Retrofit: GR Telescoping Steering Column into a GD (Part 1)

Making progress!

A while back, we talked about retrofitting a 08-14 WRX/STi GR steering column into a 02-07 WRX. This time we are going to test fit the GR column into the Bugeye to see how much work it will take to make the modification happen; or whether it is even feasible at all.

First up, disconnect power to the battery. The circuit breaker we installed for the battery relocation is proving to be a very handy item for this task.

Next, we need to remove the lower dash panel underneath the steering column; the instrument cluster shroud; the steering column trim and the dash brace/plate behind the lower dash panel.

There is a cluster of wiring harnesses around halfway down the steering column, disconnect all of those wiring harnesses; then unbolt the three harnesses from the bottom of the column, and unplug the three harnesses at the turn signal, wiper and ignition switches.

Next, remove at least one pinch bolt from the steering column (mark your location with a paint pen). It’s probably easier to just remove the second pinch bolt and slide the link back and off of the column.

Finally, there are two 12mm bolts holding the column to the dash. Once those are removed the steering column should be ready to be removed from the car.

With the GD steering column out we can compare it to the GR steering column.

GD vs GR columns
GD Column
GR column

At first glance, the GD column is narrower than the GR column and both appear to be approximately the same overall length.

The GR column is a little bit wider than the GD column from the mounting tabs down. As a result, the mounting tabs are slightly wider on the GR column; which was expected.

However, the difference is only about 6mm (1/4 inch) on each side.

And to my surprise, it looks like the top GD steering column cover might fit by just trimming down the mounting posts. The bottom cover attaches to the top cover so this aspect of the retrofit is very promising. I really wasn’t expecting any of these parts to work.

GD cover on a GR column.

The bottom cover might bolt up without any modifications but my GR adjustment arm was damaged so it hard to say where it will land. Either way, the bottom cover might need a little bit of trimming to get it to fit which is pretty awesome.

We might be able to swap the adjustment arms between the columns, however, the GD column uses a bolt setup where the GR column uses a nut with a lock bolt setup. I don’t think these are interchangeable. The nut and lock bolts are left-threaded so take care when removing them.

GD column
GR column

The GD column necks down where the bracket is tack welded on for the wiper/turn-signal switches. If you wanted to use all GD parts on the GR column you would need to grind off the welds, bore out the bracket and then tack weld it onto the GR column. The GD mounting points for the turn signal switches/module are just slightly wider than the GRs.

GD column
GR column

My plan is to cut the GD bracket off just above the edge of the steering column and bolt it to the GR bracket. The ignition lock should swap over with new shear bolts.

Inside the car, there are two strategies we can approach to install the GR column. The first is to utilize the GD mounting points at the dash and come up a couple of inches short at the firewall. The other is to place the GR column into the grommet on the firewall and make new mounting points under the dash.

Both solutions have pros and cons.

The first solution requires extending the column housing a couple of inches to the grommet along with widening the openings to use the GD mounting points. Using this method means we can most likely re-use our GD steering linkage.

The second solution requires new mounting points in the dash. This might require a bracket to be fabbed up. And since the steering shaft extends further into the engine bay we would most likely need to use a GR steering linkage.

Also, the first solution will give use the most amount of legroom by placing the steering wheel around where the GD wheel sits on the shortest GR setting.

After going back and forth over the pros and cons of each solution I decided to go ahead and try the first solution. I need to pick up another GR column anyways, so I will use my current one as a test piece.

To get the GR column into the GD dash, you need to bend down or cut off the bracket just below the right side bolt hole.

Next, we need to trim off some of the plastic from the dash. When you use the telescoping action and pull the steering wheel towards yourself, a couple of the brackets hit the dash.

It’s pretty minor; a hacksaw can make quick work of it.

Not pictured: A small piece of the corner on the right side needs to be trimmed as well.

And finally, we need to remove around 6mm of material from the mounting points. The pads are mostly aluminum with a steel tab on the bottom. I initially drilled the opening out, as I didn’t realize the pad was aluminum. The pad is actually an insert that looks like it can be removed.

I’m not super thrilled with how much material is left on the mounting pads and tabs. I may fill in the remain opening with JB Weld or something. However, it should be fine unless you are depowering your rack. If so, I would probably reinforce those areas.

Now we can test fit the GR steering column.

Ignore my duct tape shift boot.

Voila, it fits on the first try!

The only issue now is the bottom of the column does not sit in the grommet on the firewall as mentioned earlier. However, at this location, the GD steering linkage should bolt up.

I attempted to attach the steering linkage to the GR column but it wasn’t cooperating. Considering the condition of the rest of the column I think the splines might have some minor damage to them preventing the steering linkage from slipping on. I didn’t want to damage my linkage trying to force it in place.

Since I needed the car to be driveable in the morning, progress had to end here.

I am pretty stoked at the progress we’ve made. This retrofit is closer to reality than I would have expected at this point. I have some ideas about extending the column but that’s going to have to sit on the backburner for a while. I have quite a few maintenance items coming up and I am leaving my job sooner than I expected.



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