I finally changed my tranny fluid to the GM Suncromesh stuff today. Everything was fine until I was tightening all the bolts and the fluid check bolt broke off. The threads of the bolst are still in there but not head. Can I drive my car like this?

 

How much pressure did you put on the bolt for the head to break off? It sounds as if you may have cross-threaded the bolt and then when you tried to tighten it the head broke off.

I would get it checked, and also you need to make sure you are not leaking any fluid. If you didn't cross thread it and the head broke off, it may have been a defective bolt and you should check with the dealer to see what they can do. Also, without a head on the bolt, it could loosen and fall out and I wouldn't want to go on a trip and have to worry about that.

So the bottom line is to get it checked out at the dealer and maybe they can determine if the bolt was defective and warranty it.

 

There was no cross threading whatsoever. I reused the stock crush washer on that bolt and it crushed it too much. The bolt was crushing the washer and it kept turning and turning without too much resistance until snap, the head came right off. I drove it for a little while and then checked but i didn't see any fluid leakage.

Really the only way I see anyone getting the piece of bolt out now is to drill and tap the thing. Maybe I'll just drive for a while and see what happens.

BTW, what does happen when your MT gets low on fluid? Hard to change gears, noise? Anyone know?

 

Did you use a torque wrench? I don't recall what the spec is, but I seem to remember, it is not high (perhaps around 29 to 33 lb/ft).

 

That's a tough one.

I know what you mean about the bolt not feeling tight, but as SouthernBoy said, if a torque wrench was used, you'd see how little torque there is on these bolts.

It is possible that someone could drill it and use an extractor on it, but since it's only a 6mm stud, it'll be pretty hard. Other options will not be pretty.

Good Luck.

 

A 6mm stud couldn't possibly withstand 29+ lb/ft of torque. I'm guessing it's somewhere around 10-15 lb/ft. A small bolt or stud is VERY easy to over torque and break. This is the reason it is ABSOLUTELY REQUIRED to get a new crush washer when reinstalling these plugs. It takes too much torque to further crush an already crushed crush-washer...

You are gong to have the stud drilled and extracted. Have a professional do it. And don't drive the car unless your sure the stud can't spin in the hole...

 

8.7ft lbs according to the service manual

 

See! This is as much torque as a valve-cover nut requires to seal a rubber gasket. If you have never had the pleasure of torquing one of those off, you would be surprised how little wrist force it takes. Even using your smallest ratchet, they will twist the studs in half with almost no effort...

A Torque wrench and factory torque specs are your best friend when working on your car...

 

Thank you gentlemen. I wrote my response this morning while at work so I didn't have my shop manual handy. I knew it was pretty low, but I didn't realize it was under 10 lb/ft.

So I just went out to my garage and got my manual and here are the torque specs for the three manual transmission plugs in question.

Fill plug = 33 lb/ft
Sight plug = 8.7 lb/ft (also called the oil check bolt)
Drain plug = 29 lb/ft

You should never install bolts, lug nuts, or drain plugs in an engine or other parts of the car, where there are torque specs, without using a torque wrench. Not only do you risk sheering off the head (as you unfortunately have found out), but with steel and aluminum are mated via threads, proper torque is very important.

 

Sorry to hear your misfortune. I bought a 1/4" clicker type torque wrench ($25 at Harbor Freight) for tighten down any torque value less than 15 ftlb since that tends to be low end of 3/8" torque wrenches.

In terms of your problem, try to spins it out by hand. Since this is a small bolt I would be very careful drilling out the stud and using a stud extractor. Since it is small more than likely you may be able to get it out with your fingers or try a pair of needlenose pliers on the remains of the bolt to grip. I know that bolt is in a tight area so it's not easy to work on.

 

My guess is that it would leak, because there is a crush washer at the head of the bolt to help seal the hole. Good luck drilling and re-threading the hole, you then might want to change the trans fluid again after that because some debris will then fall into the trans.

 

Funny you mention a torque wrench from Harbor Freight. I went there twice in the last 2 weeks looking for one before this install but all they had each time was a 1/2" drive. I should have used a torque wrench but after reading every post about this install I never saw any specs on that particular bolt - just the fill and drain ones. I foolishly thought it must not have mattered.

As for getting the remaining bolt out - not gonna be easy. Not only did the head come off but about 3-4 mm of the thread came off too. So it's pretty recessed - I'm not sure a needle nose pliers would get the job done even if I could reach that area with ease.

What are the odds s fluid actually leaks? Does the fluid level rise inside the tranny when everything is moving? On level ground when the car is off the fluid is below that particular hole.

Also, what kind of pressure builds up in the tranny during normal use?

 

Another real danger is the threaded portion either loosening and falling out or worse, falling into the transmission case. Since it has no head to stop this from happening, I would be concerned about this. Unless the threads are stripped. Then I would worry about debri getting into the trans case.

I have three torque wrenches. One goes up to 150 ft/lbs, one to 100 ft/lbs, and the one I use when I change my TL's oil is measured in inch/lbs and I don't recall its maximum setting.

 

You can get a 3/8" drive torque wrench from Autozone that reads in "lb/in". The cool thing is that it's marked in increments of 120, so converting to "lb/ft" in your head is very easy (120 in/lb = 10 ft/lb). It's max setting is about 80 lb/ft of torque (960 in/lb)...

 

Clean the area up good then use a little silicon sealer over the broken stud to hold it for the moment.

If you are up to it search for a left handed drill bit. These are cut to drill counterclockwise and will often spin out a broken bolt.

If you are not up to it get a mechanic to do it, shouldn't be too expensive

 

I have to chewck the shop manual but every Honda/Acura that I have owned had some sort of vent tube for the manual transaxles so very little (if any pressure builds up in the transaxle).

I doubt that much if any fluid will leak out since it is at the top of the fluid level. As for getting it out that may take alot of time and patience since I know it's in a hard to reach area so getting a drill in there to drill a 1/8" hole for a extractor is touch. Also you want to drill as straight and level as possible.

What is worth check is trying out a pair of bent tip hemostats which might be able to grip something. More than likely getting the remainder out without a screw extractor is typically easy for smaller bolts. And the vehicle is new so the disimilar metals between the transaxle case and the steel bolt should not be a problem yet.