Stripped bellhousing to transmission threads

[Coal creek Chris]

Noticed today that one of the bolts between my manual transmission and the bellhousing was very loose, basically the bolt was out. I believe I have an SM465. The bolt will go in, and sort of grab, but it doesn't snug tight. Seems like threads are stripped or compromised. Checked the other three bolts and two are good, but one other is also stripped because it won't snug.

Any thoughts on how important this is? Seems like it would be important that all four bolts are snug.

Is this a helicoil type repair possible in the truck? Or maybe just red thread locker would be enough if the bolts are mostly functioning like a pin rather than in tension?

 

[Radiohead]

I would want to pull the bellhousing off and helicoil it.
But I understand the temptation to red threadlock the bolts in. You may be disappointed by doing this in the future though.

 

[fast 99]

Helicoil, not enough bolts to delete one. If there is even slight misalignment between the tranny and engine it will likely wipe out the clutch.

 

[Snoots]

It's VERY important.
You want to fix it like a Pro? Heli-coil.
You want to fix (bandage) it like a Bozo? Red Loc-Tite.

 

[Turbo4whl]

7.4 with a SM465, I would not even consider thread lock. Helicoil or key insert for sure.

 

[Radiohead]

Helicoil, not enough bolts to delete one. If there is even slight misalignment between the tranny and engine it will likely wipe out the clutch.

Input shafts and their bearings are persnickity too.

 

[Coal creek Chris]

Thanks everybody. Sounds like these bolts are important and that they need to be snug. Looks like a lot of bellhousings for sale on Ebay, so even if the bolts get stuck with red thread lock, maybe worth it as a work around. Taking these parts out to fix it right, seems like a lot of effort for this beast of burden truck.

 

[PrairieDrifter]

Buy once cry once is all I have to say.

You'll be spending more money if you don't fix it the right way as soon as possible, especially with the jarring nature of a manual, it will probably break other things, like an ear off the trans or the whole bellhousing, throwing the trans and driveshafts, or anything mentioned above.

 

[Radiohead]

Red loctite is no substitute for metal. It will pop loose in this configuration and before you realize that, something else will go pop too.

Just do it right and never think about it again. 4 bolts between you and walking at the most inopportune time. My luck, it would be on the railroad crossing.

 

[PrairieDrifter]

Also the price and labor will be minimal. There's so much room under trucks with the 465's. Sure they're heavy but any half decent transmission jack or modified car jack will easily do the job.

 

[Rusty Nail]

YUNOHAZPIX!!?

 

[Memaloose]

Repair it right the first time or you'll end up broke down on the road somewhere. Even if you replace the bellhousing rather than heli coils, you won't regret it.

 

[Snoots]

Go ahead with the lazy way and use Loc-Tite.
There are plenty of SB owners out there that would buy your parts.

 

[Coal creek Chris]

Smart advice all. I'll put it on the list to repair properly. This is a truck that drives maybe 1,000 miles per year but I don't want to wreck other important stuff. I just envision that surgery like this will lead me to all sorts of other discoveries while I'm in there that it won't just be fixing the two bolts.

Saw that there are aluminum and steel bellhousing available. Any opinions on which is better?

 

[Craig Nedrow]

7.4 with a SM465, I would not even consider thread lock. Helicoil or key insert for sure.

As a machinist, I have fixed literally thousands of stripped holes. There are many ways to fix then but depend on how bad they are. I have a 465 in an International 1600 loadstar dump truck, and had it out a few times. I believe the bolts were 5/8-11 so there is about 100 ft lbs of torque on them. Helicoil will work if the hole is not "wallered" out more then the tap drill size. If it is, like Turbo4whl said, use a keensert, get them at bolt supply, industrial supply. The location is very important as well, I would do it pon a vertical mill.