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How to do thread repairs using HeliCoil insert kit
In this next segment I will show you how to install a HeliCoil on the transmission casting.
Several months ago I performed an oil and filter replacement on the transmission of a1983 300D (123) chassis.I noticed that when I was torquing my screws back in a few of them where not tightening at all or very little at best.The previous person who performed this did not pay any attention to proper specs on re torquing,and tighten them way too much.I have been living with a minor oil leak for all this time...
Well the next best thing to do is to install new inserts with a HeliCoil.
Update....10/28/2008
Its been just over 3 months since i did this repair and the transmission oil pan is still bone dry.
First of all secure your vehicle on ramps or floor jacks.Make sure to apply the emergency brakes.
Now the tools you will need to do this.
HeliCoil set.This particular job required M8x1.25 (drill size diam)
Ratchet 3/8 drive
Short extension
Hex socket No 5
14mm socket
Drill
Drill bit 21/64
Torque wrench 3/8 drive
Phillips screw driver
Hand held remote starter (optional)
Gloves
Locate the hot box to connect your hand held remote starter,this particular one is located on the right side fender
Connect your two wires from the remote to your hot box.One on the starter wire and one on the positive wire going to your battery.
Now its time to locate the drain plug located on the torque converter.I placed the remote in between the inner fender all the way down next to the engine oil pan
This light confirms that the remote is properly connected,red light on remote is on.
I started by draining the torque converter,the transmission was hot,was on the road for a half hour.
Done
Remove screw with Allan socket No 5 and drain.
Torque converter is draining,there could be anywhere from one to two liters of oil in it.
Then drain the transmission oil pan using Allen socket No5
Now its time for business.
The oil leaks were from the two rear screws left and right hand.
Once the oil pan is removed and the continuing oil drainage is almost complete,drill a hole straight in in both the holes that need help.
You have to drill perfectly straight.
Almost done.
Then using the tap provided with your kit,start screwing in your tap straight and deep enough to be able to enter an insert.
Its a tedious process but take your time be patient and success is on its way.
Don't think I was the one taking the pictures....My daughter was kind enough to ruff it up and lay down under the car to take these pictures for me....Thanks Shelby!
Great Pictures sweety!
After finishing your threading its time to use the special tool provided in your kit and install your inserts.
Screw in the inserts until you reach 1 to 1.5mm inside the casing.
Installing an other insert on special tool before screwing it in the casing.
In this picture i removed the special tool to show you the insert in the transmission casing.
This is the HeliCoil kit.
12 inserts
Tap
Special tool to install inserts into casing.
Done
Last insert instalation
This is how it should look after completion.Your insert should be 1 to 1.5mm inside the casing.
Install your new oil strainer.
Three Phillips screws to add.
Its imperative that you clean the transmission oil pan and dry it thoroughly.Use engine cleaner or degreaser for best results.
Re tighten your screws with your ratchet until tight,later on we will use a torque wrench to finish it all up.
Re tighten all screws to specs 6 ft pounds NO MORE NO LESS!
Mission accomplished.
No more leaks total oil added approximately 7.5 Liters
Now a tally on the cost...
HeliCoil Kit.....$58.00
Transmission strainer and pan gasket...$38.00
8 Liters of Dextron III.....$16.50
2 Transmission oil pan screws OEM.....$6.00
Grand total....$118.50
I had a written estimate done at a MB Dealership.....pretty much the same work....$857.00 + taxes
Now....Who's your Daddy??
