1999 M3 Convertible Top Problem - Won't close enough to latch windshield

[padan1]

Hello everyone, I've been a lurker here for some time and I have learned a lot about my car from the help of many of you.

I have a unique problem that I absolutely cannot find a definitive answer for, so I decided that this post might actually help someone in the future so here it goes.

I own a 1999 M3 with a fully automoatic top. When opening, it POPS loudly when it detaches from the windshield. It also requires me to put a lot of downward force on it to bring the front bow (with the latches) close enough to the windshield to actually latch to it.

Shows the front bow about 6" away from the windshield. This is where the lock motor stops moving the roof and is just about to "close" the latches, even though it is not near the windshield.
https://flic.kr/s/aHsk9diEPK

The sensors are working and fooled into thinking the top is actually closed if I were to continue to push the "top up" button and let the motor move (close) the latches.

Shows the linkage rod diagram:
https://flic.kr/p/rEquy7

Now I've inspected the linkage, it does not look bent. But I can't tell if either of these linkage adjustments will actually help my problem and I fear that if I start adjusting things willy-nilly I'll be worse off than when I started.

TYIA, your help will be very much appreciated.

TLDR - Is there a roof adjustment that changes the pitch/angle of the entire roof frame?

[dano1200r]

I had a 330 cic, and I would not adjust the linkage. Mine always stopped short, though not as much as yours. Wish I could help more.

[66 6]

Was the problem there before you bought the car or did it just start happening?
Did you ever full the emergency release handle?
Post pictures of your linkage rods for us to see how they are aligned and adjusted? Stop the lowering process when the rear bow is raised and just before the tonneau cover wants to close.

Yes, there are shims to move the entire assembly up/down forward and rear but currently your top is TOOOOOOO far away that they would come into play.

[Tazmanian Devil]

Dealing with the same problem myself. Are your motors, behind the left side tail light, working? One is black, mounted right behind L/S tail light and the other is mounted to the underside of the toneau cover.

[flyfishvt]

Dealing with the same problem myself. Are your motors, behind the left side tail light, working? One is black, mounted right behind L/S tail light and the other is mounted to the underside of the toneau cover.

The one closest to the rail light is the motor for the tonneau cover. It has zero effect on the canvas top operation. The motor in front of Butkus the top motor. If you're going to work on your car it helps to know these things

[Tazmanian Devil]

The one closest to the rail light is the motor for the tonneau cover. It has zero effect on the canvas top operation. The motor in front of Butkus the top motor. If you're going to work on your car it helps to know these things

I do know which motor controls what. Reread my post the motor under the tonneau is for the top and the tonneau motor is next to the tail light. I know this since I am replacing them.

[big A]

Have you tried the top reset procedure? The procedure did not work the first time for me so I had to disengage the top motors, manually close it and then reset. It took 2 attempts but has been fine since.

[110reef]

There are two worm screws in the front of the roof, attached to the center motor in the roof. There is a slider on each one that moves when the worm gears turn. In my car, the plastic inside of the sliders, which is what engages the worm gear, came out and broke. As a result, the slider quit working, and the top would not pull down on that side and the latches would not engage. That doesn't necessarily sound like that is your problem, but if the sliders are in the wrong position on the worm gear, that could be the cause of your problem. When the top is open, they should be on one end, when the top closes they should be on the other end. This is kind of hard to explain, but if you are looking you would see what I mean.

I bought new latch mechanisms to fix the problem.

[Mikkodd]

There are two worm screws in the front of the roof, attached to the center motor in the roof. There is a slider on each one that moves when the worm gears turn. In my car, the plastic inside of the sliders, which is what engages the worm gear, came out and broke. As a result, the slider quit working, and the top would not pull down on that side and the latches would not engage. That doesn't necessarily sound like that is your problem, but if the sliders are in the wrong position on the worm gear, that could be the cause of your problem. When the top is open, they should be on one end, when the top closes they should be on the other end. This is kind of hard to explain, but if you are looking you would see what I mean.

I bought new latch mechanisms to fix the problem.

