Cannot get into gear - clutch / pedal problem?

[96terrano]

Erm only in reverse all the others have syncro cones, Rick

ok but you can still grind a syncho gearbox somehow, even though it's got synchros in it, why doesn't reverse have a synchro? i always wondered

 

[solarman216]

ok but you can still grind a syncho gearbox somehow, even though it's got synchros in it, why doesn't reverse have a synchro? i always wondered

Correct term is blocking rings cos they block the gear engagement till both at same speed, reverse cannot have a syncro as it is a separate gear on its own shaft, like the lay shaft, all the others are on the mainshaft and so can have syncros, Rick

 

[glanrichbex]

ok but you can still grind a syncho gearbox somehow, even though it's got synchros in it, why doesn't reverse have a synchro? i always wondered

Because you should be stationary when selecting reverse - same as 1st gear - you shouldn't select 1st if you're moving......... waiting for the backlash of comments on this one :augie

 

[glanrichbex]

this it what happens when you grind youre gears,

View attachment 3292

Yep - this is what I did to my gearbox - it took 18 months of grinding and I eventually wrecked the box as the swarf went round in the oil and destroyed the layshaft bearings. :clap

To the person who got my gearbox as a recon - I'm very very sorry :augie

 

[solarman216]

Because you should be stationary when selecting reverse - same as 1st gear - you shouldn't select 1st if you're moving......... waiting for the backlash of comments on this one :augie

1st has a syncro so no problem for the box when moving, in fact how often do you select 1 st from second when slowing down, as of course you should be doing, Rick

 

[glanrichbex]

1st has a syncro so no problem for the box when moving, in fact how often do you select 1 st from second when slowing down, as of course you should be doing, Rick

1st does have a synchro - but 1st is usually much lower in ratio than the rest of the gear set and the synchro has to work very hard if you go from 2nd to 1st whilst moving.

1st gear is only intended to start the vehicle moving :naughty and should only be selected when you intend to pull away. When the vehicle is slowing down, you should be in 2nd gear until the vehicle comes to a virtual stop.

 

[solarman216]

1st does have a synchro - but 1st is usually much lower in ratio than the rest of the gear set and the synchro has to work very hard if you go from 2nd to 1st whilst moving.

1st gear is only intended to start the vehicle moving :naughty and should only be selected when you intend to pull away. When the vehicle is slowing down, you should be in 2nd gear until the vehicle comes to a virtual stop.

The ratio has nothing to do with it if you road speed is such that 2nd is providing low engine revs then a drop into 1st is quite normal try towing a 2.5 tonne trailer and not use the brakes too much slowing to lights etc is regularly done on the gears breaking only on the last few mtrs, it is called reading the road, as an ex trucker with a 12 speed box that I personally did over 200,000 miles and never had a clutch and only minimal brake replacements, cannot remember the details but I had comments from the workshop as to why my brakes lasted so long, Rick

 

[96terrano]

Because you should be stationary when selecting reverse - same as 1st gear - you shouldn't select 1st if you're moving......... waiting for the backlash of comments on this one :augie

I never knew that I never usually go into 1st when moving unles useing engine breaking at very low speeds.

 

[96terrano]

Correct term is blocking rings cos they block the gear engagement till both at same speed, reverse cannot have a syncro as it is a separate gear on its own shaft, like the lay shaft, all the others are on the mainshaft and so can have syncros, Rick

Bloody interesting that:thumb2, in the above pic of a damaged gear I'm holding. I think that is the reverse gear.

 

[solarman216]

Bloody interesting that:thumb2, in the above pic of a damaged gear I'm holding. I think that is the reverse gear.

Yep that is reverse gear, and if you look it was not going in fully as well, bent/damaged selector fork? Rick

 

[96terrano]

I think when we finally scrap our Honda jazz, im going to remove the gearbox as its broken, 'jumps out of 3rd, grinds ramdomly and the bearings have let go', I want to autopsy it and see what's gone on inside.. not to fix but to learn, never taken a fwd gearbox apart, seen inside one but only pics, just looks like a scaled down rwd box only with a huge gear on the 2nd lay shaft. Where the half shafts go out to the front wheels.

 

[96terrano]

Yep that is reverse gear, and if you look it was not going in fully as well, bent/damaged selector fork? Rick

Yes the selector folk was bent slightly, I did give that box a hammering but I knew it was getting changed anyway so wasn't to sympathetic:lol

 

[solarman216]

I think when we finally scrap our Honda jazz, im going to remove the gearbox as its broken, 'jumps out of 3rd, grinds ramdomly and the bearings have let go', I want to autopsy it and see what's gone on inside.. not to fix but to learn, never taken a fwd gearbox apart, seen inside one but only pics, just looks like a scaled down rwd box only with a huge gear on the 2nd lay shaft. Where the half shafts go out to the front wheels.

That will be the Diff, Rick

 

[96terrano]

That will be the Diff, Rick

Ahh ok, are they basically a scaled down version of a rear axle?

 

[solarman216]

Ahh ok, are they basically a scaled down version of a rear axle?

yep box and diff all in one, do not know about the Honda but the 60s mini had it all in the engine ie engine oil lubricated the engine, box and diff, and it worked well, Rick

 

[96terrano]

yep box and diff all in one, do not know about the Honda but the 60s mini had it all in the engine ie engine oil lubricated the engine, box and diff, and it worked well, Rick

Cool, the Hondas use a weird 'expensive' gear oil. But the Honda jazz's gearbox a poorly designed anyways, as if you look on Google there's loads of problems with them, same with some of the civics that have the same engine and box too, I made a vid on you tube of it :thumb2

I show and let you hear the sound. As you can hear, the bearings and gears are eating themselves

https://www.youtube.com/watch?v=vDOfcLpXnnY&feature=youtube_gdata_player

 

[glanrichbex]

The ratio has nothing to do with it if you road speed is such that 2nd is providing low engine revs then a drop into 1st is quite normal try towing a 2.5 tonne trailer and not use the brakes too much slowing to lights etc is regularly done on the gears breaking only on the last few mtrs, it is called reading the road, as an ex trucker with a 12 speed box that I personally did over 200,000 miles and never had a clutch and only minimal brake replacements, cannot remember the details but I had comments from the workshop as to why my brakes lasted so long, Rick

The ratio has alot to do with it - the ratio differential from 2nd down to 1st is more than any other selection in the box because 1st gear is much lower in proportion as it is designed purely to get the vehicle going with maximum torque whilst bearing as little stress on the clutch and transmission as possible.

These days the emphasis is to use more of your brakes rather than your gearbox as brakes are substantially more efficient these days and cheaper to replace.
A gearbox is designed to cope with the maximum torque delivered by the engine in conjunction with the load. It is not good engineering practice to use the gearbox as a brake by placing heavy loads against it on over run - the forces can be massive - thats why trailers over 750kgs have to be braked.

These gearboxes are not built anywhere near to the spec of your lorry.