stripped diff studs. what are my options???

[turboweege]

i installed a j30 diff in my car a couple weeks ago and i replaced the back cover with my stock one as usual and i torque all the nuts on the back side to 40lbs since the only specs i had for it was 40-80lbs. i got the real specs for a 90 which are 60-80 so i jack up the car this morning and start to retorque them. i got the two on the passenger side to 70 and the 2 on the drivers side stripped at 40 lbs. just sit and spin, i got one off and saw the stud is stripping and the nut looks good. so i took off the washers to get them to hold on what is left of the threads but they started to strip at 40 again and they just spin when i try to back them off.2 questions:1. what is the best way to fix this since i really would rather not remove it all again. i was thinking to use a nut splitter then redye the stud to a smaller size and add a new nut and maybe torque to like 60.2.am i safe driving the car as is with 2 good in the rear and the 2 front are torqued insanely tight?thanksluigi

[IvoryJ30t]

new studs. you dont want the diff fluid leaking out and siezing on you when your driving. not a nice experience.

[TachyonS14]

While pulling one of my exhaust manifolds off my truck, 2 studs snapped off in the engine block! (exhaust leak = warped mani) So, I spent my day yesterday getting the two studs out with a drill. I suggest you do what Ivory said and get new ones because It can't be safe to drive like that.

[IvoryJ30t]

yeah, exhaust mani studs are the most annoying things. when you take the mani off, its always fun to predict how many studs will snap off at the head.

craftsman makes a really good extraction set. instead of screwing into a hole you drill [bad because it spreads the broken bolt and just makes it tighter] it drills a few mm into the broken part and then bites it without spreading it.

they work really great, i just cant remember the exact name right now.

[turboweege]

ok. the problem is that if you have even looked at a nissan diff the studs are not removable, they are part of the rear cover. i cannot just replace them or i would have. fluid will not leak.

[Onizuka]

yeah, exhaust mani studs are the most annoying things. when you take the mani off, its always fun to predict how many studs will snap off at the head.

All the studs were fine on my motor, am i magical?

[turboweege]

well i guess my only choice is to split the nut and dye the stud. anyone know what size thread the nuts are and any suggestion on a dye size since the treads are about clean and gone off of the stud. i was thinking i could go to the closest standard thread for ease of finding nuts and a dye in a close enough size. any info would be appreciate.thanksluigi

[TachyonS14]

All the studs were fine on my motor, am i magical?

Well, my truck studs were 17 years old with over 240k+ miles on them :pface

[turboweege]

can i please get some comments on my problem as much as id love to hear the condition of everyones manifold studs?thanksluigi

[xjon]

I guess you can rethread the studs but it will be smaller in diameter which you will need to buy the right size nut and washer and also remember that the torque specs will change. Don't try to tighten them to whatever you were going up to since it will be weaker. You should also use thread locker or some thing to lubricate the nuts and bolts if you're torquing them. A airplane mechanic once told me you should never torque a dry nut/bolt since it wont be accurate. To play it safe, tighten it to whatever you feel comfortable with then just keep an eye on it. If it leaks, tighten it some more.

The best thing to do is to do it right. Take the cover off, cut the stud and grind it flat. then drill and tap a stud of the same diameter.

I cant believe the diff cover is 72-87 ft. lbs but that's what it says on chilton.

[IvoryJ30t]

i guess im the only one that breaks exhaust manifold studs like clockwork.

[xjon]

Ivory, I'm doing that right now with this rb25 in my garage. Bought the engine and it had a broken stud already. Took care of that. bought a gasket and was bolting up the manifold and was torquing the nuts to 15 lbs just to even things out. another stud tore off like it was wet tissue paper. Luckily I saved the gasket this time $65.

Oh yeah, don't ever use an EZ-out that is too small because they do break. And when they do, it's a MF to try to drill into them. Cost me 2 broken and 3-4 dulled titanium bits.

So learn your lessons from me and don't skimp!:)

[turboweege]

why would i cut off the studs and tap the cover and take it all out? i could just get a new cover if i was even going to take it out. im just going to dye new threads on and get new nuts and washers. i just need to know what size the original one are because im going to have to split the nuts that are on there to get them off.

[leper421]

My FSM shows the studs as having threads on both ends, meaning they should screw out of the cover. Try clamping a visegrip onto the stud and try to unscrew it.

Most of the time the shank of a bolt or stud is 4mm smaller than the nut (eg 14mm nut, 10mm shank). I think 17mm nuts use 12mm shanks.

Never trust a chiltons. Get yourself an FSM.

[turboweege]

i seriously dont think they are true double sided stud for 2 reasons. 1. the website that had the swap directions showed how he broke off the stud competely and it just took a huge chunk of the cover. and when i had the covers off you dont see anything but flat on the inside, no hole with studs. maybe im wroong but i think im just gonna dye them. thanksluigi

[turboweege]

and leper, thanks for the info.