Clutch won't engage? Constant neutral?

[mrnine]

On my way home last night, accelerating (moderately) out of a stop sign, between 1st and 2nd (manual 5-speed), my rpm's rev'd up and I realized I wasn't in gear. I then realized that no matter what gear I was in, depressing the clutch seems to do nothing though the clutch pedal feels no different than it ever has. However, I'm in constant neutral.

What happens when a clutch actually "goes out." I would have to imagine that the clutch just gradually stops gripping. It doesn't seem like that.

What happens when you bust a clutch cable? It would seem to me the opposite. That if it was in gear, it would engage and wouldn't disengage.

I installed a short shift a couple years ago. It seemed then that it touched the driveshaft barely when I was in reverse. I always wondered if it would eventually sever the selector rod. Could it be that I've busted my shift linkage? That would explain constant neutral as moving the shift lever would never actually put it in gear.

Any help would be appreciated. My car's parked on a quiet street so I might take some jack stands down later today and lift it and have a look. Any insight as to what I might look for or consider beyond what I've mentioned would be appreciated.

Thanks!

[mooseheadm5]

Originally Posted by mrnine

On my way home last night, accelerating (moderately) out of a stop sign, between 1st and 2nd (manual 5-speed), my rpm's rev'd up and I realized I wasn't in gear. I then realized that no matter what gear I was in, depressing the clutch seems to do nothing though the clutch pedal feels no different than it ever has. However, I'm in constant neutral.

What happens when a clutch actually "goes out." I would have to imagine that the clutch just gradually stops gripping. It doesn't seem like that.

What happens when you bust a clutch cable? It would seem to me the opposite. That if it was in gear, it would engage and wouldn't disengage.

I installed a short shift a couple years ago. It seemed then that it touched the driveshaft barely when I was in reverse. I always wondered if it would eventually sever the selector rod. Could it be that I've busted my shift linkage? That would explain constant neutral as moving the shift lever would never actually put it in gear.

Any help would be appreciated. My car's parked on a quiet street so I might take some jack stands down later today and lift it and have a look. Any insight as to what I might look for or consider beyond what I've mentioned would be appreciated.

Thanks!

This car has a hydraulic clutch, so no cable. Does the shifter feel like a spoon in a bowl of pudding? If there is no positive engagement of the shifter into the gates, the selector rod is suspect. If the clutch pedal goes to the floor with no resistance the hydraulics are suspect. If these are OK and the car will simply not go into gear, you have clutch problems related to the pressure plate/flywheel/friction disc assembly which requires tranny removal. If that's the case, off to your local independent BMW shop.
-Paul

[mrnine]

Hmm...

Thanks for the great feedback. Obviously not the *best* news, but...

Okay, selector rod is working fine. I just stopped to look into it and the shifter does enter into all the gears as normal. The clutch itself feels unremarkable. Feels exactly as it would normally.

Interestingly, with the car running and the clutch not depressed at all, I can easily shift through 1st, 2nd, 3rd, 4th. Reverse provides a bit more resistance and I can't quite get it into 5th. With the clutch depressed, I can shift through all gears with no problem.

On an almost completely unrelated note. To the right of the intersection where it officially crapped out, there was a part laying near the curb that I picked up. It looks like a wheel center to a trailer or something. I would not even bring it up except for sheer proximity to the breakdown. Pictures are linked below.

As always, any input appreciated.

[mooseheadm5]

Umm, check your halfshafts. I think you will find that one of them has come apart. Because this is an open diff, the output flange that's missing the axle will spin while the other stays still. This is much cheaper to fix provided it only needs a halfshaft. Good thing you picked that up, but they can't put it back in the car. Now would be the time to get an E30 diff and halfshafts installed due to the savings on duplicate labor and parts if you do it later. i think your clutch is fine.
-Paul

[mooseheadm5]

By the way, has someone been poking around back there recently? The part that you have on your desk does not look like it was ripped out, it looks like maybe the bolts all fell out. This would be a piece that goes between the halfshaft and the output flange at the diff. Check both sides, you may need to jack up the car (supported with jack stands, of course.)
-Paul

[mohaughn]

Originally Posted by mooseheadm5

Umm, check your halfshafts. I think you will find that one of them has come apart. Because this is an open diff, the output flange that's missing the axle will spin while the other stays still. This is much cheaper to fix provided it only needs a halfshaft. Good thing you picked that up, but they can't put it back in the car. Now would be the time to get an E30 diff and halfshafts installed due to the savings on duplicate labor and parts if you do it later. i think your clutch is fine.
-Paul

But even if a halfshaft was disconnected he would still be grinding gears trying to shift without the clutch engaged... Not really something that should be diagnosed over the internet. Take it to a mechanic and you will know within an hour or two what the problem is..

[mooseheadm5]

Here is a pic from the ETK
-Paul

[mooseheadm5]

Originally Posted by mohaughn

But even if a halfshaft was disconnected he would still be grinding gears trying to shift without the clutch engaged... Not really something that should be diagnosed over the internet. Take it to a mechanic and you will know within an hour or two what the problem is..

He is not grinding gears because the output shaft of the trans has no real solid connection to the ground through the wheels. It is as though the output of the trans is spinning freely. When that is the case, you would not necessarily grind the gears because there is very little inertia for the synchros to overcome to mesh the gears properly. Trust me. I am a mechanic, BMW specialist, and mechanical engineer. That part he found should be attached to the car, and I am willing to bet money that it is related to his problem. Of course, he will still need to take it to a shop unless he can swap out the halfshaft on the side of the road, which is doable with the right tools and knowledge.

mrnine, the bolts may have sheared off, too, so you may see them sticking in the holes.

