windscreen wiper issue - help needed!

[95-540iLE]

Picked up the 3.6 M5 in Melbourne on Thursday. Drove it around there for a few days and it is now back here in Tassie with me.

Having a great time with it, love the sound and the feel of the power when the revs get over 4000, but still not sure I don't prefer the torque and more linear delviery of power from my M540i.

Anyway, on Friday night, as I drove towards the boat to take me from mainland Australia to Tasmania, a thunderstorm broke (and the temperature plunged about 10 degrees celsius to about 30 degrees). I turned the wipers on for the 1st time and no problems.

However, after about 5 mins, I noticed that the drivers arm wasn't going all the way down and in a few more strokes of the arm, stopped at the vertical position.

The passenger arm was working fine.

It appears that whatever grabs the arm and drives it no longer has the teeth or ability to grab any longer.

I stopped the car and you can now grab the arm and freely move it up and down.

Any idea what part it is that has worn out and how hard it is to fit.

Comments appreciated.

Cheers

[GJPinAU]

Have you compared the mechanism on the 540 to see what has gone amiss?

[genphreak]

However, after about 5 mins, I noticed that the drivers arm wasn't going all the way down and in a few more strokes of the arm, stopped at the vertical position. The passenger arm was working fine. It appears that whatever grabs the arm and drives it no longer has the teeth or ability to grab any longer. I stopped the car and you can now grab the arm and freely move it up and down. Any idea what part it is that has worn out and how hard it is to fit. Cheers
Sounds like the driver's arm spline is loose- not much else can cause this unless a linkage breaks (and wow) you would hear that. You need a 5mm allen key to tighten it, as well as a flat screwdriver to get it off/adjust it. Be sure to get it in the right position, if unsure make the arm overwipe the bottom of the screen rather than encourage it to go further over until you can inpsect the arm for the well known issue: 'Bonnet bashing arm'. This is common and can be caused by a twisted arm or sunken bonnet catches (caused by old bonnet struts becoming ineffective and allowing unwary persons (or the wind) to slam the bonnet (hopefully not on one's head) onto the catches (and promptly 'adjusting' them down to their lowest adjustment point on the frame).

The catches are easy to adjust (3x10mm nuts inside the gaurds near the ebox)- but that said my arm still hits, indeed almost every e34 I see seems to have this problem. ie Wiper arm hitting the bonnet risking damage to the wiper mechanism. BMW's service of them sucks (wiper component pricing is simply impossible).

Mine have just been in pieces again. They don't seem well documented by BMW or the Bently; there are two settings critical to the pressure device that are not well-covered.

I can adjust my arms to wipe correctly, ie the drivers side (the most critical from an adjustment point of view & mine has no problems with the passenger wiper) wipes from the far top corner of the screen to a horizontal position perfectly, but the arm itself hits the bonnet lip at the top of every wipe. This partly because I adjusted the arm so I got the right wipe points. I should have left it (I had originally thought it was retarded by one spline as it overwiped the bottom of the screen (no big deal) and missed going to the far corner by a fair way. After I adjusted the wipers to wipe correctly, the lower (curved) section of the arm badly hit the bonnet (as it had done before). I adjusted the bonnet locators to the highest vertical location, put 3 washers under the bonnet catches, but still the arm hits. Every wiper component is original BMW; but from inspection it is pretty obvious the arm has twisted near the pivot, from hitting the bonnet. Just now I replaced the motor due to a cracked internal cog form the strain of all the hits (Aussie stealer wanted US$400 for a new one). It is proving hard to get a new arm though- that's what I really need. For the time being I have twisted the arm back just a bit... am now considering buying a new arm from the stealer.

So don't just tighten the spline to get the wiper moving again, take care to examine why it was slipping in the first place (they don't). ie Be sure to look carefully for signs of the dreaded bonnet bash first- on the arms and the far edge of the bonnet.

:) Nick

[BobHarris]

Have you tried to tighten the nut that holds the arm onto the spline?

Edit: You seem to have it well coverded Nick. I started this before you but then got called away.

All the best

Bob

[genphreak]

Edit: You seem to have it well coverded Nick. I started this before you but then got called away. All the best BobThat's great Bob, you kinda summed up what I was on about anyway! ;) [and yet more proof that this is the board of choice for bimmer related info]

[95-540iLE]

Have taken a 5mm allen key and the arm is now engaging again. however, there are signs of the arm hitting the bonnet (hood) so, as recommended, I think I will need to investigate further.

thanks for the assistance.


