Cracked sport seat hinge gearbox - first prototype ready

tn535i · Post by **tn535i** » Mar 10, 2017 6:02 PM

And isn't it interesting that it's still worth the effort of finding solutions to problems you would never have encountered if it wasn't worth keeping the car going for so long in the first place.

Just last night in parking lot (Harbor Freight btw) some guy said to me, "I had one of those cars once and loved it and should have kept it".

Pattonky · Post by **Pattonky** » Mar 10, 2017 6:35 PM

I am interested in this as well.

BenGerman · Post by **BenGerman** » Mar 11, 2017 7:32 AM

There is so many great fixes and mods for this car that got started on this board.
If there is a problem that can't be fixed easily and parts are hard to find, somebody will get so annoyed that he will start looking for a new solution. This is what happened here.

I don't think this will happen to a lot of newer cars in 20 years.

We are still working on the program and figuring out the details but I should have a cost estimate within the next two weeks.

Yojedi · Post by **Yojedi** » Mar 11, 2017 7:20 PM

BenGerman wrote:There is so many great fixes and mods for this car that got started on this board.
If there is a problem that can't be fixed easily and parts are hard to find, somebody will get so annoyed that he will start looking for a new solution. This is what happened here.

I don't think this will happen to a lot of newer cars in 20 years.

We are still working on the program and figuring out the details but I should have a cost estimate within the next two weeks.

jon roll · Post by **jon roll** » Mar 11, 2017 9:49 PM

I'm interested

Brian O · Post by **Brian O** » Mar 12, 2017 1:50 PM

Cant wait to see these available. I need two!

BenGerman · Post by **BenGerman** » Mar 18, 2017 12:13 PM

Pauly Walnuts · Post by **Pauly Walnuts** » Mar 18, 2017 4:40 PM

This may have been asked but I'm assuming the passenger and driver's side are the same?

BenGerman · Post by **BenGerman** » Mar 18, 2017 6:05 PM

They are both the same. There is a left and a right piece.

Brian O · Post by **Brian O** » Mar 18, 2017 11:36 PM

Any chance you will be doing the other half of the gearbox?

BenGerman · Post by **BenGerman** » Mar 19, 2017 12:32 AM

We have thought about it, but it requires quite a bit more machining.
The integrated gear set would be hard to do for a reasonable price.
I have an idea how to avoid it, but I will not have time to take care of it before later this summer.

So the answer is: maybe, but not in the beginning.

Do yours break in the back, where the transfer cables attach? Do you have a picture of the defect?

Brian O · Post by **Brian O** » Mar 19, 2017 1:18 PM

Yes it is where the cables attach and turn the plastic gears. I would love to hear a workaround

I'll post pics tonight

Here is the pic of one of the broken ones. [img][http://s44.photobucket.com/user/Brianeh ... ml?o=0/img]

BenGerman · Post by **BenGerman** » Mar 20, 2017 4:53 PM

I mounted them on the seat last night, super easy.
Will do the same thing in the car next week and check how they work.

There should available capacity on the machine by late April.
We also have a pricing figured out. I will make that official as soon as the plates have been tested on the road.
Is not a super cheap fix but way cheaper then buying the whole assembly or getting a used seat for it.
Plus you won't have to worry about them braking again.

They will by anodized dark grey or black.

duggi · Post by **duggi** » Mar 20, 2017 5:18 PM

Consider me impressed! When this thread first started I'll admit I was a bit skeptical, but damn, nice job! My driver's seat had this issue at some point before I got it, as it has a replacement gear box on it already with a more modern BMW sticker, but I'm sure the others will need attention eventually.

Now..next problem: is there any effort being made to reproduce the plastic covers that hide these boxes?

(fwiw that was a total joke, you've done more than enough just doing this!)

tn535i · Post by **tn535i** » Mar 20, 2017 8:13 PM

Very very nice work by the OP.

I guess those plastic covers can be 3D printed by someone.

Yojedi · Post by **Yojedi** » Mar 20, 2017 8:19 PM

tn535i wrote:Very very nice work by the OP.

