Clunk when turning from stationary and clunk when going into 2nd gear

[MisterCruiser]

I've had a clunk sound when changing into 2nd gear from 1st for a few years now on my cruiser, it never got worse really, but I was often curious to know whats causing it. I don't think it does it or at least not to the same extent when changing down from 3rd. All other gears are fine, 2nd drives fine too, it's just this cluck or thud when changing into 2nd, it's not a grinding sound or anything like that, I don't think it's the gear itself in the gearbox, probably more like a bushing or linkage issue but you'd imagine more than 1 gear would be affected. It's hard to get a smooth gear change, as I'm letting the clutch out in 2nd the thud occurs.

I also have a loud clunk sound sometimes, seems to be louder now when occurs, when I first start the cruiser and go to move off and turn at the same time slowly. Where I usually park is just around the corner of my house, so when I go to reverse around the corner slowly I hear this loud clunk. It usually only does it once, if I start to drive forward and turn and try reverse around again, I can't get it to do it again. It's as if moving after been left overnight causes something to settle and then clunk when moving off the next day. I never hear this clunk during a trip or after the initial time it does it first, if I was stopped later that same day and went to move off again it doesn't do it. It's fairly loud as in a mate commented on the loudness the other day when he was walking towards my cruiser as I started to reverse around the corner. I think it's gotten louder recently, sort of like a loud click sound.

Could it be a CV joint, but it doesn't click any other time and when it does it's a single loud click, not a series of clicks like a CV joint, Iv'e no play in the wheel either, bushings / ball-joints seem ok, anti-roll bar bushings are all new on the rear and fronts seem ok too.

I don't know if the 2 sounds / issues are related but I'm interested to hear thoughts. I can live with these issues, have done for few years now but the Click noise from stationary is starting to get louder.

 

[Oli.g]

Sounds similar to my transfer case problem.. started out like that then gradually ended up constantly clunking with any power

 

[diggerdave]

The clunk when turning - particularly when reversing - is a red flag for CV joint or steering rack related problems. However, I'd say that the odd gentle clunk from either is not a sign of impending doom.

The other clunk could be any number of things. I get a 'clunk' or 'shunt' when changing gear due to slack somewhere in the driveline meaning that there is a minute differenece between drive being sent to the front and rear axles. It's more obvious when going first to second, but it's there throughout the range. Could that describe what you have? This is the curse of permanent 4wd and you can read complaints about driveline shunt all over the net. In my case I think it's slack in the transfer case, but it hasn't got worse in all the years and (hard) miles that I've owned it.

 

[MisterCruiser]

Hi, no that wouldn't describe what I have, I only detect the shunt going from 1st into 2nd, I don't detect it at all throughout the range of gear changes.

Just to update this, the clunk I get when reversing from stationary is loud and just has gotten a bit more regular, possibly a bit louder too. The other night I went to reverse the cruiser around the corner of my house to then drive it into my shed and the clunk happened and also the centre diff light lit up on my dash and I could feel the centre diff was engaged. I was on frozen icy concrete and could feel the cruiser "slide" or feel the diff lock as it felt diffferent. It wasn't just a case of the light on the dash coming on, the diff was engaged. I then drove forward and backward and it went off, it engaged again when turning full lock on the ice and went off itself.

I'm now wondering if my clunk from stationary is related to this incident of the centre diff engaging by itself?
Is it possible for the diff to engage by itself if there's wear somewhere in my propshafts or joints or other components?
Is it possible for the diff to engage by itself when driving on frozen icy ground? Please note I was barely driving, clutch wasn't even out full, was just reversing + using 1st gear.

Additional info specific to my cruiser that may help diagnosis - I have a small gear lever which selects between Low and High and is also used to lock the centre diff. I have a separate switch on the dash to activate the rear diff which hasn't worked since I have this cruiser, I don't need it.

 

[BobMurphy]

Changing gear shouldn't affect the Transfer Box.

Does the Transfer Lever work as expected - i.e. Move it forward to engage Centre Diff Lock then across and forward to get Neutral and then Low Ratio (Centre Diff is engaged constantly during this bit!) ?

I have seen people put the Transfer Lever back in and miss the Selector Rods. Is it possible that yours is mis-aligned and at the point of engaging the Centre Diff Lock ?

If the Transfer Lever has been out or the Transfer Box has been worked on I would take the lever out and check it. It helps if the Selector Rods are set to "Centre Diff Lock Engaged" before putting the lever back in as the Selector Blocks are then aligned and more difficult to miss.

Bob.

 

[MisterCruiser]

Hi Bob, cheers for the info. We can forget about the 1st to 2nd gear clunk / shunt then so, that‘s a separate issue.

