Drill & tap crankshaft hole?

[Got Smoke?]

Ok has anyone ever had to drill & tap a crankshaft hole because of stripping?

Long story short I have one bolt hole in my crankshaft that has been chased but still will not torque down. Went to 50ft/lbs but when I attempted 80 it spun in the hole.

Bolt size was 12x1.25 :bang ....what am I going to have to go to now? Anybody in the middle TN area that has the equipment and is willing to make a house call? I really want to get it done with the motor still in the truck, I don't want to pull and disassemble when I'm this close to finishing the rebuild. :kick:

 

[BrettWINspeed]

I haven't had to drill a Cummins crank, but you should have enough room to get a right angle drill in there with the radiator out. I'd try to get a Time-Sert kit, they come with the tools and inserts.

If you don't feel comfortable doing it, I'm sure a local machine shop could do the repair

 

[RIVERRAT]

got my time-serts from Bel-Metric, Metric Hardware and Automotive Specialty Supplies - Wholesale Direct to You best price I found had them in few days the way to go

 

[Got Smoke?]

I haven't had to drill a Cummins crank, but you should have enough room to get a right angle drill in there with the radiator out. I'd try to get a Time-Sert kit, they come with the tools and inserts.

If you don't feel comfortable doing it, I'm sure a local machine shop could do the repair

It's actually the flywheel end. Thanks I will check those out.

 

[Tate]

Can you get access to a small mag base drill? That will ensure your hole is square, and makes starting the tap square very easy.

 

[PRINCETON_JAKE]

Can you get access to a small mag base drill? That will ensure your hole is square, and makes starting the tap square very easy.

X2 use a mag, and thread inserts, not heli coils,

 

[Gasoline Sucks]

tack it

 

[Got Smoke?]

I haven't had to drill a Cummins crank, but you should have enough room to get a right angle drill in there with the radiator out. I'd try to get a Time-Sert kit, they come with the tools and inserts.

If you don't feel comfortable doing it, I'm sure a local machine shop could do the repair

got my time-serts from Bel-Metric, Metric Hardware and Automotive Specialty Supplies - Wholesale Direct to You best price I found had them in few days the way to go

X2 use a mag, and thread inserts, not heli coils,

What is the difference between a "Time-sert" and a "heli-coil"?? :what:

 

[Diesel Powered]

What is the difference between a "Time-sert" and a "heli-coil"?? :what:

Heli-Coil is just a spiral winding and shouldn't be used on anything more powerful than a stock 8hp Briggs. LOL

Time-Sert is a much better solid insert with a flange on the top edge so it'll stop where it's supposed to and you're able to use the hole at full torque.

 

[Turbonetics TQ]

Heli-coil will work, and you can usually get them at NAPA. I have never had a problem with heli-coil. They always hold the proper torque for the fastener size. I have used hundreds of them from 1/4" up to 1" (Held 750 lb/ft flywheel bot for 3516 CAT engine). Its a little unnerving drilling your own crank...but at least its not a $40k crank!
Time-Sert looks like better option but a Heli-coil will work. And if Heli-coil screws up then you can move up to a King-sert (next size up in hole repair from a Heli-coil).

You do not need a magnetic drill press (although very nice) Just a steady hand, a lot of patience, and a lot of lube!!! You can use a small square to...well..be sure that you are square and keep checking.