DIY Alternator Repair Resource -
  • 6 Post By pittmeister
  • 4 Post By theknurl
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post #1 of 3 (permalink) Old 02-05-2018, 04:56 PM Thread Starter
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DIY Alternator Repair Resource

After investing enough of my time trying to fine compatible parts for the pre-2010 F4 and B4 alternators, I figured that I could save someone else's time and post the fruits of my research.

Past resources:
Fixing an alternator/generator
MV agusta F4 Alternator

Parts resource:
Transpo parts catalog (PDF)

The stock regulator is Denso PN: 126000-2700, 57.5mm mtg. length, IG-S-L-D 4 pin square plug
The stock regulator can now be cross referenced as part # 260007180 and is available but at a cost of $120.

EDIT 11/5/2019: I was recently able to source a stock type regulator off eBay from seller justautopartsusa for $40.

I could not find an alternative that is the correct size and keeps the stock plug. Thankfully it is easy to adapt the plug and there are many options that have the same dimensions (57.5mm) and voltage set points in range.

Transpo: IN254, Nippondenso: 126000-0600, 126000-0760, 126000-1160
The replacement mentioned in gremmin's thread, IG-L, no sense wire, different plug orientation

Transpo: IN240, Nippondenso: 126000-2400
Has S-IG-L pins, different plug orientation

Transpo: IN277 Denso PN: 126000-1770
Has S-IG-L pins, same plug orientation

+many others, search the Transpo catalog for 57.5mm to see more

Replacements can be found for $30 or less + the cost of adapting the plugs.
I don't have a stock part number, but it is an 8 diode set-up with an M6x1.00 x 35mm terminal, 90mm OD, and screws that go down. The charging circuit fuse is 40A and it uses it, so my reasoning is that it has to be able of handling that supply.
Transpo PN: INR737 Denso PN: 021580-3030 and 021580-3340
Transpo PN: INR724
Can be sourced from eBay for between $20- $30, though they can be found from more respectable sources for not much more.
Again no part number but alternative PN INB220 Denso 021620-220 appears to be a direct replacement an can be sourced from $5-$20.

Alternator o-ring:
I managed to cut mine during the disassembly process and didn't want to pay the MV price. Since I have no formal mechanical or engineering training, I also apparently suck at measuring things. I measured the o-ring groove as 3.175", ~80.5mm and thickness as .930", ~2mm which didn't really match with anything. I ended up using -151 standard size o-rings, $2.73 for a pack of 10 at Grainger. They were a touch oversized, but with a bit of finesse and a healthy heap of grease the unit slid back in. Maybe opt for one size down.

Hope this helps someone in the future.

Last edited by pittmeister; 11-05-2019 at 07:12 PM.
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post #2 of 3 (permalink) Old 02-05-2018, 06:08 PM
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Good stuff !!!! Thank you.

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post #3 of 3 (permalink) Old 02-05-2018, 09:40 PM
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Thumbs up !

Thank you pittmeister, I put a link to your thread in my sticky at the top of the Tools......Section


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