Drove my E60 to the south of Spain recently for a holiday/visit to the in-laws. Wifey is perfectly able to sit at the pool sunning herself all day but I prefer to tear my knuckles on rusty bolts and cut metal with the disc grinder in my flip flops while sinking a few beers.
Lying against a shed wall for four or so years was my E39 towbar, which I removed to get the E39 inspected/re-registered in Spain, (saved a lot of extra hassle/paperwork without towbar). I had left it covered but father-in-law shifted it out of his way and it sat outside since. Long story short, it got left behind when I moved back to Ireland.
A bit of googling and I couldn't find anyone that has done this conversion before, but guides show the plastic bumper is easy to remove. So thought I'd have a look.
This is not a comprehensive guide, more of a proof of concept and I imagine towbars will vary somewhat. There are guides for removing the plastic bumper etc already out there.
The towbar is a Bosal swan-neck originally fitted to my old E39 by some absolute cowboys in Coby Autos, Dublin. More on that below. The electrics are a standard 12N 7-pin socket trailer with a PCT Automotive Towing Interface, which is a universal bypass relay type box of tricks.
Plastic bumper off, removed metal crash bumper (4 x 16mm hex head nuts), it can be seen under the car. And both LHS and RHS bumper mounts off (4 x 16mm hex head studs each side).
Rusty looking towbar offered up for inspection. Mounting holes are way off but with a bit of drilling and grinding it looks feasible.
In my hand is the LHS bumper/crash bar mount. The clean patch on car where it came off can be seen. As to remounting the metal bumper, some people seem to discard it once a towbar is fitted. This is how it was on my E39, no crash bar over the towbar, but then the installers were absolute cowboys anyway.
My research points to the crash bar being there for impact absorption and anything that absorbs energy and deforms in a rear end collision will lessen the possible injuries to occupants of the car. Also, if you check out the OEM towbars by Westfalia they have the bumper mounts integrated. So best to put it all back on as best as possible.
The E39 mounting holes looks to be a little wider than the E60, so a little trim of the inside edges of both bumper mounts (the red line in above pic) will allow them to go back on over the mounting plate. I also used the hole pattern on this mount as a template to drill new holes into the towbar mounting plate. I measured 880mm between centers of the inside mounting holes on the chassis, and worked from there with drilling new holes. The studs used are M10 so drilled new holes 15mm to give myself a little room for error.
3 x 10mm nuts hold this plastic undertray on. Cut a small section out to drop the bar into it with the swan neck removed. I thought I was being clever cutting as little as possible out of this, but in hindsight two thin slots would have been even better. I have seen a few DIY's where much more of it is cut away, but less is more and my way is better as it still has some meat either side of the hole and overall remains sturdy.
Quite a bit of drilling and a little grinding later along with a lick of heavy duty paint I found in the father-in-laws shed and it mounts without issue for a test fit. The 4 x M10 studs on each side are a little too short now though and only grabbing a few threads.
Test fit the plastic bumper back on to ensure all fits well. Good news is there is no need for any cutting of the plastic bumper.
Now, back to these bumper mounts.
You can see the one at the top of above pic (RHS one) has been trimmed down one side, it's rounded corners are gone and the edge is now closer to the holes. It can now go back on over the towbar, but it extends 10mm too far towards the back of the car to re-fit the plastic bumper correctly. Basically the thickness of the towbar mounting plate was extending it. So I had to shorten them by 10mm. I ground the original welds off where the square base meets the center tubular section. I then cut 10mm off the length of the tubular section. As I had no welding gear I prepped the surfaces for re-welding and went down to the village in search of a local workshop. 45 mins later and having spent the princely sum of €10, I had 2 mounts 10mm shorter all welded up. You can see the fresh welds on the bottom of the LHS mount.
I could have welded these directly onto the towbar instead, but if I ever want to remove it and revert to standard, it will be easier to reuse these mounts.
They were pretty rusty so cleaned them up a bit and gave them a lick of spray paint, also found in father-in-laws shed.
Bumper mounts refitted over the towbar. Original M10 bolts were now too short so replaced with longer ones. €1.60 for 8 new M10 x 40mm hex bolts in a local hardware shop. Judging by the amount of rust on the mounts it gets pretty wet in here and the clean patch in earlier pic is due to there being a seal behind the mounts to prevent water getting into the hollow section of the chassis so I used some thin flexible foam sheeting between the chassis and towbar mounting plates to seal it up, but it's not visible in my pics.
Metal bumper/crash bar was quite rusty in places also so a bit of wire brushing and some more spray can paint later it looked like new and it fits back onto the mounts perfect and clears the towbar with room to spare.
My trailer socket cable was too short to route it through the bodywork with the existing hole of the PDC cable so I removed the 4 x 10mm nuts (red arrows) holding on this plastic trim panel and went through at the green arrow where there is a rubber hole blank. Pierce the rubber and it becomes a rubber grommet for your cable, but there is another skin of bodywork behind the hole so had to drill through that inner skin. Luckily I had some of my own rubber grommets to hand to prevent cable getting chaffed over time.
Made another small cutout to enable a tidy outside location of the trailer socket.
Pretty tidy, me thinks. I had use the grinder on the 2 original M12 bolts that secure the swan neck. So 2 new stainless bolts cost €2.
Barely noticeable with the swan neck removed.
I won't go into the electrics hook up too much as there are guides out there and best practice is to get a dedicated E60 system like the Westfalia one. For my rare and light towing requirements the simple bypass relay I already had will suffice. But seeing as I was unable to find a guide as to what cables to tap into on an LCI car I had to look up the electrical drawings myself. Pre-LCI harness is different.
Here are the cables I tapped into at each light:
LHS tail-light - Black/Red
LHS indicator - Blue/Brown with Yellow dots
RHS tail-light - Black/Brown
RHS indicator - Blue/Brown
RHS brake light - White/Brown
Reverse and fog are not legally required. Some people pair up the left and right tail-lights from one source but that won't pass an inspection test so keep them separate.
There is a YouTube video here of an E61 Westfalia towbar installation which to me looks pretty much identical to the E60. It's not comprehensive but gives an idea of what's involved.
Total outlay came to €13.60 including the free paint
Overall, a great holiday was had by all
A final note.
Why did I say Coby Autos were the cowboys that did the install on my E39? Well, when I came to remove it I found their level of workmanship.
1. I'm not sure if it's acceptable to remove and discard the crash bar like they did, but it sure seems like best practice is to refit it.
2. They cut a massive hole in the bumper about 3 times the size of what was needed.
3. They tapped into all the electrical cables by stripping back the existing cables and wrapping the new cable around them, then just used insulating tape on them. Seriously, how much are a few scotchlok taps?
4. Worst of all was the "fuse holder".........
Here it is circled above in this old pic of my E39 that I had taken for future reference of the towbar wiring.
The below pic is a mock up I did for this post of what I originally found under the insulating tape, but the yellow cable and spade connector on the left are original.
Two unsheathed spade connectors tightly taped up which brought the connectors together creating a short which bypassed the fuse. Seriously, at a minimum, how hard would it have been to put some tape around one of the connectors to prevent the short before taping it all up? Shame on me for not inspecting it earlier and the car was in Spain some years later by the time I found this shambles. Cowboy Autos seems more appropriate.
From their website:
"Coby Autos have been fitting towbars, bullbars, sidebars, canopies and even bicycle carriers to cars, vans, trucks, trailers and even motorhomes of all shapes and sizes since the early 1990s. You can rest assured that we can take care of the electrical requirements as well, as we've vast experience with all modern wiring systems."