Hydro drain bolt stripped

[sgoldste01]

I just bought a used GT245, and decided to drain and replace the hydro fluid. I drained the fluid without problems, but when I was replacing the bolts I misread the unit of measurement in the owners manual, and tried tightening the bolts to 133 pound-feet rather than 133 pound-inches. :confused2:

I remember thinking, "Boy, that sure seems like an awefully lot of force to put on this thing", but that's what happened. To make matters even worse, I did the same thing on **both** drain bolts before I realized that the error was mine and not some pre-existing condition that I inherited from the previous owner. :ashamed:

Anyway, my brother-in-law is going to come over with his tap and die set and help me rethread the holes for a slightly larger bolt. Sounds like a good plan.

What's concerning me is this: How should we go about preventing metal shavings from ending up inside the tranny housing? My best idea is to pour the tranny fluid I drained back into the machine, and then drain it again as a way of flushing anything out. Will that work without me running the machine to distribute the fluid into both halves of the tranny, and without me warming the fluid up so that it flows rapidly?

 

[mrmikey]

Use a greased tap or if there's some way to slightly pressurise it you'd only need a couple lbs pressure to make sure the chips go out instead of in.....Mike

 

[Baby Grand]

As Mike suggests, the greased tap should get most, if not all of the chips. The strainer & filter will get the rest, but if it helps you sleep at night, flushing the fluid by running the old fluid thru, then replacing with fresh before restarting sounds like a good idea. I would probably do the same. That old tranny fluid cost a lot, so why not get as much value out of it as you can. Peace of mind has it's own value.
-Jim

 

[kennyd]

Man that really stinks

You should consider using Helicoils for the repair, that way the original plugs can be reused and the threads will be stronger.

 

[sgoldste01]

Thanks for the info, guys.

I was reading a posting on a motorcycle forum where an owner had the same problem on his bike. Some of the respondents said that he should go to an auto parts store and get NAPA self-tapping bolt, which is tapered so that it initially fits into the existing hole, but then widens toward the head and would tap its own threads.

Has anyone here used this process? Do you think it would work for my application?

 

[Zebrafive]

The self tapping bolt would be my last resort.
Depending on how big the boss is for the drain plug, retapping larger or a thread insert is the best bet. I would use the option that removes the least amount of metal.

It would be nice if manuals would put both a lb inch AND a lb ft spec so there would be no mistake. IE: 131 lb inch/ 11lb ft.

 

[sgoldste01]

The self tapping bolt would be my last resort.
Depending on how big the boss is for the drain plug, retapping larger or a thread insert is the best bet. I would use the option that removes the least amount of metal.

It would be nice if manuals would put both a lb inch AND a lb ft spec so there would be no mistake. IE: 131 lb inch/ 11lb ft.

Wouldn't a self-tapping bolt remove a small amount of metal? I've heard that you can get them in 1/2-size increments, so this might allow me to move up half a bolt size rather than a full bolt size. Wouldn't that remove less metal than tapping out the next larger bolt size?

 

[mrmikey]

Personally I've never been much of a fan of self tapping bolts. I don't think the threads are as deep as a conventional bolt, they also remove metal so you've got the same problem as far as crap floating around goes. If I did use it, it would be as a last resort or if the boss around the hole wasn't big enough or thick enough to go up a size....Mike

 

[TCSavage]

Helicoils® are the best and most positive way to repair damaged threads such as yours.

 

[DavHank]

I
Anyway, my brother-in-law is going to come over with his tap and die set and help me rethread the holes for a slightly larger bolt. Sounds like a good plan.

What's concerning me is this: How should we go about preventing metal shavings from ending up inside the tranny housing?

Lots of good ideas here but here's my 2 cents. Your choice of taps will determine where the chip goes. The four flute straight taps require that you back up the tap periodically to break the chip. What we used to call "gun taps" have an angled section of the flute at the front which forces the chip ahead of the tap. There is a spiral fluted machine tap that brings the chip out towards the operator-that would be my choice. These last two tap types are not reversed while cutting so the entire chip from each flute stays in one piece but are usually used in machine operations although I have used them both by hand. They are fragile and can't take any side deflection. Here is a link with pictures:
Tap Guide
Also, I have used Helicoils but they aren't my favorite. If you are in a compromised position and don't get them started straight, they can cross-thread and you need special equipment to install them. We used E-ZLOK fasteners with better luck - they are one piece and use standard tool to install. For what it's worth. :confused2: