TheSamba.com :: View topic - 140A alternator on AHU Tdi conversion: spinning problem

Mon Jan 27, 2014 8:07 pm

Aloha all!

I'm working slowly on my 1.9L M-Tdi AHU conversion and I'm mounting a Bosch 140A alternator #07K 903 023C instead of the original Tdi 120A #028903026G.
The body is plug and play on the mount.Bueno. :D

The clutch pulley on the 140A alternator is a 5 groove model instead of 6.
I didn't want to replace the pulley with a solid model, so I ordered the 6 groove INA clutch pulley like the one on the 120A alternator.
I thought this would be plug and play as well…. :x

I got a big problem, the 140A alternator has a left hand thread VS right hand thread on the 120A. I checked the pulleys, and DUH! they're meant to spin different ways. No bueno :evil:
I'm not asking for a unicorn clutch pulley with left hand threads meant to spin the other way,I know there must be a reason for the thread and rotation way.

I'm wondering here if anybody could point me towards a 140A alternator like the one I have but that would spin like on a AHU Tdi engine so I can either buy this correct alternator or at least swap the shaft/rotor to suit the AHU Tdi rotation way/pulley.

Other option I have would be to cut down the threads on the shaft, sleeve, weld and cut new threads with a die, but that would cost more than another alternator I presume :roll:

Alternator 140A

120A on the left, 140A on the right.
120A old 6 groove pulley, 120A new pulley, 140A 5 groove pulley

Thank you 8)

Mon Jan 27, 2014 9:10 pm

I have a 140A on my ALH. I'll get you the part # first thing tomorrow mornin' 8)

Mon Jan 27, 2014 9:30 pm

Sweet!

Merci Serge 8)

Do you have the clutch pulley as well on it?

Mon Jan 27, 2014 9:40 pm

Is it possible to just run a 5 groove belt?

Neil2

Mon Jan 27, 2014 10:14 pm

I don't think I'm running a clutch pulley on mine. I think it's just a 5 rib pulley that fit the offset correctly. I'll double check. I'll have to look for the 160 amp, might be nice but really have had zero issues with my 120.

Tue Jan 28, 2014 8:40 am

Darn rear hatch lock was frozen solid...crazy winter this year :evil:

06F 903 023 F , 6 rib clutch pulley. It's from a BRM TDI 2006 Jetta if my memory is good.

Tue Jan 28, 2014 9:54 am

syncroserge wrote: Darn rear hatch lock was frozen solid...crazy winter this year :evil:

06F 903 023 F , 6 rib clutch pulley. It's from a BRM TDI 2006 Jetta if my memory is good.

Merci Serge!! :wink:

Furrylittleotter, no,you can't run a 5 rib belt, I think the space between the grooves is not the same...

Tue Jan 28, 2014 10:08 am

hans j wrote: I don't think I'm running a clutch pulley on mine. I think it's just a 5 rib pulley that fit the offset correctly. I'll double check. I'll have to look for the 160 amp, might be nice but really have had zero issues with my 120.

THAT'S A TYPO

I typed 160A at the beginning of my message ,then 140A further down, I corrected it :wink:

Tue Jan 28, 2014 10:14 am

Past the 140A there is a 150A then a 180 and 190A but all those from 150A up that I have seen have a different
mount setup so won't fit earlier engines.

140A is pretty good, especially since it charges (mine at least) closer to 14.5V. All the 120A and previous seem to charge closer to 14V.

Tue Jan 28, 2014 10:27 am

syncroserge wrote: Past the 140A there is a 150A then a 180 and 190A but all those from 150A up that I have seen have a different
mount setup so won't fit earlier engines.

140A is pretty good, especially since it charges (mine at least) closer to 14.5V. All the 120A and previous seem to charge closer to 14V.

Thanks for the info Serge :wink:

Yeah I almost mounted a 150 (or 160) too, but I realized that was overkill. Dang,the T3 TD came stock with a 75A or lower alternator, that will surely make a big improvement with 140A already :lol:

I'm trying to hunt a 140A rotor, right hand threads. Bunch of cheap very used alternators on ebay I could take apart, but shipping is killing me to Hawai'i :roll:

Tue Jan 28, 2014 10:38 am

Wow, do you really need 140 A?
I "only" have the 120 A and it doesn't come close to that. Not even with the electrical coolant heaters I will.

My previous Touran had a 160 A, I had to replace the clutch after 240 000 km and let a car electrical workshop service it at the same time. They test ran it up to 180 A and he said that all fresh alternators produces more than the rate value.

Tue Jan 28, 2014 1:05 pm

ALIKA T3 wrote: ... but shipping is killing me to Hawai'i :roll:

I'm sure the weather more than makes up for that :wink:

svenakela wrote: Wow, do you really need 140 A?

