Engine/Transmission (1994 - 1998) Alternator issue

[Desperado]

So what is the life expectance of the alternator on a 1995 Cummins Diesel? I have 170,400 miles on the clock at this time and the voltmeter is now dropping below 14 volts with the fan on high and lights on, it has always stayed just a bit above 14 volts.

 

[Skydiver]

Good question Desperada,

I just turned over 167K on the way to work today.

I did notice that the last two days my meter was reading around 15 volts. I would like to know if the record cold 16 degrees had anything to do with the higher reading ?

I would like to know how long the bearings on the alt. and tension pulleys will last.

Grid heaters are disconnected and had no smoke starting with 3 hours block heat @ 16 degrees.

 

[hsmith]

Might want to try a new brush assembly from Larry B. The crank sensor is probably still good as it is still charging.

 

[HLEschenko]

I replaced my alternator brushes at 190K. I estimated the existing brushes had about 1/3 of their life left. The slip rings are grooved. The recommended change of brushes is at 100K and rework or replace the alternator because of the slip rings at 200K. I think I can get another 100K on the orignal alternator with new brushes only before I have to replace because of the slip ring grooving.



Took me about 3 hours to dress the slip rings and replace the brushes.

 

[JoeBioDiesel]

skydiver, the pcm monitors battery temp with a sensor. when its cold the pcm boosts voltage to enhance charging and when its hot it drops the voltage to protect the batteries. what you saw sounds normal to me.

joe

 

[PKirby]

I am using the Dodge Cummins Nippondenso alternator also. The rebuilder installed a new brush set, tested the alternator and only charged me $25. He stated the alternators were very durable and normally only needed new brushes to repair them.

 

[J Shocik]

If you decide to replace your alternator & you're getting one from an auto parts store, make sure you get one rated at 136 amps. All the auto stores computers show the CTD's taking a 120 & this is wrong.

 

[Andy Redmond]

I disagree, many 12v's and early 24v's have "120 amp" alternators.



If you look at the Section 8 (charging specs) of a FSM . . starting in 96 the 56027221 (Mopar) was for the Diesel. The manual shows 136 SAE amp and 120 min. amps, ratings.



Perhaps this is some of the confusion Sae amps vs. Min. amps... .



I've rebuilt many of the ND (nippondenso units), then Mopar switched to Bosch as a supplier(Mopar 56028239AB) in the 2001 MY. . For the ND you can swap the later model's rotor and stator to get the higher rating. Also necessary to assure the rectifier (holds the diodes) is matched up properly too if doing this swap.



Since the PCM regulates the charge, should you get the higher amp version on a truck the came with the lower version it won't hurt anything.



My guess is that since so many more were rated higher than lower (by the SAE method), many rebuilders would build the higher output version even though they might rate it at "120. "



For the questions on how long they last?



I've rebuild several that had 220,000 mi+ that had the beginnins of rough bearings and thin brushes, but still tested out at 120 amps +/-. .



I've also rebuilt some that had almost 85,000 mi in harsh environments (sand, dirt from off road), which would be more abrasive to the brushes.



From a practical standpoint, attach a DMM lead to the large stud on the back of the alternator at idle and rev'd up some, does it produce in excess of 13. 5 volts, but less than 15. 1? Good. .



Engine off, belt off, spin the pulley and listen for rough bearings or slide load the pulley/bearing and feel for roughness. The rear of the unit's bearing is about 1/2 the side of the pulley end and usually it gets rough first.



Dayco makes a tensioner pulley.



If you need parts for a alt. or starter repair, send me a PM, with the ND part number (side of case under bracket) and MY of the truck its on...



Be careful of the chain stores, lots of "reman" junk abounds, Hope this opinion helps.



Andy

 

[Desperado]

Thanks for all of the replys guys. I have taken the belt off to check out the end play, side play, and for roughness, and everything feels good, no play or roughness, so I ordered a set of brushes from Larry B they should be here Friday so I can put them in. Thanks again.

