How to Build a Z3 Dual Arm Rest

With a trip to your local BMW dealership for one $25.00 part and a visit to your local Home Depot for another $20.00 in hardware you can construct this dual arm rest (uncovered) for your Z3 or ///M with simple hand tools.

This arm rest was inspired by my wife Sharon. I would be the driver, she would be the passenger and as I would raise my arm to shift she would steal the arm rest or as I would raise my arm to steer she would steal the arm rest. I decided to invent my Z3 dual arm rest. In doing so I have also come to learn that it is now possible to rest my elbow on the new arm rest while steering. This is not really possible with the OEM arm rest as it is to far away. I’m 6’4″ with long arms and people with shorter arms that have tested the dual arm rest prefer this arm position. So many thanks to my wife Sharon.

I have tried many different variations on this project and what I give you now is the best I have found to work. You have a few choices to make, such as, color of hardware and felt, painting it or dipping it and whether it is going to be leather covered by Jon Maddux at www.leatherz.com. It’s REALLY not that complicated once you read through the instructions and get a better understanding of what I’m talking about. My personal choice was brass hardware with a black felt covered forward bumper support catch that was dipped in black Plastic coat. Then sent to Jon M. at www.leatherz.com for matching tan cover with the word Roadster embroidered on it.

Generally speaking the parts will cost you anywhere from $34.00 to $42.00 depending on if you get a discount at BMW dealership, the choices you make regarding felt and plastic dip, sales taxes and what you may already have available to you. The tools on the other hand could add up to $150.00 or more. Then if you are sending it on to leatherz to be covered more $. Yeah, but it’s your “baby” right.

You will need to remove the cupholder assembly from your Z. The one in your car now is not the one we will be working on but will be replaced by the new . Note: there may be cases where the one in car is the one to be retrofitted. Anyway this is no big deal. We are talking about removing one screw or one nut and bolt. OK it is a tight spot but you can do it. There is even a great article on the www. leatherz.com site for removing the cupholder assembly. See Rachels excellent cupholder assembly instructions there.

If you are not having this leather covered (why in the world aren’t you) you may want to spray paint the top ring of the rivet nut and possibly both hinges black to match the lids. If you are doing an installation WITHOUT the rivet nut the top nut and lock washer should be painted or better yet plastic dipped black to match lids and prevent clothes catching on it. This nut REALLY bothers me especially if it’s going to be leather covered so I wish you would reconsider and do the rivet nut option.

Collecting the Parts

Start by collecting all parts and tools you will need. Here is the list.

1. Cup holder assembly BMW part # 82-11-1-469-516

2. 1 pair of 2″x 3/4″ hinges. National or simuilar with removeable pin in brass or silver (your choice). Home Depot # 218-995 (brass) # 218-979 (silver)

3. 1-Grip clip. Home Depot # 201-739, 4 to a package, only need one.

4. 1-7/8″ dia. bumper. Home Depot 3 524-062, 4 to a package,only need one. Black if you can find it but I couldn’t.

5. 1- 8″x 11″ sheet of felt (or less) with sticky back. Color of your choice. I got mine at Rag Shop in black, two sheets to a package. Home Depot -Felt Gard # 423-234. Choice of biege or brown in medium and heavy grade. I suggest medium.

6. Opinional. Plastic dip. Available at Home Depot in red, yellow and blue. I used black and got mine at local hardware and also available from Harbor Freight. This is to coat brown bumper black or cover exposed nut and lock washer in non- rivet, non-covered lid. Note: you can get away without plastic dip if you chose to leave bumper brown or paint it. But you should use it on non-nut rivet installations.

7. 1-Machine screw (1 1/2″ 10-24 thread) slotted round head in brass or silver (your choice)

8. 3- 10-24 nuts and 3- #10 lock washers (color match)

9. Loc-tite or Permatex nut lock (permanent type) only for non rivet nut installations. READ ON FOR MORE INFO ON THIS TYPE INSTALLATION.

10. Styrofoam ( the softer white that comes with everything. Not the harder flower arrangement stuff.)

***Part #’s are for reference only. Please make sure you get what is described.

Tools

* Drill

* 3/16″ and 17/64″ possibly 11/64″ drill bits

* Normal rivet gun

* package of 3/16″ with 1/4″ bite aluminum rivets

* *Rivet nut gun – This can be gotten via Harbor Freight for $20.00. It is a cheap(er) version of one that is available at Napa car stores for $114.00. Both come with the 10-24 nut rivet you will use.

* Razor knife

* Scissors

* Hacksaw with blade

For cupholder assembly removeal and installation:

* Allen wrench

* Metric or adjustable wrench

* I’ll tell you how to do it without this tool but it is much better with nut rivet!

Let’s Make It

DISCLAIMER: The writer of this article assumes no responsibility what-so-ever for this armrest. It is given to you as a do- it- yourself project and you and you alone assume ALL responsibility for it’s construction, installation and any possible damage to your vehicle in connection with it. Also note that it may be unwise or illegal to obstruct the hand/emergency brake. Again you and you alone bear full responsibility. READ ALL INSTRUCTIONS THOROUGHLY BEFORE PROCEEDING WITH THIS PROJECT.