So I’m left with this 2nd clunk and the diff engaging + disengaging itself.

The small gear lever is in its correct “H” position, as I rarely ever move it, in fact the only time I do move it is when I take a notion to engage specifically to not let it seize. I probably do this once a year in the 6/7 yrs I’ve owned it. I haven’t moved the lever recently either.

Is clunking + centre diff engaging / disengaging by itself a symptom of a failing transfer box? Or could something else cause these symptoms? I renewed the oil when I bought it 6/7 yrs ago, is it worth changing it again to see if helps?

I haven’t checked to see if I can lock the diff and unlock it again or checked to see if I can select Low. Once it disengaged I just left it in case I put it in HL and it got stuck there as I needed the cruiser the next day. I might try that this evening though.

Ps: I think I read that you had to rebuild one of yours after it got stuck when there was frosty conditions, I wonder did the frost affect mine? This is the only time it’s ever engaged / disengaged by itself.

 

[diggerdave]

I've never heard of a transfer case self-engaging the differential lock and then un self-enagaging itself! It sounds highly unlikely. Are you sure that's what happened? I know you say that you 'felt' the centre diff engaged. But would you definitely know? I only ask because you say that you never use it and only engage it once a year. Also, it was on frozen icy concrete, so could that explain any strange feeling?

If I understand right, this is is the first time it has happened? But your clunk first time setting off has been around for ages, possibly getting worse? Whatever happened with the self-locking differential it doesn't sound like it's related to the clunk when setting off.

The main thing here is that your 'clunk when setting off' only happens when the car has been stood overnight, not at any other time. The 'turning' could be a red herring because, by coincidence, every time you set off after parking overnight you are turning due to where you park.

Have you ruled out the brakes sticking on?

 

[MisterCruiser]

Yes, your correct in saying the clunk that occurs when setting off has been around for ages but seems to be getting worse. The diff engaging / disengaging by itself only happened once the other night. Interesting to see if it occurs again. I am 90% sure it locked, the light lit up on the dash indicating it was on and it definitely felt different to drive.

Tbh, I don't think you could mistake it being on or off as it feels completely different when locked. I've a switchable 2 / 4wd quad and it used get stuck in 4wd sometimes, when switching back to 2wd, the light on the dash would be off and yet I'd know by the feel of it straight away that it was still in 4wd, the difference was night and day. I'd describe the same feeling with regards to the diff on the cruiser. It was werid, the rear wheel seemed like it was "slipping" or sliding or such.

When I google the symptoms of a failing transfer box one of the traits that comes up is "jumping in and out of 4wd", I know the cruiser is permenant 4x4, and aren't sure if it's possible for the diff to engage / disengage by itself due to wear or some other fault in the transfer box ? If it was slipping on ice would it have an effect? I think I read that Bob had his transfer box seize in the frost and I think he had to rebuild it because it wouldn't unseize from that state; I may be wrong on this?

It would be a very big coincidence for my diff lock light to come up on the dash and for the crusier to feel completely different to drive at the same time, I think. Hmmmm...

I think I would rule out the brakes, it's a way louder clunk than brakes, and I also overhauled all 4 brake calipers, discs + pads and some hoses a few years ago. If it was brake related, I'd say my handbrake drums would be the most likely but I don't thinks it's them. It's a loud clunk, or even a sharp "crack" type sound maybe.

 

[Jake the Peg]

Have you looked into the prop shaft joints, I’ve had clunks from them when worn and loose, and vibrations and bad driving due to them seizing up, you may net be able to judge their condition while bolted in position

 

[diggerdave]

It's a loud clunk, or even a sharp "crack" type sound maybe.

It's just that is exactly how I would describe the sticking brakes on my MR2 when I set off if it's been sat a while. You can feel it in the MR2, but perhaps a car as heavy as the cruiser you wouldn't feel it.

I'm sure the key to understanding this is that the clunk only happens after the car has been parked up for a while, but you can't replicate the clunk when the car is in use. Me? 'd try leaving the handbrake off and see whether it still happens, just to rule it out (but could still be the calipers).

Apart from the brakes, I can't think of anything that would act like that (electrical things and fuel things can change with temperature, but not relevant here). I think a propshaft UJ would either cause trouble all the time or not at all, for example. The same if there was some fault in the TB. Perhaps someone else has some ideas?

 

[Shayne]

Front lower wishbone bush , get under the truck and see how much it moves to and fro while somebody spins the steering wheel lock to lock .

 

[BobMurphy]

A strange one, this.

