What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[j91z28d1]

I tend to investigate and document the not-so-common mods. So, I take pics and measurements of a lot of critical points. There will always be newbs searching for info as we al did before and still do now.




The wider holes are to the back, so, I think once the bolts are tightened, there's more than enough clamping force to keep it from sliding. It'd actually have to twist and there's no space for that. I'm just a bit extra with some things and making those sleeves was a quick little side project. It'll be perfectly fine as-is.




I would've used that tower piece if I hadn't destroyed it while attempting to modify it. That D-shaped area directly under the tower is a cover. Pop it off and you'll see a stud and 10mm nut oriented horizontally like the original alt had, just annoyingly recessed.




Likewise!




I think so, too. GM is known for seemingly randomly changing part numbers for the exact same part. Could even be where the alt was made/sourced.




Agreed. I just get in my own way. A lot. No ragerts.

I think I'm going to order one. seems summit has one for a good price and free shipping. no pic but same part number.

in your measurements did you happen to see d the mounting hole are 5.5in spacing? I'm like. 99% sure they are but just confirming.

 

[Doubeleive]

I think I'm going to order one. seems summit has one for a good price and free shipping. no pic but same part number.

in your measurements did you happen to see d the mounting hole are 5.5in spacing? I'm like. 99% sure they are but just confirming.

the one you should get is
More Information for GM GENUINE 84143539 or 22949466

 

[j91z28d1]

the one you should get is
More Information for GM GENUINE 84143539 or 22949466

ahh. yeah that one's not cheap new lol. summit has 13534128 for 140$ with free shipping.

do you know what the difference is? correct pics are so hard to find

 

[Doubeleive]

ahh. yeah that one's not cheap new lol. summit has 13534128 for 140$ with free shipping.

do you know what the difference is? correct pics are so hard to find

More Information for GM GENUINE 84143539

www.rockauto.com

 

[iamdub]

the one you should get is
More Information for GM GENUINE 84143539 or 22949466

ahh. yeah that one's not cheap new lol. summit has 13534128 for 140$ with free shipping.

do you know what the difference is? correct pics are so hard to find

Looks like these are the Denso variant. Same specs as the other two we've been discussing but some sources list it as a 215A alt.

 

[Rocket Man]

Looks like these are the Denso variant. Same specs as the other two we've been discussing but some sources list it as a 215A alt.

I wonder if I should do this mod for my Silverado, the twin Viair compressors for the air suspension is probably tough on ( can’t say *******) the alt although I’ve never had a problem.

 

[iamdub]

I wonder if I should do this mod for my Silverado, the twin Viair compressors for the air suspension is probably tough on ( can’t say *******) the alt although I’ve never had a problem.

The compressors primarily pulling off the battery and not running for long times keeps it all "adequate" and maybe even "fine". But, just because the factory stuff is barely adequate for the stock stuff and you have items presenting higher loads than stock, I certainly would. Big 3 (or 4 or 5) and a stronger charge. Motors are affected the most by voltage supply. Having a volt or two more at the motors (air compressors, fuel pump, etc.) will drop their current draw, reducing their operating temps and lengthen their life. For the cost, it's definitely a worthy upgrade. Besides the higher output, it's a 6-phase versus the original alt's 3-phase so it's more efficient, putting out more power even at idle speeds. The entry level MechMan I almost bought is a 6-phase rated at 250A but is $400. You can get one of these for 1/4 of that with only a 30A penalty.


*EDIT*: haŕd on

 

[j91z28d1]

Looks like these are the Denso variant. Same specs as the other two we've been discussing but some sources list it as a 215A alt.

huh. it does say Denso on that tag in the pic. anyways I ordered the cheap one cause eh, 300$ is getting close to that really nice looking billet black aftermarket one lol. but I'd like to stay away from all that, I literally just need like 20 more amps at idle, the 160am truck one would probably do it. the corvette ones are notorious for bad low rpm charging and going out at high rpm. all around a bad alt in a weird size case, so why not go big lol. as long as I don't have to over drive it so it lives at 6500rpm. I have hopes it will work.

if not, eh. you guys got me back into looking at this mod again. I switched to a brushless fan towards the end of last summer and raised idle a few 100 rpm and it was enough to mostly stay off the battery. with summer coming again. time to sort it.

 

[j91z28d1]

The compressors primarily pulling off the battery and not running for long times keeps it all "adequate" and maybe even "fine". But, just because the factory stuff is barely adequate for the stock stuff and you have items presenting higher loads than stock, I certainly would. Big 3 (or 4 or 5) and a stronger charge. Motors are affected the most by voltage supply. Having a volt or two more at the motors (air compressors, fuel pump, etc.) will drop their current draw, reducing their operating temps and lengthen their life. For the cost, it's definitely a worthy upgrade. Besides the higher output, it's a 6-phase versus the original alt's 3-phase so it's more efficient, putting out more power even at idle speeds. The entry level MechMan I almost bought is a 6-phase rated at 250A but is $400. You can get one of these for 1/4 of that with only a 30A penalty.


*EDIT*: haŕd on

I agree, of all the mods I've done over the years, getting an alternator that will charge solid at idle is the best thing for drivability. not just motors, but the injectors themselves fire much more more stable at the correct voltage. there's a table in most ecm's for the voltage vs time offsets. but those spec where from the injector manufacturer when new. 150k miles later. if you can keep the voltage up at idle, there's less chasing trims for it all to do. not as huge on stock trucks, but can be a very big deal in the aftermarket world.

if you're curious about it find a good deal, seems like a 100$ well spent.


instead of all the big 3 kits, I like to move the electric cooling fan load straight from the relay to the back of the alternator. on high these modern fans can pull crazy amps and at higher voltage without the drop from running thru all the factory harness and fusible links. the motors are much happier and so is the factory harness.

I use the slow blow jcase fuses on each fan.

 

[mikez71]

More Information for GM GENUINE 84143539

www.rockauto.com

Gonna call that one the "plus sign" alternator..

That one says it's a 59 or 59.9mm pulley (maybe 60?) The one Iamdub and myself got had an A58 on the pulley. (Iamdub said it was 58mm?) Might be why the 215A vs 220A..