Corner bolts on transmission pan need to be tapped. How critical is this?

[RT Cruiser]

Hey Everyone.

Today, as I was in the process of dropping the transmission pan, two corner bolts snapped and need to be tapped out. A small amount of fluid came out of one corner when I did the refill, about 3 tablespoons. No fluid came from the other corner. After a short 8 mile drive, the LC has been in the garage for the past 3 hours. No more fluid has seeped out.

Due to time constraints, I probably won’t be able to drill and use a screw extractor to pull the bolts, replace with new bolts, until after Thanksgiving.

Is it ok to still drive it? Will the gasket and transmission housing form it’s own seal?

 

[molanginaeda]

Did you create more problem? If it's ain't broken, don't fix it.

Now you need to remove the broken bolt. Is there room for vice grip to grip on broken bolt? If not, then you need to get a broken bolt extractor to remove the remaining bolt. You definitely don't want to damage the thread. Prior to attempt anything, please drop the pan and apply heat to the bolt.

 

[RT Cruiser]

Now you need to remove the broken bolt. Is there room for vice grip to grip on broken bolt?

I tried 2 vice grips different angles and they would not budge.

 

[molanginaeda]

I tried 2 vice grips different angles and they would not budge.

You need to heat up the bolt and thread area. Heat is the key to loose the broken bolt.

 

[RT Cruiser]

If I can find a way to heat the bolt without using a flame, I’ll do so. Right now I’m wondering if it’s ok to drive for a week or so until I can repair it.

 

[bloc]

I doubt all the fluid will come out at once but if it decides to start leaking I bet it could make a mess quickly. I'm pretty sure when the truck isn't running the fluid level is above the top of the pan, so that would probably be the likely time it'd leak.

So giving a good look under the truck before driving anywhere would be wise.. and once you do, maybe stop periodically to see if it's seeping. The good thing is it should only drain anything above the top of the pan... not great, but not exactly a hole in the bottom either.

Also I doubt you'll be able to get much heat on the bolt without harming the pan gasket, if it's still in place.

 

[RT Cruiser]

@bloc again your wisdom is helpful. I’m so exhausted that in the evenings my brain can’t work. I may try a small drill then a torx head and/or extractor to pull it out.

 

[molanginaeda]

If I can find a way to heat the bolt without using a flame, I’ll do so. Right now I’m wondering if it’s ok to drive for a week or so until I can repair it.

Don’t heat the bolt without taking the pan off. Transmission pan need to be off. You have to replaced the gasket anyway. As for driving, it is a risk to drive the car for long distance. You will have to make a decision to risk or not. I won’t give advice due to the risk.
To remove the broken bolt, you only have 2 choices. If vice grip can grip, heat the bolt and area HOT and try to WIGGLE it loose. If vice grip is not an option, you need to get a broken bolt extractor tool. Still heat it HOT before attempt with the tool. The most important is to avoid damaging the thread on the transmission housing.

 

[molanginaeda]

If you recall transmission fluid check procedure, the bolt to check fluid is on the pan. That the proof transmission fluid level within the transmission.

 

[tominboise]

You might try driving the rig long enough to get the tranny good and hot, then shut it off, get underneath and freeze the bolt only with a can of compressed dust off (used to clean computers), then grab with your vise grips and see if it will turn out. You are trying to break the bind between the steel bolt threads and the aluminum tranny housing.

 

[steve berman]

If it starts leaking any amount close to noticable, I would stop driving it. Last thing you want is fluid traces covering the underside of your LC.

 

[TimCFJ40]

If it starts leaking any amount close to noticable, I would stop driving it. Last thing you want is fluid traces covering the underside of your LC.

Well I can think a few things that I would want less than that, like frying the transmission due to low fluid.

Is the transmission pan gasket a paper or cork gasket, or is it FIPG (RTV)? I think I see a paper style gasket in there, but I haven't dropped the pan on a 200 series myself.
I work in Engine Manufacturing, and many of our FIPG Gaskets will survive missing bolts for a good long while. If it's a cork/paper style gasket, it will fail pretty quickly without proper clamp load on those corner bolts. Either way, I'd closely monitor for fluid seepage and stop driving it immediately if there's been significant fluid loss. If you start to notice diminished performance from low fluid, it's probably too late. I also find it odd that a few tablespoons came out when you refilled, then it stopped. It would be really rare to have any type of gasket interface leak a notable amount then self seal....

 

[bloc]

It is a molded rubber gasket.

