Steering Wheel Spacer / increase Telescoping

[sgray944t]

Status report:

• I've ordered the physical spacer from Italy, once that gets here I'll give it a test fit. I've messaged back and forth with the owner of spacershop quite a bit. He's been very helpful and is confident this will fit. I'll take plenty of photos of the assembly process once it arrives.
• Wiring: I've ordered 3 or 4 connectors (male and female), and ultimately spoke to both the distributor and manufacturer of the Yellow steering wheel connector, and their office in Dearborn, MI. Good news is that I 100% have found and purchased the same yellow connector. Bad news is that there is no stand alone male connector that fits the "key" type of the yellow connector. It's manufactured exclusively to marry with the clock spring. There is a Gray connector that is also identical to the yellow, but has a different "key" type, so unfortunately its of no use. Further than that, even the male connector that fits the grey plug is made to be soldered directly to a motherboard, so the male pins are not removable/adjustable and aren't mean to have wires crimped to them.

So from a wiring adapter standpoint, my goal to extend the stock harness ~3 inches, with as minimal modification, minimal cuts and splicing, leaving it as OEM possible. My plan there is:

• Re-use the oem female terminals that are crimped onto the wire.
• Rather than use my OEM harness, I'll buy a brand new one (they are not expensive), and modify that. This way I always have the stock harness to revert back to.
• I will test the resistance through the harness, comparing both OEM and my extended version.

The process will basically be:

1. From the new OEM harness - de-pin the yellow connector by removing the female terminals. This is super easy, having done it on my test harness and the new yellow connectors I bought.
2. For each wire, I will cut the female terminal off right at the end.
3. From my donor harness, I will also de-pin the yellow connector and cut the wire, but this time I'll cut the wire about 2-3inches back from the female terminal. This will act as the "extension" that will be added to the new OEM harness.
4. I've been researching crimp vs. solder and the best way to splice the extension wire onto the new OEM harness. It appears Mercedes sells a splice that has solder inside and it shrinks up to make a watertight seal. That is actually the repair that they authorize on their own SRS systems, so I'm leaning this direction. That said, this is the only piece of the puzzle I'm still researching. My goal is to have a splice that adds the least amount of resistance to the circuit as possible.
5. From there its pretty straightforward, I'll be able to simply re-insert the female terminals from the extension part of the harness into the OEM harness yellow connector.
6. The only other unknown is what the physical pass-through of the hub adapter is like, if I need to secure the harness inside the adapter at all, etc. TBD once I receive that.

Totally open to any feedback / suggestions. Especially around the type of splice to use, but from initial reading that seems to be like religion to people (solder vs. splice).

I'll update again once I receive the physical adapter and get the splicing figured out.

 

[TheGBKid]

Saw your latest response and I've used these in car audio (high end) and they seem to be of very high quality. I'm not seeing any additional resistance after using them. Not a reseller or shill, just a guy that's used them. This sounds like a really cool project - good luck in finishing it up!

Solder Stick

 

[sgray944t]

Saw your latest response and I've used these in car audio (high end) and they seem to be of very high quality. I'm not seeing any additional resistance after using them. Not a reseller or shill, just a guy that's used them. This sounds like a really cool project - good luck in finishing it up!

Solder Stick

Thank you for the link!

Those are extremely similar to the Mercedes style. Glad to hear positive feedback from someone who has used them before.

 

[nordique14]

Fantastic work so far. Your follow up with the suppliers is wonderful.

I think you are on the right track with buying an extra harness and using that. As long as the splicing is good then it will be fine to use with or without the spacer. This assumes that the connector can fit through the spacer.

Please let us know as soon as you determine the spacer fits. I will then also order one along with a spare harness. I think the wiring problem is solvable. It just depends on how easily it can be put back to stock afterwards.

 

[sgray944t]

Update:

Still waiting on the physical spacer, but I’ve made the extended harness.

For my car (2023 CT5 BW Manual Trans) I confirmed with the dealer the part number for my steering wheel harness is: 85136942. It’s a little tricky as there are a number of superceded numbers and online parts stores often pull up a CT4 harness and it’s unclear if they are an exact match.
Interestingly, the Lemons free service manual that’s been posted elsewhere in the forum does not accurately show the pinout for my car. I ended up popping off the airbag on my car and comparing the X85 (yellow connector) and it matches 100%.

With that, I did a bunch of reading on the best quality, ie least resistance adding, non-insulated butt splices. Ended up with these Thomas & Betts which are probably 10x the price of what you’d get at the hardware store, but figured it was worth it given the sensitive location and possibly airbag implications (more on that in a sec).

I also got some good feedback on the NAPA adhesive lined shrink tubing, so grabbed that along with a ratcheting crimp tool.
Then just for added measure, found a $9 brand new, unused, steering wheel harness for a 2021 Sierra on eBay. Figured I could use it for some extra wires. Was hoping the coloring matched up, but it was mostly different so I ended up only using a few. If you’re going to buy a donor harness, I’d recommend a CT4/CT5 so that the wiring colors match up.

From there it’s pretty straightforward about 10-15 wires to extend. I depinned the terminals from the yellow connector, cut the terminal off, then depinned a donor x85, cut its wire about 3 inches back but left the x85 terminal, and crimped this donor piece onto the new harness. That way I didn’t have to deal with also crimping the very tiny terminals.

For the airbag - good news is that I think I might get away NOT needing to touch those wires. Looking in my car and at the bare harness, they may be long enough to work with the spacer as-is. That would be great, but even if it needs extending I’ve tested the crimping and it’s not adding any measurable resistance to the wires.

Here’s a few pics of the prototype and tools, now I just need the spacer to see if any of this was worth doing .

 

[GearUp72]

I am a new 2026 CT5 V BW owner. I am a little shocked at the poor range of the telescoping steering wheel. I am 6'2'' and luckily I have long arms. I did the Spring Mountain course on the C8 and I remember the instructors taking some time to ensure the students had the proper wheel position - this does not even come close. I enjoy reading the efforts made to get some more travel but it seems more in depth than I would go. My question is if the mods made to add a spacer would impact the operation of the air bag in case of a crash. Would it be to close to the driver or is the bag made to inflate a little larger since the wheel is farther away from the driver's head?

 

[sgray944t]

The way I think about is this:
The airbag is designed and tested to inflate at a range of distances from an occupant. That includes very short individuals who sit extremely close to the wheel, and very tall individuals who sit 4-10 inches further away. We are talking about adding a 2inch spacer behind the wheel itself, so all this would be doing for a tall individual, is returning the airbag to a more average / proper distance from the occupant. I’m 6’7 and have to sit too far back, so this spacer will allow the airbag to be the same distance from me as it would someone 6’0.

For those reasons I’m not concerned about the airbag functionality, and ideally we aren’t even touching those airbag wires.