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fakiee

Super Astute 2018 gearbox crunch

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So I've just built up a Super Astute, and when running at full throttle from stand still I get a nasty clicking sound from the gearbox.

It's a loud clicking sound on heavy acceleration, doesn't happen if I'm really slow to accelerate.

I've built these gearboxes since my 91 astute 30 years ago so was really surprised to find and messed up some how.  Now for the life of me find the source of the issue.

Anyone else experience this?

I'm running a stock 27t motor, nicd, and esc with standard gearing.

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Re-check pinion and spur mesh and see that there is no grit or dirt stuck in between spur gear teeth.  

It's more likely the mesh between the pinion and spur than the counter gear.  My SA 2018 slipper shaft had some end float so the slipper shaft and spur would walk across the pinion, changing the mesh. Try some shims behind the white plastic washer on the back of the gearbox slipper shaft to minimise the end float.  Check that the plastic insert in the back of the gearbox is correctly located too.  This worked for me.  Good Luck !

PS:  I'll take a look.... it might have even been a washer in there rather than shims !

 

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On 2/9/2021 at 11:59 PM, Thommo said:

 

Re-check pinion and spur mesh and see that there is no grit or dirt stuck in between spur gear teeth.  

It's more likely the mesh between the pinion and spur than the counter gear.  My SA 2018 slipper shaft had some end float so the slipper shaft and spur would walk across the pinion, changing the mesh. Try some shims behind the white plastic washer on the back of the gearbox slipper shaft to minimise the end float.  Check that the plastic insert in the back of the gearbox is correctly located too.  This worked for me.  Good Luck !

PS:  I'll take a look.... it might have even been a washer in there rather than shims !

 

Thanks Thommo,

The crunching sounded more like it was coming from the diff/counter gear, but I had the screws pretty **** tight.  I re-tightened all screws for the gearbox, motor mount, and bulkhead screws to within an inch of their lives and this seemed to solve the issue.

 

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1 hour ago, fakiee said:

Thanks Thommo,

The crunching sounded more like it was coming from the diff/counter gear, but I had the screws pretty **** tight.  I re-tightened all screws for the gearbox, motor mount, and bulkhead screws to within an inch of their lives and this seemed to solve the issue.

 

I had the same EXACT problem in the rere Super Astute Trans that I put in my Astute. The issue is almost the same as the one AE had with their rere World's car. 

I solved it by replacing the black insert with a ball bearing of the same size. Issue solved. I'll look for the thread now. 

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Unrelated question...is the astute and super astute body exactly the same?  Same mold?

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On 2/11/2021 at 5:28 PM, GTodd said:

I solved it by replacing the black insert with a ball bearing of the same size. Issue solved. I'll look for the thread now. 

Do you have a photo of the fix you did with the gearbox and bearing?

I can see the super astute has the plastic insert for the left side of the gearbox, but this is offset so not sure how to replace with a bearing?

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Yeah got me wondering too... do you trim back the nib inside the recess first or just jam it in there ?

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On 2/18/2021 at 4:40 PM, Thommo said:

 

Yeah got me wondering too... do you trim back the nib inside the recess first or just jam it in there ?

Yep just jam it in there! Works perfectly!

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