About to buy a tap and die set to clean (or cut new) threads on a stripped transfer case drain plug hole. I believe the threads are metric but if I'm cutting new ones and installing a new bolt, I don't have to necessarily keep them that way. I'm probably leaning metric, though, in hopes of cleaning up the threads that are there, and cutting all new ones as a last resort.
Any recommendations on buying metric or SAE? My goal for now is to buy just one set.
Buying tap and die set. SAE or metric first?
- Thread starter HawkeyeScott
- Start date
Don't.
Any set which would include drain hole sizes will be on the larger end of the size spectrum be it English or Metric.
Settle on a thread size and just buy the one you need.
I haven't looked at a catalog in a long time but I'd bet there are also "paired" sets consisting of one tap and it's matching die.
No need to buy a set of large thread cutting tools when in all likelihood you'll never use 'em.
Then again, you know what you have in mind....I'm just mentioning it.
Be careful, some drain plugs on diffs and transfer case are NPT, not common in sets. What size are you working with and what do you want to do, fit a insert or coil or go oversize?
Old timey tool and die maker here.
It is almost never a good idea to introduce a different thread system into a product that is based on one standard or another.
Pick the correct system and then exactly the size you need.
Not sure of your circumstances but large tap and die sets (8+ pieces) are almost always a loser's choice for the shade tree mechanic. They're expensive and there's just too many sizes you're buying that you will never use.
Best bet is to find a buddy or acquaintance that is a machinist or mechanic. Borrow the size you need and nothing more.
Or, buy only the size required from Ebay or Amazon.
Problem solved.
If it is a one time need, as Kira said just get that one tap.
If you primarily service modern cars, often or in the rust belt, get a small quality set of Metric most used sizes, and then add oddball sizes as needed, one by one. You will find yourself using them to clean up threads, not just tap holes and make bolts.
If doing old SAE cars or plumbing and house work, then it's SAE. Same thing.
If you really needed the big set, you would know it, and already have it... Unless you're embarking on a custom framed race car or some other grand metal project.
Thanks. My issue is that I took the drain bolt to the hardware store to find out what size of tap I needed. The guy put a nut on it and said it was 14mm, 2 pitch. Ordered a tap in that size from Amazon since no local stores had it and when it came, it was too small. It clears the hole entirely. Based on the slow Amazon shipping, this cost me about two weeks. (I'm still not clear on how I ended up with the wrong sized tap based on my field research!)
So, my goal in buying the set was to avoid chasing a second or third tap that doesn't quite work and get the situation resolved soon, even if it's a little pricier. Maybe a better decision is to order a few more single taps at once and return the ones I don't need.
Thanks for the help. This is why I appreciate this site.
If I was going to do this I would pick the Bolt/Plug then get the tap to match it. You do not want to tap a hole only to find out that you can't find what you need to properly screw into it.
How is the correct size tap supposed to work in a stripped out hole? It is going to be as loose as the original bolt. If this is holding fluid use a Time Sert M14x2 if that is the correct size.
On second thoughts give the job to a pro and save yourself the possibility of buggering the T case.
Only the first three or four threads on the case are messed up. The 14mm tap clears those and the good ones, too. It was never going to be the right size.
Originally Posted by HawkeyeScott
Only the first three or four threads on the case are messed up. The 14mm tap clears those and the good ones, too. It was never going to be the right size.
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Originally Posted by HawkeyeScott
Only the first three or four threads on the case are messed up. The 14mm tap clears those and the good ones, too. It was never going to be the right size.
Metric.
It's a 2008 Suburban 1500 with the 5.3L and 4L60E.
Here's the plug: https://www.amazon.com/ACDelco-19133162-Original-Equipment-Transfer/dp/B010GNXS72
Thanks.
I purchased a set of both SAE and metric at Harbor Freight and it was money WELL spent. There is nothing worse than being in the middle of a project / repair and have a stripped fastener stop you dead in your tracks. I put up with that enough times that I broke down and bought both sets and don't regret it for a second. It's come in handy so many times (and not just automotive stuff) I've lost count.
I don't see the exact product I bought (it was 7-8 years ago) on their website, but it's very similar to this: link
Mine has a larger metal case, but might otherwise be the same product, same titanium coating. I remember paying about $75 each. Harbor Freight has a cheaper carbon steel set, but I've learned to avoid the cheapest Harbor Freight tools like the plague, but I've had excellent luck with their mid to high tier products. I've really worked many of these tap & dies and they've never given me a bit of trouble. Would I trust HF tools if I needed them to earn a living? No. But typical homeowner / backyard mechanic type use where they'll get used a couple-few times a year, they work great in my experience.
If you have to choose one set or the other, I'd go with metric if you're primarily using these for automotive stuff. That should cover most any car made from the mid 80's forward.
I believe the Aluminum case Magna MP3023 uses NPT Pipe Plugs instead of the metric shouldered plugs found on earlier Magnesium New Process T-cases.
Originally Posted by HawkeyeScott
Thanks. My issue is that I took the drain bolt to the hardware store to find out what size of tap I needed. The guy put a nut on it and said it was 14mm, 2 pitch. Ordered a tap in that size from Amazon since no local stores had it and when it came, it was too small. It clears the hole entirely. Based on the slow Amazon shipping, this cost me about two weeks. (I'm still not clear on how I ended up with the wrong sized tap based on my field research!)
So, my goal in buying the set was to avoid chasing a second or third tap that doesn't quite work and get the situation resolved soon, even if it's a little pricier. Maybe a better decision is to order a few more single taps at once and return the ones I don't need.
Thanks for the help. This is why I appreciate this site.
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