Anyone know the part number for these latches ? Im having the same exact problem as OP.. Some help would be nice..

[110reef]

543482171987 left, 54348217198 right

Look for part numbers on realoem.com

[Mikkodd]

543482171987 left, 54348217198 right

Look for part numbers on realoem.com

Its weird because my latches move as if they was latching on the windshield when im turning the allen wrench but my top wont bend on to the windshield.

[110reef]

There are sliders in the latch mechanism. They need to positioned properly for the whole thing to work. They ride on the worm gear in the latch mechanism. Check to see if they are both in the same relative position on each latch. When the top is completely latched, the sliders are at one end of the slot, and when opened they are at the other end of the slot.

In my case, the sliders have a plastic insert that engages the worm gear, and makes it slide up and down the slot, but the plastic inserts broke so they no longer worked.

[flyfishvt]

I may have a solution for this. I'm working on my car with the battery out. I put the top down manually. Something didn't feel quite right. I probably should have cranked it a few more times but it went down into its hole. When I pulled it out and got ready to crank it closed I noticed the header seemed really high compare to normal. I cranked it down but it stopped about 6" above the windshield. I went back up and down a few times but nothing changed so I got out and looked for any hinged spots in the frame that might be binding up. That's when I found what's in this picture. It's a little hard to see but I'm pointing at a U shaped bracket. Think of it like the space between your thumb and fire finger. Now look right below it and you'll see part of the frame sticking out. It has a roller on the end. That roller is supposed to slide up into that U shape. Mine missed it and the roller went up along the outside of the U shape causing the whole thing to bind up. I inspected both sides and sure enough it happened to both. I fixed it and everything works great.

I guess it was caused by me. When I manually crank the roof up and down I like to push/pull it at the same time to help reduce some of the tension on that crank rod. I tend to push/pull it from the side instead of from the center. That's the only thing I can think of. Hope this helps

[jerber1]

I have a similar problem. My fully auto top closure motor just makes a ratcheting sound when it tries to close the last 6 inches.. It does this when I try to manually close it with a hex bit too. I am now stuck with my top down permanently until I find the fix. please help!

[110reef]

The last 6 inches is controlled by the motor on the front by the windshield. You will need to drop the plastic panel that covers it and see what is going on under there.

[jerber1]

I have dropped the panel. If I disconnect the worm gear wires the motor turns. If I reattach the wires the motor makes the ratcheting sound and there is no top movement. Both the left and right sides look to be in the correct positions but nothing moves. something is keeping the mechanism from moving either by motor or allen wrench.

[110reef]

look at the positions on the latches - are they already all the way closed or all the way open? You may have to manually get them in the correct position by disconnecting and individually turning each shaft. Also, in the case of mines, there is a plastic insert that the worm gear grips into that was broken on mine, stopping the latch from moving no matter what the worm gear did.

[jerber1]

look at the positions on the latches - are they already all the way closed or all the way open? You may have to manually get them in the correct position by disconnecting and individually turning each shaft. Also, in the case of mines, there is a plastic insert that the worm gear grips into that was broken on mine, stopping the latch from moving no matter what the worm gear did.

Yes the latches are all the way open and the sliding mechanism is where it should be on both sides to facilitate the traveling of the top the last 6 inches before the latching mechanism engages. I will look for the plastic insert tonight. I assume it is on the latch side not on the motor side of the worm gear cable?

Thanks for your help!

[110reef]

Yes, it is in the latch mechanism inside the slider piece.

[padan1]

There are two worm screws in the front of the roof, attached to the center motor in the roof. There is a slider on each one that moves when the worm gears turn. In my car, the plastic inside of the sliders, which is what engages the worm gear, came out and broke. As a result, the slider quit working, and the top would not pull down on that side and the latches would not engage. That doesn't necessarily sound like that is your problem, but if the sliders are in the wrong position on the worm gear, that could be the cause of your problem. When the top is open, they should be on one end, when the top closes they should be on the other end. This is kind of hard to explain, but if you are looking you would see what I mean.

