jdulle
Veteran Member
If the Bosch AL0723X should be avoided, what is the best alternator as a replacement for an original 120 amp alternator (96 b4 tdi)?
New Bosch Alternator
- Thread starter jdulle
- Start date
ToddA1
Top Post Dawg
Personally, I just buy used ones, as long as there’s no bearing issues. Even if the regulator needs to be replaced, they’re pretty cheap. I haven’t had had one go bad, but I’d also consider brush replacement, which is even cheaper.
-Todd
-Todd
Mongler98
Top Post Dawg
- Joined
- Mar 23, 2011
- Location
- COLORADO (SE of Denver)
- TDI
- 98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
get the parts to rebuild your 120, its a fraciton of the cost of new or rebuilt OEM, it will last forever, just like it did before, and you know it was done with proper parts. There is a thread in 101 on how to rebuild them, not too difficult, like 1.5-2/5 difficulty.
jdulle
Veteran Member
That makes sense. I'll just buy a used one from a junkyard. The only problem I am having is on the search engine there is no entry for an 120 amp alternator with the diesel. The only option I am seeing is the 6 cylinder 120 amp alternator. Is this VR6 alternator the same as the one in the Tdi?
IndigoBlueWagon
TDIClub Enthusiast, Principal IDParts, Vendor , w/
Why are you avoiding the Bosch reman alternator?
Digital Corpus
Top Post Dawg
We had two grenade themselves inside of 3 months. I did post about not using them, though if I need to redact that because of getting lemons of the shop not doing something right (2nd was warranty repair), then I will.
Replacing an A4 alternator and noticed that they’re the same part.
Replacing an A4 alternator and noticed that they’re the same part.
IndigoBlueWagon
TDIClub Enthusiast, Principal IDParts, Vendor , w/
They're not the same part.
B4: https://www.idparts.com/bosch-120a-alternator-reman-b4a3-p-257.html
A4: https://www.idparts.com/bosch-120a-alternator-reman-a4-p-2295.html
B4: https://www.idparts.com/bosch-120a-alternator-reman-b4a3-p-257.html
A4: https://www.idparts.com/bosch-120a-alternator-reman-a4-p-2295.html
turbodieseldyke
Veteran Member
What's the difference, besides the pulley?
IndigoBlueWagon
TDIClub Enthusiast, Principal IDParts, Vendor , w/
I believe the mounting points are different, the main shaft is different, the connector is different, the pulley attachment is different. Not the same part.
Digital Corpus
Top Post Dawg
I pulled two 723X’s off of two different, ‘02 ALH’s…
jdulle
Veteran Member
Several people have mentioned problems with the reman. Bosch alternators. I like the idea of rebuilding the old one, I think I will buy a spare at a junkyard and rebuild that one and put it in. It sounds like mine needs new bearings, and probably brushes too.
I just had one installed a few days ago. I will post here if it dies a premature death.
https://forums.tdiclub.com/showthread.php?t=498446
https://forums.tdiclub.com/showthread.php?t=498446
Last edited:
IndigoBlueWagon
TDIClub Enthusiast, Principal IDParts, Vendor , w/
Bosch remans are best sellers for the older TDIs. Warranty claims are so infrequent that I can't recall when we last had one.
pdq import repair
Veteran Member
Bosch reman is the only quality one i know of readily available anywhere. Avoid AZ and other parts houses junk. You will have immensely better luck with used than parts store remans. Get a good used lower mile one, or rebrush or bearing yours.
I have a very low mortality rate on Bosch parts in general. I really can't readily bring to memory the last one.
If you need to get a random reman, buy it at the parts house closest to home so you won't have far to travel for the subsequent warranties. The general rule i have heard from my customers that have gone through this ordeal report that the third one usually seems to work ok. But they do not trust that one very much either.
I have a very low mortality rate on Bosch parts in general. I really can't readily bring to memory the last one.
If you need to get a random reman, buy it at the parts house closest to home so you won't have far to travel for the subsequent warranties. The general rule i have heard from my customers that have gone through this ordeal report that the third one usually seems to work ok. But they do not trust that one very much either.
jdulle
Veteran Member
Yes I think I am going to get a Bosch from a junkyard as a spare so I can keep driving while I rebuild one.
