Pirate 4x4 banner

1 - 20 of 26 Posts

·
Registered
Joined
·
77 Posts
Discussion Starter · #1 ·
ok, made a big mistake I think, went to tighten header bolts because I heard a exhaust leak, and they didn't tighten so good, in fact I think the treads are pretty much toast. so any ideas on how to fix this, or something to get me by....

[ 09-19-2001: Message edited by: MyToy ]
 

·
Registered
Joined
·
386 Posts
<FONT COLOR="Red"> Heli-coil makes a kit especially for the Toyota's exhaust stud holes. It comes with everything you would need to do all the holes. I bought it at NAPA for about $45.... A little pricey, but it worked out perfectly. I have heard that it's commonplace for these threads to strip easily </FONT c>
 

·
Registered
Joined
·
386 Posts
<FONT COLOR="Red"> Oh yeah, if'n ya want to go cheap, sometimes you can get away with buying a longer stud (if there's sufficient threads left at the bottom on the hole) </FONT c>
 

·
Registered
Joined
·
77 Posts
Discussion Starter · #4 ·
what all is involved in the process? just taking off the manifold and drilling?
 

·
Registered
Joined
·
386 Posts
Originally posted by MyToy:
<STRONG>what all is involved in the process? just taking off the manifold and drilling?</STRONG>
<FONT COLOR="Red"> Pretty much.. Once the old threads are drilled out (the kit includes the proper sized bit too) you just put the heli-coil on the "installer tool" and screw it in until the bottom cross piece of the insert breaks away. Then the hole is ready to accept the original sized stud. I much prefer to use studs instead of bolts on the exhaust.

If you need a part # for the kit, I can look at mine when I get home from work and post it 4 ya..
</FONT c>
 

·
Registered
Joined
·
77 Posts
Discussion Starter · #6 ·
yes, part # would be good. thanks slick <IMG SRC="smilies/bounce.gif" border="0"> <IMG SRC="smilies/bounce2.gif" border="0">
 

·
Registered
Joined
·
386 Posts
Originally posted by MyToy:
<STRONG>yes, part # would be good. thanks slick <IMG SRC="smilies/bounce.gif" border="0"> <IMG SRC="smilies/bounce2.gif" border="0"></STRONG>
<FONT COLOR="Red"> Check back about 6pm PST... If I "marblehead" and forget or something, just shoot me an e-mail... I get distracted at times. </FONT c>
 

·
Registered
Joined
·
386 Posts
<FONT COLOR="Red"> OK, here's the specs on the NAPA helicoil kit:

*******************************************
Description: NAPA Balkamp HeliCoil Metric thread repair kit

Size: M10x1.25

Part#: 770-3020

Drill Size: 13/32 (.4062)

*******************************************
The kit's contents include:

10 - helicoils in a tube, Part# R4649-10
Size M10x1.25 15.0mm Length

1 - HeliCoil Tap

1 - HeliCoil Installation Tool
*******************************************

The above information is exactly what's printed on the pouch. This kit appears to be made especially for NAPA, sice it says "NAPA" right on the pouch. When I stated in a previous post that the drill bit was included, I lied..sorry <IMG SRC="smilies/glasses.gif" border="0">
</FONT c>
 

·
Does yer dewg bite?
Joined
·
5,664 Posts
the hard part is drilling out the hole straight:9
it's very common for those to strip out. Check all of them in case others a fawked, so you can do them all at once <IMG SRC="smilies/biggrin.gif" border="0">
have fun!! <IMG SRC="smilies/usa.gif" border="0"> <IMG SRC="smilies/usa.gif" border="0">
 

·
Registered
Joined
·
9,385 Posts
Use a torque wrench when you tighten them from now on too! <IMG SRC="smilies/wink.gif" border="0">
 

·
Registered
Joined
·
35 Posts
When dealing with exhaust (or any other) studs:

1 remove the nut from the stud, remove the stud from the head
2 wire brush the stud clean
3 use a tap or a rifle bore wire brush in the stud holes
4 blow out holes with compressed air
5 screw the studs all the way into the holes using vice-grips (clamped on the part of the stud with no threads to avoid buggering threads)
6 Once the studs are all the way in the head, put manifold on over studs
7 screw on nuts finger tight
8 tighten using a calibrated 3/8" drive torque wrench, DO NOT overtighten

The reason these strip out all the time (besides the head being aluminum) is because the studs are screwed in with the nut already on.
NEVER use bolts for this.
 

·
Registered
Joined
·
994 Posts
This was an old post to bring back? I hope being that its over a year later he already fixed the ehxaust leak:eek:
 

·
Registered
Joined
·
35 Posts
its reefered to on the FAQ, thats why.
 

·
Registered
Joined
·
2,774 Posts
DONT USE HELI COIL FOR EXHUAST !!

