Trans. dipstick threads

[Mav]

Hi All,I have a new-to-me Mirage 26 powered by a Yanmar SB8. When I bought the boat, the transmission dipstick was fairly mangled from someone trying to wrench it off (or on, as I now suspect.) I managed to get it out (a complex series of steps involving a drill, plyers, a vacuum and a soldering iron)and then when I tried to screw in the new dipstick, I realized I had a bigger problem. It seems the metal threads in the block are damaged. I don't think it's severe, but it certainly is binding the cap and I don't want to screw it in as it will just ruin another plastic $30 dipstick.Anyone had an issue with this? Do you think there might be a tap out there that could straighten the threads, or am I into a whole new block?

 

[Mav]

update

It's a lonely forum, this Mirage Owners forum. So I'll talk to myself. I've spoken with a local Yanmar repair/dealer, and he's recommended chasing down a 'pipe tap' with same size and thread as the dipstick cap. I've located a wholesaler, and plan to go after this in a couple days. He had a good suggestion: grease up the tap and twist 1 turn then remove and clean off any metal thread shavings--go at it again for another turn. This should minimize the metal shards falling into the transmission.I'll post the outcome, good or bad...

 

[Mav]

egg on face

to close off this thread, I can tell you how my thread problem was solved. After blowing up at the mechanic (he hadn't brought the dipstick issue to my attention during the purchase mechanical inspection) I had him go to the boat and check it out for himself. This was after I spent a morning visiting fastner shops, pipe thread shops, and tap and die shops without any luck in finding a thread mate. I really thought I was going to have to pull the engine and get the block re-threaded. But no, the mechanic put some oil on the cap, threaded it in, out,in out... no damage! Boy, I felt dumb. I guess these plastic caps aren't threaded to cleanly, so you do need to use a little muscle--something I was afraid of because the previous cap had jammed.Live and learn...

 

[Nice N Easy]

Threads

The grease is an old and fairly well know way to solve this problem. Works pretty good. Wheel bearing grease seems to work best, but any really thick grease will work. Just don't get in any rush, and you should be fine. Might help to change fluid a couple of times just to be sure.