Alternator Pulleys

[hrbergeron]

I just got a 1985 M1009 with a 6.2L. The starter and alternators were taken off prior to sale, so I can not re use the old ones. I have read that the driver side uses a DL7157 alternator and the passenger side uses one that has an isolated ground. But I have read a couple posts that the pulley on the DL7157 will not work well with a CUCV. Is there a place to get original CUCV alternators or the pulleys for them?

 

[cucvrus]

Never heard of that. I used Cadillac/Pontiac/Oldsmobile diesel alternators and had them rebuilt with an isolated ground on both. The alternators are not right/left gen 1/2. They are both the same the one on the Gen 1 drivers side has a block ground on it. I put solid pulleys on all of my alternators when I have them rebuilt. I hope that answers your questions. I go to the YOUPULLIT all the time in search of old GM vehicles from the late 70's and 80's. $20. for an alternator. I do have to have them tapped and M10 threaded on occasion for the adjustment bolt. Good Luck.

 

[HillbillyWizard]

As already mentioned, a properly equipped original CUCV uses the isolated ground alternator in both positions. The solid pulley will work but are slightly smaller. We have rebuildable alts as well as refurbished units available.

 

[Matt5]

be sure you have the starter bracket...

A stock cucv used the same alternator both sides so the military had to stock less parts

you CAN use a normal alternator on the drivers side but the passengers side MUST be isolated ground...

I would just locate 2 cores or 2 rebuilt (never new) isolated ground units... a new midsized truck is $50,000 who cares about a few bucks for a cucv.

 

[ken]

https://www.rareelectrical.com/i-26914223-new-oe-style-isolated-ground-military-vehicle-cucv-12-volt-100-amp-alternator-fits.html
I used these on my truck. They work well. Although there are no markings on them I assume they are made china.

 

[Sharecropper]

https://www.rareelectrical.com/i-26914223-new-oe-style-isolated-ground-military-vehicle-cucv-12-volt-100-amp-alternator-fits.html
I used these on my truck. They work well. Although there are no markings on them I assume they are made china.

Ken if you had your druthers, would you rebuild your original American-made AC Delco alternators or replace them with China-made units? (I think I know your answer, but just checking to see if you are awake).

 

[basdas37]

Hi am having problem finding new steel pulleys for my alternators. Mine our worn out with belt grooves. I can only find a smaller pulley which would require tossing my one year old bets and buy 3 shorter ones more money. I would even go for good condition stock ones but prefer steel ones. Any detailed information would be appreciated.

thanks

B

 

[dependable]

Ken if you had your druthers, would you rebuild your original American-made AC Delco alternators or replace them with China-made units? (I think I know your answer, but just checking to see if you are awake).

I know you did not ask me, but I had two china units fail with low hours on them.

To the original topic; it is better to use the original sized pulleys. The smaller ones are likely to overcharge a bit.

 

[ehuppert]

I know you did not ask me, but I had two china units fail with low hours on them.

To the original topic; it is better to use the original sized pulleys. The smaller ones are likely to overcharge a bit.

Google 27si alternator pulley, easily/readily available!

Not quite the same, but, my very hi-po SBC would throw belts occasionally and or squeal a little if really run hard. Alignment was good, motor would just spin up too fast. Bought an aftermarket solid pulley which was a little deeper, problem solved... Could have bought a early style Z28 pulley, but quite a bit more money than the $20 solid!

As for reman alternators..... Read in a automotive trade rag magazine that comes to our shop that the industry acceptable failure rate for aftermarket parts is 40%. And, i believe that statement, we deal with bad parts on a regular basis. Most of the time that's all that's available!!!!

Over the counter parts will have some sort of guarantee, but becomes a PITA to do a job twice!!!

Also, smaller pulley will not cause an overcharge condition. Yep, it will spin faster, but voltage regulator maintains a set voltage....

 

[dependable]

Also, smaller pulley will not cause an overcharge condition. Yep, it will spin faster, but voltage regulator maintains a set voltage....

Yes, I know the theory of the voltage regulator operation, and it is true to some extent. My observations are from real world testing, stock pulleys side by side with smaller one in same truck over operating range RPM.

About quality of cheaper auto parts store remans, I agree also, that is why I do my own. I once bought several CUCV alternators that had been rebuilt on govt contract, in original packaging with NSNs on them and all, about half did not work, slightly shorter fasteners were used inside, and required grounds were not being made.

As I have mentioned recently in another thread, since I run a fleet of CUCVs for my business, I bought a couple of new china built units once for convenience. They were not inexpensive, close to $200 each if I recall. They both were in use for a very short time before internal components failed.

And the rebuild parts available are also not 100% reliable, but at least they are inexpensive, and easy to test before installation.

 

[ehuppert]

Ahh, looked up the DL number op stated.... Duralast (aka never last). Autozone stuff, bottom of the barrel!

Better off buying used or anything and finding an old timer that can do them correctly. I was referred to a gentlemen working out of a falling down building locally when i had issues with a bosch unit. Turned out he had done work for my grandmother (i'm creeping up on 60 yo) many years ago. He's in his mid 80's and half retired! Not many of these guys around, china has put alot of them out of business!!!

With that said..... https://www.amscovf.com/ALTERNATOR-DR-27SI-12V-100A-1V-7847_p_318569.html
Has to go through a shop for purchase, but have had decent luck with their products. does say made in the usa though (Maybe with chinese parts?) Their tech guys are very good!

Eric