Manual Sport Seat Strut Replacement

[wkohler]

I'm trying to replace all 8 seat struts and I cannot for the life of me get these things to compress. I've spent about 4 hours trying various methods. Nothing is happening. The height adjustment struts have to be compressed about 2" and the backrest ones only about a 1/4", and I can't even move those.

[mooseheadm5]

How many Newtons are they?

[wkohler]

300 and 350. Two different types

[mooseheadm5]

70-80lbs. Hmm. Have you got any giant channel locks?

[wkohler]

I cannot find anything with an 8" jaw opening. I've tried bar clamps, but they don't work well.

[mooseheadm5]

I have some at the shop, but that won't help you much. Have you got a big vise? If so maybe you can compress them and use a zip tie through the holes to keep them compressed. After that you can remove them from the vise and use a band clamp to keep them compressed. Then, cut the zip tie and install the struts.

[wkohler]

Holy shit. Let me give that a shot.

[wkohler]

I decided to try the thing I had just purchased before trying the vise idea. Turned out the thing worked.

I bought a 12" Irwin Quick-Grip bar clamp:



I didn't buy that initially because I was worried about clearance, particularly on the seat-back strut. Also, with so much plastic, I didn't trust it, having had these break on the job, but I decided that if I have to die, I might as well die in doing one of the absolute least-fun things on the planet, which would be a fitting end for me.

I also didn't realize that those had considerable amount of clamping force. I figured the mechanism would start slipping.

I had been following this write-up:

http://www.strictlyeta.net/technical/seatshocks.html

Yeah, it sounds okay - except for the part about using your hands to put them in. I had a few different types of screw clamps (bar clamp, C-clamp, etc), but they didn't work since the strut just wanted to move around and would never actually compress. Another issue is that the new struts are the fork design on one end, so It's not very friendly to clamping off the seat, then sliding on like the old ones. Not really understanding that.

I also removed the seat back since it seemed stupid to try to work in that tiny space and I know my way around these seats.

Anyway, I bought that bar clamp this morning, and it occurred to me that I was worried about the space constraint for nothing since I could just simply remove the hinge assemblies. I got out my circlip pliers, then realized that it wasn't even necessary to do that. All I had to do was unlock the rear of the hinge (after removing the seatbelt bolts) and pivot the hinge assembly forward, which allowed me trouble-free usage of my bar clamp.

One seat is done, the other to go.

[TSMacNeil]

pickchurz when you can.

[wkohler]

pickchurz when you can.

What do you want pictures of? The clamp does differ slightly from that stock photo.

I guess I could have photographed the $400 in struts needed to do this job (8 total).

[TSMacNeil]

pickchurz when you can.

What do you want pictures of? The clamp does differ slightly from that stock photo.

I guess I could have photographed the $400 in struts needed to do this job (8 total).

I have the baby versions of that clamp...
I guess I should just see seats in person when I get off my trip.

[Karl Grau]

I just did mine using the Chris Kohler method. The backrest ones weren't too bad but doing the the seat base ones made me askeered like a little girl.
The backrest shocks are strong enough to launch the neighbor's cat from my backyard to the beach.

[WilNJ]

The backrest shocks are strong enough to launch the neighbor's cat from my backyard to the beach.

[Karl Grau]

[gaberdee]

It's called a catapult for a reason. Are you guys replacing these with OE or aftertmarket struts? I currently have a source for OE replacements, but was curious to know if there was a better option. The ebay and google searches I've done (i.e. "e28 manual sport seat struts"or "bmw seat struts") either links to suspension components or motorcycle parts.

So I assume there's not much else out there, but please let me know if I'm wrong.

Thanks in advance,
Gabe

[Karl Grau]

The dead, worn out ones that seemed like they had been on the seats for decades were Stabilus Lift-O-Mat and that's what I used as replacements. SG402006 & SG402005.

[Maaaate]

http://www.mye28.com/viewtopic.php?t=63114&highlight=

[stuartinmn]

http://www.mye28.com/viewtopic.php?t=63114&highlight=

Thanks for the link - I've been looking for that post for a while. I need to replace the struts in my sport seats as well.

