get the diff bracket off, but is there some trick to get the drive shaft to break free from the transmission after the bolts have been removed?

3. Lowering Subframe. When you lowered the subframe for further access, you only lowered the driver side. Why not lower both sides evenly to prevent any extra stress on the chassis when lowering one side further than the other?

Thanks!

1. Technically you only need 2 of the repair bolts. Given the steps take, it's worth the extra 20$ to just buy all 4 lol

2. The driveshaft will pull off the transmission prop because the driveshaft ends have enough movement in them horizontally. I think I might have used a crowbar to lightly pry it off. Didn't give me too much resistance.

3. You definitely could. I really only have 1 nice jack to work with so it was my only option. That transmission jack is only rated for around 100lbs (I think) so that definitely wasn't going to provide any support. With only one side support by the jack, I still had room to slide under the subframe and move around.

[Samf82m4]

Originally Posted by GuyLedouche

Let's see that video!

Finishing up the intro this week! I got tied up with wedding duties and then caught covid lol. Definitely will be up soon.

[WordOnRoad]

Great write up. Starting to feel some slop as well after a recent track day. Any reason you didn't get a diff bracket?

[Samf82m4]

Originally Posted by WordOnRoad

Great write up. Starting to feel some slop as well after a recent track day. Any reason you didn't get a diff bracket?

Didn't find it necessary. It feels great for daily driving without it.

[Samf82m4]

Sorry I took so long

[jmciver]

Outstanding work! Definitely "stickey" worthy - Mods, please take note…

Out of curiosity, why did you remove all six bolts on the driveshaft to slide off the diff brace? Since all you needed to do was disconnect the driveshaft from the guibo to slide off the diff brace, why not leave the guibo connected to the transmission? That way instead of dealing with six bolts, you only need to remove three?

[Samf82m4]

Originally Posted by jmciver

Outstanding work! Definitely "stickey" worthy - Mods, please take note…

Out of curiosity, why did you remove all six bolts on the driveshaft to slide off the diff brace? Since all you needed to do was disconnect the driveshaft from the guibo to slide off the diff brace, why not leave the guibo connected to the transmission? That way instead of dealing with six bolts, you only need to remove three?

So I tried removing the driveshaft from the guibo and I was having some difficulty. Idk if it was stuck or what but once I had all the bolts removed, I was able to easily remove everything. Maybe it's not necessary but it saved me some headache.

[Blackeyeii]

Thanks so much for the video and the torque specs. I am mid way through this job now and I had a moment of levity I wanted to share and also re-enforce for others.

If you are using quick jacks (which I bought for this and they are cool) don't forget to get those rear braces off before you get the car up in the quick jacks.

haha .. I came back to re-read and kicked myself.

Fortunately the quick jacks are just that, throw the tires back on move everything out of the way and drop it back down.

I am going to try a slightly different approach so I will post on how that goes. I am going to try to do this without removing the driveshaft from the transmission. I feel like I can swap the bushings on the shaft by rotating and swapping. (we will see)

[mfurse]

Does updating the bushings also help reduce the drive shaft seals leaking? Seems to be a recurring problem.

[jmciver]

Originally Posted by Blackeyeii

Thanks so much for the video and the torque specs. I am mid way through this job now and I had a moment of levity I wanted to share and also re-enforce for others.

If you are using quick jacks (which I bought for this and they are cool) don't forget to get those rear braces off before you get the car up in the quick jacks.

haha .. I came back to re-read and kicked myself.

Fortunately the quick jacks are just that, throw the tires back on move everything out of the way and drop it back down.

I am going to try a slightly different approach so I will post on how that goes. I am going to try to do this without removing the driveshaft from the transmission. I feel like I can swap the bushings on the shaft by rotating and swapping. (we will see)

So how did this work out for you, specifically swapping out the bracket bushings without removing it via the driveshaft?

