BMW E39 M5 Touring build

[BSSBMW]

The following thread will be posted on another forum so some of the content may be very obvious to some but not to others.

Here we are with the beginning of another project one of which I have wanted to do for some time.  
BMW over the years have teased us with various prototypes and concepts which haven't made production for one reason or another.  Concentrating on the E39 M5 touring, BMW had already made and sold an M5 touring with the previous generation E34 all be it in European LHD format with limited production only reaching 891 built.



Not long after the E39 M5 saloon was launched BMW built a single M5 touring as pictured above using a 540i as a base which was used by the then head of BMW M, Gerhard Richter.  Unfortunately for one reason or another it didn't make it into production and it wasn't until the E61 M5 touring was launched that BMW bothered with an M5 touring again and haven't since with the following two 5 series.

Since then there have been several E39 M5 touring builds around the world to varying levels of execution with some being heavily modified and some being as close to OEM as possible so what I am about to undertake will be by no means be a first in any way.  My take on it will be as close to what a factory build would have been with the probability of some suspension and brake upgrades at some point.

A previous project of mine in a similar vein was an E46 M3 touring build which got as far as a full conversion bar the bodywork.

https://forums.m3cutters.co.uk/threads/e46-m3-tour...



With that car sold on a couple of years ago a factory manual E39 540i Sport touring came my way which I started to do some work to and thats when the idea for the M5 build started to take place but being one of 13 UK RHD cars sold it was a bit too rare to mess about with so that was also sold on.



Fast forward to October this year and an Oxford green 540i touring well known in E39 circles popped up on ebay for a reasonable price and a run round the M25 from Surrey to Essex one eve to quickly view it to make sure it was ok resulted in a deal being done and it coming home with me.

This particular car appealed to me for several reasons and a big part of that appeal was the substantial retro fits and maintenance along the way, build thread here.

https://forum.bmw5.co.uk/topic/90321-pipers-e39-54...

For those of you who cant be bothered to trawl through that thread, the crux of it was a fairly basic spec pre facelift 540iSE auto in Oxford green with sand beige leather that ended up facelift sport spec with the following options retro fitted.

Complete interior swap from beige to black including headlining
Heated electric memory M5 front seats
M5 stitched leather centre console
M5 door cards with stitched leather door pulls
Birch anthracite wood trim
Power fold mirrors
Wide screen Mk4 Nav
DSP HiFi
Child booster rear seats
Rear door blinds
Slide out boot floor
Facelift sport bumper
Facelift Halo headlights and facelift celis rear lights
Eibach front springs
18" BBS style 5 replica wheels

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Buying this car has given me a massive head start by saving me a lot of time and money in parts bringing a base car up to M5 spec but there is still a lot to do!



A couple of weeks ago a suitable donor M5 that had sustained some damage popped up on facebook for a very good price.  I had to move quick to secure it as there was naturally a lot of interest in it so the following morning with a bag of tools and a pre arranged recovery truck on standby I headed up to East London to make sure it ran ok and do the deal.



Back at the workshop, the following weekend initial assessment and strip down began and its fair to say that this particular M5 was no prize even pre accident condition but the core components I needed such as engine, gearbox, rear axle and electrical components all seemed to be ok.



Bent chassis rails as a result of the accident and plenty of underside corrosion made me feel less guilty about chopping up an M5.

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Interior completely stripped to be sold on and to remove the complete body wring loom so I can harvest it for sections to integrate into the tourings body loom in the same way I did with the previous E46 so various wires unpicked from their terminals, looms unwrapped and rewrapped all to make a custom loom with correct wire colours and terminations with no cutting and soldering.

So thats were we are so far.  Next stage will be to remove the remaining parts from the donor M5 and start to go through them.

[BSSBMW]

Stick Legs said:

Amazing project, will be truly special once finished.

Oxford Green is an amazing colour on these but please please do something about the blue inserts on the seats. It looks awful anyway but worse with the green.*

• Usual caveats of 'IMHO', 'It's your project not mine', 'If you like it that's fine' etc etc...

The blue will being going for sure. The front seats will be dyed black for the time being but in the the long term I would like a heritage caramel interior which was often seen with Oxford green E39 M5's and I have started to develop a green over tan fetish as I've got older.

[BSSBMW]

Sf_Manta said:

Watching with interest, this'll be the second project where someone's converted a E39 5 series touring to M5 spec I've been following.

