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Subject: Need Help With Thread Inserts.

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Kimberly    Posted 04-11-2019 at 17:57:34 [URL] [DELETE]        [Reply] [Email]  
  • Need Help With Thread Inserts.
  • I need some help with figuring out what thread inserts I need to buy to repair the threads on the housing. The bolts I have don't seem to match the parts guide; I figured that is because someone replaced them with bolts close to what the original ones were. For the running boards to cover to housing bolts I see 21443-S; 7/16-14 X 0.94 (15/16; I am guessing a one inch bolt will work here). For the parking pawls I see 21441-S; 7/16-14 x 1 1/4. So what insert do I need to get to repair the buggered threads?

    By the way, I am thinking of replacing the bolts; some are buggered up as well and will need to be replaced. What grade do I get? I am guessing these don't need to be high strength bolts.

    Tim Daley(MI)    Posted 04-13-2019 at 07:32:21 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Need Help With Thread Inserts.
  • Kim -you sure do have a lot of issues with this 8N, and I mean a lot of stripped out threads and parts. In my opinion, mucking around with Keenserts and Helicoils should be done by a qualified machine shop especially if you have no experience doing it. You are not going to do a decent job with your Black & Decker cordless drill and a hand tap. Drilling and tapping into the case will allow chips to fall into the sump - you don't want that - no matter whet steps you may think will collect them. That means dropping the pump and taking the housing to a shop where they can do the job right. I realize cost is important as you are on a limited budget, so, for option #2 I am suggesting you look on ebay, ADS forums, and CL for a used housing and go that way. Someone here may have one to offer you as well. It may be cheaper. Did you tell us where you are located? Maybe one of us could pop in and offer advice & help in person. HERE'S A VIDEO ON INSTALLING KEENSERTS...

    Tim Daley(MI)

    Kimberly    Posted 04-16-2019 at 13:45:30 [URL] [DELETE]        [Reply] [Email]  
  • Re: Need Help With Thread Inserts.
  • Well, if I bugger up the repair, then I guess that is an option. I plan on dropping the pump; it was leaking at the gasket near the front anyway so that can be addressed. These tractors are old, you run into issues from previous owners. Like the missing control lever spring.

    I have already ordered the helicoil repair kit although the keenserts look easy to do. I will post the outcome. I really don't want to be splitting the tractor at this time.

    TheOldHokie    Posted 04-16-2019 at 16:02:13 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Need Help With Thread Inserts.
  • You should have no problem. The helical inserts are easirer to install than the keenserts. For helical inserts you only need to enlarge the old hole by the depth of the original thread (.078 in this case) which is easy to do with a hand held drill. When you get ready to tap the new oversize thread just make sure you keep the tap square to the hole. I have confidence you will do a fine job and it will be good as new when you are done.

    TOH

    PS> You might want to put a drop or two of high strength thread locker on the OD of the helicoils before you install them. Just a little insurance to help keep them in place.

    Farmer Dan    Posted 04-12-2019 at 07:01:43 [URL] [DELETE]        [Reply] [Email]  
  • Re: Need Help With Thread Inserts.
  • Iwould try cleaning up the threads with a tap before I bothered with an insert. Grade 3 bolts will be fine.

    Kimberly    Posted 04-12-2019 at 08:40:02 [URL] [DELETE]        [Reply] [Email]  
  • Re: Need Help With Thread Inserts.
  • Yes, I did that on the left-hand side yesterday. The lower hole for the running board is buggered beyond repair. The top one I may test first. Some of the holes may be good if I get new bolts. I need to look up the torque for these bolts.

    TheOldHokie    Posted 04-12-2019 at 09:34:46 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Need Help With Thread Inserts.
  • Torque is not critical here, 35-45 lb-ft is plenty. Just a good tug with a socket wrench handle. Damaged bolts do not bode well for the threaded holes. If in doubt heli-coil them.

