#ZedShed BMW Z3 Rear Subframe Bushes

[GazHyde]

As requested by @Nifty Fifty here is a basic idea of where the common bushes are that we refer to on the rear sub frame. Some of them have multiple names but I've gone with what I call them!

Someone more technical will need to explain exactly what they do, but this should give an idea of roughly what I'm always prattling on about!

The picture isn't at the best angle, but is the best I have at the moment. The location of the diff bush is just behind the differential in this picture, but the last image gives a better idea of what it actually looks like.

Viewed from above, slightly better angle.

The large components

The rear beam removed from the sub frame

Differential bush mounting off the side of the differential.

 

[Mint]

Brilliant Gaz

Now if you can just do the rest of the car............

 

[GazHyde]

Now if you can just do the rest of the car............

To be honest all the Zed work we have done has been to cure issues with the rear sub frame. Rosie needs new shocks up front and a few other bits, so will take some pictures and annotate them in the same way when we do that!

 

[Mint]

Actually I was joking - but cheers anyway

 

[Jonno Bee]

Excellent work chaps. One of the best things about this site are the practical hands on articles like this. I know what I'll be doing in the garage once winter evenings return.

Jonno

 

[GazHyde]

What with all the recent posts on sub frame refurbs in the 'Shed of late, we've getting more questions about what's involved. Thought it would be worth bumping this thread. Should give you all a good idea of what constitutes a sub frame and what each bit is.

Gratuitous picture of 'Shed refurb to compare

 

[D0nni]

As requested by @Nifty Fifty here is a basic idea of where the common bushes are that we refer to on the rear sub frame. Some of them have multiple names but I've gone with what I call them!

Someone more technical will need to explain exactly what they do, but this should give an idea of roughly what I'm always prattling on about!

The picture isn't at the best angle, but is the best I have at the moment. The location of the diff bush is just behind the differential in this picture, but the last image gives a better idea of what it actually looks like.
View attachment 12368

Viewed from above, slightly better angle.
View attachment 12370

The large components
View attachment 12373

The rear beam removed from the sub frame
View attachment 12374

Differential bush mounting off the side of the differential.
View attachment 12369

was not aware the sheer amount of bushes involved here lol. thats some amount of work

 

[Althulas]

It’s not to bad when you break it down into sections. The serious bit is when the ocd kicks in and you decide to refurb everything but think of the accomplishment and satisfaction that hard to beat.

 

[D R Oldfield]

Does the diff bush come out easily is there any tips to its removal / replacment

 

[Mazza]

Do what I did ........give it to Lee and then stand out of the way, drinking a Starbucks coffee

 

[D R Oldfield]

i would love to unfortunately i live many miles away in south cumbria , i have my 2.8 subframe off and on the garage floor and i do have access to fully equipted workshop at work with a 60 ton press but that diff casing looks easily damaged

 

[Mazza]

Lee carefully used a hacksaw to cut through the steel band , but not through the Ali casing then bent the metal by the cut inwards, which relieved the pressure and it then tapped out.

I had removed the diff cover before the new bush was installed (Lee did it on his press)

But you have to be very careful using a press when pushing the new one in. Ensure the new bush goes in square. I think there is a chamfer on one side of the bush.

On the press

New parts fitted and old bushes

 

[Althulas]

If you decide to cut the diff bush band out I advise cutting the band beat to cut towards the thick end incase you make a mistake and nick it, just be patient and you will be fine.

 

[RB2]

Not sure this is the right thread to ask but when removing the rear subframe, will it drop by removing the beam bush nuts or is it like the e30 where you need to knock the rods back up into the car and off splins? Currently sitting with just the diff and Bush bolts to go and wondering if I need to pull some interior out first.

Thanks in advance

 

[Mazza]

No once the two beam nuts (22mm??) and the diff bush bolt is removed , you will be able to lower it down on a jack

This was mine going back in.. but you get the idea.
Be careful as it can get stuck and may need to ease it off the two beam pins. ( you can see one in the picture)
Try to keep it fairly level as it decends

 

[RB2]

No once the two beam nuts (22mm??) and the diff bush bolt is removed , you will be able to lower it down on a jack
View attachment 233947This was mine going back in.. but you get the idea.
Be careful as it can get stuck and may need to ease it off the two beam pins. ( you can see one in the picture)
Try to keep it fairly level as it decends

That's perfect thanks for the fast reply

 

[Stevo7682]

@GazHyde was just reading this thread 2015 when you first put the thread together with a complete rear end out of car .
How many more have you helped do since then in the last 7 yrs ( and how more proficient do you think you guys are now at doing it than you were in 2015)
Stephen.

 

[GazHyde]

@Stevo7682 - we've done somewhere in the region of about 80 sub frame rebuilds in total now. As for proficiency, familiarity certainly helps with that. However we do get the odd curve ball here and there to mix things up a bit. With a following wind and not too much mess underneath we can remove a subframe in just over an hour from wheels off the ground.

However, probably the biggest thing that we've noticed is that we don't get any Zeds in which don't have failed beam bushes these days. We still see cars running on original shocks and starting to find that more swing arms are corroding through.

The other major thing now is that we are doing more complete restorations, previously it would be what needed doing at the time. Now, everything needs doing so it's more of a complete resto service these days.

 

[Stevo7682]

This is thing about zeds though.
They are pushing 25 years old most of them and still running totally original parts on the whole which is a testament to original build quality but also the reason you are saying its resto job to future proof the car for a good while again and return it to the way it should ride and handle instead of what people have got used to in the way it drives.
Stephen.

 

[RB2]

To the bmw engineer who decided not to use a standard bolt here... wtf