Timm's BMW E31
FITTING AN E36 STEERING WHEEL
There is absolutely no doubt that the designers at BMW excelled themselves with the interior design of the E31. It is the perfect match of form and function, a real work of art. Unfortunately, there seems to have been an awful mix up between BMW and Massey Ferguson when the steering wheel was added. Somewhere there is a farmer steering his tractor with a soft-leather rim and /M badge nestling in the lower spoke. Meanwhile, many E31 drivers are saddled with one of these:
One of the E31's I viewed had a steering wheel that looked a whole lot better. A bit of investigation on Ebay revealed that the steering wheels for the E31 even in poor condition were selling for £200. However, the wheel for the E36 looked exactly like the one in the E31 and these are available for £40, and there is a whole load of them on Ebay. So I bought these:
So, armed with a few tools and the new steering wheel in we go! The swap seemed as though it would be straight-forward but there were a few problems that needed to be solved on the way. As both steering wheels are equipped with an airbag there are certain safety precautions to take. It is extremely unlikely that an airbag will detonate, but just in case it does always store the airbag assembly upright. If it does go off, the airbag will be deployed, if stored upside-down the whole assembly will be launched at high velocity.
If you remove the steering wheel with the battery connected the airbag will be illuminated until reset with diagnostics. For this reason and for safety reasons the airbag is removed with both batteries disconnected.
You will need your radio code, if you do not have this then the radio will not work again when the batteries are re-connected. This is available from BMW but is a lot of hassle.
Here we go then, start by removing the carpeting that covers the batteries in the boot. The left-hand carpet (on RHD cars at least) has the emergency fuel-flap pull-cord, this needs to be separated at this joint:
Once separated, remove both carpets:
Don't disconnect the batteries yet, it is a lot easier to turn the steering wheel with the engine running. Adjust the steering wheel fully out and fully raised (I bet you're glad you haven't disconnected the batteries yet). Remove the lower screw on the steering-column cover:
The screw secures an expanding rivet that locates the cover to a square hole in the steering-column support:
Adjust the steering column fully down and remove the top cover screw and expanding rivet. The two halves of the cover can now be separated, it clips together quite tightly:
The lower cover pulls downwards, the upper cover is secured with these tangs. Pull forward, up and out:
Here are a few bits and bobs under the cover:
The airbag is secured to the steering wheel with two Torx bolts that are located behind the wheel:
Before the batteries are disconnected I am going to remove the securing screws fully as it is a lot easier to turn the steering wheel with the engine running. If the airbag does become disconnected I have Carsoft to reset the airbag light. You may wish to force the wheel rather than risk this:
Now it is time to disconnect both batteries. Always remove the negative lead only. Do not remove the positive, both batteries are in parallel and even the slightest touch of the positive lead on the chassis will cause all sorts of problems let alone the fact that the lead will weld itself to the chassis and not long later the battery will start to boil and then explode. Here's the right way to do it:
Wait 10 minutes before removing the airbag as the airbag system remains active until the internal capacitor storage has discharged. Disconnect the orange connector from the centre of the airbag assembly and remove the airbag, store it facing upwards. Make sure the keys are still in the ignition so that the steering lock is not activated and then remove the centre bolt. I had my mate hold the wheel while I did this as the bolt is pretty tight. Do not use the steering lock as it may be damaged:
Use an indelible pen to mark between the steering column and wheel:
This may seem like a waste of time as the wheel is being replaced but it is extremely useful if the column is accidentally turned, the original wheel can be fitted back on the splines to get the central position again. Get the steering wheel perfectly level in the straight-ahead position, Disconnect the airbag connector pair under the steering column and lift off the wheel, mine came off really easily.
It was at this point that it became obvious that the E36 steering wheel is not exactly the same as the E31 version! Sure, the splines are the same, but the E36 wheel has a 4-way connector with airbag and horn contacts:
Whereas the E31 wheel has only the airbag loom. The horn uses a separate slipring:
Fortunately the splines are the right size! I'm not put off and come up with a new plan, I'll remove the horn-slipring pogo to start with:
This leaves a perfect fixing for the new steering wheel loom! The next problem is that the locating pin which stops the rotation of the outer slipring is in the wrong place.....blast! So that's coming out too:
NOTE: The steering column switch bracket (the plastic moulding that holds the switches) is available in two forms, the one above has the locating pin on the right (32311159147), the other has it on the left (32311162088).
The latter successfully mates with the new steering wheel without removing the locating pin. Using the new part would simplify the installation - but both times I have done this I used the original bracket.
Here is where it is meant to locate with the slipring outer:
Before we go any further, the airbag slipring isn't really a slipring, it doesn't have pogo's and it doesn't have conductive tracks. It is a long ribbon cable (around 5-metres long!) that is wrapped a little like a tape-measure. The inner is connected to the steering wheel and the outer is connected to the loom shown above. This is important because the outer part of the slipring will rotate freely for around 6 turns and then it will stop. If the outer is not left in the correct position it will jam the steering wheel....and then the ribbon will snap.
For this reason the new steering wheel needs to be prepared with the slipring wound to turn number 3. That is, half-way through the 6 available turns. With the central bolt not fitted to the wheel-boss the slipring is locked and will not turn. To allow the slipring outer to turn this plastic clip must be pressed in:
Press the clip and rotate the slipring to the end of travel, then rotate it back three turns and then let go of the clip, the slipring will lock if the slipring outer is turned a few degrees.
As I cannot use the existing horn contact I will fit a connector-pair instead. It is possible to do this without a connector and instead wire it directly to the points shown later, it isn't really necessary, it just makes removal of the wheel easier. I used a Lumberg connector pair and soldered the BROWN wire to the in-line connector that was connected to the horn pogo. I soldered a large solder-tag to the BLUE wire. In retrospect it would have been just as easy to solder this directly to the steering wheel loom:
Note: The second time I did this I didn't bother with an extra connector, I stuck the Blue wire under the screw and eye on the steering column, I then chopped off the horn pogo from its in-line connector and soldered the Brown from the wheel to it. Much simpler.
With the steering wheel prepared, I disconnected the connector pair and pushed the loom through the hole left by the horn pogo:
I made absolutely sure the wheel was fitted to the column perfectly straight and then tie-wrapped the loom to the pogo hole. This stops the outer part of the slipring rotating so it is important that the tie-wrap is used:
I then reconnected the Lumberg pair and mated the BROWN in-line connector. I removed the Torx bolt on the ignition-lock assembly and fitted the BLUE wire solder tag under the bolt along with the existing earth wire. I then tie-wrapped the connectors neatly under the column, you don't want them rattling around in there:
Get your friend to hold onto the wheel and refit the central bolt tightly. Do not rotate the wheel until the bolt is in place as this will damage the loom or the slipring as the two are locked in position with the bolt not in place. Locate the airbag above the wheel and reconnect the airbag loom. Push the airbag assembly into the wheel.
Make sure all the connectors are in place and then refit the battery connections. Switch the ignition ON and make sure the airbag light goes out after a few seconds. Fire up the engine so the steering wheel can be turned and secure the Torx screws to fit the airbag in place:
Adjust the column so that the upper and lower housings can be refitted. Slide the upper housing in place as shown:
Once all the covers are back in place sit back and admire a steering wheel that suits the car!
And again, the 4-spoke swapped out with an E36 wheel (£30 from Ebay) on my new E31:
You will now have to enter the radio code, data and time, reset your seating position and save to memory and all is done.....Time for a cup of tea!