Crankshaft nut

B

brycele

Daily Driver
In searching for the best way to remove the crank nut, it looks as though an impact wrench is the general consensus. So I went down to harbor freight and picked up one of their 1/2 electric impact wrenches.

Unfortunately, this doesn't seem to do the trick for me. Is because I'm not using a suitable socket or because I'm using a 1.5 in vs 38mm?


Would this hex shape at Amazon that's a true 38mm and designed for use with an impact wrench be a better choice or waste of money?
[ame="http://www.amazon.com/TEKTON-4938-2-Inch-Impact-Socket/dp/B000NPPBBU/ref=sr_1_2?ie=UTF8&qid=1448485732&sr=8-2&keywords=1%2F2+in+drive+38+mm+socket"]Amazon.com: TEKTON 4938 1/2-Inch Drive by 38mm Heavy Duty FWD Impact Socket: Home Improvement[/ame]
 
Are you asking about the socket...

Because you stripped the nut? Or just because the impact wrench didn't remove it?

A 38mm works out to 1.49606 inches. The tolerance of the average 1.5 inch socket is way more than .004 inches, so you are fine to use either a 38mm or a 1.5 inch.

One trick I have used is to wedge the breaker bar against the chassis and tap the starter.

Pete
 
Not stripped

I stopped before stripping the nut and I didn't want to keep working on it in fear of doing just that. The hex socket looks as though it get better grip than the one I was using...
Just wanted to get other opinions before ordering.
 
brycele said:
Unfortunately, this doesn't seem to do the trick for me. Is because I'm not using a suitable socket or because I'm using a 1.5 in vs 38mm?
Click to expand...

That won't make the difference. Hit it with a bit of PB-Blaster, let it sit overnight, and when you try next day alternate quickly between tightening and loosening - the rocker-style trigger on the HF impact gun makes this easy before you loosen for effect.
 
This is a long shot, but...

I bought an electric impact wrench from eBay - it was shipped from the orient.

Before I attacked the crank nut, I held the tool in the air and pulled the trigger. Guess what? Fwd/Rev switches were arse-about.

I suggested to the seller this was NBG. He duly sent me another. Same issue!

I gave the second to my mate with strict instructions!

This isn't the case with yours, is it?

Brian
 
Hex does matter

I found a hex socket designed for impact wrenches at OReilly and believe it or not it does make a difference. Took that nut off in 2 seconds.
 
Hey Brian, maaaaaate.....!

bmck said:
......Guess what? Fwd/Rev switches were arse-about.
I suggested to the seller this was NBG. He duly sent me another. Same issue!.......
Click to expand...

Didn't ya know, cobber? Northern hemisphere electrics work in reverse when they come over the equator, and then get used in the southern hemisphere! :nuts:
You'll have to get yur "seller" to send you another one - that's made in the southern hemisphere!! :sun:
(But NOT made in Oz - their stuff is cr*p!!)

cheers, Ian - NZ
 
I have one from our local cheap tool place, Harbor Freight, that is the same way. I think it's because the main use is to loosen rather than tighten.
 
Depends on the impact wrench. Some cordless impact wrenches have impressive power, other corded impacts are powerless.

Sockets can make a difference due to fit. The slop between square drive to hex and all involved reduces torque transmitted. Fit and tolerances are one of the differences between low cost-low quality sockets and good ones. I'm allergic to poor quality sockets and such as the often cause more grief than expected results.

Sockets rated for impact wrench duty have a harder outer with a soft inner and thick walls (generally lower hardness overall compared to non-impact sockets) to prevent the socket from shattering. Sockets for hand or non-impact, non powered drive tend to have thinner walls and mostly uniform hardness. Best BIG impact sockets are made by Ozat in Israel or Momento AB in Sweden.

On larger threaded fasteners, the 3/4" drive air impact is used. This is a Mazda rotary flywheel nut, spec torque about 350 ft/lb. The ATP 3/4" drive impact removes this nut in seconds.
https://www.youtube.com/watch?v=kmTmI0_9s-I

Think those fold over "lock indents" actually do much, not really. They might prevent the nut from being lost after it works loose. Simply apply enough torque ant those locking indents do much of nothing.

Swench, 3/4" drive manual impact, about 800 ft/lb.
https://www.youtube.com/watch?v=ztFb2sld5LE


Bernice








brycele said:
In searching for the best way to remove the crank nut, it looks as though an impact wrench is the general consensus. So I went down to harbor freight and picked up one of their 1/2 electric impact wrenches.

Unfortunately, this doesn't seem to do the trick for me. Is because I'm not using a suitable socket or because I'm using a 1.5 in vs 38mm?


Would this hex shape at Amazon that's a true 38mm and designed for use with an impact wrench be a better choice or waste of money?
Amazon.com: TEKTON 4938 1/2-Inch Drive by 38mm Heavy Duty FWD Impact Socket: Home Improvement
Click to expand...
 
Agreed

Pete Whitstone said:
One trick I have used is to wedge the breaker bar against the chassis and tap the starter. Pete
Click to expand...

Perfect place to use a "broken" Torque Wrench", so you don't ruin any "good" tools.
When you "Bump" the Starter, you don't want to be anywhere NEAR it, just in case the nut slips.
Ever seen how high a Torqued Up Breaker Bar will bounce off a concrete floor.
 
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