The other would be Speed Acadamy's build on youtube currently

https://www.youtube.com/watch?v=uOfybZkMp2U&ab...

https://youtu.be/6oYwZA7LM2w

https://youtu.be/iPDlmmPSiyw

Plenty more videos of the build on their channel with a great deal of detail and what's needed to fit things in

I have seen the various E39 M5 build threads and videos doing the rounds and its interesting to see some of the choices they've made.

[BSSBMW]

After a two week delay over Christmas due to isolating with covid I got back down the workshop to carry on harvesting the M5 donor of its parts. Complete engine and transmission lowered out of the car with the front subframe and steering.



Complete body loom removed which will be picked apart for the relevant wiring and connectors that will be grafted onto the tourings body loom.





The end of the road for this M5 as the shell was collected today but not before cutting out the boot floor to unpick the panels required to graft into the touring shell to replace the spare wheel well with the relocated battery compartment so I can fit the M5's quad exhaust system.

Now that the M5 is fully stripped and disposed of attention will now turn to going through all of the parts and replacing, repairing and refurbishing where required then starting the process of converting the touring. I have decided on a plan of attack which may change but for now it centres around minimising the tourings time off the road and space taken up in the workshop which is as follows,

1. Strip down M5 donor car (completed)

2. Refurbish and assemble complete hybrid rear axle including front and rear brakes

3. Install rear axle, M5 brakes, front suspension and convert from auto to manual transmission but retaining the 540i engine

4. Replace timing chains, guides and rod bearings on engine as well as replacement of any other parts required

5. Refurbish steering box

6. Send car to bodyshop to have M5 boot floor panels and tackle corrosion on the rear jacking points

7. Build up front subframe with steering and complete engine.

8. Swap out 540i engine to M5 engine by dropping out complete front subframe, steering and engine to replace with previously assembled M5 set up and fit M5 quad exhaust, carry out all wiring alterations, swap over instrument cluster and all relevant electrical parts.

This is a simplified break down as there a lots of detail bits and pieces but it should break it down into manageable sections with the only labour doubling up is the removal and refitting of the gearbox which is only a few hours labour but by doing so means keeping the car mobile and out of the workshop as much as possible.

There are some cosmetic items such as the M5 mirrors and front bumper grill to be fitted which will go on somewhere along the line of the stages outlined above but it will not get any M5 badging until the complete conversion is done.

[BSSBMW]

LetsTryAgain said:

I assume you own the garage you’re doing the work in?
My work won’t even let us check tyre pressures or wash our cars, never mind service them or swap an engine!

Yes it is my garage so fortunate I have the use of it.

In the past when I was employed I have been allowed the use of a ramp at work for a week to carry out a project.

When I worked for Renault I reshelled my old S50B30 E30 touring into a mint 2dr shell that I had stripped already.

When I worked for a BMW dealer I had an E34 Alpina B10 3.5 which I converted from auto to manual, did the head gasket, retro fitted AC and swapped the whole interior inc carpets and dash from blue cloth to black leather.

I have heard of other places old banning non customer cars in the workshop in more recent times. The above was all over ten years ago.

[BSSBMW]

F20CN16 said:

AyBee said:

Pleased to see you plan on doing the boot properly. I watched some of those youtube videos last night and the boot floor really did seem to be a bit of a bodge which was a shame.

Transplanting the entire rear floor from one car to another is arguably no better since it is a very large piece to remove and replace, which contributes a not insignificant amount to the overall monocoque rigidity. The way they did it on Speed Academy minimised the surgery. I’d say it’s a 6 of one and half a dozen of the other.

Great project OP. Following with interest.

Edited by F20CN16 on Friday 19th March 10:06

I saw that video and in my opinion it was a bodge as the battery tray didn't even fit. Messed up with their measurements there! Never mind it not looking very "factory"

You do not need to cut the whole boot floor to fit the relevant M5 parts, the spare wheel well and the right hand boot pocket are all that is cut out and replaced, no chopping of chassis rails etc or large panels so the integrity structure is not effected.

The whole boot floor is cut out of the M5 donor so the required panels can be un picked from the original seams.

[BSSBMW]

Tommie38 said:

d_a_n1979 said:

Tommie38 said:

Great project OP.

Did the E39 M5 come with a steering box or hydraulic rack? I seem to remember the larger V8s coming with a box but I can’t be certain.

All V8s came with a box; the M5 had a better ration box, but still a box

The dervs and I6 engined E39s all came with a rack (for me it's much better and that's why I've personally stuck with 530i E39s); but the M5 box does drive very well too and I certainly wouldn't turn down ownership of one if I got the chance

Part of the reason why I was asking. Never got on with the boxes that Mercedes use.