First if your OEM arm rest has no metal rod in back for the rear lid, has only little rubber bumpers without plastic surrounding them and a rubber mat in storage compartment instead of nice soft material you have the “old style”, pre-1997, and I would highly recommend you use the new cupholder for this job. For everyone else why not use the new cupholder anyway since it’s unscratched and not in the car. Yes, you will have to remove the cupholder assembly in the car and replace with the hinged one you’ll make. I see no way to drill, align and rivet on the assembly while still in the car. It’s only one screw or one nut and bolt.

OK, Let’s begin to make YOUR Z3 dual arm rest.

If you are going to dip or paint the bumper stop DO IT NOW! Screw in 1 1/2″x 10-24 machine screw through bumper until it’s recessed under the opening and flush with bumper base. Bumper is not threaded so this will require a little force. Give bumper 2 coats of dip or paint. Try to keep dip off threads. Let dry overnight. Take lids off new assembly (un-hook o-rings). The lids in your car now will replace these on this side of cupholder assembly LATER. Remove with either a hacksaw or razor knife the lid latch tabs on both lids. Cutoff flush with lid side.

PUTTING ON HINGES

Pull the pin out of one of the hinges. Get some seperation using putty knife then use wide blade screwdriver to pry out. Align 2 barrel half with the back edge of assembly, get it lined up with lid and even with top edge. Mark holes and drill 3/16″ holes. Clean off any drilled material. Note: Line up back lid (SMALLER ONE WITH BOTH CORNERS CUT OUT) with outside edge of assembly. This gives a nice space between old and new lids. Line up hinge on lid and back of assembly. Make sure edge of hinge is even with both lid edge and assembly edge. This is very important to understand, pay close attention to this picture. First visualize that the back lid is on the top left hand side of the assembly (where I made the pen marking.) You need to line up the lid with that side in order to get space between the two armrests. Now you also need to align the hinge halfs. One on back lid and one on assembly. Take note that this hinge half is NOT centered in that assembly space so we can create that needed spacing BUT it will be centered to the matching other half of hinge. We do that by holding up the FULL hinge with lid on assembly and marking sides of top and bottom hinge. Now one more thing. When you get set to mark holes you line up hinge half with edge of assembly (this case) or in next case edge of lid. This is the model you follow for each hinge. VERY IMPORTANT!

Get rivet gun loaded with 3/16 rivet, place hinge over holes and rivet. Keep it level and flush (both assembly edge and hinge edge are flush.) **Please note these rivets touch the inside wall of the assembly when first inserted, pushing the rivet head away from hinge. With a light squeeze take up on the rivet so that it gets flush with hinge and only then finish snapping rivet. Take other 1 barrel half of that hinge and do the same to the back (2 arched cut outs) of rear (smaller) lid. Be careful to line up hinges and keep hinge and lid edges level and flush with each other

Follow the same proceedure. Remove pin from second hinge and use the 1 barrel half for the front (non arched cut out side) of rear (smaller) lid . Continue on by putting the 2 barrel half on the back (non sloped end) of the forward lid. Again be careful to line up hinges with each other and have hinge edge with lid edge and keep centered. Remember to clean off any excess drilling material. *SMALLER BACK LID SHOULD NOW HAVE A 1 BARREL HALF OF HINGE ON BOTH SIDES.

Next Step

This next step is for rivet nut installation ONLY! – Hole for and installation of nut rivet in lid

Drill 7/64″ hole in the front of front lid (large lid arch cutouts on sides) at this exact location (see picture). Hole is on the OPPOSITE side of where the arch cutout is. That is the driver side of armrest. Look at lid and you will see where rounded edge ends and flat top begins a straight line appears. Pencil (red in picture) a straight line on top of it. Do this on front edge and side edge. From front line measure in 3/8″ and place a mark and from side (non-arched side) measure in 5/8″ and place a mark. Drill a 17/64″ hole where marks meet. Clean away any drilling material. Load up rivet nut gun with 10/24 rivet nut and insert into hole, (put 10-24 nut on thread of arbor as block) squeeze nut in place. Note: I stripped 2 rivet nuts. (cheap rivet nuts??) The theaded arbor on rivet nut gun pulled right through. I suggest you thread arbor all the way through rivet nut and place a 10-24 nut on arbor thread to act as a block so arbor can not pull through. Be gentle but make sure nut is firmly in place. Feel and touch sort of thing!

