Tonneau gear grinding???? Help please

[pat101]

Ok, 1999 323 full auto convert. I start with a resync. Upon completion of resync, I try and close the roof, the tonneau tries to lift up, it releases but starts to make a racheting noise and does not lift up more than an inch. I made sure that my tonneau motor was completely snapped shut before resyncing. I have looked at my tonneau motor bracket and it seems unbent to my eye. Ok, so I went out and found a parts car and got another tonneau motor, and installed it. I resync'd and tried it...... same exact performance, same racheting noise and no lift for the tonneau.

Ok, what am I doing wrong? Does this sound for sure that my tonneau gears are stripped? They don't look stripped, bent or worn. Is it possible that there is some other part of the tonneau mechanism that is causing this issue. I am pretty confused at this point.

I have gotten really good at resyncing my system. I am very practiced at snapping both my top and tonneau motors back into place. And I am now moving along in becoming expert at removing and installing my tonneau motor. Alas this is not getting to the root cause of my vert top problem.

Any help would be appreciated.

Thanks

[66 6]

Gears are stripped, mounting plate is severely bent, tonneau cover and mechanism is binding caused undue pressure. Check all of the above

[pat101]

Gears are stripped, mounting plate is severely bent, tonneau cover and mechanism is binding caused undue pressure. Check all of the above

Thank you 66 6, bent plate it was. Although it looked hardly bent at all. Frankly I was confused and thought the all the bent plate comments had to do the primary mounting brackets for the tonneau motor. But no, the plate that is being described is on the motor mount. You have to pull the tonneau motor, a little fiddly, as the man says. Once out, oooff, you eyeball the corner of the aluminum bracket plate that the emergency release catch hooks onto. if it is not totally straight, bend it back into place using, for example, a cresent wrench, or the such. The very minor tweak that I gave my assy. made it work!! You should make sure that you can snap the motor back into place before you re install into the car. A very small amount of gear engagement seems to make a big difference. And while you are at it, you might want to improve your tonneau cover travel by making sure that the motor unit is pushed towards the front of the car when snugging down the 4 x 10mm mounting nuts. The bottom 2 nuts are the ones that seem to have this adjustability built in.

It goes up, it goes down!!!!!! Gotta love all the sunshine and wind. When putting your top up or down the first few times you may want to reach behind you and help the top and make sure that the back bow or part of the top goes all the way up and stays out of the way of the Tonneau cover. You can eyeball the clearance and how consistently you top and tonneau clear each other before learning to trust them. I am not sure, but the bent tonneau motor snappy plate may have been caused by a CRASH between these features. This is another reason why it may be a good idea to tighten up the tonneau motor position.

Thanks to all for all the postings, as a body of work it allows me to have such a fun little car and keep it running. OMG, e36 convertibles for under $2000 is just the best way to put a smile on your face.

[Richard Cranium]

I have 1994 325i Vert. Mine is not the full auto top but i'm having the same exact problem. The Tonneau cover starts to move and then the grinding noise. The motor for the tonneau cover was already off when I bought the car. can you post a pic of the plate that I should check to see if it's bent. Or is there something else I should check?? Sorry this is my first Vert. ever and my first BMW ever.

[66 6]

Hello Richard,

Check for a bent plate. You can usually straighten out the plate but your gears may be gone and the problem will repeat frequently. Contact me if you need a good motor. I keep a few.

[galuple]

I put a C clamp on my plate. Keeps it from ever bending again.

[66 6]

I put a C clamp on my plate. Keeps it from ever bending again.

That is true but then what happens when you have interference with the top etc. I imagine the first thing would be the tonneau drive rod. I've seen a few pretzel'd in the past.

[110reef]

Hello Richard,

Check for a bent plate. You can usually straighten out the plate but your gears may be gone and the problem will repeat frequently. Contact me if you need a good motor. I keep a few.

Do you have any top motors? My top motor gears are skipping now.

