Thread pitch questions

[opposedtwin]

Well, I think these are boogered beyond repair/use. I’m guessing they are 1/4 -28. If I tapped the brass piece to 1/4 -20 and bought 1/4-20 stainless bolts to replace the bad ones, what problems could potentially occur? A bag of 50 stainless screws is only $6.40 but the brass part is not so easy to find. I know it might confuse the next owner but I trust he or she will figure it out. Most people out there are smarter than I am anyway, just ask my kids. 😯
scott b

Hang on, gotta post a pic from my computer since I can’t yet do it from my phone-which is also way smarter than I am.

[wiscoboater]

Hey Scott, I have one if you need one. Can have it in the mail for you tomorrow. Let me know.

[opposedtwin]

thanks jeff. I have a NOS one too that I bought years ago just in case. I’m just being cheap I guess. thanks for the offer though!

[PugetSoundBoater]

I "fixed" a stripped thread on a connector once. went with a longer bolt and put a stainless nylocknut on the far side of the connector with new star lockwasher. Of course I would have rather used an undamaged one.

"Some people want to know how a watch works, others just want to know what time it is"
Robbie Robertson

[shoestringmariner]

I am very doubtful those are 1/4-28

[beerman57]

I doubt that you could just tap it to a course thread, without going up a size.

[johnny-infl]

how are the threads on the brass coupling ?? shot ?
Run a tap through it to see if they will clean up.

I just put a thread gauge on the one I have and it is indeed 1/4-28 x 1" .
I got a couple of NOS off of ebay.
I am "assuming" that if you tap it out to a 1/4-20 and use a good thread lock, it is ok.
(that is probably what I would do if it were mine and did not have a spare).

.

[fleetwin]

I don’t know how, but usually the threads are OK in the brass connectors when the screws come out a mess like yours, happens all the time to me too. I wouldn’t alter the thread pitch in the brass connector, just clean it up with a 1/4-28 tap and replace the screws with OEM pieces. This is not an area you want to be messed up, clutch dog damage could be a result.

[frankr]

Yes, they are 1/4-28. If they are stripped, no, you can’t retap them to 1/4-20. Yes, you can put a nut on the backside of one of them, but sort of difficult to do it on the second one. If you want to save them, do it right and install Heli-coils.

[opposedtwin]

quote Johnny_inFL:

how are the threads on the brass coupling ?? shot ?
Run a tap through it to see if they will clean up.

I just put a thread gauge on the one I have and it is indeed 1/4-28 x 1" .
I got a couple of NOS off of ebay.
I am “assuming” that if you tap it out to a 1/4-20 and use a good thread lock, it is ok.
(that is probably what I would do if it were mine and did not have a spare).

.

That’s how I got to this point. Without really thinking (because 1/4-20 is such a common OMC size) I ran a tap through the brass piece and it went through without much resistance. I thought it was because it’s soft brass, but now now think it’s because it was already stripped and wallered out.

This part seems to be a weak link for the OMCs of this era. I’ve run into stripped ones before, though not a majority. I can see the necessity for a flexible metal, but I wonder why they went with a tight thread pitch instead of the typical 1/4-20. Must have been a good reason for it. Engineers…..

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