2002 GEM blown. Differential?

Well @JarJarJava check out the video on this link below, especially about 10 seconds in when the input shaft binds up on me. Sounds like the dana diff wasn’t tough enough for this ride. Must be the extra 4hp from the racing stripes that did it in :slight_smile:

GEM Troubleshooting - iCloud Photo Sharing

Nice job

Good thing there wasn’t a chrome diff cover too, that would have been like hitting a land mine.

Need to see a shot of the teeth from the top on the input shaft. Can’t really tell from the end on photo. It’s a special bearing that also seals on that old input shaft btw. They don’t make the bearing anymore so be careful with it. If it gets damaged you need to get the upgraded input shaft that uses an external TC oil seal.

There is a trick or two to putting the short GE motors back together. There are photos here somewhere from years ago.

Make sure you fish the old bumper out of the collar and replace it and use grease on the splines, that collar looks like they forgot that the last time.

It might be easier to just buy a new used diff. Save the pumpkin, the input shaft and the two output shafts from your old one. The pumpkin and output shafts fit any classic gem diff. The input shaft fits 8.9& 10.35. there is also a 12.44 and a 14.75. you could use any one of them really but that motor won’t last long pushing the 12 & 14.

The black dust is carbon dust from the brushes. This is normal and partly why these things need to be taken apart and blown out every now hand then. The motors are not vented and the dust has nowhere to go.

The number sticker on your gearbox says this is 8.9 ratio. Seeing as the builder jumped the wheels to a 20 inch tire and being a 4 seat car I think this is a good time to change to a 10.35 set of gears to help that little motor out. The 15in(?) wheels are good for brake upgrade clearance.

The motor literally came apart as I was pulling it off the differential, was that not supposed to happen?

Yeah, they aren’t supposed to come apart quite that easy… I seem to recall there should be some long through screws from the end cap into the motor shell. Are those gone / missing?

The retainer and screws are still there,
but the shaft came out of the bearing fairly easy.

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Having recently opened up those motors a couple of times, there are 2 screws which hold the rear bearing retaining clip in place. What looks to hold the whole rotor in place is friction with the inner bearing race and the 4 brushes. The 4 brushes usually have worn a small recess in the commutator which also helps resist the rotor from just pulling out.

But with all the rust on the input shaft and motor’s splined socket there might have been some prying on the case to get the motor off the transmission. So I would look closely at the brush holders to look for any damage and be aware that you can’t just slide the rotor back in since those brushes need to be pulled back before inserting the rotor and then released.

@dougl , thanks for the info. The motor came right of the differential with no effort and as I pulled it out of the front end as I rotated it the motor the insides slid right out and dropped about 1’ to the ground. Did I screw up?

-Jeff

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Nope. You did good, that, sir, is a sign… You know what you have to do with it…

:slight_smile:

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yikes! were you able to ID which part impacted the ground since that part rotates at many thousands of RPMs so any slight damage can result in bad vibrations and eventual bearing failures. Those motor parts are not something you want to bang or knock around.

nice ride. Favor, although i found an option to help with upgrade the stock headlights, i like what they did to yours. Can you post some pictures as well as any identifying info for which lights those are? I know you don’t have it running again yet, but also a picture of light pattern in dark would be great too if you can.

Thanks!