The Centre Diff shouldn't be able to lock on its own, the lock is a sliding sleeve that prevents the two outputs from moving independently - thus jamming the gear cluster. It is moved by a very large Selector Fork attached, via springs, to the Selector Shaft. If the Planet Carrier was broken (I've seen two like this) I suppose it could cause the diff to lock - BUT.

The light on the dash is triggered by a simple switch that is set by the Selector Shaft - locking the diff by other means wouldn't cause the light to come on. There are no electrical gremlins living here.

This is why I asked about the Transfer Lever being incorrectly installed as it could point to the Selector Shaft being on the verge of being in the engaged position (a long shot I know).

You mentioned my first excursion into Transfer Boxes . . A long time ago. As I recall I couldn't find anything wrong in mine and suspect I had put the Transfer Lever back in incorrectly. I'm a lot older and hopefully a bit wiser now .

I have rebuilt eight or nine TBs and they are fairly bullet-proof, the exception being the Planet Carrier that can shatter if overloaded (by running on a dry road with the Centre Diff engaged or by tackling some extreme off-road course). I can't think of a way it could automatically engage the Diff Lock unless someone had been in there and not put it together correctly or if it was so worn that the components were flopping about . . Not even DiggerDave's was that bad - despite the oil and mud mix in there .

You mentioned cold weather and the fact that you haven't changed the TB oil for 6 or 7 years ( ) and a thought struck me . . . .

When the Transfer Lever is moved forward to the 'Lock' position it compresses a spring on the Selector Shaft that allows the Selector Fork to move the Sliding Lock Sleeve when the splines are aligned.

If the Selector Fork and/or springs are seized on the shaft it won't engage or dis-engage cleanly so I suppose your problem could be there - but you don't seem to have attempted to go into 'Centre Diff Lock' recently which rather rules that out.

A good flush with clean oil and then a re-fill with EP 90 GL5 may free everything up - but you will need to play with the TB lever to make sure that everything is moving freely.

I'd start there.

Bob.

 

[MisterCruiser]

Ok, that's interesting reading Bob, thanks for the pic of the selector fork and shaft. It's good to see what we're talking about, it looks fairly sturdy all right.

Tonight, I experimented by driving the cruiser back and forth in my yard where it has sat since Sunday night. The clunk occurred once when I turned when reversing. I couldn't get it to occur again despite reverse turning / forward turning / full lock turning, etc.. This is typical behaviour of this particular clunk.

I checked my little gear lever and it was definitely all the way in "H". I put it into "HL", lever moved in easily; had tod rive back / forth just wee bit (normal I believe) and then it engaged and light on dash. It disengaged in the same manner, lever returned to "H" easily and had to drive it back / forth wee bit.
I know the diff shouldn't be locked when driving on dry tarmac / concrete; but the one thing I will say is when I had the diff locked tonight on purpose, it didn't like turning on the concrete at all, it felt like it was struggling, or resistance, should it feel like that just turning from a stop with clutch not fully out when driving just within 2 lengths of the cruiser. It drove back + forth ok, you'd know it was on, but when it came to turning it definitely didn't like it. Almost felt like it was going to stall or stop so I stopped it. Should it feel like that just within that short distance of concrete?
I didn't put it into "LL" as the concrete didn't like "HL" and didn't want to damage it, the small lever seems to be all working ok though.

I'm now thinking that the diff didn't lock the other night and it was just the feel of the cruiser on the icy concrete whilst turning that made it feel differently, as suggested by "DiggerDave". The fact the dash light came on must have fooled me.
So does this suggest a random electrical fault occurred the other night bringing the dash diff light on. As Bob says the switch is on the little gear lever, my sunroof which I sealed up due to it leaking, still leaks a bit during frost, and I get some drops from the head lining down to the centre console area, perhaps some stray water caused it. I've had a weird "once -occurring" electrical fault before on a rainy night when the headlights switched on and stayed on by themselves so I guess an electrical oddity isn't too much of a surprise.

I guess it's looking more like a bushing / ball-joint now, I replaced the big lower ball-joints in my ownership so I'd have thought they'd be ok. When it's on my lift being serviced I always check the bushings / ball-joints with a pry bar specifically for this clunk and fi9nd no movement, it's also passed it's DOE / MOT the last 2 / 3 yrs with this clunk present but it never was detected in the tests. I know it's not the steering rack as I put a new one in it recently with all new bushings and clunk still the same.

I will check wish bones and such as suggested, I prob need to be looking under it whilst someone else turns it.
I think I can rule out brakes as it doesn't do it when starting off straight, only when turn.

 

[BobMurphy]

As Bob says the switch is on the little gear lever, my sunroof which I sealed up due to it leaking, still leaks a bit during frost, and I get some drops from the head lining down to the centre console area, perhaps some stray water caused it.

