DIY: Rear differential and Subframe solid aluminum bushings

Bartledoo · 09-09-2020, 08:59 AM

Quote:

Originally Posted by jvictormp

but did you feel a great decrease of the wheel hop or nothing?

Yea, it improved a lot when I did aluminum subframe mounts and powerflex purple poly diff bushings at the same time. It just didn't eliminate it, and I did it enough to cause another broken bolt. A stiffer poly mount could improve it further, but I'm done testing whine vs stiffness.

jvictormp · 09-09-2020, 09:09 AM

Thanks! So I'll try it.

DRLane · 09-09-2020, 09:11 AM

Quote:

Originally Posted by Bartledoo

Quote:

Originally Posted by jvictormp

but did you feel a great decrease of the wheel hop or nothing?

Yea, it improved a lot when I did aluminum subframe mounts and powerflex purple poly diff bushings at the same time. It just didn't eliminate it, and I did it enough to cause another broken bolt. A stiffer poly mount could improve it further, but I'm done testing whine vs stiffness.

Going aluminum diff bushings now?

Bartledoo · 09-09-2020, 09:27 AM

Quote:

Originally Posted by DRLane

Going aluminum diff bushings now?

Yep.

jvictormp · 11-12-2020, 11:07 PM

So guys, I ordered the solid SF bushings, waiting them to come.

I'd like to ask if it's possible to do it without disconnecting brake lines, like removing the calipers still attached to the brake lines, and let them "hang" somewhere free from the subframe movement.

DRLane · 11-12-2020, 11:25 PM

Quote:

Originally Posted by jvictormp

So guys, I ordered the solid SF bushings, waiting them to come.

I'd like to ask if it's possible to do it without disconnecting brake lines, like removing the calipers still attached to the brake lines, and let them "hang" somewhere free from the subframe movement.

No. To drop the subframe you'll disconnect the brake lines. But you can leave the calipers alone and connected to the adjoining lines on their respective axles.

You'll disconnect the 2x brake lines upstream. Just to the drivers side of the differential towards the front.

SAMM3Y · 11-12-2020, 11:38 PM

@jvictormp there's a hard brake line that runs across the top of subframe to feed the rh rear caliper. There's a bracket which unfortunately is part of the subframe which joins the hard line to the flex line, that union has to be broken to remove the subframe. I attempted to drop the subframe and change the bush in place using a threaded cup set that can be purchased on eBay. I successfully removed the bush with this tool but pressing the solid bush was to no avail. I even upgraded all the threaded hardware for the cup set and dry iced the solid bush and could only get it 2/3's in. In the end I had to remove the subframe to get it into the press. It was a waste of time and $$ for the tool. I'd recommend dropping the assembly and using a press. I did research some hand hydraulic specialty tools that could get the job done but short of spending $1k on one I couldn't source it. I'm sure the pro's might know a quicker/better method. Also don't stretch the ebrake cable.. 😞 I currently have no ebrake.... rip stick incoming

DRLane · 11-12-2020, 11:48 PM

Quote:

Originally Posted by SAMM3Y

@jvictormp there's a hard brake line that runs across the top of subframe to feed the rh rear caliper. There's a bracket which unfortunately is part of the subframe which joins the hard line to the flex line, that union has to be broken to remove the subframe. I attempted to drop the subframe and change the bush in place using a threaded cup set that can be purchased on eBay. I successfully removed the bush with this tool but pressing the solid bush was to no avail. I even upgraded all the threaded hardware for the cup set and dry iced the solid bush and could only get it 2/3's in. In the end I had to remove the subframe to get it into the press. It was a waste of time and $$ for the tool. I'd recommend dropping the assembly and using a press. I did research some hand hydraulic specialty tools that could get the job done but short of spending $1k on one I couldn't source it. I'm sure the pro's might know a quicker/better method.

I used a 10 ton press like this for $130 from harbor freight. Suspended the subframe via engine hoist and rotated the ends into the press. Used the threaded cup set for the solid diff mounts though.

https://www.harborfreight.com/12-ton...ess-33497.html

In think the best move is to remove the subframe. Strip it down and take it to a shop to have them pressed in / out.

