Tech: Lexus CT200h 5×114.3 Hub Conversion

Tech: Lexus CT200h 5×114.3 Hub Conversion

July 05 2019

Although wheels in a 5×100 bolt pattern are generally cheaper than their 5×114.3 counterparts, they are far less common, especially in wider widths and lower offsets. Adapters are one solution, but using them will require higher offset wheels. So here are the parts and process for a proper 5×114.3 hub conversion on a Lexus CT200h.

Note: This conversion was performed on a ZWA10 Lexus CT200h, but all of the following information also applies to the ZXW30 Toyota Prius, except where noted.

The Scion iM and Toyota Corolla iM share many components with the Lexus CT200h and Toyota Prius and will be the source of almost all of the parts for this conversion. Many of these parts are also shared with other vehicles like the 2006-2012 Toyota RAV4, 2008-2015 Scion xB, 2011-2016 Scion tC, and 2012-2017 Toyota Prius V, making them readily available.

Front

Hubs

Unfortunately, there aren’t any 5×114.3 hubs that will just bolt onto the front knuckles on the CT. Toyota doesn’t use the same wheel bearing diameter or bolt spacing on their 5×100 and 5×114.3 hubs. However, the iM hubs take axles of the same size and spline count as the CT and can be bolted on using a few extra parts from the iM.

Knuckles and Lower Control Arms

Theoretically the CT knuckle could be machined to accept the iM hubs, but there is a simpler - and bolt-on - solution. The critical dimensions of the knuckle, ball joint, and lower control arm assembly - overall height, lower control arm mounting points, tie rod position, shock bolt spacing - are the same between the iM and CT. However, Toyota made some sections of the steel iM knuckle thinner than the aluminum CT knuckle, so they will require spacers to fit properly.

Since the CT shocks are wider than the iM knuckles, spacers are needed to take up the extra space between them. There will be 8 of these spacers total - one spacer for each side of the shock, for each bolt, for each side of the car. Each spacer needs to be 6mm (0.236”) thick with a 17mm (0.669”) minimum ID and 35mm (1.378”) maximum OD.

The CT outer tie rod ends are not threaded far enough to properly tighten the castle nut down on the thinner iM knuckle. The simplest solution is to use a spacer on the top side of the tie rod, effectively making the knuckle thicker. Alternatively, the iM tie rod ends could be used.

The last spacer you need is for the wheel speed sensor. The CT wheel speed sensor will stick too far into the knuckle and be damaged by the axle. Placing a 4mm spacer under the sensor's M6 bolt will properly position the sensor.

Brakes

When it comes to front brakes, there are a few options.

The first option is to continue to use the factory CT calipers. The CT brackets will bolt onto the iM knuckles with no issue and you won’t even need to bleed the brakes. The challenge here is rotor selection.

You can redrill the CT rotors to add the 5×114.3 lug holes and increase the hub bore to 64mm, which will allow them to fit on the iM hub. If you do this, you will also need to add spacers to the caliper bracket to center the caliper on the rotor since the CT and iM hub heights are different. Although this option is cheap, it isn’t very convenient to have the rotors redrilled and bored whenever they are replaced.

Another potential option is to use rotors from a 1991-1994 Toyota Previa. These rotors seem to tick all the right boxes and should bolt on to the iM hub and align properly with the CT calipers. Although these rotors look promising, the fitment hasn’t actually been confirmed.

The highest performance option is to completely swap to iM brakes. Just bolt on the massive 295mm rotors, calipers, caliper brackets, and dust shields from the iM and be done with it. If the pads and rotors need to be changed anyway, this option isn’t too much more expensive as the only additional parts are the calipers and brackets which can be picked up lightly used or refurbished for relatively cheap. This setup also makes brake maintenance a breeze, as there is no machining or mismatching of parts to get the setup to work.

Rear

Hubs

The rear conversion is dead simple. Toyota decided to use the same wheel bearing diameter and bolt spacing, calipers, and caliper brackets between the iM and CT200h. That means that the iM hubs will simply bolt on to the CT200h knuckle. Due to the different rear suspension, 2008-2015 xB hubs will be needed if you are doing this conversion on a Prius.

Brakes

The only difference between the iM and CT rear brakes is the bolt pattern of the rotors. So iM rotors will align properly without any modification. No need to change calipers, pads, or bleed the brakes.

However, the xB rotors are larger in diameter than the Prius rotors. You have the option to run the larger rotors with the xB calipers, brackets, pads, and dust shields. If you want to retain the factory Prius rear calipers, you will either need to redrill your rotors to 5×114.3 or purchase some Japanese market Corolla Rumion or Auris rear rotors, which will bolt on.

Parts List

You have a few different options when performing this conversion so the parts you need can vary, but your final parts list will probably look something like this:

Front

  • Knuckles (43211-12460, 43212-12410)
  • Lower Ball Joints (43330-19245 ×2)
  • Lower Control Arms (48068-12300, 48069-12300)
  • Hubs (43550-42010 ×2)
  • Dust Shields (47781-42040, 47782-42040)
  • Rotors (43512-42050 ×2)
  • Caliper Brackets (47721-42091, 47722-42091)
  • Calipers (47730-42091, 47750-42091)
  • Pads (04465-42180)
  • Bolts - Hub to Knuckle (91552-L1250 ×8)
  • Bolts - Caliper Bracket to Knuckle (90105-12208 ×4)

Rear (CT200h)

  • Hub (42450-42040 ×2)
  • Rotor (42431-12290 ×2)

Rear (Prius)

  • Hub (42450-12090 ×2)
  • Rotor (42431-12260 ×2)

Installation

Once you have collected all of the parts you need, installation is relatively straightforward.

The new front suspension can be completely assembled outside of the car.

Once that is done, remove the axle nut, tie rod nut, wheel speed sensor, and brake line - depending on what you have decided to do for front brakes. All that holds the front assembly in at this point is the 2 lower shock bolts and 2 inner lower control arm bolts, which will be reused.

The left hand side (US driver’s side) inner lower control arm bolt doesn’t quite fit out past the transmission. You can see the issue here:

You will need to grind a small amount off of the flange of the bolt to get it out.

On the other side, you will need to remove the entire oil filter bracket to get the bolt out.

Assemble the front suspension in reverse order. Don’t forget to put the spacers between the shock and knuckle, under the wheel speed sensor, and on top of the tie rod, if necessary.

The rear installation only requires you to unplug the wheel speed sensors and remove the 4 bolts from the back of the hub. Removing the hub from the knuckle can be difficult, but a few well placed hits with a large hammer and a pry bar should do the trick. Reinstall the new hubs and rotors, plug in the wheel speed sensor and you are done.