Sounds like the driver's arm spline is loose- not much else can cause this unless a linkage breaks (and wow) you would hear that. You need a 5mm allen key to tighten it, as well as a flat screwdriver to get it off/adjust it. Be sure to get it in the right position, if unsure make the arm overwipe the bottom of the screen rather than encourage it to go further over until you cna inpsect the arm and the (well known issue): 'Bonnet bashing arm'. This is common and can be caused by a twisted arm or sunken bonnet catches (caused by old bonnet struts becoming ineffective and allowing unwary persons (or the wind) to slam the bonnet (hopefully not on one's head) onto the catches (and promptly 'adjusting' them down to their lowest adjustment point on the frame).

The catches are easy to adjust (3x10mm nuts inside the gaurds near the ebox)- but that said my arm still hits, indeed almost every e34 I see seems to have this problem. ie Wiper arm hitting the bonnet risking damage to the wiper mechanism. BMW's service of them sucks (wiper component pricing is simply impossible).

Mine have just been in pieces again. They don't seem well documented by BMW or the Bently; there are two settings critical to the pressure device that are not well-covered.

I can adjust my arms to wipe correctly, ie the drivers side (the most critical from an adjustment point of view & mine has no problems with the passenger wiper) wipes from the far top corner of the screen to a horizontal position perfectly, but the arm itself hits the bonnet lip at the top of every wipe. This partly because I adjusted the arm so I got the right wipe points. I should have left it (I had originally thought it was retarded by one spline as it overwiped the bottom of the screen (no big deal) and missed going to the far corner by a fair way. After I adjusted the wipers to wipe correctly, the lower (curved) section of the arm badly hit the bonnet (as it had done before). I adjusted the bonnet locators to the highest vertical location, put 3 washers under the bonnet catches, but still the arm hits. Every wiper component is original BMW; but from inspection it is pretty obvious the arm has twisted near the pivot, from hitting the bonnet. Just now I replaced the motor due to a cracked internal cog form the strain of all the hits (Aussie stealer wanted US$400 for a new one). It is proving hard to get a new arm though- that's what I really need. For the time being I have twisted the arm back just a bit... am now considering buying a new arm from the stealer.

So don't just tighten the spline to get the wiper moving again, take care to examine why it was slipping in the first place (they don't). ie Be sure to look carefully for signs of bonnet bash first- on the arms and the far edge of the bonnet.

:) Nick

[ILoveMPower]

I'm glad to see this, the same thing happened to me the other day for my passenger side wiper. I assumed it was from the freezing weather and the snow on my windshield. I'll be sure to check it out today...

[632 Regal]

wiper arms commonly hit the hood, something about a worn bushing or you can replace the arm to a new style one that doesnt match the other one...

[Paul in NZ]

they all hit the hood dont they....but i am sure its the passengers one that hits the bonnet on mine.....my drivers side overwipes slightly at the bottom of the wipe making a racket on fast.Glad you have got it sorted though David.
How did the melbourne meet go?

[95-540iLE]

Thanks Paul

Melbourne meet went well. Had 2 LE's (#16 & #52), my M5, an M6, an Alpina B10, some other assorted E34's, a couple of E28's and some E30's for good measure.

A pic of some of the cars attending is attached.

Cheers


they all hit the hood dont they....but i am sure its the passengers one that hits the bonnet on mine.....my drivers side overwipes slightly at the bottom of the wipe making a racket on fast.Glad you have got it sorted though David.
How did the melbourne meet go?

[genphreak]

wiper arms commonly hit the hood, something about a worn bushing or you can replace the arm to a new style one that doesnt match the other one...I never got the worn bushing theory. Mine hit like boxing legends but the pivot bushings are fine, no play at all. Even though RHD and LHD cars have different mechanisms and wiper arms, but it seems to affect both alike. I put this down to the latches dropping when the hoods collapse (from worn (old) bonnet struts)- ie this should fix most problems.

Phil Sanderson had a lot to tell me about it- he solved it on his 525 as such, but I've tried everything he told me. My passenger side one is made good by the bonnet-latch adjustment (not sure if it needs the spacers or works OK without). When I get a new driver's side wiper arm we'll see- I get the feeling the arm will wipe properly when set back one spline. I guess the bent ones simply cannot (ever) be trusted...