SAMM3Y · 11-12-2020, 11:59 PM

Lol yeah I have that same press, to clarify I was attempting to leave the diff, driveshaft, axles etc. in the assembly and change them. Just drop the assembly 12" off the car. It wasn't happening with a eBay cup set. In the end I pulled the subframe out and put it in the H frame harbor freight special. The HFS though is definitely worth its weight in... iron? They go with a pop

DRLane · 11-13-2020, 12:12 AM

Quote:

Originally Posted by SAMM3Y

Lol yeah I have that same press, to clarify I was attempting to leave the diff, driveshaft, axles etc. in the assembly and change them. Just drop the assembly 12" off the car. It wasn't happening with a eBay cup set. In the end I pulled the subframe out and put it in the H frame harbor freight special. The HFS though is definitely worth its weight in... iron? They go with a pop

Yeah I realized that after reading your post for a second time. Reading comprehension 🤦🏻*♂️...

jvictormp · 11-13-2020, 07:10 PM

Thanks.

About trying to use dry ice, did you guys also try to heat the subframe with some torch or heat gun?

I ain't got no dry ice or liquid nitrogen, so I'm thinking on 24 hours of freezer, plus heat gun.

It may affect my clarity of decision that one's got only one chance, right? If he gets to push the bushing 1/3 into the subframe, and it stucks, he's not gonna be able to pull it off again to make a second attempt.

SAMM3Y · 11-13-2020, 08:51 PM

Quote:

Originally Posted by jvictormp

Thanks.

About trying to use dry ice, did you guys also try to heat the subframe with some torch or heat gun?

I ain't got no dry ice or liquid nitrogen, so I'm thinking on 24 hours of freezer, plus heat gun.

It may affect my clarity of decision that one's got only one chance, right? If he gets to push the bushing 1/3 into the subframe, and it stucks, he's not gonna be able to pull it off again to make a second attempt.

I tried heat gun which doesn't get hot enough really, thought about blow torch or oxy/acetylene but didn't want to damage the subframe or stress the steel/make it brittle. Some light blow torching probably wouldn't hurt but it'll just heat soak the subframe and new aluminum bush probably which would work against the ice. You could probably hammer it out if it doesn't go in all the way but the bush is aluminum and it will gouge as it goes in so then you might have high spots on the next attempt. There has been people who have successfully used a sledge/lump hammer to get them in providing you can get enough space to swing it with a hard wood medium to protect the hardware of course.

jvictormp · 01-12-2021, 06:25 AM

Hey guys. I was looking the TIS about rubber bushings replacement, and it says to use a kind of oil in the new bushing before inserting.

Can I do that with the aluminum bushings?

Move Over · 01-12-2021, 07:24 AM

Quote:

Originally Posted by jvictormp

Hey guys. I was looking the TIS about rubber bushings replacement, and it says to use a kind of oil in the new bushing before inserting.

Can I do that with the aluminum bushings?

Oil/grease won't really help with aluminum bushings. I just did some solid trailing arm bushings and all the grease I used just simply pushed out when the bushing went in. Too tight of a fit.

Grab yourself a propane torch, and a cooler full of dry ice to put the bushings in before the job. Work quick and take them out one at a time.

Move Over · 01-12-2021, 07:31 AM

I also wanted to chime in here about AKG bushings.

The car I purchased had AKG solid bushings installed, when I bought it, I had some really nasty clicking/clunking back there. I did a couple of track days and really started bugging me. I thought it may had just been the nature of solid diff bushings.

I went to go pull my diff and I noticed that the bushings were able to be slid out BY HAND and had some side to side play. I reached out to AKG and they said this was not normal, however the bushings were about .5mm smaller than bimmerworlds, MS and VAC solid bushings.

AKG was great and swapped the solid bushings out for poly 75D, and those fit much, much better. The solid bushings were 48.7mm and the poly bushings were 49.21. Big difference in my opinion and just enough to fix my "problem".

