Got tips or tricks to make Helicoils installations come out best?

We had an impact gun thread awhile ago, and someone said ‘I have seen impacts do so much damage on transmissions.”

Awhile ago the local Dodge Dealership had a $130 special on ATF and filter change.
When I got my Mothers van back I looked underneath and saw what looked like a grey colored messy Permatex Form-A-Gasket application.

I complained to the Service Writer and he said:
No, Chrysler now officially endorses a new silicone sealant from a tube, and that is what you see.

Well yesterday I took the pan off.
The grey goo is not silicone like at all.

NEARLY ALL OF THE 8mm 1.25 ALUMINUM THREADED HOLES FOR THE TRANS PAN ARE STRIPPED.

The dealership tech probably stripped the threads with the impact on his first try with a conventional gasket,
found the ATF leaking out badly,
and used a heavy application of grey Permatex to essentially glue it in place.

The Tech was not even good enough to know about “The Right Stuff” gasket maker.

It has been awhile since I have used Helicoils,
but that is all that is available locally for 8 mm 1.25 thread.

Anyone have tips to make Helicoils turn out the best possible?

The Stanley Engineered Fasteners Helicoil instructions say to
break off the “tang” as a last step.
The kit does not contain a tang breaking tool to accomplish this,
just a tap and an insert tool

I now have the V-Drill Guide made by Big Gator Tools
to help keep the portable drill bit and tap at a near perpendicular against the Trans flange.

https://www.shop.biggatortools.com/main.sc

My back is already hurting,
and I probably have at least 2 days of work, since I have to replace a solenoid pack once the pan holes are repaired.
Sucks to get old.

use timeserts instead of heilcoils,easier to install&they hold better.On the helicoils break off tabs with needenose pliers.

The only thing easier than installing a Helicoil is not having to install any thread insert at all.

There is nothing tricky about installing a helicoil. Using the proper drill size, drill out the hole, using the special Helicoil tap, tap the hole. Screw the insert in till it sits just below the surface of the pan rail. Break off tang, do next hole.

I just use a nail with the point filed flat, ight be tricky getting needlenose into an 8mm hole, but if you had a tiny pair ot maybe some Hemostats it might work.

Yes I agree Timeserts are a better design, and that is why I stopped using Helicoils on mining equipment a long while ago

Unless you have a 42/904 or 46/727 style trans in your mothers van there is no gasket, and Mopar doesn't use Right Stuff.
To break off the tang I use a small drift pin punch, blow it out with air if it didn't come out. You don't need the fancy tool either, don't apply a lot of pressure on the drill, allow the bit to do the work and it will be fine.

I use a punch to break off the tang. Pops right off.
If it were me and a shop did that to my car the next conversation they had would be with my lawyer.

Building a fair amount of Torque Flites I have to install Heli-coils often. These transmissions have been around years and many have been apart many times. Heli-coils are easy and quick. Make sure you use a Heli-coil with a length that goes slightly below the surface. If they are to long you can cut off a coil with a Dremel cut off wheel. Time-serts have their place as well. But not necessary in this case.
Doug

I had two very narrow needle nose pliers
and a pair of narrow hemostats in my soldering kit.

I used the needle nose to break off the tang,
but the hemostats will also work, especially in even smaller diameter holes.
The hemostats I have are for creating temporary heat sinks on delicate electronic leads,
not medical ones for clamping off blood vessels..

In this application the 8 mm small head pan bolts are so short
that even fully screwed in only to the transmission housing
without the extra metal thickness in the pan
they do not bottom out against the tang.

In the first hole I just did
Mother Mopar very thoughtfully placed a brace close by that prevented me from rotating my tap handle 360 degrees.
Mopar engineers are good at placing those braces “just so.”

The 2005 T&C FSM does say
“new Mopar Silicone Adhesive sealant” on page 21-232
but this grey wimpy stuff was like Permatex Form A Gasket.

Did Mother Mopar not design in enough thread length
in the aluminum threaded holes
for 8.8 steel M8 1.25 pan bolts
at the bottom of the case of the 41 automatic transmission ?

http://genfast.com/wp-content/uploa...Engagement-Bolt-Failure-Chart-Metric.pdf

Look at the 2nd line,
the one colored white for M8 1.25
and continue over right to the 7th material column
where the nut material is aluminum A356 with temper T6

The engaged threads of steel bolt to aluminum nut must be longer than
16.8 mm ( 0.66 inches)

The cast aluminum in the case of the 41 automatic is probably weaker than A356-T6 aluminum in a nut.

To snap the steel bolt head off
rather than pull the threads out of the aluminum hole
the engaged thread length should have been more than 16.8 mm, maybe 18 to 25 mm

These Chrysler small hex head
steel M8 1.25 bolts
seem to have only
5.5 mm of engaged thread
if you subtract the thickness of threads held back from engaging the aluminum
by the thickness of the steel pan.