[DJM1986-5]

I'm adding to this post....thank you Chris Kohler for saving me a ton of time and frustration....I purchased the 300# Irwin clamps in 12" and the 100# in 6 inch...just to have. I replaced the shocks without removing the seats - took the seat caps off the sides and removed the seat belts from the base.

On the lean back shocks, I placed the shock on the bottom pin first - that's a tight fit against the leather seat bottom, then used the horizontal leanback frame rail (just above the bottom pin) as the bottom fulcrum and clamped down on the top of the shock with the smaller, 100# clamps. Took me several tries, but I finally took off the rubber clamp cover which allowed me to compress the shock in the tight quarters and push it onto the top pin. Using that method, it took me about 10 minutes per shock. If the shock slips off the clamp, it goes nowhere as it's secured by the bottom pin.

On the vertical height shocks, I used the bigger, 300# 12" clamps. Install the shock on the top pin first. Then turn the clamps upside down, opening towards the front of the car. Remove the rubber clamp cover from the end (bottom end closest to the floor) that will be pushing the shock into place. The plastic has a waffle pattern in it which was perfect to keep the shock tip engaged while compressing. Once compressed you can easily push the shock onto the lower pin. This was done of course with the seat raised in the top-most vertical position. And if anything slips, the shock goes nowhere as it's secured by the top pin. The vertical height ones took 15 minutes (learning curve to figure angle and positioning for the first side - the inboard side) and 3 minutes for the outboard side, each seat.

And thanks again to Mr. Kohler for saving all of us a bunch of time. All 8 shocks were right at about $250 from BMW.

[Karl Grau]

All 8 shocks were right at about $250 from BMW.

Wow, they've really gone down in price.

[John in VA]

"jeffnhiscar" over at R3VLtd has received his struts & has sets for sale. Each set of 4 (enough to do one sport seat) includes 8 push nuts which ECS sells for $1.50. All orders include 2 day flat rate priority post and PayPal fees.

1 set $80
2 sets $150

http://www.r3vlimited.com/board/showthread.php?t=379102

[ovide]

We have them in stock as well since January.



Normal price is €19 each, a set of 4 would be €76 ($84), but I have them discounted for boardmembers at only $75 including all new securing clips!

http://www.e28.nl/product/e30-e28-e24-e ... 101965645/


I can also bring sets to the St. Paddy’s day event/gathering around March 18th.

[davintosh]

Sorry to dredge this thread up from the depths; I just finished this job, and thought I'd add my experience.

I bought a set of eight struts from https://bmwseatshocks.weebly.com/order.html , and judging by the banner that was on the page yesterday, I got his last set; out of stock until next month. The web page at that link has links to eBay where you can buy a set of 4 for $55 more, or a set of 8 for $60 more; they must be MUCH nicer than the ones you get directly from that link.

One thing that seemed a little out of the ordinary though is that the struts I got were all identical. The originals had different spring ratings for the lift and the recline struts. I'm guessing that that was intentional; there's only a minor difference between the two items -- 300 Newtons on one and 350 on the other -- and by selling just one item he's able to reduce costs.

The job turned out to be easier -- and less dangerous -- than I expected. I ended up with a little gash on my left hand from the screwdriver that got loose while prying one of the old push nuts off, but that's the only casualty. Using the Kohler Method with the 12" Irwin Quick-Grip clamp, I had all eight of them done in less than an hour, and that included pulling the seat back off of one of them.

I had the seats out of the car for the job; not sure how much more difficult it would be with them in the car, but just having them on a bench where I could see things without having to bend over/crawl around made it worth the time to take them out of the car. Getting the lift struts onto the two studs was pretty straightforward, but had to futz around to get them to line up properly without the clamp getting in the way; just a little trial and error. The recline struts were trickier because one end has the seat padding & leather in the way; I just mounted that end where it belonged, then braced one side of the clamp under the seat below where the strut attaches, squeezed the strut down, and then pivoted the clamped strut up to where it attached.

I haven't sat in the seats to try them out yet -- still working on the Leatherique treatment -- but it's good to just have the job done. I'm already liking the fact that the seat back doesn't just flop down.

[LeiseyJr]

I need to do this soon.