Window regulator stoppers.

Layne

Layne

Well-Known Member
Site Donor
Messages
292
Reaction score
74
I thought I'd buy all new ones since they are hard and cracked, but I notice there's two different parts. One with a spring 51 33 1 837 518 and one rubber-only, which is NLA 51 37 8 545 198. I don't know how many of each are needed or which positions take which bumper. I found some generic replacements for the solid rubber stopper on McMaster.com but they come in "hard" or "soft". No actual hardness spec is given. I'm assuming "hard" would be more appropriate. What do you think?
 
My mistake, they do tell the specs. Soft is durometer 40-45A, hard is 75-80A. There's also another type at 50-55A, but they are larger and would probably need the diameter reduced.

80A is pretty hard, the same as a lot of polyurethane suspension bushings. Might be too much.
 
So the ones with the spring, do I need those? Or just use 8 solid rubber bumpers?

51331837518.jpg
 
Last edited:
I replaced mine last year. NO SPRING.

I found that one rear on each side needed a longer stud, both in acceptable condition, so didn't replace them.
I have an early 2800cs.

While you are doing this , consider also replacing the door activated light switches. You need 2,
one side is a single electrode and the other is a dbl.
 
I ended up using McMaster part # 9546K212 which does not have a stud on it, but a threaded hole in it. They only offered studs up to 16mm long, and my old ones were 30mm long. So I also bought part # 92605A138 a 35mm set screw, and put them into the bumpers with loctite (5-ish mm's goes into the bumper, 30-ish sticks out). I had forgotten about Steve in Reno saying that two had longer studs. Hopefully 30mm is good all around, but they can be swapped for any length. The diameter of the bumpers is larger than stock, but they still fit with no problems.
 

Attachments

  • IMG_2478[1].JPG
    IMG_2478[1].JPG
    1.7 MB · Views: 254
Layne said:
I'm assuming "hard" would be more appropriate. What do you think?
Click to expand...

My sense is that anything will do - hard/soft, with spring / without spring. The key is that the window's movement is restrained at the regulator, rather than by the glass coming against the body. But sure, if you have the choice, go for "hard"; if nothing else, it will probably last longer.

contact details of 'mcmaster' website
Click to expand...

McMaster-Carr is a "gem" for DIY mechanics and restorers. If you are willing to study their extensive website, you can find lots of things that may not pass the 100% concours test, but will be inexpensive, functional, and often look pretty good.
 
Readie, since you are on the other side of the pond ... wouldn't it be smarter to just order these from W+N for 5.8 euro a piece.
 
Hint : On my CS 2800 the original rubber was soft , and bulged up under pressure when hitting the stop plate at the end of the travel. The bulged rubber rubs against the adjacent wheel/ arm and acts as a brake restricting movement. When trying to reverse the motion motor has a tough time trying to pull back ....
I plan on putting all new but it should be hard enough of the rubber that wouldn't bulge up! Once I get my new ones I will double check that...
 
4 springs needed up front and 4 rubber stops in the rear.
All available at W&N

+
» detailed description
series:
BMW 2,5 CS - 3,0 CSL (E9)
Rubber buffer for rear elec. window lifter you need 2 for 1 car
Your price:€6.90




  1. Catalog picture / Position no. 51/26/00
    A51331837518
    +
    » detailed description
    series:
    BMW 2,5 CS - 3,0 CSL (E9)
    Rubber buffer for front electric window lifter fits for all models and years of manufacturing
    Your price:€12.95 Incl. VAT + Shipping(Excl. VAT €10.88)
    (Delivery Time: 2-3 Tage)
 
I just installed these in all 4 windows and work great. They are wider than stock, so make sure they don't rub on the gear by slightly bending out the mounting ear where it threads in if necessary, I had to do this on one. And most importantly, make sure the windows don't stick in the tracks at full up and down positions which will also make them jam. They should lift up easily and drop down from gravity with no resistance.

Layne said:
I ended up using McMaster part # 9546K212 which does not have a stud on it, but a threaded hole in it. They only offered studs up to 16mm long, and my old ones were 30mm long. So I also bought part # 92605A138 a 35mm set screw, and put them into the bumpers with loctite (5-ish mm's goes into the bumper, 30-ish sticks out). I had forgotten about Steve in Reno saying that two had longer studs. Hopefully 30mm is good all around, but they can be swapped for any length. The diameter of the bumpers is larger than stock, but they still fit with no problems.
Click to expand...
 
Last edited:
jmackro said:
My sense is that anything will do - hard/soft, with spring / without spring. The key is that the window's movement is restrained at the regulator, rather than by the glass coming against the body. But sure, if you have the choice, go for "hard"; if nothing else, it will probably last longer.



McMaster-Carr is a "gem" for DIY mechanics and restorers. If you are willing to study their extensive website, you can find lots of things that may not pass the 100% concours test, but will be inexpensive, functional, and often look pretty good.
Click to expand...

Since you put this in here, another great place is Belmetric for metric nuts and bolts and other stuff.

https://www.belmetric.com/
 
I bought the front and rear bumpers from W&N. The front springs diameter is much too large so I used the rear rubber ones in the front. It works well. It seems like the issue is that when the windows are left full up over time the rubber bumpers flatten and expand in diameter then drag on the gear. I have taken all four regulators out and serviced them with Lithium grease and oiled the motors. They work much better now. If anyone wants the 4 front bumper springs I will make you a deal.
 
You must log in or register to reply here.
Back
Top