VW put a 120A in the cars but my van is a Westy with 2 heather fans, a fridge, an aux. battery, Espar heater etc..
A lot more power demand so I figure it can't hurt...besides..we don't "need" a Syncro Westy..a good pair of boots, a backpack
and a tent are enough but... :lol:

Tue Jan 28, 2014 1:14 pm

Alika, I think the only purpose of the "clutched" pulley is for fast RPM changes like a GTI manual transmission would see in running to redline in the gears. Are you planning on racing around the Island with your rig?
I am putting a 120AMP unit on my 1.8T conversion and am not too worried about not using a ovverun clutch set up on my installation plus, they are prone to failure from corrosion something to consider in your local. Aloha from the mainland :D

Tue Jan 28, 2014 1:24 pm

The TDI came with a clutched alternator pulley stock even on the 90amp alternator. It is unlikely the engineers put it there for no reason. Redline in a TDI is around 4000 rpm, well that is about where max hp is.

Some AGM batteries have listed recommended charging voltages. 14.5 volts seems high from memory.

Even though alternators are rated for high amp outputs, it is unlikely you would see extended high amp outputs. On a discharged battery, they tend to spike out high and then taper way off. This keeps from cooking the battery. There are ways to work around this limitation, but get quickly complicated monitoring battery temp etc.

We have found the stock 120 Amp alternator more than adequate for maintaining our 115 amp AGM along with our wet cell starting battery. Diesels don't have a lot of electrical loads stock.

Tue Jan 28, 2014 1:42 pm

syncroserge wrote: ALIKA T3 wrote: ... but shipping is killing me to Hawai'i :roll:

I'm sure the weather more than makes up for that :wink:

svenakela wrote: Wow, do you really need 140 A?

VW put a 120A in the cars but my van is a Westy with 2 heather fans, a fridge, an aux. battery, Espar heater etc..
A lot more power demand so I figure it can't hurt...besides..we don't "need" a Syncro Westy..a good pair of boots, a backpack
and a tent are enough but... :lol:

Naaah, not really. They put 120A alternators in the cars after the vanagon production ended. Even the 90 A versions came after the Vanagon.
But that's not my point, why spend the time and hours for only a few amps more? Sure 140 A is nice, it's not like you gonna get better acceleration out of it. Are you gonna reach 120 A in a Westy? Not likely.
BTW, the slip clutch pulley's were introduced when the alternator's got damaged by the heavy retardation caused by the belt. Specially in diesel cars. Don't use a solid pulley, big chance is that you all of a sudden have no charge at all.

It's gonna be a pretty long walk to get to the ski slope with boots and a back pack. Of course you need a Westy!

Tue Jan 28, 2014 1:43 pm

Plus on an ALH eTDI conversion, I believe the ECU can regulate the output amperage of the alternator? There is the W controller wire from ECU to alternator, and when I was doing my conversion, that was the only info I could find on the wire.

I have two bad batteries running my van and fridge (I use used batteries that don't test well) and have had zero issues with the 120amp alternator charging them. I'll be getting new batteries this summer when I run my fridge more!

Tue Jan 28, 2014 1:56 pm

I tied in the W lead to my ECU because it was there and in the diagrams, but have no idea what it does. I also tied in my AC compressor to the ECU and again, have no idea what that does either. The ECU seems to maintain the idle regardless of load?

Tue Jan 28, 2014 4:24 pm

Makes sense a oil burner would have a clutched alternator dutifully schooled :D

Wed Jan 29, 2014 8:07 pm

Hi Serge, yes the weather makes up for it for sure 8) 8)

I'm gonna try to answer the questions:

140A, because I tried to find a good 120A used online (don't want a crappy new chinese alternator) and I couldn't find a decent one.
I found a near new 140A alternator for less than 90 bucks shipped to Hawai'i: DEAL :D

So, well, cool, I have an extra 20A, can't hurt,right? :oops:

The Tdi I'm mounting it on is built with a mechanical injection pump.

Now I need a 140A rotor from a Tdi or equivalent right hand threaded …. :roll:
As far as the clutch pulley, I made some research a while back, and all I remembered is I need to have one :lol:

I found this video that's kinda cool:

Wed Jan 29, 2014 10:22 pm

Interesting, please post the part # when you figure out which alt works. Most of you probably already know this but definitely run the clutched pulley on a TDI. The belt runs so much smoother its crazy. I have replaced two alternators on the road on my TDI van and the new alts never come with the clutched pulley so make sure you keep the special tool in the van so you can switch them out on the road if needed. I used to run the 120a....and now run the 90 as they are so easy to find. It has no problem topping off my 130A/H Trojan battery.