So just food for thought if you are thinking about going solid, maybe measure your tolerances before you go with AKG solid bushings because you may run into the same issues I did. The bushing recesses for me were about 49.01 front and 48.9 rear. And, if you feel like any diff bushing went into the recess too easily, it probably did. The 75d poly bushings took a good bit of force with a deadblow and a press for the rear bushing.

jvictormp · 01-12-2021, 11:35 PM

What about this procedure guys? (0:44)

Move Over · 01-13-2021, 06:12 AM

Quote:

Originally Posted by jvictormp

What about this procedure guys? (0:44)

Yeah that's how most of these "presses" work. Two things bout the video:
1. make sure you don't press bushings in sideways like that. A little bit is ok but that's how you warp sleeves and wind up buying a new subframe. He's lucky his corrected as quickly as it did.
2. I'm not sure if we have two piece sandwich bushings like that available, if so, that makes the process a heck of a lot easier

Throatpunch · 01-13-2021, 06:31 PM

This guy did it with subframe on car. Anyone try it this way?

Move Over · 01-13-2021, 09:05 PM

Quote:

Originally Posted by Throatpunch

This guy did it with subframe on car. Anyone try it this way?

Shouldn't be much of an issue, all the bushings are pretty exposed once the diff is out

SAMM3Y · 01-13-2021, 09:22 PM

Quote:

Originally Posted by Throatpunch

This guy did it with subframe on car. Anyone try it this way?

I just skimmed the vid but it looks like he only did the diff bush on the car which I did originally too using the same cup kit he used. I did attempt to do the subframe bush by just lowering the subframe about 10" and managed to get the old ones out but couldn't get the new ones in using this tool https://www.ebay.com/itm/333158778716. In the end I cost myself some time and $ and had to pull the subframe. From what I've read malek @ MRF does them with the subframe still attached but uses his own spec bushings. Knowing how much pressure it takes to get the bush in the sleeves on the BW spec bushing I can't see a work around without an expensive specialized hydraulic tool at ones disposal.

jvictormp · 02-05-2021, 10:57 AM

I'm doing only subframe bushings.

Can I drop the subframe with the diff bolted on it, only drive shaft removed?

jvictormp · 02-05-2021, 12:59 PM

Hey guys. I'm doing the job right now. I'm removing the brake disc in order to disconnect the hand brake cable.

I already removed the two bolts that hold the disc to axle and loosen it up, so it's moving, but there something holding it back. I don't know what that could be.

Edit: forget about it, it was the hand brake itself, it was pulled.

09-09-2020, 09:09 AM	#46
jvictormp Captain 881 Rep 787 Posts Drives: 2008 M3 E92 6MT Join Date: Dec 2018 Location: Brazil iTrader: (0)	Thanks! So I'll try it.
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11-12-2020, 11:07 PM	#49
jvictormp Captain 881 Rep 787 Posts Drives: 2008 M3 E92 6MT Join Date: Dec 2018 Location: Brazil iTrader: (0)	So guys, I ordered the solid SF bushings, waiting them to come. I'd like to ask if it's possible to do it without disconnecting brake lines, like removing the calipers still attached to the brake lines, and let them "hang" somewhere free from the subframe movement.
	Appreciate 0 Quote

11-12-2020, 11:38 PM	#51
SAMM3Y Colonel 3085 Rep 2,747 Posts Drives: 2008 m3 Join Date: Feb 2018 Location: NorCal iTrader: (2)	@jvictormp there's a hard brake line that runs across the top of subframe to feed the rh rear caliper. There's a bracket which unfortunately is part of the subframe which joins the hard line to the flex line, that union has to be broken to remove the subframe. I attempted to drop the subframe and change the bush in place using a threaded cup set that can be purchased on eBay. I successfully removed the bush with this tool but pressing the solid bush was to no avail. I even upgraded all the threaded hardware for the cup set and dry iced the solid bush and could only get it 2/3's in. In the end I had to remove the subframe to get it into the press. It was a waste of time and $$ for the tool. I'd recommend dropping the assembly and using a press. I did research some hand hydraulic specialty tools that could get the job done but short of spending $1k on one I couldn't source it. I'm sure the pro's might know a quicker/better method. Also don't stretch the ebrake cable.. 😞 I currently have no ebrake.... rip stick incoming __________________ 9ers
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11-12-2020, 11:59 PM	#53
SAMM3Y Colonel 3085 Rep 2,747 Posts Drives: 2008 m3 Join Date: Feb 2018 Location: NorCal iTrader: (2)	Lol yeah I have that same press, to clarify I was attempting to leave the diff, driveshaft, axles etc. in the assembly and change them. Just drop the assembly 12" off the car. It wasn't happening with a eBay cup set. In the end I pulled the subframe out and put it in the H frame harbor freight special. The HFS though is definitely worth its weight in... iron? They go with a pop __________________ 9ers
	Appreciate 1 DRLane3985.50 Quote

