Torque and turn equals what?

[Cmark]

I also recall an incident with the installation of the swing bearing on a Cat 390 using a hytorc. Someone got the translation between Kpa and psi mixed up. When the first one let go it left a nice impression of a bolt head in the top of the carbody.

 

[Truck Shop]

The sad fact is many engines assembled even after a visit for machine work the thread bores are never checked. Standard thinking is it's all clean and just needs to be blown out.
Most cleaning tanks/washers don't really clean those areas, any metal removed from machining because of it's irregular shape can wedge in threads and won't come out with just a blow
gun. It's just something I learned doing automotive machine work-it never fails the crap stuck in flutes of a tap used on a fresh machined and washed cylinder block.

 

[Nige]

The sad fact is many engines assembled even after a visit for machine work the thread bores are never checked. Standard thinking is it's all clean and just needs to be blown out.
Most cleaning tanks/washers don't really clean those areas, any metal removed from machining because of it's irregular shape can wedge in threads and won't come out with just a blow
gun. It's just something I learned doing automotive machine work-it never fails the crap stuck in flutes of a tap used on a fresh machined and washed cylinder block.

Same thing assembling these machines I'm working on right now. I posted some pics of cleaning out the holes. Last truck the boys forgot to run a tap through the threaded holes in the diff housing with the result that 2 out of 20 of the 1-1/4" bolts didn't want to run all the way in. Fortunately the rattle gun got them out but they looked a bit 2nd hand. I put them up on the "Employee of the Week" board in their crib room just to remind them why we run taps through all the big critical threads before going near them with hardware. I don't know which one of them did it but I'm sure they know and they're ripping the pi$$ out of him............

 

[Nige]

I also recall an incident with the installation of the swing bearing on a Cat 390 using a hytorc. Someone got the translation between Kpa and psi mixed up. When the first one let go it left a nice impression of a bolt head in the top of the carbody.

That's not bad. It's only a factor of 7 in round numbers.........

 

[JD955SC]

I did a Cat 3176 where the manual actually specifies to use a tap to clean the head bolt threads before assembly. I think there was even a special part number for an extended shank tap too

Cat uses torque turn a lot, especially undercarriage and engine. I have never seen an equivalent value given. What I have seen before is “bolts MUST reach a minimum torque of X ft lbs after final torque”

 

[fastline]

I'd only add that all taps are not equal! Being in manufacturing and wrenching, I see the disconnect. Sometimes a "thread chase" is much safer and more appropriate than a cut tap. There are also various flutes, spiral and straight, cut and form, and various tolerances. I swear I have seen more damage from idiots with a tap in their hand!

But just as advice, I typically would recommend a chase as they are designed to chase existing threads and usually have gullets for chip extraction. Aside from that, I have lost could how many "chase tools" I have just fabbed in a pinch. About any bolt with do! Taper the first 3 threads and cut 3 minor gullets axially with a cut off wheel. I have actually had to make real taps in a pinch but this really does work.

I keep rookies away from cut taps. If they have no feel for what they are doing, they can cost you an engine. As well ,if you have a through hole, you don't play this game. You run a chase with grease, clean, and reverse.

I usually tell people if you experience "the pop" or jerky torque/slip when torquing, stop and add a little lube. I too typically use motor oil or similar. Aluminum is the worst at binding up and I can feel it. Usually I likes me a little grind and bind But not with my threads. I do find hardened steels to be much easier than Aluminum but working around race engines mostly, that is the bag. Drop several points if you see several threads come out with your bolt! That I hate because I have to start making decisions and scoping things. More than once I have been all the way at assembly of the head before having to divert due to a head bolt that is not feeling right.

 

[John C.]

The first torque turn I did was on a Fairbanks 38D8 1/8 main bearing cap. THe cap weighed about 70 pounds and was pushed up on studs, then the nuts threaded on. As I recall the nuts were 2.5 or 3 in. There was a special wrench that a bar fit into and a six foot heavy wall pipe fit on that. Our biggest guy pulled those nuts as hard as he could, then the pipe was installed and the nuts pulled two more flats. It took three more people to pull that. The rest of the story was that this was done through a six inch window at each main cap. The procedure was set up so that no torque wrenches were needed.

 

[Truck Shop]

I swear I have seen more damage from idiots with a tap in their hand!

Now that I haven't because few have taps but easy outs, broken easy outs because of broken bolts or studs because someone didn't use a Tap to Chase the threads before
assembly--------Now that I have seen and had to repair on the Quick Way or Rottler.