help! cracked bellhousing and bolt hole on motor

995speed · May 29, 2013

99 XJ 4.0 Ax15
Was driving home from school yesterday on the highway when the 2 month old u joint bindrd up on me and caused the rear drive shaft to propel underneath my jeep. Buddy came to the rescue with a tilt trailer and a pickup cause I had my front one out while I was rebuilding upon putting it in I noticed that my bell housing got cracked and the hole on the motor that the trans bolts into as well. I am not concerned about the bell housing that much they are around for cheap enough my concern is the bolt hole that cracked on my block ik it's cast iron and a pain to weld I'd really rather not put a new motor in cause the one I have is cherry and I don't have the money for that either has anyone experienced this before what did you do? I've heard that some marine tex epoxy to put it back then drill it out and tap it to size could serve as a temp fix but I'd rather have it welded if it'll hold for long time. Any input is greatly appreciated cause not only is this jeep my baby its my only way to go to and from school .

Flyfisher · May 29, 2013

Wow...maybe a period or comma now and then please? Very difficult to read and understand without some punctuation.

I'm still trying to figure out how your rear driveshaft "propelled" forward far enough to knock a hole in the bell housing.

I'm no expert, but I think a welded repair is your best bet.

8Mud · May 29, 2013

Epoxy isn't going to hold much if anything.

I'd likely find me a piece of flat stock (steel) 1 1/2"-2 inches wide, three inches long and 1/4"-5/16" thick, drill it and use it as kind of a washer. Put a bolt all the way through with a nut. You may have to bend one end of the flat stock steel a little or notch it (even better) to clear the strut brace behind the the bell hosing mounting ear sticking off the side of the motor.

Spot weld the nut to the flat stock and the flat stock to the cast iron. Near full power on a MIG. A deep spot weld will work on cast iron, a typical bead not so well. If you pre heat the cast with a torch you can get a decent weld with a MIG, a deep burn spot weld, then another and another, also works after a fashion. Ypu just have wire brush each weld to get the carbon and splatter off before making the next weld, be quick, heat is your friend here.

If you are still worried about strength, get a longer bolt, screw it in there, cut off the head and weld it to the cast iron. Turn it into a stud.

I popped one of the mounting ears off of my tranny to transfer adapter, on my Chev 1500 sliding over a rock. Instead of four bolts holding the tranny to the transfer, I had only three. It never caused me any issues.

I'd also pull all the bolts from the bell housing and inspect them for cracks, the same with the bottom opposite side mounting ear on the block for the bell housing. If one broke off maybe the others got stressed.

995speed · May 29, 2013

8Mud said:
Epoxy isn't going to hold much if anything.

I'd likely find me a piece of flat stock (steel) 1 1/2"-2 inches wide, three inches long and 1/4"-5/16" thick, drill it and use it as kind of a washer. Put a bolt all the way through with a nut. You may have to bend one end of the flat stock steel a little or notch it (even better) to clear the strut brace behind the the bell hosing mounting ear sticking off the side of the motor.

Spot weld the nut to the flat stock and the flat stock to the cast iron. Near full power on a MIG. A deep spot weld will work on cast iron, a typical bead not so well. If you pre heat the cast with a torch you can get a decent weld with a MIG, a deep burn spot weld, then another and another, also works after a fashion. Ypu just have wire brush each weld to get the carbon and splatter off before making the next weld, be quick, heat is your friend here.

If you are still worried about strength, get a longer bolt, screw it in there, cut off the head and weld it to the cast iron. Turn it into a stud.

I popped one of the mounting ears off of my tranny to transfer adapter, on my Chev 1500 sliding over a rock. Instead of four bolts holding the tranny to the transfer, I had only three. It never caused me any issues.

I'd also pull all the bolts from the bell housing and inspect them for cracks, the same with the bottom opposite side mounting ear on the block for the bell housing. If one broke off maybe the others got stressed.

Im going tonsee if I can find someone willing to try that. as for running with the broken ear I tried that just in my driveway. got an awful scrapping noise when pressing in the clutch cause the trans is shifted to one side I noticed last time I took this trans out which was to do a throwout bearing the two E12s up top were not existing if I were to gry some hex bolts to replace them, and put all the other volts back in will it be in driveable condition?