-Paul

[mrnine]

Wow! You guys are so right. mooseheadm5, I can't thank you enough for your expertise. My driver side halfshaft is separated from the differential.

Let me start by saying that I am not a mechanic, I am not a BMW specialist, nor am I a mechanical engineer.

Yes, I was "poking around back there recently." In fact, a buddy of mine and I recently swapped a diff. Indeed, it is open and not LSD. My diff started making a racket with metal shavings visible upon draining the diff. I couldn't afford an LSD, needed my car and found a great eBay deal on an open diff from a totalled Z3 with 1,000 miles for like $150. A quick fix and in the end not terribly hard to swap out.

I never would have suspected this as the culprit as I too believed that I would have grinding gears no matter what. It completely makes sense that with no resistance whatsoever, I could put it in gear and the driveshaft would engage with a disconnected rear end, no questions asked. Also makes sense that 5th provided more resistance.

Upon inspection this evening, mooseheadm5, you're right that several of the bolts are sheared. I have threee that seemed to have just worked themselves loose and three that sheared. Four of the six bolts (some sheared, some whole) still are hanging in the halfshaft flange. My guess is that upon acceleration at that particular moment, three bolts were still holding the halfshaft and sheared right off. Maybe even 1-2 of them were already sheared and one was holding it.

My question is: should I really expect that the entire halfshaft itself needs replaced? The flange of the diff, the halfshaft flange and the halfshaft itself look undamaged. Clearly I need to replace the end cap that I showed in the pics. The break happened at perhaps 5mph, so the "dangling" halfshaft was never subjected to high rpm's or heavy force. However, I have two replacement halfshafts on hand in the garage, again from eBay. I saw a good deal with no bidders and grabbed them to have around just in case I ever needed them.

I'm thinking get it on a lift, examine the halfshaft. If undamaged, replace the end cap (with the one from my replacement eBay halfshaft, or a new one), drill out sheared bolt ends from the diff collar, replace all six bolts and bolt up the halfshaft; (note to self) triple check the torque settings on the bolts. Examine bolts (as I should have done) after a few hundred miles.

1) Would I have been completely screwed if this happened at 80mph?

2) Could this be the result of that 6th beer in the six pack (12th beer in the 12-pack) during the differential swap? The beer ads never give any fine print warning as to this sort of thing.

3) Is there anything else that could have caused this other than undertorquing the bolts? The other side is tight with all bolts still looking just fine. When I get it on the lift, I'll retorque them to spec as well.

Thanks so much you guys. I love 318ti.org!! Never failed me yet.

-mrnine

[aceyx]

If there is minimum of 1/4" of the bolt sticking out, try these. Hammer them on, PB Blaster/Kroil, and use a 1/4" socket to remove.

Sears/Craftsman also has a set of 5 if you can't find these.

[mooseheadm5]

Originally Posted by mrnine

Yes, I was "poking around back there recently." In fact, a buddy of mine and I recently swapped a diff. Indeed, it is open and not LSD. My diff started making a racket with metal shavings visible upon draining the diff. I couldn't afford an LSD, needed my car and found a great eBay deal on an open diff from a totalled Z3 with 1,000 miles for like $150. A quick fix and in the end not terribly hard to swap out.

Upon inspection this evening, mooseheadm5, you're right that several of the bolts are sheared. I have threee that seemed to have just worked themselves loose and three that sheared. Four of the six bolts (some sheared, some whole) still are hanging in the halfshaft flange. My guess is that upon acceleration at that particular moment, three bolts were still holding the halfshaft and sheared right off. Maybe even 1-2 of them were already sheared and one was holding it.

My question is: should I really expect that the entire halfshaft itself needs replaced? The flange of the diff, the halfshaft flange and the halfshaft itself look undamaged. Clearly I need to replace the end cap that I showed in the pics. The break happened at perhaps 5mph, so the "dangling" halfshaft was never subjected to high rpm's or heavy force. However, I have two replacement halfshafts on hand in the garage, again from eBay. I saw a good deal with no bidders and grabbed them to have around just in case I ever needed them.

Hope this reaches you in time
Yes, if the CV joint is not f'dup you can use the piece from the other axle. If it is f'dup, read here: http://www.318ti.org/notebook/diff_c...ion/index.html
and swap the inner cv joint complete.

Originally Posted by mrnine

I'm thinking get it on a lift, examine the halfshaft. If undamaged, replace the end cap (with the one from my replacement eBay halfshaft, or a new one), drill out sheared bolt ends from the diff collar, replace all six bolts and bolt up the halfshaft; (note to self) triple check the torque settings on the bolts. Examine bolts (as I should have done) after a few hundred miles.

1) Would I have been completely screwed if this happened at 80mph?

2) Could this be the result of that 6th beer in the six pack (12th beer in the 12-pack) during the differential swap? The beer ads never give any fine print warning as to this sort of thing.

3) Is there anything else that could have caused this other than undertorquing the bolts? The other side is tight with all bolts still looking just fine. When I get it on the lift, I'll retorque them to spec as well.

Thanks so much you guys. I love 318ti.org!! Never failed me yet.

-mrnine

Good plan.
1) Maybe, the shaft could have whipped around causing damage, you could have been run over by a semi.
2) Maybe. Could have been that when you went to torque that side the phone rang or nature called. Check safety items like that twice from now on.
3) Overtorquing could have done it. My bet here, though, is that since only a few sheared off that the others fell out. You should be able to get the nubs out easily unless you used loctite or something.

Good luck! Lesson learned and no-one injured. Let me know if you need anything else.
-Paul

[pdxmotorhead]

I use a yellow paint pen to mark the CV bolts after I tighten them, that way if they move the paint cracks and I can see they are loose. BTW I also use a torque wrench on them.

Dave