FSM says these M8 bolts should have been hand torqued to just 165 inch-lbs ( 14 ft-lbs/ 19 N-m )

There is plenty of thread engagement. If the heli coil is too long I cut them with a pair of dykes. You are way over thinking this. However if a vehicle had been returned to me in that condition I would be back in the service drive having a conversation with the service manager. They should fix it at no charge.
One problem with the sealer is many guys don't know how to use it properly. The surface must be clean, oil free and dry. A 1/8" bead is all that's needed, excess will fill the blind hole and pop the threads. Do not wait to assemble the components after laying the bead. Don't wait for it to skin over or set up, assemble within 10 minutes then allow it to set for 30 minutes. The biggest thing is that the surfaces are absolutely clean and dry. That is hard to do on most transmission/transaxle pans that are still in the vehicle but it is possible.

Chrysler has been using an RTV like sealant for decades on fwd transmissions, and later rwd transmissions. ATF requires a specific rtv for success, and completely dry surface. Right stuff, although good stuff, would be the wrong stuff. Typically black or grey in color, but a thin layer is all that is required between the two machined surfaces. Time serts work very well, but read the instructions carefully to ensure the sert sits flush or slightly recessed.

And ya', technician messed-up.

Me, over thinking something?
Naw, never!
No one from “Happy Holler” thinks too much, or too little.
Guitar, it is clear ya gotta move from that West by God Virginia Holler
to the totally superior land west of the Big Sandy River.

Getting up at 4 AM and working until 9 AM.
Then from 9 PM until 11 PM, or when I realize brain fog could get me hurt working alone under a car.
The rest of the time I am a Geriatric nurse to a 91 year stroke victim.

I did find that the right size Torx bit will back out a Helicoil without damaging it, allowing to tap a bit deeper.
The german company with Youtube videos showing their Helicoil remover and tang-less powered inserter is interesting.

I now have all holes good, after test torquing to 14 ft-lbs.
I would have saved time and cuss words by just Helicoiling every hole to begin with,
which I eventually did after seeing aluminum threads come back out of “good holes” after test torquing.

I am off the opinion that Chrysler designed this to fail by stripping out aluminum threads rather than snapping off steel bolts.
Chrysler considered a repair with Helicoils acceptably cheap.

In Machine Design classes students are taught:
Design for the cheapest, easiest & quickest to replace part to break first,
for example make the nut weaker and of a material that will not damage the stronger, harder bolt or stud,
and design in thread engagement lengths so this will happen.
( Think ARP cylinder head stud kits)

In mining we have big precisely made heavy steel doors with special air gaps on all electrical boxes.
These are held on with multiple allen head cap screws of Grade 8 that will strip the steel threaded hole in the electrical box body if miss threaded.
It is against USA law to have even a single cap screw or threaded hole bad.
I could cause a mine explosion... and has in the past.

When I visited coal mines in South Africa
I noticed that they had replaced the allen headed cap screws with hardened steel studs with brass nuts, like ARP cyl head stud kits.
I asked why and was told:
cheaper and quicker to replace a brass nut than repair a threaded hole, and just as explosion safe.

For cost and factory reasons
Chrysler would never replace the M8 1.25 steel bolts with only 5.5 mm of thread engagement in soft aluminum,
with say...
steel studs in much longer aluminum threaded holes and soft brass lock nuts,
but maybe students should read about this as an alternative.

You know I had the same exact issue on the 64 PB 727 I swapped into my 64 300 years ago.

Same repair was done.

My first duty station in the Navy was overhauling shipboard satellite antennas, aluminum castings with every bolt hole helicoiled and all corrosion resistant steel hardware. When we got them for overhaul you can bet cash money some of the hardware would snap off due to corrosion. I got real good at fixing that problem and it would have been damned simpler and quicker to have fixed a stripped thread than dealing with what we had. Once we had it all repaired and during final assembly every bolt got antisieze.

Amazon now says they have “lost” my next day delivery Solenoid Pack (was supposed to be Sunday by 5 pm) and are offering a refund.

One reviewer said Borg Warner is OEM to Chrysler.

I would have had time to get Timeserts, or re-tap to 10 mm bolts, or even install 10 mm studs with lock nuts

There is always a new sub-paragraph to
Murphy’s Law,
ain’t there?

I have heli-coiled both of the starter bolt holes in my 727. They are holding fine. Easy install.

Thanks but we are perfectly happy here in this holler.

Never used timeserts. Have used E-Z Lok. They are not my favorite as they have a large OD for the thread size.

E-Z Lok

Pretty much stick to Helicoils.