 

[J Shocik]

Andy, I'm quoting from the window sticker that came off my '97 when I bought it new ( yes, I kept it):

Under the heading of Standard equipment on all '97's: 600 amp maintenance-free battery & 117-amp alt.



Under the heading of optional equipment, Diesel engine, 136 amp alt. /750 amp battery.



That is where I got my info. from... that & numerous chats w/ others on this web-site about this very issue. I'm not saying all CTD's came w/ the 136, but on the other hand, I can't see why it is part of the diesel option package on my truck, and not part of it on other CTD's.

 

[Cessna421]

Anyone know where I can buy genuine Bosch parts for my 2002 Bosch 56028239AB alternator? All I can find are Chinese junk parts.

Mike

 

[Andy Redmond]

mike

dealer will have a new alternator..for 60ish more than the cheap chainstore "chinese $rap."

sadly most rebuiding supplies for these are now chinese mfg'd to vs bosch (germany) nd (japan)

 

[Cessna421]

Bosch alt parts

Hi Andy,

I know what you are saying however I would rather spend more to rebuild mine than to buy a reman or a new Denso from the dealer.

Thanks,

Mike

 

[Andy Redmond]

mike*

i buy from major reman parts folks that distribute rebuilding/repair parts for ur unit..unless its "nos"in some local alternator/starter repair shop the rebuilding supplies (chinese) may be similar to the chainstore reman or new units..quality..

i dont like the disposable concept either..bite the bullet and go to the dealer and buy new..then it wont fail at the most inopportune time.

 

[Cessna421]

Bosch Alt

Actually I did buy a new alternator from the dealer some time ago and was very disappointed in the fit since my wiring harness is set up for a Bosch alt the
wires were in a strain when attached to the Denso replacement alternator. I hardly ever drive the truck so I can wait until I run across the genuine Bosch parts and I know I will eventually find them.

Mike

 

[GAmes]

Did you look at what Genos has to offer?

https://www.genosgarage.com/product/gould-ark-bosch/engine-rebuild-kits-2

 

[Cessna421]

Bosch alt

I checked with another supplier which has the same ad and these items are made in China and I just don't want to go that route. I guess genuine Bosch parts
are impossible to find in the US.

Mike

 

[GAmes]

Did you know that genuine Cummins lift pumps for 12 valves are made in China? The one I have installed has over 300k miles on it, the original lift pump, a Carter made in the USA didn't last that long. The genuine Bosch injectors I have on the shelf for when I need them were made in Brazil. Like it or not, a lot of the things we use every day were made in a foreign country. There's a good chance your truck was assembled in Mexico. Genos takes pride in selling quality products. If the product quality doesn't prove to meet their standards they quit selling it. I suggest you give them a call to see if their repair kit is just made to fit Bosch alternators, or if the kit is in fact a genuine Bosch parts kit.

 

[Cessna421]

Bosch alt

I know my truck was made in Mexico and I have no problem with that or Brazil for that matter, I have had bad experiences with things made in China. When a
supplier offers Chinese parts, I always feel they are trying to maximize profit and minimize quality....just my opinion.

Mike

 

[Missouri Mule]

My alternator lasted aprox 17 yrs/ 285,000. Have to look see what kind it is but I think he put a napa life time junk one on it. But he mite off put one on from car quest. I had a quite conversation with his office girl who usually did the ordering ( but he liked napa because they were close by and delivered and after there junk starter died after 3 year) I did not any junk put on my truck. Unfortunately he all ready put a napa piece of junk ac compressor on ( at least I think that's the problem. The mechanic that checked it told me it my evaporator was the problem and it was a 10 hour job. But I know one mechanic that used top work for him and now goes to the problem vehicles ( mite still be working for him mite be on his own) did so many that he could have the dash off take care of the problem and put it back on in 4 to 5 hours. He did hire a very quick and good mechanic but unfortunately a tan skinned mechanic came back who is slower than snail and keeps letting service my Mule. The new guy could service and change the fuel filter in 30 minutes the snail takes an 2 hours. Needless to say I'm back to changing my own fuel filter. I'm not even hurrying and can do it in 20 to 30 minutes.