stuck tranny plug solved!

After going at the tranny fill plug on my M47 gearbox two or three
previous times, I went out this AM with purpose. My goal was to get
the thing out even if it took explosives.. well, not quite, but I
wasn't going to quit until it was out.

I had formulated a series of attacks, starting with benign and ending
with felonious. After jacking the car about as high as I could get it,
putting it on stands, and assembling the tools, lights, etc, I went to
work.

My first attack was to use the Dremel tool and cutoff wheels. These
are very thin and brittle, 1" abrasive wheels that when spinning at
30,000 rpm will cut just about anything (eventually) including
hardened steel. I made a series of cuts along the outer edge of the
plug, beign careful not to muck up the case, with the intention of
relieving the tension on the sealing washer.

Next I used the same tool to cut what was left of the hex head area-
The hex was completely gone, so I cut the long sides of what was left
parallel to each other and perpendicular to the surface. This left a
ridge that looked like the turn-off on a gas main valve on your home.
Viewed from above:
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With that done I gripped it with an adjustable wrench, slowly
increased the force against it, and it broke free! ...and there was
much rejoicing.

If that hadn't worked (like if the tab broke off and left a nearly
flat surface) I was going to use a narrow, tapered carbide burr to cut
a slot into the plug. Into that I was going to place the blade of a
wide screwdriver and then gripping the blade with an adjustable wrench
for leverage, break the plug free.

If that failed I was just going to drill the thing out, bit by bit,
until it came free.

My biggest worry was if the fill plug had the magnet in it like the
drain plug. You don't want to drop one of those into the box!

Then it was finally time to remove the drain plug. The head on that
was intact, so I used a 6pt. socket 3/8" drive ratchet, and it took
another 18" long piece of pipe and a good amount of force to break
that one loose. What the heck were they thinking!?

Even after all that, I checked the new replacement plugs I had already
received from Volvo and when I tried screwing in the drain plug the
case threads buggered up the plug.. so I used an old trick i learned
from Popular Mechanics back in the 60's-

I took the old drain plug that was still intact (the fill plug was
pretty much FUBAR) and using the cut off wheel once again and cut
three slots across and through the threads, and then cleaning it up
with a power wire brush. I turned the old bolt into a thread clearing
tap! If the case of the tranny had been made of steel I would have
"case hardened" the tap by heating it up and dropping it into powdered
sugar. It adds just enough carbon to make it last a couple of uses.

I screwed it into the case a few times, each time a little further,
cleaning out the slots I had made after each removal, and after about
three times the threads in the case were clear.

The magnetic dran plug was quite covered in thick, grey, magnetic
sludge, so after the case had completely drained I cut some strips og
rags and using my claw retrieval tool (long, spring-like tool with a
push button at one end and four claws that open and close at the
other), I swabbed out the inside of the tranny case's bottom as best I
could. I didn't get much dirt of filth out of that at all and was
happy about that!

So my gearbox is done, and while I dirty and laying under the car I
did an oil change as well, both cases now filled with Mobil 1 full
syn.

And for my next trick, ladies and gentlemen....

....I'll be here all week,

...Try the veal...

__ __
Randy & \ \/ /alerie's
\__/olvos
'90 245 Estate - '93 965 Estate
"Shelby" & "Kate"

 

Glad you got it loose. I noticed you tried to remove the fill plug
before the drain plug--the correct order IMHO

 

Absolutely, and I take no credit for that. Another a.a.v. participant
mentioned that he had done it the wrong way. It is natural to open the
drain plug first, or so it would seem- it's the one you need first and
the easiest to get to, but thinking outside the (gear)box makes quite
the opposite being the best order.

On the other hand, most of us don't over-torque the plugs!

I sure do miss the wonderful 17mm female hex socket plug that VW used
on the air-cooled cars. I still have the 17mm hex wrench for that job!
I got it at Sears back in the early 70's. The soft plastic case/snap
bag it came in said "For VW transmissions and other jobs requiring a
17mm hex wrench" right on it.


__ __
Randy & \ \/ /alerie's
\__/olvos
'90 245 Estate - '93 965 Estate
"Shelby" & "Kate"