[genphreak]

wiper arms commonly hit the hood, something about a worn bushing or you can replace the arm to a new style one that doesnt match the other one...Can you shed any light on the worn bushing theory Jeff? I just rebuilt my wiper mecho, adjusted the drivers wiper so it did the right wipe and then thought I nailed the problem by adjusting the bonnet lock bracket so it holds the bonnet as forward as far as it will go (didn't seem to make much visible difference :p and the new wipers still hit. Consolation- new motor is 200% better than the old one though :)

The I added another spacer so now my bonnet is higher than the imaginary curve following on from the edge of the fender. Wiper still hit.

So I adjusted the hood latches so they were located towards the maxium passenger side- to push the bonnet to the drivers side. This is the best thing as it got the bonnet away as much as possible- slight hit.

Bent my wiper arm (back to what I think is std) and it made a small amount of difference too, barely any knock. What a problem these wipers are!

Looks like I am still going to have to stump up for a new arm! :) Nick

[632 Regal]

I read about the bushing somewhere, no bookmarks on that one. BMA has the new style arms but like I said they dont match the other one from what I heard.

[genphreak]

I read about the bushing somewhere, no bookmarks on that one. BMA has the new style arms but like I said they dont match the other one from what I heard.Thanks Jeff, Doh. I can't find anything either.. my problem is the car is RHD so the BMA's new arms will be no good (I doubt they have RHD). The stealer has 'em, but as usual they charge with 110V applied in full- they are like $300. :) Nick

[Blitzkrieg Bob]

is the easiest way to stop the hood rub problem.

Just grind down the wiper arm, re paint it.

No worries

[genphreak]

is the easiest way to stop the hood rub problem. Just grind down the wiper arm, re paint it. No worriesTHanks Bob, my PO did that without a dremel, (they burned out the wiper motor doing it naturally). Seriosuly to fix it I'd be taking a 10mm chunk out of the arm, its that bad! Still- it's probably the best fix so far after adjusting the bonnet latches, bending the arm and moving the bonnet-latch lock back to its original position... :)

[632 Regal]

Wow! Maybe you should look into the bushing deal, sounds like somethings way off.
Seriosuly to fix it I'd be taking a 10mm chunk out of the arm, its that bad!

[genphreak]

Wow! Maybe you should look into the bushing deal, sounds like somethings way off.Thanks Jeff- I have been... but no luck yet. To clarify things, I'll post some info (http://www.realoem.com/bmw/showparts.do?model=HD12&mospid=47382&btnr=61_0831&hg=61&fg=45&hl=45) from the realoem ETK. As you can see below, there is no bush (unless it is the one pressed into the main linkage (part #01).

What makes this problem even harder to work out is that my car has never had a collision, so it is not bad bonnet adjustment etc. that can normally cause such painful problems in cars.

Incidentally, here is one of the best technical info pages (http://bmwe32.student.utwente.nl/johan/wiper_mechanism/wiper_mechanism.html) I found terribly interesting on the subject. Here is another (http://bmwe32.student.utwente.nl/dutch740/wipertensioner.htm) (also from Sean & Johan's site) on the more complicated wiper system fitted to many euro and all top-e32 and e34 models - but beware, parts may be similar but are not all common between e32 and e34). This last link one helps people to understand the Pressure Adjusting Device (Part #04).

The PAD on mine jammed up so I took it out, dismantled and re-greased it, now it works like a trooper and gives a nice consistent wipe. Note that when dismantling one should take care- especially if yours is jammed (in fact I'd check out a good one to get the right positions set before putting the jammed one back together) Doing so risks pressuring the device internally as it winds up (once you are driving)- and as it is designed to do at high speed.

If not jammed, one should take care not change the position of the cam that operates the microswitch. When reinstalling the nylon worm gear (after greasing) one shoud wind the gear down to the lowest point before installing the black cover plate (with a new gasket of course (make your own :D) so it doesn't fill up with water, corode internally and jam up again!

This PAD can also contribute to the bonnet bash problem if yours winds itself up somehow and won't give way (jams), in fact it might even cause the arm to bend and possibly scratch the bottom of the windscreen.

BTW; tools needed to dismantle- 7, 10 and 13mm socket with mini ratchet and extension bar. T-15 torx head screwdriver and also a 5mm allen key, 4 or 5mm flat blade screwdriver. Time and patience, especially removing the blower unit if removing the main wiper linkage (something I have not had to do servicing the motors)

[632 Regal]

new idea, why not get some Aquapel or rainex and forget the wipers? Im using the aquapel and dont need the wipers much at all unless misty conditions and slow.

