I broke the bell housing and I didn't even have to drive the car

Printable View

10-20-2010, 12:54 AM
TurboSinceBirth

I broke the bell housing and I didn't even have to drive the car

I got the stock transfercase bolts in yesterday to replace the longer EK2 ones I had since I replaced the brace with a SS front and mid housing on my 5-speed. Last night I tightened up the bolts finger tight and started to torque them all down. One of the bolts didn't even make it to 63 ft-lbs before the ear broke off on the bell housing. Now the transfercase is held on by 4 of the 5 bolts. I'll have to get some pics of it this weekend. I don't know why it broke off. It could be from 17 y.o. fatigue of the aluminum, overtorque sometime in the life of the transmission, some other stress that caused a crack to propogate which only spread at the border of the grain, or something else. I did not see it coming and it almost makes me question the integrity of the rest of the transmission case.

I know the metal gets fatigued and is one reason why a lot of the 6-speed housings are cracking besides the large amount of power being put through them. My buddies' father-in-law has a big spool gun and can weld thick aluminum so I'll try that out. I may see if some brazing will work before that. I'd rather not heat up the material too much so it becomes brittle and just breaks at the edge of the weld. Anyone else that has busted an ear off their bell housing what did you do to fix it?
10-20-2010, 03:57 AM
MR2

Need pictures :)
10-20-2010, 10:07 AM
Chris@Rvengeperformance

I'm sure you know what you are doing, but it didn't get caught on the doll pin, did it?
10-20-2010, 10:33 AM
Austin@STM

^this. For it to break chances are it wasnt on all the way yet, and was being pulled in crooked. If it was tight on there there wouldnt be room for it to bend the ear and break it off, it would usually strip the thread before breaking.

Also are you sure it was the right bolt, if the shoulder on the bolt was to long then once the shoulder hits the threads as you keep tightening it will push outwards and break the casing around the threads.
10-21-2010, 12:29 AM
TurboSinceBirth

Quote:

Originally Posted by Austin@STM

^this. For it to break chances are it wasnt on all the way yet, and was being pulled in crooked. If it was tight on there there wouldnt be room for it to bend the ear and break it off, it would usually strip the thread before breaking.

Also are you sure it was the right bolt, if the shoulder on the bolt was to long then once the shoulder hits the threads as you keep tightening it will push outwards and break the casing around the threads.

No because it was already on the car tight up against the bell housing. There was no misthreading because I hand tightened them all. They were all OEM bolts because I ordered them and doubled checked the threads. I had 3 of the 5 bolts since the EK2 brace uses longer ones. I ordered the other longer bolts I needed. It's possible that it got stuck on the pin but I didn't think it did. The car wouldn't have been moveable pushing by hand since it would have binded before. I checked the torque on the bolts and none of them were loose after the ear broke off. I watched it as I tightened and the housing was flush against the transfercase in the spot it broke. It still is against it flush. I've had the transfercase off and on quite a few times so I knew what it felt like when not everything lined up right, it wasn't on all the way, or it was hitting against the dowel pins. I had it happen a few times. I didn't put any bolts in though. I kept adjusting the driveshaft in and out of the transfercase to where everything lined up just right and it fit fine on the pins.

Don't you think if it was on there crooked and binding that it would have taken more than the service manual torque specs to break off the ear? It's not necessarily true but I think like you said it would have stripped or something else before it broke. My torque wrench didn't click when it happened but I think it was getting close to it.

I have some dark cell phone pics of it but I'll get some better pics this weekend when I go to work on the car some more. It's one of the shorter bolts and it's the bottom right one I believe.