DupermanDave

I'm looking to fix the stripped threads on my exhaust. I have an exhaust leak that needs fixed, and I'm sure this is the cause.

I have a question: is M10x1.25 the correct helicoil repair size? If so, do I need a fine or coarse repair kit?

I went to autozone and a few other places looking for an M10x1.25 repair kit and could only find M10x1.5.

iamsuperbleeder

stripped where, in the head?

DupermanDave

Yes, they're stripped in the head.

iamsuperbleeder

theoretically, you could use the 10x1.5, and just put in a new 10x1.5 bolt but yeah the correct way would be to use the same thread pitch as what's already in there

DupermanDave

Are the threads coarse or fine?

yotaman90

Any updates?

DupermanDave

Not yet. I'm trying to replace the clutch this weekend and ran out of funds to purchase the new tools I need for the exhaust. I'm going to make some new threads one size larger than the stock size, but I need to buy the tap & die set. I'm pretty broke as-is from purchasing the heavy duty clutch from marlin crawler, so I'm dealing with one thing at a time.

yotaman90

Sounds like me; fix one thing, then another, then another. And all that fixing leaves me broke!

DupermanDave

Yup. Just got done fixing the parking brake cable when the exhaust leak showed up. Then the clutch started going out really bad when I was in the middle of pulling the engine from the subaru. Now the subaru is fixed, it's time for the truck

ilostmypants

I have a 88 pickup with 22re and i fixed the 2 rear most exhaust manifold bolts that were striped out.
I used the helicoil kit number 5543-10
and the thread is M10x1.25
the kit requires that you use your own 11/32 (.406) drill bit to and i had to unhook a bunch of lines and junk to get enough access to drill out the damaged threads and i used a air right angle drill.
the helicoil kit cost me around 100 dollars cnd
witch was surprising because i was in school at the time and my prof said a helicoil kit should cost like 30 bucks max.

but it worked well i used all new toyota studs and nuts. torqued to the factory service manual number i think it was 22 ft lbs iirc.

the kit looks like this


good luck and remember to get new exhaust manifold gaskets. and the toyota nuts and one use because there crimped on the top edge to lock onto stud. and remember to torque them up slowly the head is aluminum after all and check them a few days after to make sure nothing has started to loosen up i had to do this a few times.

Patriot

Any chance of doing all this without removing the manifold?

Co_94_PU

iTrader: (-1)

Not sure that insert tool is long enough but you can work around that. So I can't see why not, the bigger problem is getting a drill to fit like the last post indicated needing a right angled compact type drill.

Sensei

The manifold is easy enough to pull. If you use the helicoil "guide" tool that comes in some of the sets then yes, you have to pull the manifold. If your exh leak has been there awhile then you probably would want to install a new gasket. They run about $30.00 or so.
You could do it with the manifold installed but you will not be able to tell if the helicoil went in properly or if it is set at the correct depth.

Patriot

Actually did it today.. without pulling the manifold. It was really quite easy. I think I was fortunate because I didn't have any threads left. So I just used a manual tap and inserted a single helicoil purchased from my local ace hardware..$3.. and voila.. no more clackaty down the lane!

Blueman

I had a leaking exhaust manifold gasket at the front by the distributor, and found upon replacement that the front two studs (upper and lower) wouldn't torque tight and the threads were pulled. The manifold had never been removed.

Repair was fairly easy:
- Remove heat shield
- If the stripped stud is still present, simply keep trying to tighten the nut to loosen the stud
- Remove 8 manifold nuts and old gasket
- Clean off the old gasket (this may take awhile)
- Disconnect catalytic converter hanger bracket
- Disconnect tail pipe hanger bracket
- Slide the exhaust assembly rearward to get the manifold out of the way
- Drill out and Heli-coil the two front stud holes as described earlier

All in all, a fairly straightforward job. Be especially careful that you drill the holes straight or you'll not be able to install the manifold.

I used a stubby 13/32nds bit and a Dewalt DW160V right angle drill. I marked the depth of the hole with blue painter's tape on the drill bit, but you should also feel when you hit the bottom of the existing hole if you pay attention.

Tapping the hole was slow as there wasn't room for a full handle, and it required a small (7mm) open end wrench on the tap, and a lot of flipping of the wrench. Be sure to put a little oil on the tap during the process, and I used compressed air to clear the hole of chips. I took three passes at each hole to keep the chips from piling up. Also, I put tape on the tap so I'd know when I was getting close to the end as the tap can take some effort to turn and you want to ensure there is full depth for the Heli-coil insert.

New studs are a couple $ at the local dealer, and you'll be set.

83danimal

Man i wish i wouldve taken somebody elses advice n done all of em while i had it on the stand. Now ive gotta work around the engine bay...

boxer.fan

I had to replace my rear lower stud because it striped out. I figured out when and how it striped. I was cruising the mountains and seen a water puddle and decided I would splash through it, well water hit the hot exhaust manifold and warped the manifold causing it to pull the stud out striping the aluminum head with it.
I had to pull the manifold and have it planed. As for the aluminum head I obtained a longer bolt that reached the threads all the way in the back of the head. Worked and has been on for over a year.
I was going to helicoil it but it was expensive and I didn't want to remove anything to drill out the block.

Brando338

^^^I really doubt splashing through a puddle warped your exhaust manifold, being as somehow people drive 4x's underwater with snorkels. The manifold stripped out because the soft aluminum threads have been constantly heating and cooling to extreme temperatures, with a steel stud in them, for 30+ years. And aluminum expands much quicker than steel when heat is applied.
I am having the same issues on my 83, not sure if I should heli coil or just jump up to the next thread size on the stud.

buildayota

Can u heli coil while the motor is still in the truck? Sorry to bring up old ˟˟˟˟ haha

4RunnerFreak12

Hey welcome to yotatech!

See above to answer your question!

YES but you need to use a right angle drive bit or right angle air drill. Something compact and powerful. It's there in this thread.

Great at info on this site, nice job searching out this thread but can't just skim through it. If you do atleast look for things u need and things to look out for then double check if you have any questions.

Good luck!