Stripped Transmission Bolt

[TheYoungSir]

As I reported in my last thread, I decided to replace the clutch, upgrade the flywheel, and see if there were any clues about my sticking clutch (which was becoming a drivability problem). After no small amount of hassle, I've managed to remove the heatshield, guibo, driveshaft, lower the exhaust (disconnect all mounts from the car), disconnect the speed/reference sensors, reverse switch, bitch clip & shift linkage, and the rusted trans-exhaust mount.

Fortunately for me, the car has spent much of it's life in the salt-free state of Colorado, preventing any serious rust from forming. Everything around the back of the transmission is covered in transmission oil, thanks to a leaky selector shaft.

But onto the problem:
I decided to remove the hardest screws first on the transmission (good idea), and have successfully removed two from the car thus far. (Green arrows indicate removed bolts, yellow indicates stripped bolt)


The first half of those threads were rounded too much for an E10 socket to fit on, so I tried to fit an E12 on, which promptly slipped and slightly further damaged the bolt. A trip to Harbor Freight to get an E11 (clearly the correct size) did even more damage, and was unable to completely seat on the bolt. After some searching online, I tried to fit a hex socket (8mm) onto the bolt, which grabbed tightly, but ended up rounding out the bolt even more. I have an old set of Craftsman Bolt-Outs, but the smallest one is unable to adequately grab the head of the screw. There's plenty of stuff left to bite onto, just not enough for any of the tools I have. Any advice from you guys? I don't want to throw a bunch of tools here if you have a recommended solution ready.
--
Thanks,
TheYoungSir

[ahab]

Support the back of the gearbox with a floor jack, undo the motor mounts, hoist the motor and gearbox together and roll them towards the front of the car, exposing the entire bellhousing. Remove the stripped bolt by whatever means necessary.

[TheYoungSir]

Support the back of the gearbox with a floor jack, undo the motor mounts, hoist the motor and gearbox together and roll them towards the front of the car, exposing the entire bellhousing. Remove the stripped bolt by whatever means necessary.

At the risk of displaying my naivité, will this require an engine hoist, or can it be done with my trusty floor jack? Also, does the radiator need to be removed/disconnected?

[ahab]

It's helpful to remove the radiator because it give you more clearance, which allows you better access to the stripped bolt with which to work your magic. It does require an engine hoist for sure. If you don't have one, this is not the only way to fix your problem, but the method I would use in my garage.

[demetk]

^^ Agreed. You need access to the stripped bolts. At this point, you're only a short step away from removing the engine/tranny.

[D.]

I used to cut a slot in the bolt with part of a hack saw blade. Wrap one end of the blade with masking tape. Cut, cut, cut. Then, three hours later, a big screwdriver with a " visegrips" locked on positioned at a 90 degree angle AND your neighbor putting pressure on the end of the screwdriver with some sort of lever. OR, drive a socket and extension onto the end of the bolt with a 3 pound hammer. If you break the socket, you're on the right path. Just get the brand name socket that fits perfect.

[Tophdrive4u]

Pretty limited space there, I would agree with others that a floor jack on the front oil pan area is your best friend. Once you have the tranny supported, it is a matter of what you want to use, I would recommend one of those stripped head sockets, beat it on, roll it out. I think I have a set made by dewalt.. I know they work I had a stripped m10x75 on the last trip under... You may also consider relieving pressure to that bolt, even if it mean reattaching the ones you took out, that bolt is pretty long and strong, and obviously ready to get the friction on... Good luck op, fill us in

[foamy]

https://www.google.com/search?q=strippe ... B400%3B400

something like these is what you need. they sell small ones i had a stripped bolt from not using the right socket when i did my transmission and those did the trick.

[TheYoungSir]

Good luck op, fill us in

Don't we all hate it when someone fails to update? I'm still here. Due to some unforseen circumstances I was away from the car for a few weeks, but I really need to get it done now. The local mechanic wants over a half thousand just to replace the transmission (towing it in and out myself with everything else disconnected).

I've managed to borrow someone's engine hoist and load leveler for an indefinite amount of time, so the plan right now is to take out the radiator, support the engine via the lift, undo the mounts, then slide it forwards before getting the bolt off with some vise-grips. I'm hoping that the only things I'll need to disconnect are the coolant hoses to the radiator - can anyone chime in on this? Is there anything I should know about lifting the M30 (or an engine in general) ? I'm in over my head now, but I'm convinced that I can figure it out.