[PGS2016]

Hey Gents & Gals,
My problem is a simular one and I'm trying to remove the tonneau motor. I disconnected all the cables and the rod and the 4 10 mil nuts. I get the motor housing to clear either the two top bolts or the two bottom bolts. Do you have any advice? I believe the plate on the back is bent causing it not to fully engage. Seems like a little fix if I can get the thing out.

[66 6]

Pull the motor bottom towards the center of the trunk and then lower it. It's sort of wedged in there. Just need a little more man handling as long as everything else is disconnected.

[bmwbob89]

My top saga continues. The top was working fine after the main motor replacement and adjusting the forbidden screw on S2. Then somewhere along the line the top cover hit the top and made a nasty noise. Then came the grinding and cover inop. I pulled the motor and straightened the plate as good as I could. The c clip for the rod went flying and somehow had one in my junk collection. Re-synced and all seems good. One question for those who straightened the plate. Does the fix last or is the metal now fatigued and doomed to repeat. I also turned the S2 screw back 1/2 turn to see if that's why the top wacked together in the first place.

[leedawg]

My top saga continues. The top was working fine after the main motor replacement and adjusting the forbidden screw on S2. Then somewhere along the line the top cover hit the top and made a nasty noise. Then came the grinding and cover inop. I pulled the motor and straightened the plate as good as I could. The c clip for the rod went flying and somehow had one in my junk collection. Re-synced and all seems good. One question for those who straightened the plate. Does the fix last or is the metal now fatigued and doomed to repeat. I also turned the S2 screw back 1/2 turn to see if that's why the top wacked together in the first place.

Its more than just that latch plate bending. If you drive the pin out at the hinge and remove that entire top bracket from the gear box I bet you will see that the hole that is cut for the pinion is oblong where the pinion teeth have literally ground away at the diecast case of the gear train. Most of the ones I have seen the two extensions that come off the gear case to form the bottom of the hinge for the upper bracket plate. Those legs are actually bent in a twisted fashion thus causing the pinion to move away from the bull gear. BMW really should have made a better reinforced part here. Id far rather replace a "pretzeled" lifting rod than this whole motor assembly. When you could purchase them new they were just north of 1k. Now you cannot even purchase one if you want a new one so have to find a used one that is in better shape then the one you have. I have one that I am attempting to bend back into the original specs then machining some pieces of aluminum to beef up the hinge, and also making a new upper bracket that the motor mounts to with a stronger hinge release plate. BMW did a great job at making this part super unique with almost no flat consistent surfaces. They also did a good job at making it very hard to add or modify due to there being stuff all around the motor.

Take the motor out again and break apart the hinge section see what it looks like then see if there is a bend in the entire upper bracket as well as at the release point and then see if the hinge legs are twisted

[bmwbob89]

If you have a picture of the bent legs please post as it will be of great help.

- - - Updated - - -

I have only opened the top a few times since all of this and it is working fine now. I have a spare motor I bought that was already straightened. I'll take that one apart and inspect it.

[bmwbob89]

I just looked at my backup motor and it looks like the pin or legs have bent a bit. I don't want to take it apart at this point. I will see how the original lasts first.

[jerrycastillo]

Pull the motor bottom towards the center of the trunk and then lower it. It's sort of wedged in there. Just need a little more man handling as long as everything else is disconnected.

Hello 66 6,

I read your post mentioning you keep several spare motors for the tonneau cover of the E36.
Having the same ratcheting noise coming from the trunk, I disassembled the tonneau cover motor and tried to straighten the aluminum motor mount but still not working.

Would you sell me one of your spare motors? Price?

Thank you!

Jerry

[M3rocket]

Just going to add this tip to the mix, in case it helps anyone: I recently had to reset my top and when re-engaging the tonneau cover motor, it seemed to engage but didn't. After a few tries, I realized the release cable had not fully retracted, even though I returned the lever to its original position under the back seat. I had to manually pull on the exposed section of cable and lever, that's next to the tonneau motor, to get it to fully release. Then the motor would fully engage and stay in place for the reset.