8Mud · May 30, 2013

There is only four (sometimes five) main bolts holding it all together along with the spacer.. The two (sometimes three) at the top are two of the four you have to have. You can likely get away with three until you find somebody to do the welding for you. Best to have somebody that is familiar with cast welding do it. Rod welding cast with nickle alloy rod isn't that difficult. MIG is a little harder, especially with normal gas and wire, but doable.

You may just get unlucky, welding sometimes cracks the cast in a different spots and is kind of unpredictable. It is kind of a get it hot, but not too hot, then keep it warm and let it cool slowly. A lot like welding sheet metal body panels, you have to control the heat or things flex and bad stuff happens.

It will likely never be as strong as the original, but like I said, three good bolts should be enough anyway.

You might want to think about adding a top center bolt. My 88 never had one, my 87 did. I don't really know if it is still a unused threaded hole on the 99 or not.

995speed · May 30, 2013

8Mud said:
There is only four (sometimes five) main bolts holding it all together along with the spacer.. The two (sometimes three) at the top are two of the four you have to have. You can likely get away with three until you find somebody to do the welding for you. Best to have somebody that is familiar with cast welding do it. Rod welding cast with nickle alloy rod isn't that difficult. MIG is a little harder, especially with normal gas and wire, but doable.

You may just get unlucky, welding sometimes cracks the cast in a different spots and is kind of unpredictable. It is kind of a get it hot, but not too hot, then keep it warm and let it cool slowly. A lot like welding sheet metal body panels, you have to control the heat or things flex and bad stuff happens.

It will likely never be as strong as the original, but like I said, three good bolts should be enough anyway.

You might want to think about adding a top center bolt. My 88 never had one, my 87 did. I don't really know if it is still a unused threaded hole on the 99 or not.

I will look for an threaded hole when I get home. As for how the drive shaft managed to do this idk. I go to porter and Chester institute for automotive it is a technical school it was shop day and I was under my jeep putting a new upstream 02 sensor in and my bell housing and trans bolt ear were not destroyed

old_man · May 30, 2013

A pix is worth a thousand words.

Devilfrog · May 30, 2013

995speed said:
Im going tonsee if I can find someone willing to try that. as for running with the broken ear I tried that just in my driveway. got an awful scrapping noise when pressing in the clutch cause the trans is shifted to one side I noticed last time I took this trans out which was to do a throwout bearing the two E12s up top were not existing if I were to gry some hex bolts to replace them, and put all the other volts back in will it be in driveable condition?

SO am I understanding that you were driving around without thee in place? And yes, the E12 bolts can be replaced with a standard hex bolt, done all the time, the E12 was just Jeep's way of saying "gotcha!"

995speed said:
I will look for an threaded hole when I get home. As for how the drive shaft managed to do this idk. I go to porter and Chester institute for automotive it is a technical school it was shop day and I was under my jeep putting a new upstream 02 sensor in and my bell housing and trans bolt ear were not destroyed

I my above question is correct, then the driveshaft itself didn't hit anything on the engine, it was the shock and stress of the failure that would have caused the damage. I you were rolling around with only 2 of four bolts holding things together ... it was likely already cracked anyway.

joe_peters · May 31, 2013

WELD it!

If you don't have the skills, find a friend or pay to have it done RIGHT.

The bellhousing can also be welded up by a pro with the right welder for aluminum--again, if you don't have the tools or skills, find a friend or pay to have it done.

995speed · Jun 4, 2013

joe_peters said:
WELD it!

If you don't have the skills, find a friend or pay to have it done RIGHT.

The bellhousing can also be welded up by a pro with the right welder for aluminum--again, if you don't have the tools or skills, find a friend or pay to have it done.

I bought a bell housing found some bolts have three for the time being seems to be fine I think my mistake when I did the throwout bearing was not putting those top bolts in

help! cracked bellhousing and bolt hole on motor

995speed

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Flyfisher

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8Mud

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995speed

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8Mud

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