Occasional gear clunk!?

[JakeM]

Hello all

I am just a few weeks in now to ownership of my 2001 d4d 95. It's going brilliantly, absolute beast of a car, very pleased.

Being 15 years old, there are a few faults which I am slowly working through. This one I need your help on please.

It's a manual gearbox. Occasionally when stationary and putting it into first from neutral, there will be a jolt as if the clutch wasn't fully depressed.

This isn't very often. What is more often is the same jolt when changing from 1st to 2nd. Not all the time, maybe only 1 in 20 times.
Only 1st to 2nd. No other directions or gears.

Now you'll have to correct me if I am wrong here. When the clutch pedal is pressed the gearbox is disengaged from the engine. When the jolt occurs (neutral to first) there is slight movement forward. So is the clutch not disengaged properly or am I misunderstanding the mechanics here?
Or am I barking up completely the wrong tree!?

Thanks in advance
Jake

 

[Shayne]

https://www.landcruiserclub.net/community/threads/excessive-play-in-transfer-box-kzj90.143198/

And still not satisfied that i have found the answer .

 

[diggerdave]

Jake, it's hard to diagnose these things over the internet but it sounds to me as if you're on the right track. The clue is when you say that shifting into first from neutral with the 'clunk' you get slight forward motion, even though the clutch pedal is fully depressed (if I understand you right). That would indeed indicate that your clutch is not fully disengaged when it should be

It could be a fault in the clutch mechanism itself or a fault in the hydraulic circuit. The latter is the cheaper option, so hope it's that! In the first instance check that the fluid reservoir is full and that there are no leaks from the clutch master cylinder or slave cylinder. Even if all looks well, either cylinder could still be worn but before replacing parts at random, the feel and operation of a clutch can be transformed by bleeding the circuit.

Jolting when changing gear can also be from driveline shunt which can be difficult to trace and expensive to fix as Shayne's thread will show. But I think your fault is clutch related due to the moving forward issue

 

[Shayne]

Perhaps i shouldn't have posted that link because its discouraging and contains no answers .

Change clutch fluid and new panhard and trailing arm bushes are next on the agenda when i get around to it .

 

[JakeM]

Thanks Shayne
And thanks diggerdave

I've been slowly reading through the above thread with great intrigue as guess what, yes I have a very similar problem, which yes can be one or several of many potential causes. Suspension, drivetrain, clutch, bushes, engine mounts...and now it seems transfer box chain!!!

It was the clunk when stationary which seems more achievable to find a diagnosis.
I'll do some more research on the clutch. I do know the fluid appears to be very clean and not low.

 

[JakeM]

My Discovery did exactly the same, albeit not quite as aggressively.
I've been putting that down to 50% more power with the d4d.

Come to think of it, working on a farm many of the tractors had similar traits. Just had to try and drive more smoothly.

 

[Shayne]

There is some adjustment to be had from the clutch pedal , you can alter height and where in the travel the clutch bites . It didn't help me but your symptoms sound different

 

[JakeM]

Thanks Shayne
Was your problem just when the clutch engages?

 

[Shayne]

Yep i have tried all sorts of lunacy to try and produce the clunk without using the clutch and can't .

I will honestly be gutted if it turns out the rear axle is moving and something as simple as new bushes on it fix the problem but that's the way i'm leaning now . Simple things first is how i should have started .

 

[Shayne]

If your clutch isn't fully disengaging the push rod behind the pedal can be shortened which should let the clutch plate disengage more i think . It's just a lock nut then you can turn the thread to alter push rod length . I went in blind and found a turn of just 2 threads alters thing a lot . Easy thing to try .

 

[Beau]

Shayne, are you saying that when you roll through the gears, well 1st to second without using the clutch, that there's no clunk?

The only thing I can think of is normal wear and tear in the driveline, that may be more prevelent in a manual than a auto box. I have some of this play and can feel it when shifting from reverse to drive and vice versa.

 

[diggerdave]

The more I hear about your shunt shayne, the more I realise we've independently been through the same/similar steps. I too went through the pedal-adjustment-phase... also without any success whatsoever. I've given up now!

I do think that Oak's issue is with the clutch, but if it IS the dreaded 'shunt', Oak, then I would learn to live with it unless you have long pockets. It is NOT easy to diagnose and some of the most likely causes are high-budget

 

[JakeM]

I believe I have both problems diggerdave. The shunt I realised was a long road to go down. Also if driven carefully can be almost eliminated.

The clutch may also be in question here. I have just driven to work and found that it is the path from 1st to neutral, i.e. Coming out of gear, that gives the jolt/clunk/..

Must do some work.....

 

[Shayne]

Shayne, are you saying that when you roll through the gears, well 1st to second without using the clutch, that there's no clunk?

The only thing I can think of is normal wear and tear in the driveline, that may be more prevelent in a manual than a auto box. I have some of this play and can feel it when shifting from reverse to drive and vice versa.

Im convinced that's exactly what it is Beau , I can feel the shunt (though not nearly as bad) in my kzj occasionally as the result of bad driving .

Stuck between a rock and a hard place because I can't convince myself I want to keep the kdj I guess I wanted it to be a one component quick fix . I spent to much buying the truck chucked at least another 2 grand at it without actually driving it . So what I've ended up with is a truck that's worth a good bit more than market value but wouldn't sell for market value due to the shunt


It's Helens daily driver but she prefers my truck so the damn thing has done about 3000 miles in 2 years , it's a good truck in all other respects it's in very good condition with about 103k on the clock and if I listen to my head rather than my heart I know there's not a better truck out there to replace it with .

I need to bite the bullet , it's a cruiser it can be fixed I just need to invest some time in it , I think there's 6 rubbers on the rear axle and if each gives 1mm extra play due to wear ........ simple things first .

 

[Beau]

That's breaking in millage! you have spent a fair bit on it so I'd stick it out and fix it eventually... The good thing is you can drive it on a daily with this problem. I assume it's not getting worse?

 

[Shayne]

I reckon it will do another hundred thousand without being fixed that's what makes it so bloody frustrating .

 

[JakeM]

After finishing work today I started the engine then had the idea of pumping the clutch pedal a few times to see if that made any difference. It sure did. There was no shunt engaging first, then pulled away, and there was no shunt leaving first.

Up through the gears, drove about half a mile to the junction. Into first fine. Then leaving first there was a mini shunt.

If the clutch needed bleeding would pumping it have disengaged it better/more fully?

I'll keep an eye on this going to and from work. I don't have any more time until the weekend to look further.

 

[Shayne]

Just tried that Oak and it makes no difference for me .

 

[JakeM]

Yeah I can still get the other shunt (which I believe is similar to yours) in any gear by having the revs higher than the transmission speed and dumping the clutch so to speak.. clutch catches and engine gives a shove, transmission bangs!

I often get it through my bad driving technique. Well, when driving golf gti's in my youth. I'd purposely rev slightly between gear changes to get the shunt/shove !
Also on 2 stroke mx bikes - rev between gears, drop the clutch, get a shove!

Bad habits the landcruiser and many other cars don't like...

 

[Shayne]

I spent plenty of time on motorbikes watching the red line rather than the speedo so i get what you mean , but the shunt is not because of my driving . I have two trucks identical in everything but the engine and i do drive my truck in a similar fashion to how i rode a bike , but no shunt .

In the other truck i can eliminate the shunt by driving like miss daisy and i have asked others to drive it , all said they thought the noise was their fault because they weren't used to the clutch . I could sell it to someone who has never driven one no problem at all i think but i know its not right .