Rear lower shock mounts - thread details please?

[AussieHJCruza]

Howdy 'Mud crew - I'm in the middle of putting a slinky kit on the 80 and naturally I've broken off both bolts inside the rear lower shock mounts.
I'm gonna have to drill and tap or helicoil as I can't get an ezy-out to do anything.
Question is, does anyone know the size and thread pitch of the bolts - I have new ones on the way but would like to get prepared beforehand if possible.
And of course, thread useless without pics so...

 

[Box Rocket]

Which bolts are you talking about? How a pic of the broken ones. The lower shock mount should just be a bracket on the axle with a hole for the Shock pin to pass through.

You should be able to see the lower shock mount (empty hole) on this photo. Are your's different than this?

 

[AussieHJCruza]

Sorry for the lack of clarity - the mount in question is on the rear axle - please see below pic

 

[bigredmachine]

should be 10x1.25

 

[Box Rocket]

Ah gotcha. The pics you posted before were of a front end so I assumed you were asking about the front.

Dont remember the size off the top of my head, but maybe this will help.

 

[AussieHJCruza]

should be 10x1.25

Aargh, some moron must have been in here before then, I reckon what's in here has gotta be M12 based on drill bit shank comparisons. Damn...

 

[AussieHJCruza]

Ah gotcha. The pics you posted before were of a front end so I assumed you were asking about the front.

Dont remember the size off the top of my head, but maybe this will help.
View attachment 1939036

Yeah, sorry, lack of clarity/detail on my part.
I've got new ones on the way but I had a suspicion that perhaps someone had been messing in here before because the bolts in there seem to be of a particularly low class judging by how they drill out.

 

[AussieHJCruza]

So...if someone has been screwing around here as seems to be the case, what are my options? Do Toyota sell the 'boss' that is on the diff as a weld-on item?

 

[bigredmachine]

if its is a 12mm shank that it should still be 1.25 thread, that's pretty common pitch for Toyota.

Do Toyota sell the 'boss' that is on the diff as a weld-on item?

not that Im aware of but maybe you could get the whole lower shock perch and weld that onto the axle if need be.

 

[Box Rocket]

If memory serves correct, the factory bolt head is a 17mm and the bolt is a M12, thread pitch should be 1.25 as others mentioned.

Edit: confirmed my suspicion. OEM Bolt is 12mm with 1.25mm thread pitch

 

[pandathrust]

I'd try to weld a nut to the broken thread shaft and heat it up a good bit and torque it out hopefully. Those bolts usually get pretty buggered up with all the crud so it might be good to put some pb blaster in there first. I always try to weld a nut on it before I drill it since you'll most likely have to go up a size and there probably isn't enough wall thickness. If all else fails then any machine shop should be able to lathe the whole insert so you can fix it if you give them some dimensions.

 

[BILT4ME]

Worst case:
Drill a hole in the bracket and through-bolt it with a sleeve on the OD of the bolt, then tighten the bolt against the bracket. Most of the Chevy's are made this way on the barrel connector ends.

 

[tplane2]

Resurrecting with a slightly different problem. I BELIEVE I have stripped out, not sheared, either the bolt threads or the mount threads when torquing my rear lower shock bolt.

Bolt/shock are installed and are there are no issues.

Anybody have a good guess on which one would fail first? I would assume the bolt and that the mount threads are still intact, but dont want to assume before removal. I have an OEM bolt ready to go back in, just want to be prepared before repair.

 

[Relyk711]

Okay my turn for the thread revival. Looks like the sleeve is cracked. What are the options here... Get new OEM lower rear shock mount and weld it on? Is there anything aftermarket or reinforced, it looks like people usually have issues with the bolt not the mount.

 

[Box Rocket]

Can't you just weld up the crack in the sleeve?

 

[Relyk711]

Can't you just weld up the crack in the sleeve?

I suppose that would be easiest. Just have to make sure the shock bushing fits over it correctly without any weird angles.

 

[Box Rocket]

Yeah that can be a little tricky to get it smooth for the bushing to fit. But that sounds easier than cutting off the entire shock mount and welding on a new one.

 

[PolarRunner]

Okay my turn for the thread revival. Looks like the sleeve is cracked. What are the options here... Get new OEM lower rear shock mount and weld it on? Is there anything aftermarket or reinforced, it looks like people usually have issues with the bolt not the mount.

View attachment 3086826

That's what it's supposed to look like? I'm in for a world of hurt then.