Crunchy Third

Hello,

Seems like a bad day for my 90 today. It's just decided to start really crunching into third gear, however, it only does this when changing down gears, it's smooth as anything changing up. It's an LT77 box, and I did have a bit of trouble with it a while ago (synchromesh?), but an oil change seemed to sort this out. It's just as if I'm not pushing the clutch right down (even though my foot is flat to the floor.)

The master cylinder reservoir isn't full of fluid right up to the level line, but it is full of fluid none the less - this won't be the cause of the problem will it?

I don't know what else to try, it's horrible! There's no resistance when pushing into third when changing down, it just goes straight in and grinds. When changing up however, there's a nice kind of spongey click when it goes in.

Any ideas as to what's wrong?

Thanks in advance

-Pos

It's a common problem on LT77's. I had a disco for 2 years that was like that it never got any worse I'd just learn to live with it.

it never used to do it though, and everyone will be looking at me when im driving past, thinking that I can't drive

You might find that keeping thr revs down while going into or out of third will smooth things a bit.

Just like hughsey said, you learn to live with it. I had a disco 1 and it always did it, and it does it now years later! (neighbours bought it!).
If your reducing speed and going 5th to 3rd it was at it's worst. Try slowing more before changing, or when changing down, clutch down, out of gear, clutch up and then back down, and then into third.

Try having two goes at it drop into nuetral foot off yer clutch then back on and into third.

Double clutching doesn't work, it's really bad, not just a little crunch either. It's just as if I'm not pressing the clutch at all and the only wyway it crunches slightly is if I slow right down to about 10 mph.

GRUNT said:

Try having two goes at it drop into nuetral foot off yer clutch then back on and into third.

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Double clutch - Wikipedia, the free encyclopedia

Nope, docuble clutching has absolutely no effect what so ever. Still just as bad. It's the only gear that does it, and only when changing down.

Could there be something wrong with my clutch?

wah said:

Try slowing more before changing, or when changing down, clutch down, out of gear, clutch up and then back down, and then into third.

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Ere Grunt - yu having a bad week?

My 110 did this for a while - i assume you have checked the oil? Mine had all 'gone'. Turned out it had leaked out, and the rest had migrated into the transfer box. Put some more oil in, was fine.It could be your clutch, as if the synchro is weaker on 3rd, which is possible, and the clutch is just dragging, then it will crunch on 3rd only. Check the fluid, top it up, bleed the clutch, someone said on here park it nose uphill to do that. Worked on mine. When you double de-clutch do you match the engine rev's to the speed they will be doing one the gear in engaged? That is the simplest way to remove crunch, but it is hard to get it right though.

Mine also did this for a while, and it started particularly after a service, but i kind of got used to trying to match the revs with the road speed (so a bit more gas when changing down, and a bit less when changing up!) but i noticeds when i went to check my levels that they'd overfilled the gearbox (the checking process emptied a bit - all over me sundy best!) and now it's down a bit the problem seems to have gone away. My theory is either:

-It only did it when the car was cold, for about the first 10 minutes, and the weather has warmed up a bit and thinned the oil

-The oil was too full and emptying a bit out sorted it out

-My driving style has subconciously changed to accommodate the crunch (i do notice myself changing very slowly in and out of third now to give the syncro a chance to catch up)

-The gearbox is about to go pop big time (hope not!!)

Don't despair, you don't need to be talking toyota just yet, everyone seems to say they can crunch for ages and still be fine. The matching engine speed to road speed tip is my favorite though, and all your passengers will think you're a professional chauffeur!

My gearbox was grindin into second and reverse till it warmed up, changed me oil to MT 75 and both problems disapeared and changin is so much smoother. When you last change yer oil?

pos said:

Nope, docuble clutching has absolutely no effect what so ever. Still just as bad. It's the only gear that does it, and only when changing down.

Could there be something wrong with my clutch?

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Clutch - give it a load of revs and then clutch and push it into 3rd, at 30 mph, to go into 3rd you need to be doing about 2000rpm.

get an Ashcrofts exchange with warranty and get piece of mind.

He's at school! He won't have enough credit cards.

Just to clear some things up:

landy10 said:

My gearbox was grindin into second and reverse till it warmed up, changed me oil to MT 75 and both problems disapeared and changin is so much smoother. When you last change yer oil?

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I changed my gearbox oil about 3 months ago, so that's pretty fresh.

Matching the gearbox and engine speed doesn't seem to make much difference (I've been trying and trying), the bugger still grinds.

Ashcroft aren't all too clear with their prices. Would I be better of exchanging my LT77 for a new one, or would I be better buying an R380, and how much are they?

Also, how could too much or slightly too little oil cause the gears to grind on just one gear? It has only happened since the weather has warmed up a little though, so you do have a very valid point Odene!

I'm stumped!

If you match the engine speeds, then you will be able to engage the gear without depressing the cluch - it should slide effortlessly in. This will tell you how well you are speed matching. What could be happening is the bearing/s on the input shaft are wearing out, and are binding slightly so when you match the engine speed and de clutch to select the gear, the 'box slows down very quickly again, and so crunches. I am not sure why this would only affect one gear though, unless the syncro is just a bit more worn on that one.

I've been told that it is my down synchro on third, so I will either replace the box, or have a go at fixing it over Summer.

When you change down to third, try keeping your right foot exactly where it is on the accelerator, ie not lifting off, and do the change really slowly in two deliberate movements, slowly out of fourth and then purposefully slowly into third (with the engine now revving quite high) - bit of a knack but if it works you'll get used to it!