Difficult to change gear

[eiregti]

Okay so another issue I've had since purchasing my march is the gear selection. Whether it be hot or cold the car is incredibly difficult to get into gear whether it be moving or from stopped.

I've adjusted the clutch in and out to see if it alters the difficulty and it doesn't. I've done it with the engine off and it's not too bad.

I have two videos, one showing the gear selection whilst running and foot pressed in on clutch and second whilst engine is off





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[pollyp]

where's the bite point? it should be below 1/2 way.

to check if the clutch ain't fully disengaging, run the engine, hold the clutch down for few sec then very slowly select reverse.
if the clutch was still dragging and allowing some torque from the engine to drive the input shaft, this would make the reverse gear crunch.
if the clutch was truely disengaging fully, the input shaft would've came to a stop after afew sec and you'd be able to slowly slot it into reverse without any crunching at all.

the synchro's try to only allow a gear to be selected when both the shaft and gear are sync'd & aligned.
so if the dragging input shaft and the stationary gears are not in-sync, it'll be hard to select and will also rapidly wear out the synchro's.

another reason for difficult & "notchy" gear selection are worn loose bushings in the gear linkages. usually starts off as a stiff resistive movement when the metal bushing dries up & rusts & binds up inside the plastic outer casing.
and then as the driver ignores the stiffness and just applies more wd40 & brute force, the thick hard rust eventually eats away at the soft plastic and may feel looser but it's actually become looser, which then leads to notchy selection and rattling 5th gear.

 

[eiregti]

Well all gears are tight not just 1-4 and it's also a low mile box (109km) so can't see it being that.

To be honest the bite point is rather high, maybe a little over half way. I didn't actually show reverse in the video but it crunches like a mofo while selecting

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[pollyp]

Well all gears are tight not just 1-4 and it's also a low mile box (109km) so can't see it being that.

To be honest the bite point is rather high, maybe a little over half way. I didn't actually show reverse in the video but it crunches like a mofo while selecting

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you were selecting reverse whilst stationary right?
so it crunches in reverse repeatedly? (ie whilst always holding clutch disengaged, select reverse = crunch, pop to neutral for few sec, select reverse = crunch again?)
sounds like dragging clutch.

but with the bite point above 1/2way, more than half the pedal travel would be used to try disengaging the pressure plate, and if it still crunches with that amount of pedal travel either:
- the clutch pedal resting point needs raising (via adjustable bolt) and clutch bite point needs raising (via thumb dial on end of cable under battery) to provide more travel dedicated to overcoming the pressure plate.
- the pressure plates pivot point geometry is incorrect (amount of leverage required to fully relieve the pressure plate off the clutch plate no 1 side of the pivot far exceeds the available travel of the release bearing and clutch assembly on the other side)
- flywheel face is machined too much so the whole clutch assembly is too far away for the release bearing to fully disengage.

 

[eiregti]

you were selecting reverse whilst stationary right?
so it crunches in reverse repeatedly? (ie whilst always holding clutch disengaged, select reverse = crunch, pop to neutral for few sec, select reverse = crunch again?)
sounds like dragging clutch.

but with the bite point above 1/2way, more than half the pedal travel would be used to try disengaging the pressure plate, and if it still crunches with that amount of pedal travel either:
- the clutch pedal resting point needs raising (via adjustable bolt) and clutch bite point needs raising (via thumb dial on end of cable under battery) to provide more travel dedicated to overcoming the pressure plate.
- the pressure plates pivot point geometry is incorrect (amount of leverage required to fully relieve the pressure plate off the clutch plate no 1 side of the pivot far exceeds the available travel of the release bearing and clutch assembly on the other side)
- flywheel face is machined too much so the whole clutch assembly is too far away for the release bearing to fully disengage.

Okay had a look at the car just now, whilst stationary the car repeatedly grinds into reverse even after a swapping returning to neutral and trying again.

Wound the thumb screw in right to the very end of it's travel and still no change whatsoever in gear changing. Still grinds into reverse and just as stiff into every other gear.

I'll have and look through Haynes for the guide on proper clutch adjustment from the pedal side and reset the lot before I resort to removing the gearbox


Also it's fairly easy to swap from third gear up and back down especially while driving.

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[pollyp]

Okay had a look at the car just now, whilst stationary the car repeatedly grinds into reverse even after a swapping returning to neutral and trying again.

Wound the thumb screw in right to the very end of it's travel and still no change whatsoever in gear changing. Still grinds into reverse and just as stiff into every other gear.