I guess those plastic covers can be 3D printed by someone.

That's a really good suggestion. Since the 3D model is now available would the OP mind getting a quote for 3D printing? Could be a "possible" low-volume, low-cost option but don't quote me.

BenGerman · Post by **BenGerman** » Mar 20, 2017 10:04 PM

Thanks guys!
It still needs little adjustments here & there but thats why they are prototypes.

tn535i wrote:Very very nice work by the OP.

I guess those plastic covers can be 3D printed by someone.

Yojedi wrote:That's a really good suggestion. Since the 3D model is now available would the OP mind getting a quote for 3D printing? Could be a "possible" low-volume, low-cost option but don't quote me.

I think we are talking about two different things here. The actual gearbox plate that I machined and the plastic covers that go on the outside to cover the gearbox. (who would want to cover some shiny aluminium anyway, haha)
I was thinking about 3D printing before but I don't think a material that will be strong enough is actually a lot cheaper than machining it.
Maybe I will find some time later to contact a couple places. For now we have all the soft jaws made up and everything in place to machine them.

Potentially by the end of summer/fall there could be a solution for the back side of the gearbox as well.

Yojedi · Post by **Yojedi** » Mar 21, 2017 5:06 AM

BenGerman wrote:Thanks guys!
It still needs little adjustments here & there but thats why they are prototypes.

I think we are talking about two different things here. The actual gearbox plate that I machined and the plastic covers that go on the outside to cover the gearbox. (who would want to cover some shiny aluminium anyway, haha)
I was thinking about 3D printing before but I don't think a material that will be strong enough is actually a lot cheaper than machining it.
Maybe I will find some time later to contact a couple places. For now we have all the soft jaws made up and everything in place to machine them.

Potentially by the end of summer/fall there could be a solution for the back side of the gearbox as well.

BenGerman, nevertheless kudos for undertaking such project. As most of parts for E28 are already NLA these 3D models you are constructing will be invaluable to the preservation of these fine German specimens and our community.

BenGerman · Post by **BenGerman** » Mar 21, 2017 11:40 PM

Negotiations with the machine shop are completed.
I started a group buy thread here:

http://www.mye28.com/viewtopic.php?f=4&t=143376

I will keep this thread updated with pictures and a install video.

BenGerman · Post by **BenGerman** » Apr 25, 2017 6:41 AM

We got 14 pieces together, I'm about to place the order with the machine shop.
If you still want one, let me know until 8pm ET tonight.

tn535i · Post by **tn535i** » Apr 25, 2017 2:36 PM

I was looking at the gearboxes on my 6er's driver's seat last night which is out of the car and they look perfect to me. I'm unsure how the box gets so much stress to crack but I trust you that they can. I remember my driver's seat somehow the two sides were clocked wrong when I got the car with one side leaning forward of the other. It really bugged me and felt different than the passenger seat until I discover and fixed that. I'm thinking it was mostly due to things being loose.

This part is so well executed I almost want some for that reason alone. I will take a much closer look at mine tonight and decide.

BenGerman · Post by **BenGerman** » Apr 27, 2017 12:38 PM

Thanks for the compliments again.

If yours are not cracked, that's awesome! It probably also has to to with the previous owners: how often it was used, weight,...
I will send everybody that was initially interested a mail, since I would like to close things by tonight.

Raw material is in stock and there is a slot in 2 weeks on the machine that I would like to use.

The final part will be black anodized.

I will bring some with me to the Vintage.

Post by **tig** » Apr 30, 2017 7:14 PM

I have aluminum over this (that's like wood, but more metal).

Take my money! Seriously.

BenGerman · Post by **BenGerman** » May 01, 2017 8:39 PM

cek wrote:I have aluminum over this (that's like wood, but more metal).

Take my money! Seriously.

I can make you one out of wood for your money?!

ElGuappo · Post by **ElGuappo** » May 02, 2017 12:17 PM

This is sofa king cool.
I love these modern solutions to old problems.
For a while it seemed like everything had been figured out on these old girls...

