M70 Starter on M60

[Shoomakan]

Hello all,

So I got into my car today and the starter was just spinning itself silly and not cranking the car. It only cranks the car when the car is warm. So, I have decided to replace it.

Now, my question is this... Can I install an M70-M73 starter? I've been reading around and some have said that the tooth rings are compatible between the V8's, V10's, and the older V12's. Is this true?

Also, has anyone here done this?

Cheers, and thank you.

[91e34M5]

Here's a thread where an M70 starter was installed on an M30. But it doesn't answer your question regarding installation on an M60.

http://www.mye28.com/viewtopic.php?t=102100

[Shoomakan]

Yeah I know, I saw that. Need more M60 content.

[TGreene]

I have a M60 starter from a parts car and will be taking a M70 starter out of another parts car in about two weeks. I don't know if you could wait that long but I would be able to compare them then.

[bubba966]

Hello all,

So I got into my car today and the starter was just spinning itself silly and not cranking the car. It only cranks the car when the car is warm. So, I have decided to replace it.

The solenoid on your starter is bad. That's what makes the starter engage the flywheel. The starter motor is still ok as evidenced by it spinning. But the starter isn't cranking the engine over because the solenoid isn't kicking the starter gear into the flywheel to engage it.

If you can replace just the solenoid it'd work fine again. But if I was going to do that I'd cut the comm & install new brushes as well. Which is exactly what was done to the old starter on my '79 Chevy. After 20 years or so the solenoid died. So it was replaced, the comm was cut, and new brushes installed. Worked for over a decade. Until the magnets in the starter became weak enough that when the starter was heat soaked it was too weak to crank the engine. It'd still work fine when the magnets were cold.

[shogun]

sometimes it is enough just to remove the solenoid and to polish it. I refurbished my M70 starter with parts from a Mercedes Benz starter, the starter motor itself is almost same from Bosch except the number of teeth, on my old 11/88 the Bosch starter innards were still made of plastic + all crumbled, newer ones made of cast iron, these I used to replace them.
Pics are on my website below under fixes>engine general
M70 starter has

Starter, 12v, 2.2kW, 9t
Voltage 12
Kilowatt 2.2
Teeth 9
Note: fits BMW 750, 850


M60

Starter, 12v, 1.7kW, 9t
Voltage 12
Kilowatt 1.7
Teeth 9

here you can compare the single parts
http://www.woodauto.com/default.aspx
they supply reman ones and single parts, so just compare their part numbers or the Bosch part numbers.



Rotation

CW

[Shoomakan]

Well, if there's no info on this I guess I'll go buy the starter anyway and see if it will work. I will be one of you inventor/pioneers at that point!

Wish me luck.

[K Fox]

Hmm...but why did the M70 get a 3hp starter when the M60 got a 2.5hp one?? Is it really that much harder to turn? I do know that the V12 starters sound cool, but I also know that half of that is the fact that it's 12 cylinders. Still, has anyone confirmed that the V12 starter is physically different - ie, how it mounts/interfaces?

Fox (a 3hp starter...that's awesome)

[Leonator134]

M70 sounds so cool starting up... would love to make my M60 sound like that!! Do post results!

[dgoodsy]

Hmm...but why did the M70 get a 3hp starter when the M60 got a 2.5hp one?? Is it really that much harder to turn? I do know that the V12 starters sound cool, but I also know that half of that is the fact that it's 12 cylinders. Still, has anyone confirmed that the V12 starter is physically different - ie, how it mounts/interfaces?

Fox (a 3hp starter...that's awesome)

According to the link shogun posted the m70 starter has the solenoid rotated around the starter body a little compared to the m60. The m5x starters are also slightly different in regards to the solenoid placement. However according to that website the m5x, m60 and m70 starters all have 9 teeth of their gears and all look to mount the same.
Some of the later m5x starters had threaded holes, earlier ones had non threaded thru holes and pelican parts website says they are not interchangeable. I wonder if there are similar differences between starters in the m6x family or between the m6x and m70..

[Leonator134]

Any updates here?

[richinvan]

I wish I'd have known there was so much interest - when I parted out my 740, I would have checked when the engine was out.

[XAlt]

Necro necro necro. The M60->S62 starter is 1.7kw, apparently the replacement for the SR441X in the Big Six. The M70's SR444X might be both backwards compatible with the Sixes and also work with the V8s.

There's also the L322 starter motor, has a nice high pitched whine to it, but it's quite large.