Implement mounting holes

[Mht]

I’m working on a final drive that has implement mounting holes that a PO has drilled out and tapped to 3/4-10. I would like to repair them to the original 5/8-11. It appears that the hole is too big for a helicoil and too small for a threaded insert. Can I drill and tap the housing to 7/8 and use a threaded insert without problems or should I find a replacement housing.

[Barnyard]

https://www.mscdirect.com/browse/tnpla/ ... 0-EALw_wcB

[Mht]

That is a fine thread insert. They make a 5/8-11 internal 3/4-16 external but not one with 3/4-10 external threads so that leads me back to my original question

[Stevetractor]

I get mine from a local industrial supplier. They are 7/8 fine external and 5/8 corse external. Sorry I haven’t got the part number but they are available. They were called keenserts but can’t remember new trade name. After there threaded in, I use red thread locker too, 4 small stainless pins are driven in down the side of insert to provide a positive lock. Work great, absolutely no issues. Get you hole drilled nice and straight. Hope this helps.

[Bob McCarty]

I think E-Z lok may have what you need.

[Mht]

It appears that the only inserts that are 5/8-11 internal are either 3/4-16 external (fine thread and my holes are already tapped to coarse thread or I’ll have to go to a 7/8 inch insert and I wasn’t sure about how strong that would be to drill out for that big of an insert. That is what Stevetractor said he has used with no problem. I may just replace the final housing if I can find one cheap enough

[SamsFarm]

Well, if you find better ones, please dont scrap the ones you have!

Sell them or give them away.

Some day the used parts might dry up!

I thought I saw new ones from Case IH, but for like $300+!

Doubtful they sell many of them!

[Barnyard]

Why not reverse them if the other holes are okay?

[SamsFarm]

Something else for everyone to keep in mind, (if you do not already know) is a bolt in a tapped hole should have 1.5x the diameter of threads engaged in the tapped hole minimum!

Example a 1/2" bolt should have 3/4" of threads screwed into the tapped hole.

If the tapped hole is worn and sloppy, a some extra threads (length) on your bolt can be beneficial.

On a side note, be careful you do not use too long of a bolt in a blind tapped hole.

You can over torque the bolt that is too long and break something easily!

Happy Tractoring!

[Mht]

Thanks for all the advice. I’ve ordered some 5/8-11 internal, 7/8-10 external threaded inserts to make the repairs. I had a 7/8 tap and the correct 49/64 drill bit so I just decided to drill and tap to the correct size for a readily available insert. The drilling and tapping went fine so now I’m just waiting on the inserts from McMaster Carr

[SamsFarm]

Great!

Happy Tractoring!