Alternator Pulley

[Skippy]

Hi, this is my first post to the forum. I have enjoyed reading about the projects forum members are doing.  I  have read Mobile Bob's White Paper on battery charging with an automotive alternator and I am collecting parts for one.   I have an 160 AMP Leece-Neville 110-555PHO alternator and have a question about a pulley.  The alternator shaft has a keyway with a woodruff key. I am wondering if a pulley with out a keyway can take the torque with out slipping on the shaft under load? Is it common to use a pulley with out a keyway on this alternator?

[SteveU.]

Welcome Skippy
Yes it is common for automotive/truck alternator pulleys and shafts to not have keyways.
Yes the pulley will not slip if it is the proper pulley for the alternator.
Pulley MUST be a snug NO Rocking slip fit onto the shaft.
Pulley shoulder at the shaft MUST extend past the shoulder on the alternator shaft to be able to be clamped down tight!!!
The pulley IS clamped between the bearing inner race and the alternator shaft nut. It is these surfaces that hold it tight from slipping. If need be spacers under the pulley or under the shaft nut may have to be used or the pulley itself be machined modified to get a pulley nut seating shoulder stand up from the shaft shoulder.
Nut tightening spec is ~30-60 ft/lbs. Ha! Ha! Hard to do with no key to hold the shaft from turning.
Easy. Use an air or electric impact gun to remove or tighten the shaft nut. Once the nut seats on the pulley shoulder (Never the Shaft shoulder!) 1/8 more turning of the impact gun socket is just about right. Do a few and you will learn to hear the "just right" sound.
Not tight enough and the pulley will slip. Hint: check for slipping friction heating up after starting up and driving under a load.
TOO tight and you WILL strip the shaft treads! Laying on the impact gun for longer than ~3 seconds after the nut is seated WILL be too tight!
With your off hand ALWAYS hold the pulley and pull forward toward the nut while tightening or removing the shaft nut. Most alternators if the rotor shaft is allowed to slip back inside and then turned there WILL be internal damage requiring expensive disassembly repair.

Regards
Washington State Steve Unruh

[Skippy]

Thank's Steveu.

[dieselgman]

It was also common for certain automotive pumps and alternators to have pressed-on pulleys. They required some minor special tooling to remove and install but were very effective and I have not seen any failures. I do not remember clearly, but I believe they used smooth shafts without any alignment keys.

dieselgman

[XYZER]

It was also common for certain automotive pumps and alternators to have pressed-on pulleys. They required some minor special tooling to remove and install but were very effective and I have not seen any failures. I do not remember clearly, but I believe they used smooth shafts without any alignment keys.

dieselgman

Yep...I had a 89 ford bronco and the power steering pump started to weep. I had to build a special puller to get the pulley off. No key holding it just a press fit. IMO they started this when they could mass produce and hold tolerance close enough for a proper shrink/press fit.

[Tom Reed]

Isn't the timing gear on a Listeroid a non-keyed press fit?

[mobile_bob]

historically delco hd alternators that use the 7/8 inch shaft never used keys, and the leece neville alternators always used them
with their 7/8 inch pulleys

it worked fine for delco, so i see no reason why leece alternators cannot be run without the key in place

as steve stated, just get it torqued properly, the fan on the 555 should state the required torque

bob g

[Henry W]

If you think the pulley might have an issue of spinning on a keyless shaft just get some Loctite 7649 primer and Loctite 680 retaining compound. It will hold it from spinning. (Warning do not use Loctite 271) With Loctite 680 the pulley can be pulled off with a puller when needed.

Loctite® 7649™ Primer N™ decreases the set-up time of Loctite brand threadlockers and increases breakaway torque on most fastener surfaces. This anaerobic primer allows application of threadlockers in cold weather. Contains no ozone-depleting compounds. Mil Spec: Mil-S-22473E Grade N Form R. ASTM-D5363: Approved.

Loctite® 680™ is a high strength, high viscosity room temperature curing adhesive used to join fitted cylindrical parts. It fixtures in 10 minutes and provides a shear strength of 4,000 psi. Capable of filling diametral gaps up to 0.015 in. (0.38 mm). Loctite 680 allows relaxed machining tolerances, and replaces clamp rings, set screws, and snap rings. Gives best resistance to dynamic, axial and radial loads. Recommended for retaining shafts, gears, pulleys and similar cylindrical parts. NSF/ANSI 61 Certified. ABS Approved.



Henry

[XYZER]

I used that stuff on the end bearings for the auger ends on a snow blower.....had to take it apart to change some things.....I cussed a little bit for awile......it aint snake oil!

[Carlb]

I used that stuff on the end bearings for the auger ends on a snow blower.....had to take it apart to change some things.....I cussed a little bit for awile......it aint snake oil!

Next time just heat the nut or bolt up some it will come out easily. 

[XYZER]

The auger had self-aligning bearings on the ends of the shaft, the shaft had suffered from the previous owner and the fit was....not perfect. I did use heat on the shaft after I got it apart to clean it up but I didn't want to put heat on the sealed bearing to get it apart.

[Henry W]

Use it only where you can use a press or a good pulley puller otherwise you will have a rough time getting it off. We use 680 daily where I work and I know that once it sets you better have the proper tools disassemble parts when needed. Many times a 15 ton press is required. Heat will work as long as other parts don't get damaged by heat.

[SteveU.]

Yep.Yep. On the Loctite. I HAVE had to use it out on fields service repairs AFTER a pulley has spun and damaged it bore and the alt shaft. These were Always due to pulley mis-installations. I came to hate individual pulley sales.
Then future pulley removal became a heat and puller job with the bearing always damaged.
BTW since many of you fellows now work with sleeve locked in place pulleys these are NOT what you want to use on automotive/truck alternators. 99.9% of these types of units are designed for the spinning rotor to be fixed in place by being clamped to the front ballbearing inner race between the inner rotor/shaft collar/shoulder and the pulley base shoulder. NOT doing this will let the rotor slip backward while spinning in service resulting very expensive internal unit destruction.
On the press on accessory drive pulleys I've only done a few hundred non-alternator types. Power steering, A.I.R. and vacuum pumps important to measure the shaft/unit mounting spacing on pulley removal and reinstall exactly the same distance. These units DO float internally and belt misalignment forcing side pressure will eat then up internally. I have done under my responsibility about 100,000 Chrysler PITA press on pulleys. These DO have to be pressed on far enough and deep enough to lock the rotor to the inner front bearing. All applications of these press-ons with pulley re-usage requires a lot of experienced "feel". They must go on "sc-r-e-e-ch" Hard. Even with the best experience still a 1 in 10,000/50,000 odds one is going to come off in service. Three radiators and one hood bought out of my own pocket in my 16 years of experience doing these. Yep defiantly a manufacturing $$ connivence. Not a servicing connivence at all.

Regards
SteveU.

[scottpeterd]

Skippy,

Where did you get your pulley, and what series belts are you using?

Pete