BenGerman · Post by **BenGerman** » May 04, 2017 12:35 PM

Thanks for all the good feedback. I'm glad stuff like this is appreciated!
Only because of the interest and amount of parts that we got it was possible to produce these goodies for a reasonable price.

I'm always up for new solutions on stuff like that.
I'm about to close out on the orders tomorrow, by next week I will have a anodized sample for pictures.

If something similar ever comes to somebody's mind, I can see if we can realize it again.

I will have a couple samples with me at the vintage!

BenGerman · Post by **BenGerman** » Jun 11, 2017 7:56 PM

All the plates have been sent out two their new owners. Again, I'm sorry for the delay caused by the plating process.
I hope everybody is happy with the outcome. Let me know if you have any issues mounting them.
Thanks again everybody for making this happen, without I would still be sitting sideways in 2 of my seats.

Here are the instructions. I tried to cover it in a video, but it didn't work the way I wanted int to. I think the pictures are easier to follow.

Please remember that these are tips from my side, I will not be responsible for any damages caused during the steps of this manual or afterwards.

You need:

17mm
7mm
6mm
4mm
3mm Allen
Flat head screwdriver
Knive
Plenty of rags
Cold Beer

Bring seat in a position where you can easily reach all the bolts.
Remove seat belt.
Remove plastic cover nut (that is missing in all of my cars

).
Pull off cover

Remove 4x7mm Hex screws
Carefully pry work your way around the front cover with a small flat head screwdriver, do not lever to hard one one side, or you will break the plate in half

Be careful not to loose any of the 4 plastic guides or the washer setup, take them off the plate, clean and place in their position. The grease will hold them.
The washers go on the worm gears in the bottom. Order: metal, rubber, metal.

Time to Press out the bushings:
Place the 17mm socket under one of the big bushings to support, use a 6mm socket from the top. A couple of gentle hits with a plastic mallet should break them loose.
Repeat for second bushing.

Place the socket below the red plastic bushing in the bottom of the plate. Using a 4mm socket, repeat as before. These usually can be pressed out by hand.

Take the new aluminium covers, place them on a soft surface (rag).
Start with the two big bushings, gently tapping them in with a plastic mallet. Make sure they stay straight. It takes a little bit of force, to get them back in.
Press the two red bushings in by hand.

Time to get the leftover grease of the old plate. The grease should be in great shape, I decide not to replace it. If you do so, please remember to take a grease with a really high drip point. It gets hot in these cars in summer and the last thing you want is grease dripping on your nice carpet.
Place the leftover grease around the seat gears, don’t forget the two little plastic gears in the bottom.

Place the new plate on the gearbox, make sure all the plastic pieces and washers from the beginning are still in place. Make sure you align all the 4 shafts that go into the bushings. Press it onto the shafts by hand. You might not be able to fully seat the front plate. No worries, the bolts will take care of this in the next steps.

Take 4 of the M4 stainless bolts out of the bag, place them in the holes and use a 3mm allen to tighten them down. As usual, don’t tighten one screw down all the way, as the plate needs to be seated. Work your way around the plates a couple of times.
Wipe out the leftover grease out of the busing holes.

Now it’s time to modify the plastic cover, probably the “scariest” step of all. Place the plastic cover on a soft rag.
Take a thin blade and slowly cut your way through the three main “ribs” of the back side. Do this in multiple slow steps, not to break the plastic cover. I modified all 12 of my covers without breaking one.

Place the modified plastic cover over the plate, make sure to align the top threaded bolt with the “guiding rod” on the back of the plate. Tighten down the nut.

Mount the seatbelt back to the seat, make sure to align the little tab with the hole in the seat.
Tigthen the bolt to spec with NM. Remember, the seatbelt is safety critical, you don’t want to realize in a crash that the bolt was not tight to too tight and the seatbelt comes loose.

Repeat 4 more times for the remaining covers.

