Stripped Engine Bolts in case

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magrahamkp08
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Stripped Engine Bolts in case

#1 Post by magrahamkp08 » Wed Feb 07, 2018 11:31 pm

Need some help here. I stripped the screws that hold the retaining plate for the transmission in the crankcase. and to compound upon it the heads broke. Im going to take my case to a machine shop to drill out and helicoil the case to make it useable again. Can somebody share the size and pitch of the screws used. It is #15 in the diagram.
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Zedixe13
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Re: Stripped Engine Bolts in case

#2 Post by Zedixe13 » Thu Feb 08, 2018 5:49 am

This is the answer to all your problem ,
https://www.ebay.ca/itm/Neiko-10038A-Le ... Sw6ShZOkyo

I bought this kit and used them with a simple reversible drill , in 30 sec. the broken bolt was out .

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JonW
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Re: Stripped Engine Bolts in case

#3 Post by JonW » Thu Feb 08, 2018 7:47 am

ive never had any luck with my set like that, upside down bolts work differently perhaps lol

spark erosion is a good technique to get them out if totally stuck.
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hablair
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Re: Stripped Engine Bolts in case

#4 Post by hablair » Thu Feb 08, 2018 10:03 am

LH drill bits and square end easy outs worked for me on the opposite plate, these were the counter sunk screws whose heads had been stripped before i got to them

Use the smallest drill possible and centre punch the head of the screw first, tap the easy out in as far as possible, take it slow and careful and they should come out

A bit of freezit spray on the screw also helps too

magrahamkp08
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Re: Stripped Engine Bolts in case

#5 Post by magrahamkp08 » Thu Feb 08, 2018 10:26 am

When i went that route, the bit walked on me so it cut into the threads on the case just enough that the square extractor no longer works. It HAS to get helicoiled now (or some kind of thread repair). A bit frustrating, so thats why i need to know the screw size and pitch.

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Re: Stripped Engine Bolts in case

#6 Post by Headcoats » Thu Feb 08, 2018 11:32 am

These screws are notorious for refusing to budge and then strip

Welding a nut on the screw will do the job and the heat helps to loosen it too
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T.RexRacing
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Re: Stripped Engine Bolts in case

#7 Post by T.RexRacing » Thu Feb 08, 2018 1:25 pm

Avoid EasyOut tools. There are other fastener removal tools that don't break off making things worse.

First I take a good chisel and make a slot in the remaining screw. Heat with a heat gun to loosen and try removing with flat head screwdriver. If that fails the left hand drill bits are next. Then use the removal tools that come with my left hand drill bits. That fails and it's into the mill and gently cut out with carbide end mills.
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Re: Stripped Engine Bolts in case

#8 Post by hondaror » Thu Feb 08, 2018 8:44 pm

Another tip is to impact the end to shock the threads loose, before you try and back them out. Hit them hard and often enough and they'll back right out.
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Re: Stripped Engine Bolts in case

#9 Post by bitzz » Fri Feb 09, 2018 2:11 pm

M6x1.0
Next time use a impact driver and heat. Those screws have thread locker on them.

If you are going to drill it out, use the hardest, stoutest drill you can find. A carbide spotting drill works well.

Removing broken bolts is an art form that only comes with experience... meaning you're going to screw up a bunch of 'em till you figure it out.

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Re: Stripped Engine Bolts in case

#10 Post by bitzz » Fri Feb 09, 2018 2:20 pm

Real "Easy Outs" are great. I haven't seen a real "easy out" in years, just crappy knock offs made from oriental monkey metal, that twist off the first time you use them.
I have had good luck using Ridgid Pipe extractors.
Image
I have had a set of these for at least 30 years... the small one is getting kinda short though.

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Re: Stripped Engine Bolts in case

#11 Post by JonW » Fri Feb 09, 2018 6:47 pm

bitzz wrote:M6x1.0
Next time use a impact driver and heat. Those screws have thread locker on them.

If you are going to drill it out, use the hardest, stoutest drill you can find. A carbide spotting drill works well.

Removing broken bolts is an art form that only comes with experience... meaning you're going to screw up a bunch of 'em till you figure it out.
This is all sound advice IMHO. I use a Vessel impact screwdriver these days, its the correct JIS type for the screws and the impacta unit in it works very well.

Its defo an art form, Im much better at it now than I ever was, plus I have a full set of helicoils on hand for when it all goes wrong, but rarely get to use em.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

Like Watches? www.PloProf.com & www.DeskDivers.com

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L.B
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Re: Stripped Engine Bolts in case

#12 Post by L.B » Sun Feb 11, 2018 2:32 am

Replace with hex drive/allen head bolts/screws.
I used ss with nickle silver never seize.

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Re: Stripped Engine Bolts in case

#13 Post by hondaror » Mon Feb 12, 2018 3:25 am

L.B wrote:Replace with hex drive/allen head bolts/screws.
I used ss with nickle silver never seize.
As L.B. Says, antisieze is really important with dissimilar metals.
Rory
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Re: Stripped Engine Bolts in case

#14 Post by T.RexRacing » Mon Feb 12, 2018 8:59 am

Cleaning threads on assembly is important. Some threads are to be oiled,check manual. When using anti-sieze or other lubricants torque must be reduced to avoid over tightening-UNLESS manual directs you to lube threads. Unless specified torque specs are for dry clean threads.
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