Several years on from the initial unveiling of the facelifted Mk3 Foci – the Mk3.5s – the debate rages on over which is superior. Some prefer the original and arguably more unique styling while others prefer the midcycle revisions and quality of life interior upgrades, but thanks to the shells basically being identical all the way from ’12 through ’18 (the RS’s flat rear floor and the 3.5 hatch’s revised back end being the exclusions of note) you can of course mix and match pieces to create your own ideal combination of the Mk3/3.5 offerings.
This is something we’ve touched on before with a few articles over the years; of note and relevant to today’s post, we covered one of the first known Mk3.5 front end swaps way back in 2017 (which to this day is still one of our most-referenced articles) but it was the matching rear end conversion which always remained as a special case when it came to these vehicles. For quick reference, in the above photo you can see a Mk3.5 hatch rear end (Gage’s ST, foreground) versus a Mk3 hatch rear end (Dijon, background).
For those unaware, a Mk3.5 front end will bolt on to any Mk3 Focus (and vice versa) and is the most commonly-seen conversion. Equally, a Mk3.5 sedan rear end will bolt on to a Mk3 sedan, and from what we know it’s the same case for the wagons (which we can’t test ourselves until at least late 2025, not that we’re counting or anything). The Mk3.5 hatch rear end stood out as the one swap to which the short answer was always “it doesn’t fit”, whenever owners would ask on forums or other groups.
Now, technically speaking, there’s not really anything that can’t fit a given car; it just comes down to how much work (including custom) the owner is willing to carry out. After all, Project Binky proved that a Toyota Celica driveline will fit in a classic Mini if you’re liberal enough with the grinder and welder (and have a loose enough definition of the word “fit”). However, with the specific hope and question typically being whether or not a Mk3.5 hatch rear end will bolt on to a Mk3 hatch shell, the answer is no. With bolting on being the definition in this case of “fitting”, it does not fit. But it can.
One other owner on a forum a couple of years back had delved into the swap and pulled it off, but this time around it was a fellow Canadian owner with whom I’ve talked a bit over the years, Karan Singh, that accomplished this conversion and was able to provide some additional insights into the process as well as some photos so that we could at long last compile an article for all other owners who are curious about the swap and want to explore it as an option for their own builds.
To accompany his documentation I have also compiled the part numbers for the various pieces should anything need to be purchased from the dealer or searched for online. We imagine many would be carrying out such a swap with junkyard parts or used pieces otherwise sourced locally, but it only made sense to include as much of the information in one place as possible. I’ve also listed the part numbers for the other facelift valances, in case one didn’t wish for the ST piece specifically.
The Install:
This write-up came to be thanks to a combination of Karan’s notes as well as our own research for both prior articles as well as this one. It is not detailed to the level of “drill in this exact spot using these precise measurements” but still showcases what is required to adapt the facelift components to the rear end of a pre-facelift hatch. And yes, you will need a drill for this one.
The original Mk3 hatch panel, tail lights, and bumper can all be removed from the vehicle and set aside as none will be reused (the spoiler can though, as previously discussed on the site. Mk3 hatchback spoilers are all interchangeable regardless of model or year); these are the easy steps as they all bolt on and off. The key to this entire swap is actually the pair of bumper retaining brackets, riveted to the car from the factory. With the 3.5 update the tail lights were famously shortened in height which meant the bumper came up higher to meet them; and not surprisingly, the brackets to hold the bumper also grew to accommodate the redesign.
The Mk3 brackets need to be removed by having their rivets drilled out prior to the updated 3.5 brackets going in their place and being riveted on themselves. You can see here one of the new 3.5 brackets fitted, and as noted by Karan the upper most hole (above the line noting the top of the Mk3 bracket for comparison) lacks a rivet here as the sheetmetal of the Mk3 tail light pocket does not reach the highest point of the Mk3.5 bracket. This matches with the early reports that noted sheetmetal changes with the facelift for the hatchbacks. Side note, have we used “Mk3”, “Mk3.5”, and “bracket” enough yet?