That said, E39 M5 has got to be up there as one of the best all rounders of all time, and you’d think BMW could get the steering set up properly.

The reason the used a steering box rather than a rack was purely because of space reasons.

The box isn't really as bad as the internet makes out, its more a case of that as there are other E39 models with a rack which is better, it automatically makes the ones with a box bad when they really aren't.

As mentioned the M5 uses a quicker ratio box over the standard V8 models and it also has variable assist which weights up the steering a bit when the sport button is pressed.

E28, E24, and E34's all used a box as well.

[BSSBMW]

Gooly said:

Are you going to be removing the SLS rear suspension? If not, are you going to relocate the compressor etc if you cut out the boot floor? As far as I understood the saloon rear subframe isnt compatible with the touring but the diff and driveshafts are.

I will be keeping the SLS.

You are correct, a saloon rear subframe is no use in a Touring as the tourings rear shock absorbers mount to the sub frame instead of the top of the inner rear wheel arches like the saloon.

Gooly said:

Green over tan/caramel is a fantastic combo. I’d be tempted to put prefacelift clear lights in - there was something very 90s-prototype-cool about them as the launch spec M5s and M5 touring prototype ran them. Would also recommend the OEM optional rear spoiler as well, which helps neaten up the rear profile of the touring.

My F82 is green over tan and I ordered it new like that.... I've started to develop a green over tan fetish in older age!

The lights will be going back to clears as per all M5's, not sure on going pre facelift.

Gooly said:

In terms of the S62 it may be worth doing the rod bearings while the engine is out - whilst S62s aren’t as bad for them as S54s and S65/85s are, its still a known issue and much easier to do when engine is out - the price of S62 cranks is eye watering these days. Can’t wait to see this done and please post a walkaround / exhaust note video when its done!

We replace rod bearings on M power engines all the time and having rebuilt more than one S62 I know all their issues. If you scroll back through my posts on this thread you will see what I have planned for the engine.

[BSSBMW]

Carrying on with the stripping the M5 rear axle was harvested of its LSD, drive shafts, rear brake callipers and hub flanges.





I picked up a complete touring rear axle which was stripped down to the bare subframe, hubs and lower arms.



Above is a pic of what all non M5 rear sub frames are like where the rear of the diff mount is and below is a pic of how an M5 is constructed. The middle section is cut out and the two sections are tied to the main frame by tabs either side.







I had the M5 subframe difference replicated on to the touring subframe as well as having the front diff mount strengthened which is a common thing to do on supercharged M5's, made sense to do it while it was all stripped.



Subframe vapour blasted and all the bushes replaced with new. Touring for the rear pair and saloon for the front pair so I can use the M5's chassis brace struts that link to the transmission tunnel.

On to the LSD.....







Stripped apart to asses what state everything was in to find the bearings and gears ok but the clutch plates clearly worn.











New clutch plates, bearings, seals to build up in to a blasted and painted casing, vapour blasted back plate and electro plated nuts and bolts.



Trial fitting of the LSD into the modified subframe shows the clearance to the diff back plate. After watching various you tube videos and looking at pics on line it seems others have just ground down the bolt heads to allow some clearance which despite being at lot easier, is a bodge in my opinion.



So there we have it, a touring subframe with an M5 LSD fitted the factory way.

[BSSBMW]

ChocolateFrog said:

It's great to see things done properly.

That donor M5 looks like it's lived a hard life.

I didn't feel so guilty chopping it up as it was not the nicest example.

[BSSBMW]

RelentlessForwardProgress said:

I think the idea is that everything is transferred over- like reshelling an M5 into a touring body. Obviously quite a lot involved in doing that, as already seen, but I think the full engine, gearbox, prop, rear differential etc etc is going into that touring!

Exactly this.

[BSSBMW]

From fully trimmed load area fresh from a dump run to stripped out ready for the bodyshop. Yep, a change of order from the original plan means a slot has been booked next week at the bodyshop for the spare wheel well delete and a deposit has been taken on the M62B44 540i engine so that will also be coming out sooner than expected.

This means the whole conversions should be a more speedier process.

[BSSBMW]

bolidemichael said:

Barry, is the wheelbase the same as the saloon i.e. will you expect the handling to be the same?

As with all BMW touring versions of a saloon, the wheel base is identical.

That said the E39 touring rear shock absorber mounts at an inboard angle as opposed to the saloons vertical mounting and the touring uses a separate air or coil spring as opposed to the saloons spring over shock absorber and having owned several E39 saloons and tourings there is a noticeable difference in how they handle and feel at the rear but not in a negative way, just different.