This next step is for those NOT using rivet nut. – Hole for machine screw with nut on lid

Dril1 3/16″ hole in the front of front lid (large lid arch cutouts on sides) at this exact location (see picture). Hole is on the OPPOSITE side of where the arch cutout is. That is the driver side of armrest. Look at lid and you will see where rounded edge ends and flat top begins a straight line appears. Pencil (red in picture) a straight line on top of it. Do this on front edge and side edge. From front line measure in 3/8″ and place a mark and from side (non-arched side) measure in 5/8″ and place a mark. Drill a 3/16″ hole where marks meet. Note: If you have a 10-24 tap drill a 11/64″ hole instead and tap it. This will add some strength.

Felt and Grip:

Place grip onto felt and trace width of grip. Add 1/16″ to 1/8″ when you cut felt with scissors. I found it better to use one continuous strip from inside grip from bolt hole around both loops and back to other side of bolt hole (approx. 7″x 1/2″ ). Leave hole uncovered. Trace open sides (outside diameter) to exact size. Flip over grip and do other side. This makes a “butterfly” shape. One for each side. DO NOT COVER YET! Now place the grip on the Styrofoam and push grip into it to fill holes. My piece of foam was 1/4″ thick and I placed on ground and hammered on block of wood. Did this twice. This filled the cavities in grip. Cut off any extra so foam is flush with sides of grip.

Next Step

Bumper support catch for nut rivet installation:

If you have not done so already, remember dipping, thread the 1 1/2″ 10-24 machine screw through the bumper. After screw is all the way into the bumper ( screw head is recessed in bumper) put screw through hole in grip from the inside to the outside. Push bumper to be flush with grip metal. This can be very tight. You need to bend the grip a bit for bumper to get seated and you also need that bend plus a little more so grip guides onto hand brake and does not clamp it. It should have just some grip. This is a good time to test it on your hand brake. OK, now put on a #10 lock washer and 10-24 nut and tighten. Put another 10-24 nut and #10 lock washer onto screw about 3/4″ down. This is then screwed into the nut rivet on the front lid. The nut down the threads is to adjust height of arm rest to match other and then tightened to lock in place. ** You do not send this to Jon M. Put aside with your hinge pins. Remember where you put them! You can install this when they are returned covered.

Bumper support catch for non-nut rivet installation:

If you have not done so already, remember dipping, thread the 1 1/2″ 10-24 machine screw through the bumper. After screw is all the way into the bumper ( screw head is recessed in bumper) put screw through hole in grip from the inside to the outside. Push bumper to be flush with grip metal. This can be very tight. You need to bend the grip a bit for bumper to get seated and you also need that bend plus a little more so grip guides onto hand brake and does not clamp it. It should have just some grip. This is a good time to test it on your hand brake. OK, now put on a #10 lock washer and 10-24 nut and tighten. Put another 10-24 nut and #10 lock washer onto screw about 3/4″ down. This is then screwed (if tapped) or put through hole on the front lid. The nut down the threads is to adjust height of arm rest to match other and then tightened to lock in place. If there is extra screw protruding out top cut of with hacksaw and grind /sand. Use permanant lock thread compound on top nut and thread to help prevent it coming off. If you are not and perhaps even if you are sending lids to be covered I’d suggest you use plastic dip on top nut. Tape around it leaving a little hole cutout enough for dip to attach to lid and then coat nut. Let dry and razor cut dip in circle shape. If you are sending this to Jon M for leather covering YOU MUST SENT IT ATTACHED WITH LIDS. He will cover over that nut and washer.

CONGRATULATIONS! YOU ARE DONE.

Well I don’t know about you put but I sure would want to test this out in my Z. It takes minutes to exchange the cupholder assembly in your car PROVIDED you take your time AND do not drop the nut into the well. Go to www. leatherz.com and read Rachels how to install cupholder assembly. My first experience in removing the assembly I encounter “old style” anchor screw (see picture in extra picture section) that just keep on turning and turning. Finally I lifted up on back of unit and forced it up. New style gives bolt and nylon lined nut. That nut is what you DON’T want to drop. It’s a tight fit but I haven’t dropped one yet. I would suggest to you, DO NOT put on the nut for testing out your new dual armrest. Just the bolt in hole and tabs in front will be OK for now. Plus nylon lined nuts are meant to be screwed on ONCE. Have Fun!

Final notes:

You need to talk to Jon Maddux concerning filling the front corner. Originally I had all 4 corners filled with Styrofoam. When Jon went to cover it his glue dissolved the Styrofoam. Jon made up wood corners for my arm rest and covered it. This was alot of work for Jon and also caused some “stacking” problems with the leather. We feel it is best if only the front corner is filled. The back two you don’t see and the other front lids back corner is on the side facing the other arm rest and will also be unnoticed. Besides Jon does great work on the regular corners and it may well look fine with out ANY corners being filled.

When you put lids on assembly for “final” time push pins in all the way. this takes out some play in them. This is a little tough if assembly is in car but I use a pair of wide channel locks and squeeze pin in WHILE supporting lid and hinge with my other hand. You will find it is also a little harder now that it is leather covered. You will also notice arm rest unit is less wobbly. A putty knife blade will seperate pin from barrel enough to get a wide blade screw driver in that space to remove pins.