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-   -   Bottom rear Engine Stud came out (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/bottom-rear-engine-stud-came-out-891201/)

Captain_Panic 03-07-10 12:43 PM

Bottom rear Engine Stud came out
 
1 Attachment(s)
How concerned should I be with this stud coming out. (Taking the manifold off for NS conversion) Everyother one came out just fine but this one was a little stiff as it came out. If you look at the threads, from the picture, it appears to have taken material out of the block as it came out. It wasn't siezed, but it didn't come easily either. My concern is getting a new stud back in...

will I need to repair the block to do this? Thread Chaser a good idea?

Mahjik 03-07-10 12:44 PM

Thread chaser yes. New stud yes.

Captain_Panic 03-07-10 12:57 PM

Thanks for the quick note back. Planning on contacting Ray for the first time to get new gaskets and any other pieces I will need to replace. Looks like the thread chaser will be one more thing to order from Mcmastercarr this week.

Out of curiousity, what size are these studs? I couldn't find the detail in the FSM. WIth a Thread Chaser you want it to be the same diameter as the stud as you are simply repairing the thread right?

alexdimen 03-07-10 02:05 PM


Originally Posted by dfoster154 (Post 9851659)
Thanks for the quick note back. Planning on contacting Ray for the first time to get new gaskets and any other pieces I will need to replace. Looks like the thread chaser will be one more thing to order from Mcmastercarr this week.

Out of curiousity, what size are these studs? I couldn't find the detail in the FSM. WIth a Thread Chaser you want it to be the same diameter as the stud as you are simply repairing the thread right?

If it pulled the threads out of the aluminum... and it looks like it did, simply repairing the threads isn't a good fix IMO. You may want to put some kind of thread insert in there (helicoil) because the remaining threads may not be able to hold the load generated by torquing the mani nuts... guess it depends on how bad it is in there.

If you chase it, yep, it needs to be the same diameter and pitch. Use the wrong pitch and shit goes from bad to worse... ask how I know. :)

DaleClark 03-07-10 02:25 PM

Depending on how much aluminum came out (it does look like the threads are pretty full of aluminum) you'll have to use a Helicoil or something. It's fixin' to get not fun.

I'm pretty sure those studs are M10 or so. Use a thread gauge and check everything first.

Read up on using Helicoils, I'm sure you can find plenty on it if you Google. I know Harley guys use them a lot.

Dale

Mahjik 03-07-10 02:45 PM

Considering the location, I would try the thread chaser first. Yes, you may need a helicoil, but try the easy way first.

GoodfellaFD3S 03-07-10 05:23 PM

It's M10x1.5 thread pitch. Btw, if you're interested in an already-converted non-seq manifold that's been ceramic coated PM me, I have one I'm almost giving away.

Captain_Panic 03-13-10 04:32 PM

Now that my turbos and manifold have gotten the rich mans Non Seq treatment (port matching etc) and that I have gotten my order in to Ray for the new gaskets, it is time to tackle this. I just bought a m10x1.5 thread tap/chaser. Any tips for using this thing. I saw a couple of great You Tube videos on how simple the HeliCoil process is, but I don't think I need to go to that extent as I believe it is just the outer threads that were messed up.

I will be using a hand tool to do this
I will be using a MMO 3in1 Lube
Go Slow, *ie few turns in, backout.. clean tool... few turns in, back out, clean, etc.

Any other recommendations?

RotorRyan 03-13-10 07:34 PM

careful when you start it and make sure you dont crossthread it in there and cause a mess. i like to go in 1 turn and back 1/2 a turn but its whatever you want as long as your going back fairly often as you go in. you shouldnt need to back completely out and restart(unless the threads are REALLY bad), just make your way in and out.

make sure you have a bottoming tap(flat bottomed) as you may not get the bottom threads without it. oh and use lube and dont force it to go!

GL!

Captain_Panic 03-14-10 10:32 PM

Majhik, you were dead right! Thread chaser worked perfectly.

I know it is hard to see from the picture but the nut actually siezed on the very end of the stud (even though i MMO'd plenty ahead of time) and when the stud started to back out it initially became difficult, but then it came easy. Then as it was almost out it got difficult again. I thought this through, and realized the threads on the very outer edge most likely were the only ones in need of repair. The nut was slightly cocked on the end of the nut so I was problably putting slightly off center torque as the stud was near out. Thread chased the first 4-5 turns and then I backed it out. Tested with one of the 10x1.5 bolts from the turbos to the mani, and it went all the way in and started to tighten. I didn't tourque it in to spec yet (I will save that last bit when my stud arrives from Ray), but I definitely felt it start to lock in so I think I am good.

Thanks for the advice guys, this club of mechanics, engineers, and problem solvers has always been their when I needed you! This NS process has had me run into some interesting hurdles I have never encountered before. So glad I am doing this myself, as I have left my fear of working on my car completely behind, well except for transmissions.... ;) that still scares me a bit.


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