Recommended starter motor grease

[VincentVega]

What would you guys suggest for starter motor grease? In my case, it is a gear reduction unit with 3 metal planet gears and a plastic ring gear. The original armature shaft grease appeared to be a very dark green, and it was used both in 2 bronze bushings as well as a steel on steel bushing. The planet assembly had what really, really looked like molybdenum sulfide (moly) grease on it (can't be sure) which surprised me because of the plastic. That was a very dark gray in appearance, but smeared out on paper with an almost brown hue to it. I live in a pretty cold climate, so I was also looking for stuff that had a pretty good temp range. Thanks for any advice

 

[andyd]

Chassis lube for the gears,just a smidge on the starter drive.. The dark green grease may be a marine grease that might be good. I use whatever grease is handy when assemble a DC motor.

 

[SubLGT]

Quote:

Starter motors must withstand the elements, temperatures from -40C to 200C, and 50,000 duty cycles or more. Issues of high load and torque, especially during cold crank, also have to be considered. Effectively lubricating the motors’ gears, bearings, and splines requires a careful blend of synthetic oils, additives and gellants. Popular starter motor lubricants feature PAO and ester blends with additives for extreme pressure, corrosion protection, and friction reduction.

https://www.nyelubricants.com/powertrain-components https://www.dowcorning.com/content/auto/automaterial/electrical-lubricants.aspx

 

[Merkava_4]

+1 to the Dow Corning recommendation. They have an excellent line of application specific greases.

 

[VincentVega]

Thanks!

 

[nthach]

The Japanese bearing OEMs as well as many electric motor manufacturers are fond of using "synthetic" polyurea thickened greases like Chevron SRI or Mobil Polyrex EM, those greases are bluish green to green in color. Dow tends to recommend Molykote 33 for most electric motor uses, it's not an EP grease - it's a silcone-based lithium grease that's friendly to most plastics. You could get away with SRI/EM grease on all the parts. If the bushings are accessible externally or have an oil reservoir, a light non-detergent oil like Zoom Spout might be a better choice.

 

[VincentVega]

thank you!