Errr NO - The switch is in the Transfer Box. There are two in a Manual box (Three on an Auto box) and they can be seen here:

The switch on the right (blue wire) is worked by the 'Centre Diff Lock Selector Fork'. So, when the Transfer Lever is moved the Selector Shaft tensions the spring and the Selector Fork moves when everything lines-up. THEN the dash light comes on. Its the same when unlocking the centre diff, the Transfer Lever moves the Selector Shaft which tensions the other spring and the Selector Fork moves when its ready - switching the dash light off.

The other switch (green wire) is on the High/Low Ratio Selector Shaft. There are no springs here as the Selector Fork is rigidly attached to the Selector Shaft. There are detents in the shaft that set the dash light switch - so no delay in the light coming on. There are two switches here on an Auto TB as the Auto ECU needs to know what's going on as well as the dash light letting you know that its in 'LOW'.

The 'feel' of the car on concrete when the Centre Diff is locked sounds right to me. The front & rear axles will take a slightly different path which puts a strain on the centre diff. You can feel that in the steering and power delivery. In extreme cases the tyres will 'skip' or something will break. Hence only using it on snow, ice, mud, wet grass and so on.

I had an Auto '90' brought to me three times as the owner said the drive was 'skipping' under load. I stripped the Transfer box three times and after the first re-build couldn't find anything wrong with it. Eventually the problem proved to be worn splines on a front drive shaft - skipping in the hub !

What's the mileage on the truck and what sort of use has it had? The occasional 'clunk' may be something moving under load that doesn't move in normal use - just something else to worry you .

Bob.

 

[MisterCruiser]

Ooops, sorry Bob, I misunderstood you regards the switch location. Once again, thanks for the pic.

So stray water on the sensor can be ruled out as the cause of the diff light coming on, perhaps the beginning of faulty wiring caused it; if the 2 switch wires get damaged and contact each other will the light come on? Maybe it will turn out to be a one time only glitch.

The history of my cruiser is I bought it 7yrs ago, it’s a 2nd vehicle so I only do 5k miles a yr on it. 135k miles on her now, I renewed all the fluids etc when I bought it. Don’t know it’s complete history, was parked up a couple yrs before I bought it. I don’t do heavy towing with it.

I do have it in fields but rarely get stuck so don’t need to use the diff or low much.

 

[Shayne]

You can't lock the centre diff without going into low range its mechanical and if it locked on its own while you were driving it would be like changing from 4th gear to 1st and removing your foot from the clutch quickly , manual description, but you couldn't fail to notice the same in an auto , so a dash light is likely just a loose bulb or something .

I'm convinced my transfer box clunk gear change shunt results from a loose and stretched chain , once its pulled taught it stays taught and no more shunt . Its more a feel than a noise its loud but its not its violent but its not , while sat in the truck its like someone hitting the chassis hard with a big rubber hammer . As times gone on we both learned almost subconsciously to drive it without making the noise and i'm not even sure how but i'd guess its a tiny pause while releasing the clutch to sort of take the weight before powering on .

Change the oil just because and make sure you remove your filler plug first , but i reckon your issue is a worn bush front or rear , at the age of the vehicle most of us have replaced them all by now because while they very rarely fail catastrophically they simple to old and hard to do the job they are supposed to do which is to cushion the drivetrain so everything feels smooth .

 

[MisterCruiser]

You can lock the centre diff on my model without going into Low box. I can’t go into Low without locking the centre diff though.
I’ve got High, High Locked and Low. High locked is centre diff locked.

I’ll have another look at bushings, ball joints, etc...

At least I know the transfer box is prob ok now.

 

[BobMurphy]

You can't lock the centre diff without going into low range its mechanical.

Its t'other way about - Diff can be locked at normal road speed (Toyota say 50mph max, I think) - transfer lever forward for lock, back for unlock.

You have to be in 'lock' before moving the Transfer lever across to the right, then forward for 'N', then 'Low'. On a manual you can change into low at up to 5mph (they say) but in an Auto the gearbox has to be in neutral (well, that's the case with my '100').

Its a long time since I was inside a Transfer Box and I've had to scan all my re-build photos to remind myself of how it works - old age, I remember nothing these days .

Bob.

 

[Shayne]

Ah mines a manual 90 and the lever to me is pretty much high and open or low and locked though i think there is a high ratio locked option i've never had reason to use it .

 

[diggerdave]

Yes, why would anyone need high locked? Never understood it myself. Maybe there's something I've been missing all these years. Is it a snow and ice thing? It just seems unlikely I'd ever find myself in a situation when I needed to lock the centre diff at 50mph!!!!!!!!!!!!!!!!!!!