[TheYoungSir]

This is becoming a giant repair, but at least I'm making a little progress.

I removed the radiator, spilling the yellow contents all over the garage floor. There's a bit of corrosion on the thermostat housing where the foremost hose connects, so I might splurge on some fancy BMW coolant next time, since I'm pretty bad about draining/flushing/refilling my coolant on any schedule. Of course, that will have to wait until I can replace my leaking water pump in some other project.

I disconnected most of the coolant hoses on top of the back of the engine so I could get clear access to the bellhousing. I recommend against using screw-shut D-clips on the rear-lifting point, as trying to line up the screw is next to impossible. Nevertheless, I got it attached and started to hoist the engine. If you want to move the engine forwards, you are going to have to get around/over the motor mounts somehow. I tried to lift the engine over the mounts, but the transmission kept getting hung up in the bellhousing, and with the exhaust still attached (should have removed that a long time ago, btw), I couldn't get the lean required. I suspect it would be difficult anyway, as the bellhousing can't drop very far with the swaybars(?) in the way. You'll need to remove the motor mount brackets if you want to leave the exhaust on with the A/C and PS pumps attached, since the engine can't move sideways without hitting one or the other against the frame.

You'll also want to disconnect the point near the compressor where the line runs to the A/C radiator. There's a little clamp there that will give you some more flex-room if you disconnect it. I dragged the engine forwards a bit, and lowered it as far as I felt comfortable doing, then proceeded to jack up the transmission. It's still tight, but at least you can reach at it.

At this point, you can try all of your tools, but you don't have very much/any space for a rachet there. Vise-Grips would be a good idea, but the bolt was too far gone. A bi-metal steel cutting hacksaw did most of the work, and the Dremel ground the rest of it away. I used a grinding stone at the fastest speed mine could to, and watched the sparks fly. Keep going until they stop, or until you feel the washer come off. Use a mirror to check your work.

I'm debating whether or not to remove the transmission while the engine is still on the hoist, since it's leaning at such a convenient angle right now. Fortunately, the hard part's over now!

[demetk]

You're at the point right now of being able to remove the engine/tranny out of the car. Is there any reason you're not considering that option?

[TheYoungSir]

I don't believe there's a reason to take it all out. I don't think it makes removing/installing the transmission significantly easier. There's still a lot of stuff that would have to be disconnected. wiring, fuel, exhaust headers.
Mainly, I'm trying to get this done as quickly as possible. The car's been in the garage since early June, and the rest of my family is eager to put their nicer cars into it. I'm hoping against hope to have it done before the 18th when college starts.

[demetk]

There's still a lot of stuff that would have to be disconnected. wiring, fuel, exhaust headers.

So you're lifting the engine up and forward with all of those things connected? Carry on then.

[TheYoungSir]

So you're lifting the engine up and forward with all of those things connected? Carry on then.

It's worked out okay so far, most cables have the slack to move a little bit. Do note that the throttle cable does not, and I broke mine.

[jodystevens]

Too bad it wasn't a Getrag 265/6. Then you could remove the case and have infinitely more room.

Perhaps post up a picture, I'm interested in helping because it would seem this may be out of your skill level and because I know what it feels like to be in over your head. If I am understanding correctly the trans mount is undone, the motor mounts are undone and you have tilted the whole thing back to gain better access?
Which bolt is it that is stripped, the one around the starter(color blind, yellow and green look the same)? Your best option may be to remove the intake and slice the head off the bolt with a dremel, but post a picture from under the car so I can see what your up against. It all depends on how bad the bolt is stripped, a bolt extractor may work. I have had little luck with them in the past.

[davintosh]

When you get to the point of putting everything back together, don't bother replacing that bolt. The next guy who pulls that transmission will thank you.

[JohnH]

I do wish that people would stop saying that the bolt is stripped. If it was you wouldn't be making a meal out of this. Its the bolt head that is rounded.

Having got this far take the damn engine and gear box out and split it on your garage floor. You will thank me for telling you this.