The brackets aren’t the only pieces for which a bit of effort – as in, beyond using a wrench – is required though. The Mk3.5 tail lights’ two mounting studs also won’t line up with the holes in a Mk3 shell; the upper holes were noted as having to be elongated and new lower holes drilled into the car. Remember to paint any resulting bare metal so it doesn’t rust! The tail lights’ connectors were also noted as having to be changed to match, and were side-specific. For those wondering, when bought new the lights come with their harnesses and in our experience people usually sell used pieces with them as well.
The final trick to all of this was the hatch’s wiring harness. In Karan’s case, installing this on a friend’s car, the donor had a camera and the car receiving the parts did not. Digging into the system, it would appear that there were only two harnesses made for the hatch panels themselves and it came down to whether or not the car had a backup camera; if for whatever reason you get a hatch without the harness or handle, you’ll need to match them to each other (a camera harness if the handle has a camera, and non-camera if it doesn’t) so that the handle can be plugged in.
Worth mentioning is that Karan also noted some fitment issues with the Mk3.5 wiper motor position against the Mk3 lower interior trim panel, but the Mk3 wiper motor part number has officially been replaced with that of the Mk3.5 in the parts system and I also found the original lower interior panel being noted as fitting all build dates so it should all play nicely together? Regardless, the upper trim panels are confirmed to be a direct swap – perhaps some other owners can experiment with combinations of pieces and find out why this specific car had some concerns with the wiper motor and lower panel.
As for the parts themselves now, you can use the numbers listed below to aid in the search in case local junkyards don’t turn up everything that’s required.
Parts List:
Mk3.5 Hatch Panel: F1EZ-5840110-A
Mk3.5 Tail Lights:
- Standard: F1EZ-13404-AG (RH) & F1EZ-13405-AG (LH)
- LED (as seen on Electric and RS):
- Electric part numbers: F1EZ-13404-FB (RH) & F1EZ-13405-FB (LH)
- RS part numbers: F1EZ-13404-X (RH) & F1EZ-13405-Y (LH)
Mk3.5 Bumper: F1EZ-17906-MAPTM
Mk3.5 Reflectors: F1EZ-13A565-A (RH) & F1EZ-13A565-B (LH)
Mk3.5 Valances:
- Base: F1EZ-17F828-A
- SAP: FM5Z-17626-AAPTM plus FM5Z-17765-A (grille)
- ST*: F1EZ-17F828-DAPTM plus F1EZ-17232-A (grille)
*Mk3.5 ST Valance Supports (only required for an ST valance. All ’12-18 SE-Ti hatches and S-Ti sedans feature the same pieces, STs and RSs each have their own unique supports): CM5Z-17D942-A (x2)
Mk3.5 Bumper Mounting Brackets: F1EZ-17D948-E (RH) & F1EZ-17D948-F (LH)
Mk3/3.5 Hatch Wiring Harness:
- With backup camera: DM5Z-17K400-D
- Without backup camera: DM5Z-17K400-C
At this time I’m afraid I don’t have part numbers for the different hatch handles as I hadn’t found a clear answer, but the camera is quite obvious so you’ll know if a 2015+ piece is correct at a glance.
Final Notes:
As a wrap up it’s worth mentioning in case any owners are curious that – unlike with sedans – hatch rear valances cannot be swapped between Mk3 and Mk3.5 bumpers, so if you’re finding you want to change just the valance on your hatchback and don’t want to go down the route of custom bodywork to blend together two different bumper shells, you will need to swap the entire back end as shown here.
I want to say thank you again to Karan for providing photos from the process and letting me pick his brain about the swap so that we could put together this article for the site – as a thank you some officialTHREETWENTY goodies will be making their way in the mail over to him! I have lost count of the number of times over the years that I have seen the same “can I” question posted on various platforms and now at last some more information can be provided for those looking into this.
Now we just need to wait for wagons to be legal here in Canada so we can properly cover the how-to for that body style and discover if there are any hidden tricks for those as well…
-Bill