I'll have and look through Haynes for the guide on proper clutch adjustment from the pedal side and reset the lot before I resort to removing the gearbox

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are you tightening it or loosening?
tightening it up the cable will shorten the cable ends hence raise the bite point and apply more force on the release bearing to help disengage.
but not too much or else the bite point will always be near the top and it'll be constantly near disengagement mode = slipping clutch under power & worn release bearing.

loosening the screw towards the tip end of the cable will slacken & lower the bite point so the clutch would be less likely to disengage.

 

[eiregti]

are you tightening it or loosening?
tightening it up the cable will shorten the cable ends hence raise the bite point and apply more force on the release bearing to help disengage.
but not too much or else the bite point will always be near the top and it'll be constantly near disengagement mode = slipping clutch under power & worn release bearing.

loosening the screw towards the tip end of the cable will slacken & lower the bite point so the clutch would be less likely to disengage.

I tightened the cable to apply more force and achieved much of the same results. I made maybe a full rotation of the thumbscrew or two and checked back before adjusting further.

I'll go wind it out and see if perhaps if it was over adjusted to begin with

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[eiregti]

Okay a short drive to demonstrate the ease of shifting gears whilst in motion. 1st and 2nd are difficult and clunky but over that it get increasingly easier.




I also wound the cable thumbscrew out to the end of adjustment to the point of nearly being able to slip off the clutch arm and tightened in just enough to take the slack off the arm of the clutch arm.

The clutch bite point was about half way to slightly below half (which is where it's supposed to be according to Pollyp)

1st 2nd and reverse are hardly on the same shaft so that they would be affected by a low oil level? Considering the half arsery the rest of the car has been treated with i can't imagine much care was taken to refill the box with enough oil...... or perhaps even installing clutch during the engine swap


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[davyboy]

Had similar to what you're having, changed the clutch....sorted.

 

[pollyp]

when it's low in gear oil you'll be able to hear it whine a little.

a notchy 1st/2nd & reverse is caused mostly by sloppy gear linkage bushes (selector mechanism not aligning properly) and dragging clutch (fighting the synchros) but is also a slight design issue with the gearbox selector mechanism cos my 1st/2nd gear is notchy too, even with ball bearing bushes

 

[pollyp]

hmm thinking of design flaw,
I was just looking back at pics of the disassembled gearbox and here's a pic of the selector pin itself. the middle "striker" bit is what moves the selection mechanism while the blocks on both sides "striker inter-lock" basically lock the other 2 forks in place.

http://micra.org.uk/threads/pollymobiles-rebuild.35251/page-11#post-419711

on one side of the interlocker, it has a rounded smooth chamfered edge to help the selector slot into 5th/reverse, whereas the other side has a squared edge, which could be the cause of the notchy 1st gear cos there's no chamfer to help guide it into place made worse by the loose linkages and perhaps restricted movement to the left where 1st/2nd gear are.
so the next time I take the box apart I think I'll chamfer those edges of the interlocker so they're more likely to let the selector mechanism slot in gear.

 

[frank]

how much throw have you got on the arm ? this is the cable movement on mine (the molegrips were clamped pedal fully down)
i have enough slack that i can just about unhook the arm without slackening the thumbscrew, that gives me a bitepoint about 1/3 rd up

 

[plmval]

Okay a short drive to demonstrate the ease of shifting gears whilst in motion. 1st and 2nd are difficult and clunky but over that it get increasingly easier.




I also wound the cable thumbscrew out to the end of adjustment to the point of nearly being able to slip off the clutch arm and tightened in just enough to take the slack off the arm of the clutch arm.

The clutch bite point was about half way to slightly below half (which is where it's supposed to be according to Pollyp)

1st 2nd and reverse are hardly on the same shaft so that they would be affected by a low oil level? Considering the half arsery the rest of the car has been treated with i can't imagine much care was taken to refill the box with enough oil...... or perhaps even installing clutch during the engine swap


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Okay a short drive to demonstrate the ease of shifting gears whilst in motion. 1st and 2nd are difficult and clunky but over that it get increasingly easier.




I also wound the cable thumbscrew out to the end of adjustment to the point of nearly being able to slip off the clutch arm and tightened in just enough to take the slack off the arm of the clutch arm.

The clutch bite point was about half way to slightly below half (which is where it's supposed to be according to Pollyp)

1st 2nd and reverse are hardly on the same shaft so that they would be affected by a low oil level? Considering the half arsery the rest of the car has been treated with i can't imagine much care was taken to refill the box with enough oil...... or perhaps even installing clutch during the engine swap


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Stiff Gear linkage and possible misalignment of engine and gearbox
Your third video, whilst driving on the move, has an excess of cluncks and rattles on the move with few crunching sounds from the gearbox, only a notchy stiff gearshift?