[genphreak]

new idea, why not get some Aquapel or rainex and forget the wipers? Im using the aquapel and dont need the wipers much at all unless misty conditions and slow.Awww ****, well I could perhaps try WD-40, it works wonders in the rain I hear.... I'd love to, but actually its so dusty here i don't trust it, but I might have a go and see, Tx, Nick

[Paul in NZ]

i reckon my psgr wiper arm has a 6mm v in it...my drivers arm doesnt hit the hood just overwioes a bit(and the adv sounds sick when disengaging)

[632 Regal]

gen, not to sound retarded but did you go to the sticky that says search? I know there were a few threads on some bushing or crap a long time ago that causes this problem. I mean I'm sure BMW didnt just overlook a 45,000 car where a wiper simply "hits" the hood and blew it off. It might have been in the old forum thats why the sticky is there, it searches everything.

[genphreak]

gen, not to sound retarded but did you go to the sticky that says search? I know there were a few threads on some bushing or crap a long time ago that causes this problem. I mean I'm sure BMW didnt just overlook a 45,000 car where a wiper simply "hits" the hood and blew it off. It might have been in the old forum thats why the sticky is there, it searches everything.Hi Jeff, thanks for your continued attention and help with this. It is something we really need to address so perhaps I will do a write up with pics and suggestions. Yes, I have searched, several times- a wide search like wiper bush, wiper bushing and so on... (accross all forums) going real wide and searching for just wiper I found this again

My car has the same fault and is due to the wiper spindle bearings wearing out. This allows the wiper arm to go a little off course and therefore clips the bonnet edge. The problem is worse on the fast setting - it really makes a racket! I have just bought another wiper mechanism from a breaker (with good bearings) and have just got to figure out how to get enough access to fit the damn thing but looking closely at mine this doesn't make sense (there's no play/movement in the mecho at all). Also, I found Dan's post
It's likely to be a combination of all the above issues, but if you're like me and don't want to raise the resting position of the wiper arm, there is another solution. Open the hood and look at the wiper arm. Between the sheetmetal and the underneath bit of the wiper there is a spongey washer, the washer compresses, goes brittle and breaks after many years, this causes the wiper to stick up a little bit more. If you can replace this washer, the wiper will sit a few mm closer to the glass, and not touch the hood so much and I can't see where this applies on my car either, however 525s do not have the Pressure Device so perhaps they are a tad different anyway... :( Also found plenty of peeps with big chunks taken out of their wiper arms, so perhaps that is going to be the fix in my case also...

I only persist because like you I cannot fathom how BMW could have got these setup screwed up so badly the first place. It makes me wonder whether they had any recalls or known procedures to follow during dealer servicing. :) Nick

[Paul in NZ]

i too remember nick that there was discussion re this washer that Dan alludes too.Surely with so much talk about it there must be a proper BMW fix

[genphreak]

i too remember nick that there was discussion re this washer that Dan alludes too.Surely with so much talk about it there must be a proper BMW fixYea tell me about it Paul, I've been looking for ages! At least my setup is usable again, but I really want it fixed right... :) Nick

[Yorkie]

I believe you are having problems as i am with my E36. I have a link to a technical page which may help with the bonnet wiper arm issues. Even tho its for the E36 it may halp you guys out.
www.e36coupe.com and select the technical page and you will find an article about the wiper arm problem. Good luck!

[genphreak]

I believe you are having problems as i am with my E36. I have a link to a technical page which may help with the bonnet wiper arm issues. Even tho its for the E36 it may halp you guys out.
www.e36coupe.com (http://www.e36coupe.com) and select the technical page and you will find an article about the wiper arm problem. Good luck!Thanks Yorkie, I checked it out but the pdf is not too specific about the descriptions and there are no pics. Has anyone seen this washer? It is not described in the ETK for e34, perhaps it is not applicable to e34.

Update; I have fixed my problem completely:

The wiper arm had been bent by the pressure device overloading it. I fixed the pressure device (details are on the forum) and then bent the arm back into place. It works a treat, but I had to sand the arm and polish it up and repaint. No problems now. Also, the bonnet postion was adjusted (up by raising the guide rails/lock assy) and more forward by adjusting the bonnet catch- it is a most critical thing. After that clearance galore and no more bash.

