6 replies to this topic

[anth]

A while back I posted a video of my car ('91 Rover Neon, but with a 1275) with an awful noise coming from it and seemingly not engaging the gears properly. I've taken my time getting the engine out and taking everything apart, bt now down to the gearbox, and the damage is obvious.

 

Basically the first cog inside the box, on both the first motion shaft and the lay shaft have broken or ground down teeth.

 

Untitled by Anthony Robson, on Flickr

 

Untitled by Anthony Robson, on Flickr

 

The rest of the cogs seem absolutely fine. I was wondering about simply replacing the cogs, but wanted to make sure the same thing wouldn't happen. The first motion shaft has a lot of back and forth motion in it (video below) - I'd put the case back on and the shaft itself is seated perfectly.

 

 

So I'm now thinking.... Do I replace the first motion shaft, and the cogs; or is this indicative of a bigger issue, and I'd be better off just getting a reconditioned unit?

Thanks, as always, in advance!

[Cooper Mac]

There is no reason why you can't replace the first motion shaft, BUT the whole gearbox will need stripping to check for debris from the broken teeth. You would be amazed where the debris can get....... 

 

You could either rebuild the whole GB yourself, or just buy a recon one for ease. It will depend on your ability, time frame and money!

 

Oh by the way if I'm going to be pedantic, they are gears, cogs are wooden pegs or teeth that are used in windmill and watermill gearing....    

[anth]

Oh by the way if I'm going to be pedantic, they are gears, cogs are wooden pegs or teeth that are used in windmill and watermill gearing....    

 

I'm more used to fixing up (push)bikes and we definitely call them cogs :) As a fellow pedant I'll remember for next time!

[Spider]

As Cooper Mac has suggested, yes, repair it, but I'd also suggest while it's out and all in front of you, stripping the whole box down, checking everything and fit new bearings and baulk rings. Put all new parts through the diff too.

[MiniMadRacer]

Check the layshaft for lateral and up and down movement in the casing.. casing could be foo barred.. any perceived movement in the shaft.. (shaft not the lay gear fitted) and I would be worried...

[GraemeC]

There is no reason why you can't replace the first motion shaft, BUT the whole gearbox will need stripping to check for debris from the broken teeth. You would be amazed where the debris can get....... 

 

You could either rebuild the whole GB yourself, or just buy a recon one for ease. It will depend on your ability, time frame and money!

 

Oh by the way if I'm going to be pedantic, they are gears, cogs are wooden pegs or teeth that are used in windmill and watermill gearing....    

 

To be real pedantic - the teeth on any gear are cogs, on either a metal or wooden gear.

 

A gear is a wheel with cogs which mesh with the cogs on another gear (also known as a cogwheel)

A sprocket is a wheel with cogs which mesh with a chain

A pulley is a wheel with no cogs and drives a belt via friction

Edited by GraemeC, 05 August 2020 - 09:51 AM.

[Cooper Mac]

 

There is no reason why you can't replace the first motion shaft, BUT the whole gearbox will need stripping to check for debris from the broken teeth. You would be amazed where the debris can get....... 

 

You could either rebuild the whole GB yourself, or just buy a recon one for ease. It will depend on your ability, time frame and money!

 

Oh by the way if I'm going to be pedantic, they are gears, cogs are wooden pegs or teeth that are used in windmill and watermill gearing....    

To be a real pedant - the teeth on any gear are cogs, on either a metal or steal gear.

 

A gear is a wheel with cogs which mesh with the cogs on another gear (also known as a cogwheel)

A sprocket is a wheel with cogs which mesh with a chain

A pulley is a wheel with no cogs and drives a belt via friction

 

Hmmm....... it seems that outside of the gearing industry there is a different terminology!   Within the world of high speed gears, a cog is only ever a piece of wood on a very low speed wheel, everything else has teeth!