stripped SX-A (3L VP) dipstick threads

boatdude100 · Jul 20, 2026

I read a Threadsert may be the way to go?
Can anyone confirm the thread gage for SX-A outdrive thread and/or dipstick thread?
Can I take the top off carefully, insert threadsert and just re-use the shims/gasket if ok?
Can the dipstick be reused with threadsert as this will widen top hole?

Cecil Marine seems to have the best price but for us it is almost $600 CDN. Can this part be had anywhere else at a better price perhaps? ("upper drive top cover and service kit")

Any other thoughts on fixing this brutally common issue?
Many thanks!

Bondo · Jul 20, 2026

Ayuh,....... Every drain/ fill plug I've ever seen is 3/8"- 16,......

boatdude100 · Jul 20, 2026

Thank you, is the helicoil route generally the way people go or do the wise cough up the $ and replace the cap?

boatdude100 · Jul 20, 2026

Still looking for helicoil size for the
Top of outdrive dipstick tap. Its not the drain/fill plug at the bottom.
Thank you

Scott Danforth · Jul 20, 2026

3/8-16 Thread-sert

Horigan · Jul 21, 2026

The challenge with an insert is getting the a good seal with the O-ring. Oh, and keeping metal debris from entering the drive... I'd just get a new cap.

Bondo · Jul 21, 2026

boatdude100 said:
Thank you, is the helicoil route generally the way people go or do the wise cough up the $ and replace the cap?

Ayuh,...... No way I'd spend $600. for a new cap,.....
Working on the bench, tap for the helicoil/ thread-sert, clean everything up, 'n slather it with Perfect Seal, 'n send it home,...
Then clean it all up again, 'n reinstall the cap,....

Scott Danforth · Jul 21, 2026

or pull the cap and take it to your local radiator shop. they will weld it and re-tap it for about $30

Blue Bomb · Jul 21, 2026

I had that happen about 4 years ago. Took it to a local shop at the lake They helicoiled it for 100 bucks.

Lou C · Jul 22, 2026

If you have a decent automotive machine shop they could fix that easily.

boatdude100 · Jul 22, 2026

Thanks for the great replies, have a Marina (Hurst Marina) who said they do helicoil all the time. Easy as this job appears as DIY I think I'll bring it to them although I agree a time sert makes more sense. I would silicone top each year in case of leaks

stripped SX-A (3L VP) dipstick threads

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