S3 layshaft slop

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fluff34567
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Sat Mar 16, 2019 3:56 pm

Newly rebuilt engine, zero miles. new MB hub bearing and new SKF end plate bearing. Gearbox shimming close to the minimum gap.. Can't remember exact figure.

When on the centre stand I can move the rear wheel slightly and hear a knock which I guess is shaft in the end plate.

Hub correctly torqued.. Guessing its not normal and side case has to come off??

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garry inglis
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Sat Mar 16, 2019 4:09 pm

I've found most problems with wheel wobble is endplate bush but I've had mb bearings that failImage

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Scooterdude
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Sat Mar 16, 2019 4:46 pm

Easy to diagnose, with the side case off place a wide bladed screwdriver between 1st gear and the casing give it a wiggle and see if there is any movement.

Ive done a couple recently and have replaced with the excellent Scootopia bearing and track.

fluff34567
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Sat Mar 16, 2019 5:39 pm

Will start taking the side case off and see what's going on inside. Strangely there is more movement when on the stand compared to rear wheel off the ground.

fluff34567
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Sat Mar 16, 2019 6:14 pm

So side case off and there is some movement of the shaft at the end plate needle cage.. That's a bit s**t as I had replaced the needle roller and the holder during the rebuild.. It could also be the shaft.

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garry inglis
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Sat Mar 16, 2019 6:35 pm

if you still have the old endplate race measure the inside dimension and check the new one as theres nothing to say the new one is made to the exact tolerence needed

fluff34567
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Sat Mar 16, 2019 8:07 pm

As Gary has suggexyed/suspected, the new bush/bearing cage is a big bigger compared to an original unit.

Would anyone have an MB layshaft and a good set of digital verniers or a micrometer and can measure the end of the layshaft for me so I can compare to mine before I lay out £150 for a new one.


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garry inglis
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Sat Mar 16, 2019 8:13 pm

I would put your old bush back in and put the endplate back on and try that

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fluff34567
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Sat Mar 16, 2019 10:40 pm

New replacement bush is too big.. Typical

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garry inglis
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Sun Mar 17, 2019 8:44 am

Well I've measured my bits as you can see the new scootopia bush is spot on a nice fit to layshaft with a bearing in the Spanish one was a right fit but good the first Italian at 23.43 was slack so would definitely wobble but a good example of how little ware can cause a problem

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