Exhaust manifold to pipe bolts

On My 96 Ranger the guy that took my transmission out had to take loose my exhaust and the threads on the bolt were bad and he just put some smaller ones in thru the old holes and now i have an exhaust leak. Can someone post a pic or part number for these bolts and how many i will need

Ya know... some details, like mabey what engine you have? would help enormously...

Ya might want to consider adding that information to your avatar or sig.

AD

thanks for the tip. Its a 4.0

The proper bolts are 12mm X 1.75 thread.

Some engineer at ford being excessively paranoid
Not only specified that the threaded holes in the manifold
be cut to a "Truncated root" (a form of self locking threads)
but the original bolts also had a truncated root thread.

this rather firmly keeps the bolts from vibrating loose....

Frankly on a cast iron manifold with a steel bolt having them vibrate loose
isn't anywhere near being an issue...


Further considering the NECISSITY of removing the Y-pipe to do any kind of clutch/transmission repair and frankly? I think e engineer responsible should
have his nuts clamped in a vise then someone should push him off the
workbench backwards, but that's just my repeatedly irritated sense of outrage
brought on by dealing with this problem.

What works well are some 3.0 Taurus bellhousing bolts but these require
a short stack of washers on them because otherwise they are too long

the thing is that a standard 12mm bolt has an 18mm or 19mm/3/4" head
and that causes clearance issues when trying to get a socket on it to
tighten it.

And even then if you don't run a thread CUTTING tap
to cut clean full depth threads into the manifold before
inserting new bolts (a thread chasing tap should be used
as a suppository and then licked clean before threading it
into an exhaust manifold) you will have a day of misery at
some later date.

Personally I had issues with my tube headers (Borla) with a cracked primary tube
and was forced to (atleast temporarily) switch back to cast manifolds
but before I put them on I helicoiled the threads in the manifolds.

What did I use for bolts? Not that this will do you much good, but...

I modified (shortened and extended the threads up the shank with
a thread cutting die) E-torx headbolts from a 16-Valve Saab engine

Why those? they were the first bolts I came to in my shop that
had the right thread, a "Reduced" head size with an integral washer
in the head shape and the fact that I needed to extend the threads
and shorten the bolts wasn't particularly relevant to me...

AD

Hey thanks for the rely, We took the transmission out yesterday and changed the slave cylinder. We didn't have the right bolts to put back in so we just used longer bolts with nuts and lock washers. I have the old bolts now so i'll take them to the dealer or parts store and get new ones. The old bolts were in pretty bad shape. I will take your advice and run a chaser tap into the threads of the manifold and put anti-seize on the threads. Again thanks for the help

Steve

Holly Crap! a 12mm-1.75 bolt? The V-8's only use a 3/8" but they have more of course.
AllenD, a lot of engineers get kind of anal on things, sometimes forced to be to meet the "Almighty Rules and Regulations". Worked in the Aviation industry a bit and GE required all threaded holes to have strict test to see if they met spec. We had a couple of threads just used to remove a small plunger and had a 1/4-20 thread. Instead of having to go thru all the required testing, our engineers started calling those threads a 1/4-20 sprial "V" groove and got away with it. And also, the normal anti-seize is good to 2200 degs F.
Dave

2200F? regular neverseeze?

I don't believe that,

I personally prefer either the nickel or the moly stuff on exhaust parts

It's not that I'll ever see those temps on anything, but
repeated temp cycling is just as bad if not much worse
than a single high spike temp.

AD