:) nick

[joshua43214]

lol, so odd to see so man posts on this issue of wipers hitting the hood. The cast aluminum portion of the arm bends over time.

I have repaired dozens of them with a hammer. Just remove the arm from the car, lay a piece of sheet metal on a brick or the floor. Gently drop a top maul (one of those mini sledge hammers) repeatedly on the bowed part of the arm from a hight of amout 1 inch. takes a few minutes, but I have yet to break one straightening it out. The sheetmetal is to protect the arm from being marred by the concrete

Repaint and adjust the wiper stuff as normal.

[genphreak]

lol, so odd to see so man posts on this issue of wipers hitting the hood. The cast aluminum portion of the arm bends over time.

I have repaired dozens of them with a hammer. Just remove the arm from the car, lay a piece of sheet metal on a brick or the floor. Gently drop a top maul (one of those mini sledge hammers) repeatedly on the bowed part of the arm from a hight of amout 1 inch. takes a few minutes, but I have yet to break one straightening it out. The sheetmetal is to protect the arm from being marred by the concrete

Repaint and adjust the wiper stuff as normal.Yep I am glad to hear mine is not an odd one out. Being aluminium it has to react to the load over time and changes in temp. It was only when I worked out what the pressure device was all about that any of it made sense!

I bent mine back bit by bit with a large shifting spanner and a rag to protect the arm's surface- but that fix sounds a treat, Joshua.

I can tell you that from an owners perspective, it would help to alleviate some of the pent-up stress from troubleshooting the wretched pressure device and for putting up with bonnet bash and replacing wiper motors in the first place!!!

[kbchia]

inserted between the spindle and the bodywork works for me. It has been four years since and it still works like a charm. There is no need to adjust the bonnet at all. There is a similar bush on the other side too.

kbchia




Yep I am glad to hear mine is not an odd one out. Being aluminium it has to react to the load over time and changes in temp. It was only when I worked out what the pressure device was all about that any of it made sense!

I bent mine back bit by bit with a large shifting spanner and a rag to protect the arm's surface- but that fix sounds a treat, Joshua.

I can tell you that from an owners perspective, it would help to alleviate some of the pent-up stress from troubleshooting the wretched pressure device and for putting up with bonnet bash and replacing wiper motors in the first place!!!

[genphreak]

inserted between the spindle and the bodywork works for me. It has been four years since and it still works like a charm. There is no need to adjust the bonnet at all. There is a similar bush on the other side too.

kbchiaSounds quite different kbchia. Ours don't have much lattitude vertically, and there is no bush from factory. The problem is more that our wipers utilise a pressure device which bends the arm over time (in the way Joshua mentioned). This is a different issue, but I suspect all our cars share a major compound cause; that is that e36 and e32/4 have front hinging bonnets which panelbeaters have to reset after the slightest front end damage. When doing this I bet they do so without appropriate regard to clearance for the wipers travelling a little beyond their stationery positions.

Thanks for the heads up, it is good info.

[Paul in NZ]

all this is good but on my RHD car its the PASSENGERS wiper that hits the bonnet

[joshua43214]

all this is good but on my RHD car its the PASSENGERS wiper that hits the bonnet

My bendy thing works on passenger side wiper arms too=)

[genphreak]

all this is good but on my RHD car its the PASSENGERS wiper that hits the bonnetSo did mine, a nice little gouge. Until I adjusted the bonnet forward properly... have you tried moving the locking catch Paul?

I reckon the bendy thing would be wrong (but no doubt it would work) on that side, the cause of the bend is the PAD and the passenger side does not have that.

[Bill R.]

windshield wiper pressure control or APV as its called,is only on the drivers side wiper not the passenger side so that does away with that theory. I would imagine that the australian cars are a mirror image with the wipers exactly reversed from the US ones. Thats why the passenger side on US and Aus. both hit.. There is a factory service bulletin out regarding the problem And it calls for the hood to be adjusted forward and up. Or to use the later model wiper shafts which are a shorter stub lowering the wiper arm itself. Most people end up doing a combination of fileing the wiper arm, adjusting the hood and relocating the arm one tooth.





So did mine, a nice little gouge. Until I adjusted the bonnet forward properly... have you tried moving the locking catch Paul?

I reckon the bendy thing would be wrong (but no doubt it would work) on that side, the cause of the bend is the PAD and the passenger side does not have that.