impact wrench

IrishGuy

Active Member
I've had my engine nut back off twice. it doesn't come all the way off and still seems to be tight. but it does seem to back off after 200 or so miles and then I have to retighten.

I'm using red loctight too. my impact wrench does 400 ft/lbs of torque i think. do I need a more powerful torque wrench to get this sucker to stay on better?

:cheers:
 

Little-Boo

Well-Known Member
Troop Supporter
I've had my engine nut back off twice. it doesn't come all the way off and still seems to be tight. but it does seem to back off after 200 or so miles and then I have to retighten.

I'm using red loctight too. my impact wrench does 400 ft/lbs of torque i think. do I need a more powerful torque wrench to get this sucker to stay on better?

:cheers:
I would not trust the Impact wrench to give you the torque needed for this old boy. Use red loctite and torque it to 165 Ft lbs using a 1/2 inch torque wrench and that should do it.

Carlos :2thumbs:
 
Little-Boo is right on with what he's saying.
And I don't even think I've seen an impact guns that torque up to 400 lbs.! That must be one hell of an impact gun! :D 200 lbs. maybe (big trucks), but not 400 lbs. Hell 400 lbs. would ring off lug nuts like they weren't nothing at all, rather than tightening them! :lol: But I do however like the idea of "MORE POWER"! :lol: :loony: :lol: :roll:

Just one thing to add to what Boo's saying, make sure the threads on the shaft and inside the nut are free of "any" oil before you use loctite and tighten it down!

Good Luck! :2thumbs: :cheers:
 
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Fibersnake

Banjo Playing PsychoBilly
I would be very cautious about depending on any Impact wrench to come down to a final torque spec. That is not what they are designed for. If using only an impact wrench to achieve torque such as tire shops do, normally they use a torque socket that is pre-designed to give a the specified numbers. A good tire shop will always verify with a hand torque wrench.

Also there are many impact that will give 400 plus easily. That said such are not normally associated with home use and rarely in 1/2 drive (at least one that can do it consistently). You get into 3/4 and above such as spline not an issue.

Not sure what the new specified specs for the but the 165 seems right. If one uses a impact wrench and such does lay out torque that exceeds the specs, you may get it tight and it may not come off, however like any design, there is a risk of elongating the threads and possibly even breakage and thus a major problem.

As already said, good clean threads, check for damage and then the proper Loctite to proper torque using a good quality and perferably calibrated torque wrench (applied in steps is idea). If using a impact wrench, my suggestion is to start by hand to insure no cross threading and then lower setting on the impact to bring the nut up to seat and then hand torque wrench.

A side note, for me torque are a pet peave, Was beat into by my late dad to do it right. During 35 years of turning wrenchs on ships and other stuff, still remember my first ship, where one of the snipes did not want to take the to torque a head bolt on a Copper Bessemer using the long method of a 4 x multiplier, a ratcher wrench that was nearly 5 foot long, etc and decided he would run it down with a large spline drive impact while watching the torque gauge. Reached and exceed the specs fairly quickly and the damn bolt broke. The required torque was 2400 lbs. You can not imagine the PITA it takes to replace a head bolt on a big rock chunker Copper that goes from top level to lower crank area and the bolt is probably 8 foot long.
 
Brake Clean or carb. cleaner, brass brush, clean towels Make sure to check for removal of "all" old loctite material
 

Fibersnake

Banjo Playing PsychoBilly
ok great input guys :cheers: what is the best way to ensure that the threads are clean?
I use BrakeKlen or some other type of spray cleaner. Also inspect the threads to make sure there is no burrs or damage, if so may require a thread chasing die to clean up. Allow the recommended time for the Loctite to fully set up as per the instructions on the bottle also. Way too many times, some will put Loctite on and not give it enough time to set properly and lessen the ability of the Loctite or other thread lockers to fully meet design.
 

Fibersnake

Banjo Playing PsychoBilly
Without hijacking this thread. Would like to pass on one other bid of advise that has worked for me.

As we have many of bolts and nuts that require Loctite, when one puts it on and torque, during the routine maintance checks, we tend to check the torque.

What I was told years ago and try to stick to, is that for critical areas, a calibrated torque wrench with a history of the torque cannot be over emphasized. So having a few torque wrenchs, I have two very good ones (250 inch pounds and 150 foot pounds) that I keep calibrated (Snap-on can do them). Used to have them checked once a year when doing more wrench turning, now more like every 2, but at least they are checked.

What I learned, if going over routinely a torque bolt or nut that was loctited, using the same torque and same wrench that stay calibrated will insure less chance of the checks actually tighten the threads more and breaking the bond of the Loctite. Little anal I know, but the point is, if one torque say to 25 foot pounds to a thread with loctite and then a couple months later rechecks with the same non calibrated torque wrench or another, it may be off enough that checking actually breaks the bond allowing the Loctite to not hold has designed.

Without a good calibrated torque wrench, it is safe to check but say at 90-95% of the original specs this help insure that breaking the bond is less likely. If for some reason the threads are loose, best to remove, clean and re loctite and torque new to specs.

This is for threads that use a thread locker such as Loctite. Dry threads are different. I keep all of my numbers written in a little book myself and have never had any of the bolts that I have torque come loose. Still I check, especially prior to a long trip.

Just my 2 cents.
 
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