I bought new latch mechanisms to fix the problem.

I'm sure the worm screws are working as they properly 'latch' down and the locks work. Usually you would maybe need to pull down on the center handle of the top as it closes to bring the locks an inch or so closer to the windshield. I have to pull down with a good amount of force, enough to break that center handle trying to pull it down one day to latch it.

If I try to close the top without pushing down on it, the latches will still 'latch' when it is in the position shown in my pictcures. I have fiddled with that part quite a bit, and it looks as though the sliders are in the correct position when fully latched.

When I do push down and close it, it seems like something is binding in the rear linkage rather than any of the hardware for the lock motor. I feel like the whole top moves a bit when I pull it down to close it.

I'm still at a loss as to what my problem is. I've had to do the reset procedure a bunch of times, so it's not that.
It has gotten somewhat harder to push down as well in the two years I've owned the car.

- - - Updated - - -

I may have a solution for this. I'm working on my car with the battery out. I put the top down manually. Something didn't feel quite right. I probably should have cranked it a few more times but it went down into its hole. When I pulled it out and got ready to crank it closed I noticed the header seemed really high compare to normal. I cranked it down but it stopped about 6" above the windshield. I went back up and down a few times but nothing changed so I got out and looked for any hinged spots in the frame that might be binding up. That's when I found what's in this picture. It's a little hard to see but I'm pointing at a U shaped bracket. Think of it like the space between your thumb and fire finger. Now look right below it and you'll see part of the frame sticking out. It has a roller on the end. That roller is supposed to slide up into that U shape. Mine missed it and the roller went up along the outside of the U shape causing the whole thing to bind up. I inspected both sides and sure enough it happened to both. I fixed it and everything works great.

I guess it was caused by me. When I manually crank the roof up and down I like to push/pull it at the same time to help reduce some of the tension on that crank rod. I tend to push/pull it from the side instead of from the center. That's the only thing I can think of. Hope this helps

I hope this is all it is.

I'm going to check in the morning.

Thank for all the responses, it has been very insightful.

[Mikkodd]

I ended up taking mine to a shop before you posted that pic 110reef :/ but they got it back latched and going to put a new convertible computer in. Believe thats why mine wont get back in sync

[ShinySideUp]

I may have a solution for this. I'm working on my car with the battery out. I put the top down manually. Something didn't feel quite right. I probably should have cranked it a few more times but it went down into its hole. When I pulled it out and got ready to crank it closed I noticed the header seemed really high compare to normal. I cranked it down but it stopped about 6" above the windshield. I went back up and down a few times but nothing changed so I got out and looked for any hinged spots in the frame that might be binding up. That's when I found what's in this picture. It's a little hard to see but I'm pointing at a U shaped bracket. Think of it like the space between your thumb and fire finger. Now look right below it and you'll see part of the frame sticking out. It has a roller on the end. That roller is supposed to slide up into that U shape. Mine missed it and the roller went up along the outside of the U shape causing the whole thing to bind up. I inspected both sides and sure enough it happened to both. I fixed it and everything works great.

I guess it was caused by me. When I manually crank the roof up and down I like to push/pull it at the same time to help reduce some of the tension on that crank rod. I tend to push/pull it from the side instead of from the center. That's the only thing I can think of. Hope this helps

Ok so how did you get the roller to cooperate & did it last ?

[mdwilf]

If the "flipper" in the pic isnt in the right place the top will not come down without some serious damage to the frame. Also, There is an adjustment on the linkage that goes up to the latch from the "flipper", might try shortening it.

[emccallum]

When I replaced my elastic straps, the top wouldn't close the last couple of inches, and the latches would latch without benig engaged in the windshield. I loosened the straps a bit and after a couple of cycles it works perfect.

Is it possible someone rigged the straps too tight or something is keeping them from letting the top completely close? Just a thought.

Edit: New elastic straps really made my top work properly.

[Kirkbride]

Did you ever figure this out? I have the same issue. The top is 6 inches above the windshield and the locks close completely. I can force the top down with help from another person and the top closes and locks.