The tdi 97-98 Jettas are the same alternator, except with a clutched pulley, correct?
There seem to be more of these available.
The tdi 97-98 Jettas are the same alternator, except with a clutched pulley, correct?
There seem to be more of these available.
Steve Addy
Top Post Dawg
The TDI 120A alternators are getting a little more difficult to find on the used market. I have one that should probably be rebuilt and then it would be ready for use if needed.
I believe the VR6 120 uses the same brushes but they aren't the same alternator. I've snagged a few regulator / brush sets from VR alternators as spares.
As an alternate remember that the 90A alternator from a 4 cylinder Mk3 will work in a pinch, and those are fairly easy to find. I keep one of those around to just in case too.
Steve
I believe the VR6 120 uses the same brushes but they aren't the same alternator. I've snagged a few regulator / brush sets from VR alternators as spares.
As an alternate remember that the 90A alternator from a 4 cylinder Mk3 will work in a pinch, and those are fairly easy to find. I keep one of those around to just in case too.
Steve
jdulle
Veteran Member
I am guessing that the 97-98 Jetta tdi uses the same alternator as the b4 Passat, except that it has a clutched pulley.
Can anyone confirm this?
Can anyone confirm this?
IndigoBlueWagon
TDIClub Enthusiast, Principal IDParts, Vendor , w/
I don't believe either alternator originally had a clutched pulley, but they're now available. And yes, they're the same alternator.
Steve Addy
Top Post Dawg
I believe that all Mk3 cars came with the clutched pulley from the factory, every one I've seen has one.
Steve
turbodieseldyke
Veteran Member
My first Mk3 had a clutched pulley (non-clutching anymore, until I replaced it). I highly doubt any of the P.O.'s had changed the fixed pulley to a clutched, or followed a mechanic's advice to do so. That leads me to believe it was factory (1998).
Digital Corpus
Top Post Dawg
Sorry for the delay. The confusion may be due to two things: errant label, and the supposed clutched pulley causing the failure. Here are some comparison photos.
Labels, click to embiggen:
Backsides with the cover off of the B4's/MKIII's:
They appear to be the same base and are modifiable from the manufacturing line. Since we needed the car up and running, I didn't have time to disassemble them further, but I have a need-to-be-rebuilt MKIV that can be torn down more and compared to the MKIII.
The MKIII alternator label states "AL0723X 095 71903 A4405"
The MKIV alternator label states "AL0723X 095 30208 A5154"
IndigoBlueWagon
TDIClub Enthusiast, Principal IDParts, Vendor , w/
The Bosch number for a 120a ALH alternator is AL9352X. I'm not sure what you've got there, perhaps someone has modified them to work on an ALH. The Bosch number you show is correct for an A3/B4. The ALO723x also has a conventional nut for the pulley attachment, not a triple square. And in response to an earlier post, replacement alternators for the 1Z/AHU come without pulleys.
Steve Addy
Top Post Dawg
According to specs listed on RA that AL0732X alternator is a 90 amp unit for Mk4 and it does show up for ALH+:
Beetle 98-04
Golf 99-06
Jetta 99-05
It doesn't show up as fitting any other engine for those years, at least that I could check on. Be interesting to see what Bosch actually claims it fits.
Steve
Beetle 98-04
Golf 99-06
Jetta 99-05
It doesn't show up as fitting any other engine for those years, at least that I could check on. Be interesting to see what Bosch actually claims it fits.
Steve
Back in my B4 days, between my two B4s (680k miles between them), I replaced the alternator brush assembly in both cars once. I never did replace the alternator.
As for Bosch remans, I used a reman starters in each of my VWs, and a reman starter and alternator in my old 85 MB 300D. I never had any problems with Bosch remans.
As for Bosch remans, I used a reman starters in each of my VWs, and a reman starter and alternator in my old 85 MB 300D. I never had any problems with Bosch remans.
jdulle
Veteran Member
I just ordered the gates clutched pulley from Rock Auto. I think I will stick with my alternator for now, and put new brushes in if it needs it. The bearings make a small amount of noise, but I think they have quite a bit of life in them yet. Hopefully this smooths out the jumping tensioner pulley...but I might have to do a harmonic balancer too. Yesterday I replaced the tensioner pulley, the bearing was on its way out.