Open Cold beer and enjoy it in your car seats.

dan101smith · Post by **dan101smith** » Jun 14, 2017 11:35 AM

Having almost rocked myself to sleep on the drive to Le Mans today, please let me know if you're doing another run as I'd like to order. Thanks!

BenGerman · Post by **BenGerman** » Jun 16, 2017 7:28 AM

I have already arranged getting a second batch made, but we have not timed it yet.
Before we do that I would like to have more feedback of the first round buyers.

BenGerman · Post by **BenGerman** » Jan 19, 2022 12:52 PM

Since I keep getting requests for these from time to time...

I won't have the time to organize another group sale.

If anybody wants to take the lead and organize a larger batch, I can still have these made at a minimum order quantity of 20 plates (10 left, 10 right). Price will be $100 a plate with about 3-4 months lead time.

TroyArboc · Post by **TroyArboc** » Jan 19, 2022 4:25 PM

I would be very, very interested (in a few sets) should anyone else take the over and move forward with a group buy.

BenGerman · Post by **BenGerman** » Jan 19, 2022 6:55 PM

Let's give this a month or two and we see how it goes.

lswoboda · Post by **lswoboda** » Jan 19, 2022 7:20 PM

I’d be in for a set (whatever I need for both front seats).

To be clear, this fixes the “rocking” that affects (plagues?) our cars, correct?

Btw, the “how to” by BenGerman is excellent! Very clear and well written. Thank you for all your efforts.

Thanks.

TroyArboc · Post by **TroyArboc** » Jan 27, 2022 10:29 AM

jayjaya29 · Post by **jayjaya29** » Jan 27, 2022 1:21 PM

In for 2 sets as well if it happens.

TroyArboc · Post by **TroyArboc** » Jan 31, 2022 12:07 PM

jayjaya29 wrote: Jan 27, 2022 1:21 PM In for 2 sets as well if it happens.

Halfway there

BenGerman · Post by **BenGerman** » Feb 01, 2022 9:08 PM

Might be worth sharing in the Facebook groups and on Bigcoupe?
The E24 has the same issue.

joema · Post by **joema** » Feb 02, 2022 12:30 AM

I'm in for a set too, if/when it becomes available.

Badger · Post by **Badger** » Feb 05, 2022 1:53 PM

I would be in for a set for both front seats also.

Mike W. · Post by **Mike W.** » Feb 05, 2022 8:11 PM

Is the rocking the entire seat assembly or just the back to the seat cushion?

TroyArboc · Post by **TroyArboc** » Feb 07, 2022 9:11 AM

Mike W. wrote: Feb 05, 2022 8:11 PM Is the rocking the entire seat assembly or just the back to the seat cushion?

It could be a combination of things but the most common cause is cracked motor casings.

charofire · Post by **charofire** » Feb 07, 2022 10:39 AM

Count me in for a set. Thanks!

elcrazon · Post by **elcrazon** » Feb 21, 2022 11:38 PM

Interested in two sets, if this happens

BenGerman · Post by **BenGerman** » Mar 01, 2022 4:06 PM

Alright, let’s do this.

Closing date for orders is 3/15/22. Write me a PN with:

Your Name
Your address
How many left and right pieces you want

lswoboda · Post by **lswoboda** » Mar 06, 2022 1:05 PM

Sent PM. Thank you!

BenGerman · Post by **BenGerman** » Mar 07, 2022 10:02 PM

Anybody else? Haven’t received a PM from everybody that was interested yet.

Chimi-Changa · Post by **Chimi-Changa** » Mar 08, 2022 8:41 AM

Let me know when you make manual sport seat parts! ( You know how my seats are...)

Northeast OH?

SharKnows · Post by **SharKnows** » Mar 08, 2022 9:40 AM

I would like a set for my drivers seat . Tried sending you a message Ben but I couldn’t get it to work, maybe because I’m in my phone

Badger · Post by **Badger** » Mar 08, 2022 10:00 AM

Sent one earlier!

BenGerman · Post by **BenGerman** » Mar 11, 2022 5:33 AM

Got some PMs. Will Follow up in a few days with details.