[tn535i]

Well, most would say the bolt head is rounded off. I feel you're pain and I've has this in difficult locations before too. Consider rusty suspension parts in near impossible locations to reach and only a wrench will fit.

Just to reiterate what has probably already been suggested.

With access put the bolts back in either side of it and torque those down to relieve some of the pressure on it, or that pressure will fight you trying to remove it. Then hope that a good pair of Vise-Grips will break it. Good ones (I prefer the originals) with shortest stubiest jaws and sharp teeth. Not some knock off or you will just round it more.

If that doesn't work then as others have said you could put it back without that bolt. So get a die grinder or Dremel or whatever and cut the head of that thing and don't worry too much about some damage to the trans case. If you do mess up the trans case a little you could dress it and put a bolt back in anyway, maybe with a washer underneath, or just skip it.

It's brute force time, you have 12 days, no problem. Stay determined.

[jodystevens]

I do wish that people would stop saying that the bolt is stripped. If it was you wouldn't be making a meal out of this. Its the bolt head that is rounded.

Having got this far take the damn engine and gear box out and split it on your garage floor. You will thank me for telling you this.

Quit being such a pedantic asshole, we're trying to help a fellow who is having a hard time, not teach him the technical terms. For all intents and purposes everyone understands what "Stripped Bolt" means.

[TheYoungSir]

I'm not sure I was clear, but I ground the head/washer off of the transmission in my last post. I was trying to decide whether to put the engine back on the mounts when I continue removing the transmission.

<snip> Which bolt is it that is stripped, the one around the starter(color blind, yellow and green look the same)? Your best option may be to remove the intake and slice the head off the bolt with a dremel, <snip>

The leftmost one is the one with the rounded head. Pretty much what I did, but my long slender arms let me use a grinding stone without having to remove the intake.

When you get to the point of putting everything back together, don't bother replacing that bolt. The next guy who pulls that transmission will thank you.

That's the plan

I do wish that people would stop saying that the bolt is stripped. If it was you wouldn't be making a meal out of this. Its the bolt head that is rounded.

I decided to put the engine back on the mounts, since it seemed a bit dangerous to do it while it hovered in the air. Only broke a cable grommet (Image) (35411152744?) , and badly mangled a coolant hose; upper left corner of second pic, attaches to heater valve (Image1 Image2). Where would I buy a replacement for the hose? It doesn't seem to have a P/N on realoem (do you even buy hose like that?). Hopefully those will be here by the time I get the tranny back in place.

[tn535i]

So the bolt is out without having to pull everything? Good for you. I guess you put the engine back on the mounts and let the transmission tail drop down to get it out. I don't like to let the engine rest hard against the firewall if I can avoid that and prop it up near the rear.

[TheYoungSir]

Maybe I'm just a terrible mechanic, but I have no idea why there aren't pages and threads dedicated to the difficulty of this job; stripped bolts notwithstanding. Hopefully the next person to do this will be able to get some use from this thread.
Last night I got the transmission out of the car. Much brute force was involved, and I had to lower the front swaybar to get the transmission down.

...I guess you put the engine back on the mounts and let the transmission tail drop down to get it out. I don't like to let the engine rest hard against the firewall if I can avoid that and prop it up near the rear.

I actually jacked up the transmission so I could get at it from the topside. Unfortunately, it is resting on the firewall at the moment, as I don't see a way around it.

Today I removed the pressure plate from the flywheel. As it's name implies, it applies pressure to the flywheel. If you remove the bolts one at a time, the last one will not be removable, and will strip. These bolts are a lot harder than the ones that hold the transmission together, so I needed to use the cutoff wheel to get rid of it.

Now that I'm inside, I'm realizing just how few parts came with the bavauto clutch kit. It's just exhaust flanges/nuts and seals/bearings with the alignment tool and the pivot pin. Rich Euro M5 suggests here:

1) Remove / replace the crankshaft rear main seal.
2) Install new input / output and selector shaft seals on the transmission. Replace the reverse switch on the transmission.
3) Replace the plastic pivot pin with the metal part from the E31 8er.
4) Replace the clutch release fork and the little retention spring.
5) Replace the pilot bearing
6) Replace the all the rubber pieces in the shift console, including the forward console mounts and the foam isolation donut.
7) Replace the Shifter selector knuckle and the little rubber disk between it and the selector shaft
8.) Replace the 2 plastic parts in the shift console cup.
9) Use new flywheel and pressure plate bolts.
10) Replace the guibo and the center bearing.
11) Replace the drive shaft if the rear u-joint has any play.
12) Replace all the gaskets in the exhaust system from the manifolds back. Replace the rubber hanger donuts.

