G27 Knee Clearance Mod (4 screw attachment)

[pilmat]

Being gifted/cursed with long legs, I often suffer from low knee clearance in seated positions (cars, planes, sim rigs, etc.). When I brought home my shinny new G27 a few months ago, I immediately smacked my knee on the table clamp. Flipping the base over, it is immediately apparent that Logitech intend you to use the clamps even when mounting off the rear bolt mounts on a rig. Not good enough!

I pulled the base apart to see what was inside. I had a fix within a few minutes: mount the base with 2 of the screws used to hold the main steel frame inside the base. The biggest pain was removing the clamps! The wheel needs to be removed and the base cover removed to get access...

This mod is only good if you are mounting the G27 "permanently" (i.e. on a rig), as the clamps are removed and screws are necessary.

Here is what the mod looks like, as I'm doing it for a friend's new Human Racing GT Chassis install. At 6 foot, I'm not extraordinary, so others must suffer from the same affliction (my friend SGPracing, for one). Here is is what the issue was on my old rig, here it's not bad but the pedals were a bit too far away here too:

See the photo sequence in full size here. There is descriptions there too.

G27 Table Clamps

These are the buggers.

Underside (stock)

This is the underside of the G27. The crooked row of black Philips screws is used to attach the internal steel frame to the base. We will use the middle two to replace the clamps.


Chassis screws used for front screw mounting

Here the screws are removed. They are M4 and need to be at least 16 mm plus the thickness of your mounting plate.

Screw instalation

This is what the mounting will look like. This is the plate from the Human Racing GT Chassis. The insanely long M4 screws are for demonstration purposes

Remove the wheel

Now the painful part: removing the clamps. Start by removing the wheel. Note that when the last screw is removed, it will want to come off, but the button wire harnesses are still attached. Don't pull too hard!

Remove the wheel PCB screws

(sorry about the shaky cameraman)
Now take off the two little Philips screws that hold the wheel PCB on. You will also need to take off the shift light "periscope". Again, the PCB is still wired to the base, don't pull too hard.

Disconnect the wheel PCB

Here you see the PCB to base wiring attachment. Just pull that plug off (carefully).

Remove the wheel hub

Now take off the 3 center screws. Not the outer ones, they only hold the paddles on.

Wheel hub removed

The hub removed and ready to remove the base cover.

Remove all the OUTER base screws

Remove the outer 8 screws, not the two other chassis screws or the cord winder.

Clamps as installed

This is what the clamps look like inside. Just a threaded rod in a plastic U-clamp.

Clamp and rod removed.

Just unthread the rod and push the clamp out the bottom. Now put it back together

The holes left from the clamps

Here is the base back together (you did remember the shift light periscope?) and the gaping holes left by the clamps. I put a piece of clear packing tape over them for dust. But maybe somebody has a creative use

The base drilling pattern

This is the drill pattern: the holes are off set 108mm from the back mounting holes (centre to centre) and are 107mm apart (53.5mm to the centre line on the photo).

Finished

And a nice, elegant installation (minus the two holes on the base top...)
​

If I missed anything, please ask

 

[jaycee_xr3]

Great guide, I'm really having hard times with the same problem.
Thanks!

 

[NABeast]

I was thinking about taking them out when I had the cover off but left them in,but they annoy the crap out of me. I had it apart to cut the grill out and remove the blockers behind the " headlights" to help cooling. I have it mounted with bolts so I may take it apart ant remove them anyway.

 

[pilmat]

Glad you guys like the how-to. I am surprised more people have not had issues with this! I have done 4 wheels so far and have a couple more in the near future to do (that one will be a whole big thread on its own ).

Please let me know if anything is not crystal clear. I should have a few minutes to make a CAD drill template next week if anybody is interested. Let me know

 

[Spike125]

Nice how to,thx for sharing.
Always nice to see, when follow modder shower their improvements

 

[sherpa25]

Thanks @pilmat. Would you have a link for the drill template? Thanks.

 

[bokimoto]

since nobody has posted their solution to the 'gaping holes', i'll show the way i resolved it.

after pulling the clamps out, i am re-using just the screw posts to finish the housing top, and it looks the same as if the clamps are in place.

one wrap of gaffer's tape, or what you have, to hold the caps in the down position, and also to provide a little cushion between the screw posts and the housing.

then push them up into the place they came from, fitting the tape in carefully to fully seat them in the holes

now, drop a couple scraps of foam into the bottom section, where the bottoms of the screw posts will rest

this foam will force the screw posts gently up against the housing, and hold them there without rattling ... i put the top on for a few moments, to get the screw to make an impression in the foam for a photo, to show you where they locate

NOW VERY IMPORTANT - if the foam is providing firm resistance to the housing fully coming together,
squeeze the housing together with your hands, while putting the screws in
DO NOT rely on the screws to draw the housing shell together, as they might strip out under the strain

it's all closed up now ... those annoying clamps are gone ... and the top looks exactly the way it came from the factory

 

[grog]

since nobody has posted their solution to the 'gaping holes', i'll show the way i resolved it.

after pulling the clamps out, i am re-using just the screw posts to finish the housing top, and it looks the same as if the clamps are in place.


now, drop a couple scraps of foam into the bottom section, where the bottoms of the screw posts will rest

Nice write up 👍

I did a similar thing but in a different manner, It was a while ago but I think I just shaved the lip down on the plastic screws so that they can be dropped into the wheel from above while fully assembled. I wrapped a bit of tape around the bottom of them to get them to stay put and not rattle around.

I also did a mod a long time ago to allow the wheel to be clamped to thinner surfaces, I did this by gluing a few coins to the the inside of the housing (on the bottom near where you put the foam).

I meant to mention this when this thread popped up a long time ago but I didn't want to make this write up look like overkill, so props to pilmat for going above and beyond. Anyway I did a similar "no clamp" mod which consisted of removing the clamps and that's it, I just used the 2 hard mount holes and some large fender washers. Only using 2 holes has worked out perfectly fine for me with the FFB turned all the way up.

Also I'm not a tall person, hitting the clamps with my knees was just a result of my seating position.

 

[DigitalRelay]

I know this thread is a thousand years old, but wanted to say thank you for this write up. I upgraded my rig to a a Playseat Trophy last week and smashed my knees a bunch of times getting in and out of the seat. I did this mod today, and although tedious and time consuming, it’s so much better now.