S1 Gearbox backlash

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Kinger
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S1 Gearbox backlash

Post by Kinger » Wed Sep 22, 2021 2:53 pm

I've noticed a bit of backlash on the driver side drive shaft at the gearbox. Its not at either of the UJ's, no movement there. There is no backlash at the Passenger side of the gearbox. I have noticed a slight clunk during vigorous gearchanges.

I'm looking at a used C4BP Gear as I will definitely need to replace it sooner or later.

Is this common on old S1's ( 92k miles), and any thoughts on how long its likely to last ? Is there anything I can try before changing a gearbox.

Other option is to wait until it goes pop and get it done with AA parts and labour ?

Appreciate thoughts of you experts.

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Stu160
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Re: S1 Gearbox backlash

Post by Stu160 » Wed Sep 22, 2021 9:20 pm

I have similar, but thing it's my drive shafts, so I am going to replace them over the winter.

Interested to see what you find.
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Kinger
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Re: S1 Gearbox backlash

Post by Kinger » Wed Sep 22, 2021 10:01 pm

Stu160 wrote:
Wed Sep 22, 2021 9:20 pm
I have similar, but thing it's my drive shafts, so I am going to replace them over the winter.

Interested to see what you find.
I was half hoping it was my drive shaft, but no play in the UJ’s.if I grip the solid part of the inboard joint, even turning very gently you can feel the backlash in the gears. If I do it quickly I can feel the clunk on the gearbox housing.

I’ll rag the car a bit over the coming days to see if it gets much worse.( certainly isn’t going to get any better 🤣)

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campbell
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Re: S1 Gearbox backlash

Post by campbell » Thu Sep 23, 2021 6:22 pm

Never had a peep of trouble from gearbox or driveshafts. 118k Miles.

Hope you get to the bottom of it!
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Stu160
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Re: S1 Gearbox backlash

Post by Stu160 » Thu Sep 23, 2021 8:25 pm

We are all getting older 😂😂
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TarmacTerrorist
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Re: S1 Gearbox backlash

Post by TarmacTerrorist » Fri Sep 24, 2021 8:16 am

Have you checked the tightness of the nut holding the Driveshaft in the upright? Had the same, nut had come slightly loose. IIRC the torque setting is quite high on them.
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Mikie711
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Re: S1 Gearbox backlash

Post by Mikie711 » Mon Sep 27, 2021 8:52 am

You worry to much, check your drive shaft nuts (Torque = 220Nm and make sure the indents are knocked in with a punch) and then drive it till it breaks.
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Kinger
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Re: S1 Gearbox backlash

Post by Kinger » Mon Sep 27, 2021 8:59 am

Mikie711 wrote:
Mon Sep 27, 2021 8:52 am
You worry to much, check your drive shaft nuts (Torque = 220Nm and make sure the indents are knocked in with a punch) and then drive it till it breaks.
Drive shaft nuts fully tight, just hoping it keeps going and doesn’t sh*t itself on the first day of the winter frolic.🤣🤣

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Re: S1 Gearbox backlash

Post by Mikie711 » Thu Sep 30, 2021 12:29 am

Takes quite a lot to break a PG-1 with a standard engine.
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robin
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Re: S1 Gearbox backlash

Post by robin » Sat Nov 13, 2021 8:09 am

The shafts are weaker than the box I think. But driving over the kerbs on full throttle is definitely tough on the shaft and box as the wheel alternately spins and grips.

When you are turning the shaft is the other wheel locked, so the diff is pushing against the output shaft of gearbox or is the other wheel free (on which case the diff is pushing against the other wheel).

Either way I don't think there should be any backlash.

The torque reverses through the gear box each time you come on and off the throttle. If there was backlash then it would be hammering whichever part has the play, especially on track (where you jump from zero torque to full torque).

You report a clunk on gear change ... that would make sense.

For all a standard box costs from the scrapper I might be inclined to pick one up and change it.

You can overhaul of course, but is it worth it?
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