I'm doing 1,2 (not reverse switch),5,9,10, and 11.

Here are my questions:

1. How important is it to replace the fork? Mine looks a little worn, but I don't know how to judge it. (Front, Back)
2. Is the metal pin (21511223281) still considered a good upgrade?
3. Am I crazy for not redoing the whole shifter (non-sheetmetal type) while I'm in here?

----
Thanks for all the help!
More pictures can be found here.

[Mark 88/M5 Houston]

I would follow Rich's list and not skip any points. From the pictures you posted I'd have the flywheel resurfaced. You don't want to have to redo the job because you cheap out on a couple of "minor" parts.

Pressure plate bolts should be removed evenly around the circumference of the plate. Break all of them loose and then back each one out one turn and eventually the spring pressure releases and they will all come out with no cutting of metal. Re-installation is the reverse. Use blue loctite on the pressure plate bolts and the proper torque specs from the pressure plate spec sheet.

[tn535i]

I think you said up front you have an upgraded FW and clutch, I assume also new PP. Personally I don't mind leaving old seals alone if they do not appear to have leaked but never old bearings like the pilot and TO. Replacements seals not done just right might also leak soon so it's a gamble in a way I think. If the fork is not damaged it would be fine and yours looks that way. If the TO spins on the fork it needs replacement though(not your case). The pin for sure, the spring ?, cleaning and lubricating everything with the right materials definetely.

Only you know how the shifter felt. If you thought it was OK you might just put it back together since you can get to it later. Same for the guibo, CSB and such. These can also be done without removing the exhaust but you do need to carefully lower it all.

I think a lot boils down to if the goal is to R&R a car you plan to keep a very long time or just get back running again and don't see it in your future. If a long term keeper do as much as possible now.

[TheYoungSir]

Well, today I found the source of my shifting problems. The plastic pivot pin isn't just busted, it has been busted for a long time. So long, in fact, that the fork has worn a decent groove into the bellhousing wall. You can see the wear on the left side of the fork in this picture. I'm getting a new fork in case this one has bent due to the abuse.
The clutch was replaced at ~100k by the PO (thanks for that top bolt), and I can't help but wonder if the pivot pin was one of the infamous "extra parts" left over at the end of a job.

I would follow Rich's list and not skip any points.

I'm skipping out on 6 and 8 since I can do them later, as well as the reverse switch (doesn't seem to be a common failing). You are absolutely correct though, I'm going all new in the bellhousing area.

Personally I don't mind leaving old seals alone if they do not appear to have leaked but never old bearings like the pilot and TO.
I think a lot boils down to if the goal is to R&R a car you plan to keep a very long time or just get back running again and don't see it in your future. If a long term keeper do as much as possible now.

The rear main engine seal is leaking a little, so I'll take my chances and replace that. I will give the rear trans seal a pass though. It can be replaced while still in the car, I believe, and appears to be extremely difficult to remove.

Looking forwards, I'm praying that I don't screw up the rear engine seal. Then I get a few days off until my parts roll in; transmission mounts, steel pivot pin, bolts, etc.
Based on the advice of this thread, I'm going to use 83 23 9 416 138 to lube the input shaft. It was completely dry when I pulled it off, but not stuck.

Thanks for all the support, there's no way I would have been able to make it this far without your advice, both here and in the archives.

[tn535i]

The difficulty with the rear main is the oil pan is also involved and you need some sealant at the corners of the pan and rear cover. Otherwise the cover and seal are not too bad. You can skip the pan and do it later but what I would do is loosen it up so it drops slightly or at least relieves pressure then retighten after the rear seal and cover are done. I did that years agao and have yet to have any more than a minor drop or two. I think you also want a sealing type thread locker on the flywheel bolts since I think the tapped holes go through to the crankcase. It's also a watch out when cleaning or you could force crud into the pan.

Using the proper grease on the splines is a good idea but go sparingly. Not so much it might fling out onto the friction surface. I've used a high moly grease spline grease I read others recommended but no doubt the BMW part is a good choice.

