Alternator OEM Toyota or Bosch

I’d recommend going by a local Toyota dealer parts department and getting an OEM replacement. It’s more pricey than aftermarket but… it’ll last as long as the original Toyota alternator did.

I only trust OEM, Denso, Valero, and Hitachi. Bosch isn't too bad.

I have one. I replaced a Bosch with it. Hasn't had an issue and had a lifetime warranty.

Yes. I had one on my e39 (M54) for a long time. Probably put close to 75k miles on it before I sold it. It was the Bosch variant. No issues with it at all. In fact, it appeared to be a Bosch reman in an Autozone box. Hard to tell what the internals were but they looked exactly the same.

Owned a 4th gen 4runner for over 10 years. Boring to drive and look at, but it took a lot of abuse and never gave me any problems. It only had to be towed once due to the alternator going out on me 50 miles from home.

If anyone is curious, the 120a Bosch and Valeo alternators (rectangle ground connection) are completely interchangeable despite the statements online saying they have different pullies and mounting points. They are slightly different but everything lines/bolts up the same. The Bosch (left) is a decent amount larger in size, not sure why, but it fits perfectly with no clearance issues.

I order a Bosch AL113MX Reman Alternator (yep Bosch reman the Motorola) since that was what was currently in there. The 81 has a big square York compressor mounted right on top of the alternator which means that to get the rear alternator bolt you better have the right extensions and you are going to do it blind. So after at lot of effort I got the old alternator out and the new one in and only then did I notice that the pulley did not line up.

13V is normal for a stock Bosch alternator. There are 14V or adjustable voltage regulator available as a replacement.

I when my original alternator failed in my 540i/6, the replacement rebuilt Bosch unit would produce 13.5-13.7v for a while after the car had warmed up, then would gradually fall to less than battery voltage. Running the A/C and revving the engine at stoplights would keep the battery light from flickering, but eventually, it would show full symptoms of a dead charging system.

ended up going with a Bosch remanufactured alternator. Installed it today, went super smooth, charged up the battery as I was installing it, got everything buttoned up and started it up. Battery light still on, voltage is at around 11.9 and dropping. Will randomly jump up to 14.4 volts, no correlation with revving the engine or putting a load on the electrical system.