11-13-2020, 07:10 PM	#55
jvictormp Captain 881 Rep 787 Posts Drives: 2008 M3 E92 6MT Join Date: Dec 2018 Location: Brazil iTrader: (0)	Thanks. About trying to use dry ice, did you guys also try to heat the subframe with some torch or heat gun? I ain't got no dry ice or liquid nitrogen, so I'm thinking on 24 hours of freezer, plus heat gun. It may affect my clarity of decision that one's got only one chance, right? If he gets to push the bushing 1/3 into the subframe, and it stucks, he's not gonna be able to pull it off again to make a second attempt.
	Appreciate 0 Quote

01-12-2021, 06:25 AM	#57
jvictormp Captain 881 Rep 787 Posts Drives: 2008 M3 E92 6MT Join Date: Dec 2018 Location: Brazil iTrader: (0)	Hey guys. I was looking the TIS about rubber bushings replacement, and it says to use a kind of oil in the new bushing before inserting. Can I do that with the aluminum bushings?
	Appreciate 0 Quote

01-12-2021, 07:31 AM	#59
Move Over Colonel 1257 Rep 2,492 Posts Drives: M3 6MT Join Date: May 2015 Location: Peninsula iTrader: (9)	I also wanted to chime in here about AKG bushings. The car I purchased had AKG solid bushings installed, when I bought it, I had some really nasty clicking/clunking back there. I did a couple of track days and really started bugging me. I thought it may had just been the nature of solid diff bushings. I went to go pull my diff and I noticed that the bushings were able to be slid out BY HAND and had some side to side play. I reached out to AKG and they said this was not normal, however the bushings were about .5mm smaller than bimmerworlds, MS and VAC solid bushings. AKG was great and swapped the solid bushings out for poly 75D, and those fit much, much better. The solid bushings were 48.7mm and the poly bushings were 49.21. Big difference in my opinion and just enough to fix my "problem". So just food for thought if you are thinking about going solid, maybe measure your tolerances before you go with AKG solid bushings because you may run into the same issues I did. The bushing recesses for me were about 49.01 front and 48.9 rear. And, if you feel like any diff bushing went into the recess too easily, it probably did. The 75d poly bushings took a good bit of force with a deadblow and a press for the rear bushing. __________________ 2010 E92 M3 DCT
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01-12-2021, 11:35 PM	#60
jvictormp Captain 881 Rep 787 Posts Drives: 2008 M3 E92 6MT Join Date: Dec 2018 Location: Brazil iTrader: (0)	What about this procedure guys? (0:44)
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01-13-2021, 06:31 PM	#62
Throatpunch Captain 365 Rep 674 Posts Drives: 2008 E93 M3 Join Date: Jun 2010 Location: Philly, PA iTrader: (0)	This guy did it with subframe on car. Anyone try it this way?
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02-05-2021, 10:57 AM	#65
jvictormp Captain 881 Rep 787 Posts Drives: 2008 M3 E92 6MT Join Date: Dec 2018 Location: Brazil iTrader: (0)	I'm doing only subframe bushings. Can I drop the subframe with the diff bolted on it, only drive shaft removed?
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02-05-2021, 12:59 PM	#66
jvictormp Captain 881 Rep 787 Posts Drives: 2008 M3 E92 6MT Join Date: Dec 2018 Location: Brazil iTrader: (0)	Hey guys. I'm doing the job right now. I'm removing the brake disc in order to disconnect the hand brake cable. I already removed the two bolts that hold the disc to axle and loosen it up, so it's moving, but there something holding it back. I don't know what that could be. Edit: forget about it, it was the hand brake itself, it was pulled.
	Appreciate 0 Quote