1. As hinted at by Pollyp, it might be useful to thoroughly lubricate the gearshift linkage pivot joints under the vehicle with penetrating and engine oil. Remove the heat shield aside to gain access to the gearshift front and rear linkage pivot joints. Then refit the heat shield or heat from the catalyst will quickly dry out the gear linkage pivot joints lubrication.
2. Check the engine and gearbox mountings and their rubber bushes (possible source of rattling clunking sounds due to excess engine gearbox movement whilst driving) to ensure correct alignment of the engine and gearbox that may indirectly affect gear change selection linkage alignment and its efficient smooth operation?

 

[eiregti]

Stiff Gear linkage and possible misalignment of engine and gearbox
Your third video, whilst driving on the move, has an excess of cluncks and rattles on the move with few crunching sounds from the gearbox, only a notchy stiff gearshift?

1. As hinted at by Pollyp, it might be useful to thoroughly lubricate the gearshift linkage pivot joints under the vehicle with penetrating and engine oil. Remove the heat shield aside to gain access to the gearshift front and rear linkage pivot joints. Then refit the heat shield or heat from the catalyst will quickly dry out the gear linkage pivot joints lubrication.
2. Check the engine and gearbox mountings and their rubber bushes (possible source of rattling clunking sounds due to excess engine gearbox movement whilst driving) to ensure correct alignment of the engine and gearbox that may indirectly affect gear change selection linkage alignment and its efficient smooth operation?

Okay so first thing on the agenda this evening was to grease up the gear selectors, inspect bushings and sus out the rear mount.

Gear selectors came out rather easily, disassembled each part as best I could, cleaned thoroughly and reassembled greased up.

Fitted back into car and checked the mounts. Rear seems fine but front was clearly shot. As a temporary measure I replaced the lower bush with a block of wood to make it more solid. Fitted the lot to the car just now and went for a quick spin to try it out and although I do prefer the better response from the solid front mount the gear selection is still shocking as ever so looks as though it's a gearbox off Job.

I'm going to organise a clutch kit first just because it's better safe than sorry. The last time I had a gearbox off to inspect why the car (almera gti) didn't change gear all too well it as good as fell out of the car haha

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[frank]

a problem gearchange is,nt gonna make the gears crunch tho eh, only the clutch not fully releasing or a syncro problem will (hence my pic of the clutch arm throw ^)
if the cable or bulkhead are flexing you wont get the full throw on that arm

 

[eiregti]

a problem gearchange is,nt gonna make the gears crunch tho eh, only the clutch not fully releasing or a syncro problem will (hence my pic of the clutch arm throw ^)
if the cable or bulkhead are flexing you wont get the full throw on that arm

Crap didn't see your post above, I'll have to check the movement of the arm tomorrow, have the day to tinker with it within reason.

I'm going to hazard a guess and say it is moving as much as it should though, the over adjustment of the cable should have ruled out any flex in either bulkhead or cable

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[eiregti]

Quite a bit of travel as you can see in the photo so doubt it's the firewall flexing or cable stretch.

It appears to be intermittent to an extent while moving and warmed up. Sometimes it just slips in smooth as silk. Usually on deceleration.

Would the back mount on the gear lever under the car affect shifting much? I know there's room for adjustment in that but wanted to run the idea past someone first

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[frank]

does,nt look like enough throw to me, have you tried adjusting the bumpstop that sets the height of the pedal at rest ?

 

[eiregti]

I haven't adjusted the pedal at all but like above, would the adjustment of the cable to it's tightest not rule out any need for adjustment in the pedal or elsewhere for that matter? Or would it be a case that if my pedal only travels X amount it doesn't really matter how much my cable is adjusted?

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[frank]

you just get a bit more throw if its adjusted fully upwards eh
was the car originally auto btw ?

 

[eiregti]

you just get a bit more throw if its adjusted fully upwards eh
was the car originally auto btw ?

I must take a quick look before setting off for work this morning. To the best of my knowledge it was always manual, don't see any hints that it may have been modified in that sort of way at all

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[eiregti]

Okay pedal was adjusted out to give more travel and still nothing.

Disconnected the selector rods and pushed them forward more using the rear bush under gear shifter leaver. Made a touch of improvement to selecting the gear but still not fully disengaging by the sounds of it.

Clutch cable adjusted to suit selector rod being shifted. Still no better

Looks like it's the clutch that'll need changing after all

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[eiregti]

To close this one up, Davey was right, clutch was at fault, couldn't find any obvious flaws with the old clutch but new unit solved problem. Unfortunately the old unit took reverse with it, still selects and moves but pops out and start grinding bad