What is interesting is that BMW's own prototype used a saloon rear sub frame and shock absorber location with a partial bulkhead fabricated to low the use of this so one would assume BMW thought there would be an issue with using the touring set up.

Having said that, there are several S62 converted tourings around the world including some with supercharges and have no issues with the touring set up.

[BSSBMW]

peetee7 said:

This is fantastic ! Subscribe’d.

If bmw made an estate version of the E39 M5 id be the owner of one for sure. I’ve DM’d you btw

Hi, I have replied to your email.

[BSSBMW]

Sf_Manta said:

Something for inspration OP

Thanks.

I have watched a few of their videos.

[BSSBMW]

Easter weekend allowing for some spare time to prep for the bodyshop and as I had sold the M62B44 engine it was time to get that out.



A before shot of the underside. The last time its going to look like a non M5 V8 E39!

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Underside stripped down (rear air springs and accumulators aside) to reveal a relatively corrosion free underside. When the bodyshop it will be fully cleaned before any repairs.





The usual jacking points at the rear of the sill corrosion common to E39's has started to take a hold. Not the worst as E39s go but once the rot is cut out the hole will be a lot bigger.

[BSSBMW]

Last weekend saw the return of the rolling shell after a longer spell than was anticipated.





Before work started on the cutting and welding, the underside of the car including all four wheel arches was cleaned of years of built up mud and road grime to reveal a reasonably clean underside with only the jacking points and a few small patches that had suffered from corrosion.







The M5 boot floor with all the excess metal not required now cut off. Unfortunately the donor M5 was not as clean as the touring shell which meant there was only one way to go with this.....







All of the relevant panels needed to be split apart to repair or clean up the corrosion. This added quite a bit of time to the process and a new boot floor panel (now NLA from BMW) would have saved a lot of time (money!) in doing this but when you can't buy new you have to work with what you have.



No turning back!!!







The boot floor conversion progressing













The E39 bodies Achilles heel, jacking points and the sills in general are usually the first area for them to start to corrode and a collapsed rear jacking point is often the death knell for an old lowly spec/engine E39.





















The end result is now a rust free E39 "M5 touring" shell ready to start putting back together.

After all of the fabrication was completed and primed, 3M sprayable sealer was used then a combination of beige paints to match the factory sealer and E- coat then a dusting of Oxford green base coat to replicate the factory look of overspray from when the shell is painted at the factory then application of Tectyl ML cavity wax to all of the box sections and a few key locations.

Both rear quarters, both sills a new M5 rear diffuser and the pair of genuine M5 mirrors all painted at the same time.

Now the fun begins........!

[BSSBMW]

pistonheadforum said:

This is fantastic and I'm so glad people doing these kind of projects exists!

I don't mean to de-rail, but what can you do about rust at the front skirt showing?



Is this a replacable skirt or thick enough metal to sand down and repair?

It seems like a common issue and appreciate that yours doesn't have this but mine does and I don't want to make it worse by waiding in with a grinder.

Many thanks.

The skirt is actually the outer sill panel and is welded to the body. Small areas of corrosion can normally be cleaned up ok but if quite bad the some metal needs letting in.

[BSSBMW]

A large pile of parts accumulated while the car was away at the bodyshop so it was time to get cracking with it.



New OEM brake and M5 fuel lines fitted up along with new accumulators for the self levelling rear air suspension.







Rear axle built up using the modified rear subframe, rebuilt M5 LSD, refurbished lower arms and hubs, new bushes throughout, all new upper arms, new wheel bearings, new top mounts, new drop links, new nuts and bolts, Bilstein B6 shocks, Eibach ARB, Arnott air springs, refurbished drive shafts plus other bits and bobs.



Blasted and painted subframe built up using an M5 ARB, M5 steering box, new centre drag link, all new bushes, all new M5 PAS pipes.



Original rod bearings replaced with the engine @ circa 125k miles



Rear axle bolted up and in along with the fuel tank using new tank straps



Engine and box mated along with the recently replaced clutch and flywheel, bolted onto the built up front subframe using new engine mounts ready for its "marriage" to the body





All bolted up in to the engine bay and back on all four wheels with the rear air suspension inflated.

The result of 27 hours over the bank holiday weekend. Lots more to do!

[BSSBMW]

Gallons Per Mile said:

Superb! You can't be far off having it on the road now

Still plenty to do but a big chunk of work done.

I hope to have it up and running by the end of the month.