 

[RT Cruiser]

Thanks everyone for stepping in to help. I'm tight on time today so I can't address everyone individually - but a huge thank you. I tried many things yesterday such as heat, cold, big tools, small tools, different sprays.... nothing worked. I decided to drill through the seized bolt so I could install a new bolt with a locking nylon nut on top with another nut on top of it. Thanks to @bloc and @Taco2Cruiser for providing support and guidance privately. I can't thank these two enough.

We are leaving tomorrow and this Cruiser MUST be ready - not exceptions. So far I've completed new rotors and pads front and rear, new hand brake shoes and fasteners, brake fluid bleed, stainless steel brake lines, serpentine belt, engine oil, front and rear diff oil, transfer case oil, power steering fluid, thermostat/hoses/coolant, pcv valve, engine air filter, cabin air filter and repairing the cabin filter cover, dash cams all 4 sides, transmission fluid and filter, grease the driveshaft, new Interstate battery, new wipers, low and hi headlight bulbs, spark plugs, and cleaning out my wonderful son's collection of sticks in the cargo area.

I highly recommend everyone to remove, very SLOWLY and CAREFULLY, the bolts in the transmission pan - do it one by one. When you pull one out, put on CRC anti-seize, then gently put it back in. If you do it this way you will not need to drop the pan and it will increase the odds the bolts in the transmission pan will not seize/corrode. If you don't have a clue what I'm talking about, hire a professional. Maybe I'll post this on a new thread.

 

[steve berman]

Well I can think a few things that I would want less than that, like frying the transmission due to low fluid.

Is the transmission pan gasket a paper or cork gasket, or is it FIPG (RTV)? I think I see a paper style gasket in there, but I haven't dropped the pan on a 200 series myself.
I work in Engine Manufacturing, and many of our FIPG Gaskets will survive missing bolts for a good long while. If it's a cork/paper style gasket, it will fail pretty quickly without proper clamp load on those corner bolts. Either way, I'd closely monitor for fluid seepage and stop driving it immediately if there's been significant fluid loss. If you start to notice diminished performance from low fluid, it's probably too late. I also find it odd that a few tablespoons came out when you refilled, then it stopped. It would be really rare to have any type of gasket interface leak a notable amount then self seal....

I mean, I agree.. My wife's civic had a minor valve cover leak for a while which leaked just a tad of oil each day. When it came time to replace the radiator (unrelated event), the work was such a mess. Everything was riddled in oil.. I swear went through two boxes of latex gloves just to perform the work..

It was a disaster.. and I wouldn't want to wish that type of mess on anyone.

 

[KLF]

Last thing you want is fluid traces covering the underside of your LC.

Hehehe... I actually paid $250 just yesterday to have a place SPRAY oil under my entire truck. It's home now, sitting on the dirt part of the driveway, dripping and curing, airing off the stink. (not it's not Fluid Film)

I highly recommend everyone to remove, very SLOWLY and CAREFULLY, the bolts in the transmission pan - do it one by one. When you pull one out, put on CRC anti-seize, then gently put it back in.

This is actually a really good idea. I've already done every single bolt under the truck that I could reach and remove, I should do those pan bolts too.

If you don't have a clue what I'm talking about, hire a professional. Maybe I'll post this on a new thread.

Funny about that... 2 years ago I paid the local dealer to drop the pan, clean the screen and magnets, then do a full flush with new WS fluid in my previous '11 LC. It wasn't cheap, but it really made the thing drive like new. The "best tech they had" broke 4 of the bolts off, just like you did. He had to drill them out and helicoil. So apparently seasoned pros break them.

It was a disaster.. and I wouldn't want to wish that type of mess on anyone.

That's what pressure washers are for.

 

[turbo8]

I ran into this same problem, both rear corner bolts were seized in there and snapped pretty easily. I was able to extract 1 of them. The other one, not so much. I guess I'll drill the hole bigger and put a thru bolt and nut on top.

 

[bloc]

Interesting. Might we worth adding this to the PM list.. occasional anti-seize for those corner bolts?

Anyone know what the ideal anti-seize compound is for a steel bolt into an aluminum housing?

 

[turbo8]

Yes, they are the only ones that are tapped all the way through, which will allow the upper parts of the bolts to corrode.

 

[4gotalot]

Interesting.might we worth adding this to the PM list.. occasional anti-seize for those corner bolts?

Anyone know what the ideal anti-seize compound is for a steel bolt into an aluminum housing?

I agree, this should be a PM item.
++If rust already has started on the protruding portion of the bolts then use some navel jelly or a rust remover of your choice.
-Wash off rust remover and let dry
-Apply LPS 3 to the rust free protruding bolt
-Crawl out from under the cruiser, check it off the list, have a beer of your choice.
-Repeat with LPS 3 if you find yourself under there any way or reapply every 3 years