I started the coach in preparation for a quick trip to NAC to get new tires. The alternator locked up and the belt broke. The belt takes power from a pulley on the crank shaft. It delivers power to a pulley straight above, and to the alternator. Is the large upper pulley an idler, or does it drive sometime important - like the water pump?
The alternator is frozen securely. It will need to come off for replacement or repair. Until it turns freely, the ribbed belt will not drive the upper pulley. Am I stuck in the driveway, or can I drive 200 miles to NAC using the Powertech for electricity?
JD,
On my engine, the alternator belt only drives alternator. Your description of drive pulley, idler pulley and alternator pulley says to me, remove belt, use gen and boost relay and go.
Hope this helps.
If your belt setup looks like this...that would be the water pump on the same belt as the alternator.
Probably not a good idea to drive it...
JD, I beleave you are stuck. The alternator belt also turnes the water pump.
Are you saying that your alternator is seized up? If so, you will be completely stuck until you can remove the alternator as it will keep snapping the belt, I would guess.
JD we are four builds apart. That belt on mine drives the water pump.
Look's to me that your alternator runs your AC pump, so you should be able to drive
That belt also runs the water pump
That is the water pump below the top tensioner so if same engine "NO" unless you drive for 50 miles at a time them let it cool down !!!!
Post a pic if not sure JD
JohnH
This won't help J.D. now, but I would advise anyone to consider packing a spare alternator. Here is a case where even running on the gen and boost won't get you going.
Thanks for the timely answers and suggestions. The answer is, "I'm stuck for now."
I have already pulled the alternator. I can see where the water pump is located. It is driven by the "flat" pulley that looks like an idler. The two ribbed belts must be operating in order to have power steering, coolant circulation, and power from the alternator. The V-belt to the compressor for dash air is optional.
I'll take the alternator to a local shop tomorrow and see if they can get me an exact replacement. Part of the deal will be that they have to help me move the ribbed pulley to the new alternator. Yes, I have pulled the ground side connectors for ALL the batteries in order to avoid an accidental short. I took pictures of the connections. It looks like the replacement should be relatively easy. I have a new belt that should fit.
A breakdown at home that delays a trip that has flexible dates is a pretty easy breakdown.
If you don't have luck with finding a replacement I had my alternator rebuild by BCS Starter and Alternator in Bryan, and am very happy with the job they did. If interested their phone number is 979-775-9470. Good luck.
You might be fortunate in one respect. If the alternator is locked, it could be the bearings are seized. Probably the easiest fix.
Removing the pulley from the old unit is no problem. Easiest way is to use an impact wrench, the nut will back off real easy, no impact wrench, use a vice grip on the pulley and a breaker bar and socket. Alternator shop will do it and not even comment on it.
Do take a good look at the lower street side bolt on the WATER pump, this bolt also holds the strap to the alternator and it has been known to wallow out the hole. Bolt may break off when you remove it.
Gary B
If you need parts, the ball bearings and front cage from our alternator are spread along I-80 just east of Davenport, IA two years ago. Sure wish ours had broken at home. No, wait, the coach is our home so I guess it break at home.
Sorry to hear about your problem Dave. A good alternator, starter shop can rebuild it to like new for less than buying a new one.
I ordered a new alternator and belt from FOT. They dropped shipped it from a supplier in Tyler, TX. I ordered on Monday and it arrived Tuesday afternoon.
Wiring up and mounting the alternator was easy. Getting a belt installed was NOT easy. The belt FOT recommended and sent was a NAPA 080605. It was at least three inches too short. See an excellent article from Neal Pillsbury regarding his experience with belts here: Cummins Mechanical water pump/alternator belt (http://beamalarm.com/Documents/belts-filters-hoses/cummins_mechanical_water_pump_alternator_belt.html) Fortunately I read that article a long time ago and happened to have on hand a Gates K080638HD. After two 1 1/2 hour sessions struggling to get the belt on, I succeeded. I left the alternator attached by the two top bolts. I was able to get the belt seated on all the pulleys. I used a long breakover 1/2" driver to pry to tensioner to it's maximum extension. I braced the handle of the breakerover driver against the hydraulic pump pulley. Then I used another pry bar to pull the alternator to a position where I could insert the final bolt. Whew! It might have been easier with one or two more strong hands. Even the K080638HD seemed a bit short for my engine.
I made a 400 mile round trip to NAC today to get new X-line 275/80R22.5 LRH tires. It looked like the belt had stretched a bit and the tensioner was slightly more relaxed.
FOT did not have a K080638HD in stock. I did receive credit for the NAPA 080605 that I returned to them. I plan to order Gates K080638HD _and_ K080645HD for spares.
It seems to me that a belt to short could stress bearings on tensioner & alternator and prevent tensioner from doing its thing. Even worse for hydraulic pump belt. This only applies to C8.3 & ISC engines, not M11.
Mine is a K080644. I'll bet a 638 was "fun" to install. Dito to the too much tension will smoke the bearings post.
Thank you for suggesting a longer belt to avoid too much tension. Also, the suggestion of the K080644 caused me to do some searching. I found a chart of Gates belts here: http://www.gates.com/oreilly/PDFs/SizeListings.pdf .
I've had the K080638HD for a while as a spare. It appears to have been discontinued. The chart should enable me to find a belt of suitable length for my engine and alternator.