Asking help regarding the thread “Quincy woes”

[Horst]

First step; first problem. I can’t loosen the nut on the flywheel. I’ve got a 24" breaker bar on it and it is giving through 60°, about all the throw I’ve got, but the nut is not breaking loose (I’ve got the flywheel immobilized). I am turning counterclockwise, the same direction the flywheel turns.
I have read that Quincy has some super thread locker and likes to use it; don’t know if that’s what’s going on here. Left to my own devices, I would put the propane torch to the nut and try again, but, being rather out of my element here,* I will wait to hear from those who have offered their help. How can you put a price tag on that? Thanks!!

*You can teach someone the steps, but you can’t teach them to dance. They either can, or they can’t.

[BobinOK]

Heat, impact wrench and make sure you are turning it the right way.

[Horst]

Heat, impact wrench and make sure you are turning it the right way.

• No impact wrench – no air!
• Turning the right way: I have not encountered a nut on a rotating shaft that did not loosen in the same direction that the shaft rotated, i.e. table saw blade retaining nut. Otherwise the nut would tend to loosen from starting torque. Other than that I have no way of knowing if the nut is left-hand thread (I suppose other than trying it).
• Yes, heat.

[wierdscience]

• No impact wrench – no air!
• Turning the right way: I have not encountered a nut on a rotating shaft that did not loosen in the same direction that the shaft rotated, i.e. table saw blade retaining nut. Otherwise the nut would tend to loosen from starting torque. Other than that I have no way of knowing if the nut is left-hand thread (I suppose other than trying it).
• Yes, heat.

Manual says the nut is lefthand thread and torqued to 45 ft/lbs.So you need to turn it clockwise to loosen it.

Page 4-

http://engineservicesupply.com/conte...RTS%20BOOK.pdf

[lakeside53]

No, he will now need to 100 ft-lb to loosen it

Other then reading the manual (!) you can often see the thread start on the shaft end and follow the direction.

[wierdscience]

Also since the pulley is mounted on a taper,use a two or three jaw puller to apply some tension to the pulley grabbing it by the hub and the not the rim.Then apply some heat to the pulley hub,it should pop off once it expands just a bit.

[KJ1I]

The manual shows they used Locktite 272. From the 272 datasheet:

LOCTITE 272™ is designed for the permanent locking and sealing of threaded fasteners. The product cures when confined in the absence of air between close fitting metal surfaces and prevents loosening and leakage from shock and vibration.

For Disassembly: Apply localized heat to nut or bolt to approximately 250°C. Disassemble while hot.

That's 482F. if you don't want to do the conversion yourself.

[bfjou812]

The manual states the Loctite 272 is to be applied to the outer race of the bearing being assembled to the crankcase. The only thing it says about the nut id torque to 45 ft. lbs, left hand thread.

[Horst]

“Manual says the nut is left-hand thread and torqued to 45 ft/lbs. so you need to turn it clockwise to loosen it. Page 4- http://engineservicesupply.com/conte...RTS%20BOOK.pdf ”


The link you provided is for Record of Change #204. The manual I previously downloaded was for ROC #104, the lowest I could find. My pump is ROC #100. In the #104 manual there is no mention of LH threads in the plan portion but there is in the “part description” panel, which I did not bother to look at, so yes; clearly, I am going to have to read more carefully. The nut came right off. Thank you for having my six.

Step 2; roadblock 2. I can’t get the flywheel off. I’ve got a 3-prong puller on the hub, tightened as much as possible, and have heated the hub to 300°. No joy.

I have a thought. The only reason to remove the flywheel is to remove the pump. What occurred to me was that that might not be necessary if my problem is with the heads or cylinders. While I would prefer to have the pump on the bench, I am considering pulling the heads in situ.

[Horst]

I think it is worth mentioning that none of the “QT-5” manuals bear any resemblance to my pump, which is clearly marked QT-5. My pump is a single stage V-4. Correction; pump is a "QTS-5"

[Horst]

Update; pulled the heads and definitely need valves. Unless I do have bottom end problems I do not need to remove the flywheel.

[Joel]

I can’t get the flywheel off. I’ve got a 3-prong puller on the hub, tightened as much as possible, and have heated the hub to 300°. No joy.

While the puller was tight, did you give the center bolt a good, sharp pop with a largish hammer?

[lakeside53]

Heating of a hub on taper isn't effective unless the heat is applied in mass and quickly; slowly and the crank stub simply is at the same temperature. yes, whack it when under tension

[cijuanni]

Update; pulled the heads and definitely need valves. Unless I do have bottom end problems I do not need to remove the flywheel.

Not sure how bad reed valves would make the compressor have a 'nasty noise' < your term.
Now when the reed valve retainer breaks off and falls down in the cylinder, banging to and fro, that can be a nasty noise. That is what happened on a QT 15 I tore down.

Leave the flywheel on, pull the cylinders and rods and inspect, rotate crank and flywheel and feel for binding/rough crank bearings.

[Bob Fisher]

Lakeside has a good thought, the threads can often be observed past the nut, this will tell for sure RH or LH. If you are turning the wrong direction, it will. NEVER come Off. Bob.