And for the OP, how much force was required to get out those bushings using the busing removal tool? They seemed to come out relatively easily, but difficult to tell in your video with the time lapse…

[Samf82m4]

Originally Posted by jmciver

So how did this work out for you, specifically swapping out the bracket bushings without removing it via the driveshaft?

And for the OP, how much force was required to get out those bushings using the busing removal tool? They seemed to come out relatively easily, but difficult to tell in your video with the time lapse…

Very easy. You know what they say about having the right tools for a job, it makes it 100% easier

[Samf82m4]

Originally Posted by mfurse

Does updating the bushings also help reduce the drive shaft seals leaking? Seems to be a recurring problem.

Mine appear to be slightly leaking so unless I get it fixed, it's gonna be hard for me to determine. I think it would definitely help reduce this but I'm not positive.

[Blackeyeii]

I just finished this job a couple weekends back. Had a nasty bit of covid for a week so I am just getting to posting.
For the most part it went just as described. The scariest moment for me though was when I realized the maintenance bolts can and do actually pass right through the subframe unless you put oversized washers on them.
(these are the two in front, that have the square locator "pin" in the subframe)



I realized this while looking up from underneath the subframe and it definitely woke me up. At the time the rear one was holding the subframe and on the other side I had a nice floor jack holding the dropped lower subframe to remove the brace.
You need to put some good big washers around that bolt. I got lucky I suppose.


The other part that stuck me was using the bushing extractor tool. The first time I used it I chose a washer/plunger/piston that was silver in the kit and it was just a tad smaller than it needed to be. The bushing (one of the small front ones) went all wrong and wedged some of the exterior shield metal edge of the bushing between the piston and the receiving cup. This took me quite a while to extract back out. The second time I did it again on one of the small ones It extracted perfectly with the gold plunger into the silver cup that I had used the first time. The downside is that it fit so well in the silver cup that it wouldn't come out. I put that one in the freezer over night and hammered it out in the morning.

Needless to say I found out that if you can use a larger receiver cup (like you can on the two internal ones) do it. It works so smooth.
When it works, the bushing extractors work great, if I had this to do again, I would be much better at it.

Other than that though it all went pretty by the numbers, it did take me about two days though, but lots of time spent fighting bushings in that. Thanks for putting this post together Samf82m4!

[Samf82m4]

Originally Posted by Blackeyeii

I just finished this job a couple weekends back. Had a nasty bit of covid for a week so I am just getting to posting.
For the most part it went just as described. The scariest moment for me though was when I realized the maintenance bolts can and do actually pass right through the subframe unless you put oversized washers on them.
(these are the two in front, that have the square locator "pin" in the subframe)



I realized this while looking up from underneath the subframe and it definitely woke me up. At the time the rear one was holding the subframe and on the other side I had a nice floor jack holding the dropped lower subframe to remove the brace.
You need to put some good big washers around that bolt. I got lucky I suppose.


The other part that stuck me was using the bushing extractor tool. The first time I used it I chose a washer/plunger/piston that was silver in the kit and it was just a tad smaller than it needed to be. The bushing (one of the small front ones) went all wrong and wedged some of the exterior shield metal edge of the bushing between the piston and the receiving cup. This took me quite a while to extract back out. The second time I did it again on one of the small ones It extracted perfectly with the gold plunger into the silver cup that I had used the first time. The downside is that it fit so well in the silver cup that it wouldn't come out. I put that one in the freezer over night and hammered it out in the morning.

Needless to say I found out that if you can use a larger receiver cup (like you can on the two internal ones) do it. It works so smooth.
When it works, the bushing extractors work great, if I had this to do again, I would be much better at it.

Other than that though it all went pretty by the numbers, it did take me about two days though, but lots of time spent fighting bushings in that. Thanks for putting this post together Samf82m4!

I updated the instructions to indicate the use of the washer. I put the part number in the list but didn't actually mention it in the steps.

[NORAGRETS]

What are all the bolt sizes and how many of each are needed?