I'm telling you that's a HUGE Mistake, Trust me I did it

Problem with heli coil is it's a small fine thread! the head is Aluminum !

It will only stripp out !!

USE " TIME CERTS " from PIONEER EL-42-F-10 10 mm 1.25 thread pitch

Engine shops use these and similiar to them. They are solid type course thread not skimpy wire, ask them to install or order for you.

Tork to 33-35 ft-lbs
 

·
Registered
Joined
·
1,402 Posts
toy4crawlin said:
USE " TIME CERTS " from PIONEER EL-42-F-10 10 mm 1.25 thread pitch
OK, so where the heck do I get these things? Got a stripped out exhaust stud (the rear one, of course) in my son's 4Runner, was just about to buy the Helicoil kit. Google is no help finding a source.
 

·
Registered
Joined
·
1,360 Posts
Well, I've drilled tapped and replaced every exhaust stud in my 1985 22R, more than once. I've worked at doing this at least 3 or 4 different times. Heli-coils work fine, so do timecerts. Here's a couple tricks I learned: 1) use a course thread stud that goes into the head, as I recall they weren't easy to find, but I found them. 2) soak the studs and nuts you are going to remove with liquid wrench or penetrating fluid, over night. 3) when drilling the hole for the tap, use a drill size 1 size smaller than what is recommend for the tap, this is 1/64" smaller usually. Drilling the hole is critical, proper alignment is a bitch, but getting the tap straight is more critical and it's really a bitch, so pay attention. Mark the drill bit so you don't go past the bottom of the hole!! 4) run the tap in and out until it's smooth, blowing out the hole with compressed air. Take your time, run the tap out and clean the threads on the tap with a little wire brush. A little extra time spent here will make a huge difference. Don't force the tap too much, run it in and out. I used WD on the tap. 5) Do not insert the helicoil/time cert until your thread hole is smooth and the heli-coil spins in fairly easily. You DON'T want to "break off" the tab while inserting the coil, the insert tool probably couldn't do it anyway. 6) use brake cleaner in the stud hole and clean out really well with compressed air before you insert the coil, the insert needs to go into the head flush or just inside the outside surface. 7) Before you screw in the helicoil, coat it with Locktite (I used Red), coat the stud with Locktite and screw in the stud. DON'T use vise-grips on the stud! -- put two nuts on the very end, and use a wrench. Do not over tighten the stud. 5) wait over night before installing your exhaust manifold, if you can. 6) Use liberal amount of anti-seize compound on the nuts and manifold threads. I used hex nuts and lock washer and NOT the stock self-locking nuts. When you go to start tightening the exhaust nuts, go slow, don't over torque them, I would not use a torque wrench for this. Start and run the engine for 15 minutes, then retighten the exhaust nuts. Then check them again in a couple days, assuming you drive the vehicle. I had to cut the drill bit down because the first stud I replaced was on number 4 cylinder and the space was tight. I did all of these with the head on, but of course with the head off, it's way easier! The reason the studs strip is because the steel studs and the alloy head cause corrosion due to dissimilar metals, the corrosion powders and the stud will then spin inside the head. The stud threads are too fine, they should have been course and even larger diameter inside the head. The first time I drilled and tapped, I used the same stock size studs, they came loose again. The next I used larger studs with course threads NOT fine threads, they held and never came loose again. That's just my humble opinion.
Gnarls.
 

·
Registered
Joined
·
2,143 Posts
Dunno the stock length of the studs, but they are metric "fine" thread - 10mm x 1.25.

I also recommend replacing them with standard thread, if they are stripped - 10mm x 1.50. Easy to find stainless nuts for them in this size. Also, you can cut a long bolt, file it, fix the initial threads, and use it as a stud in a pinch.

Don't use locking pliars on the threads. Use two nuts tightened against each other.
 

·
Registered
Joined
·
1,360 Posts
mkmarz said:
hey garls,
what size studs and what tread? stock length?
thanks
mkmarz
mkmarz,

I ended up with a 7/16" x 14 thread into the head. The other end was SAE fine thread. These are not metric. The course end of the stud that goes into the head is about 7/8", then non-thread area about 1/4", then the fine thread part is about 1.25". I went a tad longer than stock because I put a flat washer and a lock washer with a hex nut. I found these at NAPA in their exhaust stud bins. For the nuts, be sure to get the smaller hex dimension 11/16". The first time I did it was on number 4 exhaust (at the fire wall) I had to cut the drill bit and use the smallest drill I could find to get into the space and still get it perpendicular to the head. Never did pull the head to do the rest. I did both studs on number 4 at the same time. I had to drill the stock manifold holes out just a tad. Like I said, the first time I used the drill bit size according to the tap, but it was too loose, so the next time I used a drill bit about 1/64" smaller than what the tap size says. It was harder to tap, but when I finally got it tapped, I had full depth on the threads.
Gnarls.
 
1 - 20 of 26 Posts
Top