    TOH

    Kimberly    Posted 04-12-2019 at 10:06:43 [URL] [DELETE]        [Reply] [Email]  
  • Re: Need Help With Thread Inserts.
  • There is a Fasternal not too far from me. I thought I would visit to see if they had what I need. Whatever you recommend for this application. Not a lot of thread depth in this hole. Someone in the past may have gotten too aggressive trying to stop a leak; or the bolt just worked loose and then getting up and down on the tractor keep wiggling the bolt. Whatever the reason, I now have to repair it. It was leaking bad on the inspection cover side; I haven't ran the tap through them yet but suspect that some threads may be damaged and it couldn't be tighten properly to prevent the leak.

    TheOldHokie    Posted 04-12-2019 at 10:26:22 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Need Help With Thread Inserts.
  • Here is a 7/16-14 heli-coil kit that should do the job. Fastenal will probably have something similar but I suspect for a good bit more cash. The McMaster kit includes 10 inserts which is more than you should need. That 7/16-14 thread is used a lot on the tractor so IMO having the tap and some spare inserts is not a bad thing.

    Heli-Coil Kit

    TOH

    Kimberly    Posted 04-12-2019 at 10:58:51 [URL] [DELETE]        [Reply] [Email]  
  • Re: Need Help With Thread Inserts.
  • OK, thanks, much appreciated for taking the time to help me with this. I have never done a thread repair job so was pretty much in the dark on this. I will get the kit ordered and move ahead with the job. Thanks again.

    TheOldHokie    Posted 04-12-2019 at 12:44:23 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Need Help With Thread Inserts.
  • Here is a kit for a lot less. Has six inserts instead of 10 and you will have to buy the drill bit separately.

    7/16-14 Helicoil kit on Amazon

    TOH

    Kimberly    Posted 04-12-2019 at 16:12:05 [URL] [DELETE]        [Reply] [Email]  
  • Re: Need Help With Thread Inserts.
  • Thanks, I have a set of tap drills; should have the right one but will check. I was reading on these and someone said they had issue with them in cast iron.

    TheOldHokie    Posted 04-12-2019 at 16:23:42 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Need Help With Thread Inserts.
  • In today's internet world you can find someone that has a problem with just about anything. But there is no factual basis for suggesting there is a problem with heli-coils in cast iron. It is a time tested (decades) and proven repair. Just as an example tens of thousands of cast iron spark plug holes have been repaired using them. Probably just as many exhaust manifold bolt holes. They are a staple of automotive machine shops around the world.

    TOH

    Kimberly    Posted 04-12-2019 at 20:20:14 [URL] [DELETE]        [Reply] [Email]  
  • Re: Need Help With Thread Inserts.
  • Probably had one to fail and blamed the insert instead of maybe the work done. I see that the drill needed is 29/64. I am not sure I have the tap needed; what size is the tap? If I have the tap, then can just purchase the inserts; if not, then I need to purchase the kit.

    TheOldHokie    Posted 04-12-2019 at 22:23:29 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Need Help With Thread Inserts.
  • Helical inserts require a special screw thread insert (STI) tap. The kit will have the tap, installation tool, and inserts.

    TOH

    Kimberly    Posted 04-12-2019 at 23:26:17 [URL] [DELETE]        [Reply] [Email]  
  • Re: Need Help With Thread Inserts.
  • Kit is ordered, comes with the tap and the inserter but no drill bit. Six helicoils.

    Thanks for your help TOH, I would have probably got the wrong ones :-). Big Hugs :-).

    R Geiger    Posted 04-12-2019 at 12:12:33 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Need Help With Thread Inserts.
  • A helicoil repair is pretty straight forward, when you install the insert you will have a little tang that is used to turn in the insert. You will have to break that off. I use a punch, but don't lose it inside the housing.
    you might drill and tap a hole to practice with.

    Kimberly    Posted 04-12-2019 at 16:13:44 [URL] [DELETE]        [Reply] [Email]  
  • Re: Need Help With Thread Inserts.
  • OK, thanks. I think I am dropping the pump since I don't want to worry about shavings getting into the pump and lift cylinder.

    TheOldHokie    Posted 04-12-2019 at 07:00:38 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Need Help With Thread Inserts.
  • You need 7/16-14 repair inserts. Since you have multiple holes to repair I would probably go with helical inserts since the are more compact and easier to drill out the old threads. A repair kit with inserts, tap, and drill will run you about $45. I buy all of my cap screws online these days and only keep grade 8 in the parts bins. The price difference is almost negligible.

    TOH

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