[TheYoungSir]

As you may have surmised, I didn't get it done by the 18th. As a direct result, I've had very little time to finish the project. Nevertheless, it's almost finished.

A few notes from the process:

• The steel pivot pin has a larger pole, so you'll need to drill out the hole in the transmission case.
• When packing bread into the pilot bearing, use just a little at a time. You'll need a hammer to drive it in at some point.
  The flywheel bolts are perfect for smashing the bread into the center of the bearing.
• When replacing the input shaft seal, make sure the input shaft spins freely after replacement. If it doesn't, then the seal wasn't driven in far enough.
• The easiest way to hold the engine still when tightening the flywheel bolts is to get a helper with a breaker bar on the front side of the crankshaft.

Last time I posted, I had just removed the flywheel from the crankshaft, and was preparing to reseal the transmission and engine. I have since replaced the pilot bearing (the bread method really works), rear main seal, transmission input seal, upgraded the pivot pin, added a second selector shaft seal, and topped off the fluid in the transmission. Now I've got the flywheel, clutch, and pressure plate successfully installed. The only things left to put back together are the transmission, transmission mounts, driveshaft (rebuilt), exhaust, speed/reference sensors, throttle cable grommet, radiator hose, radiator, coolant, main relay, ecu, coil, and cap/distributor.

No questions this time, just a few things I encountered on my quest to get the job done.

[demetk]

Nice work. You should be able to handle just about anything now.

[TheYoungSir]

Nice work. You should be able to handle just about anything now.

Indeed I have. Installation was essentially the reverse of removal. It is worth noting that a floor jack is adequate for transmission reinstallation, since the transmission-area is too small for it to fall off of the jack.

All of you were right in my previous thread. It's amazing. The shift point is more than a half inch off of the floor (more towards the top half of pedal travel), and the transmission shifts much smoother now. The synchros in the transmission have seen far better days, probably before being driven for ~100k with a bad clutch, but it's something I can deal with. I'm a little worried about the rear main seal leaking, only because it would mean a complete teardown that I don't have time for.

At the end of the day, it drives, feels great, and works properly, for the first time in a long time.

[rollcentre]

Maybe I'm just a terrible mechanic, but I have no idea why there aren't pages and threads dedicated to the difficulty of this job; stripped bolts notwithstanding. Hopefully the next person to do this will be able to get some use from this thread.
.

The young sir,
Please tell me you found my thread. I've been there done that and documented some tips and tricks I found while doing the job here on mye28. So here it is, let's compare notes-


http://www.mye28.com/viewtopic.php?t=125484

[TheYoungSir]

Please tell me you found my thread. I've been there done that and documented some tips and tricks I found while doing the job here on mye28. So here it is, let's compare notes-
http://www.mye28.com/viewtopic.php?t=125484

Your thread was like a second Bentley to me. There are only a few things I did differently:

• I used 3 studs (plain old studs, since I don't have a lathe) when installing the transmission. I don't know if that made a huge difference, but it comfortably sat on the studs while I lined up the input shaft.
• You also need to get the transmission in gear before you put it under the car. Use a screwdriver (No specific advice here, just wiggle it around until something happens) on the selector shaft until both the input and output shaft spin together. At that point, you line it up on the studs, and push it forwards while spinning the output shaft.
• Also, if I were to do this again, I would bag and label groups of screws. It is a true miracle that I managed to solve the puzzle that is 4 bins of vaguely sorted fasteners after four months, and get everything back where it belongs.
• The picture on RealOEM for the shifter rod is upside down. If the transmission is hard to shift, with reverse almost impossible, ESPECIALLY if the shift knob moves around as it hits the nuts and bolts on the guibo, you need to get in there and flip it around.

[rollcentre]

[*]Also, if I were to do this again, I would bag and label groups of screws. It is a true miracle that I managed to solve the puzzle that is 4 bins of vaguely sorted fasteners after four months, and get everything back where it belongs.

I pretty much do the same thing. On my last driveway job I ended up throwing the hardware in one pile. Took it to work to clean it, and then bagged it up and sorted in individual baggies.

If i can get the work completed within a weeks time i won't have a problem.. any longer than that and it turns into a game of Husker Du?