Technical Panda 4x4 clonking/juddering

[Jamie KC]

Hi,

I bought a wee Panda 4x4 yesterday, 2014 car with 49.5k on the clock as I wanted a low mileage vehicle to last many many years. Visited the car twice, test drove twice (1 long drive, up to motorway speeds and lots of junctions, second one short after a couple of issues resolved), felt happy with it.

About 30 mins into the journey as pulling out onto a roundabout gently in second there was a bit of a juddering sensation, and bit of a knocking noise which seems to be coming from the rear diff area. I tested it with a few more roundabouts and it seemed to ease off so I continued with the journey home. It raised it's head again about 30 mins or so later, so I did a wee bit more experimenting to see when it happens.

It seems to happen predominantly when in the speed range of 10-20 mph. If pulling gently in gear at this speed it happens, if a bit more throttle applied it eases off. As coming to a stop it happens a little as you slow in gear under 20mph. If you dip the clutch and coast then as you drop to that speed range it really does knock a bit. Noise and feeling through the body.

It drives really well apart from this, although a slight bit more vibration noise above 70 compared to other vehicles I've seen (noise only, no sensation). On switch on all lights illuminate and go out incl ELD and EM light. No lights come on whilst driving nor when it is suffering the issue.

Any ideas? Common problem? I guess my gut says diff bearing or a prop connection, but thought I'd ask before I start poking about.

Thanks!

 

[jackwhoo]

Front to rear prop shaft centre bearing rubber mount on these fail very very often and the fix is to replace the propshaft complete.

Under body corrosion, subframes etc is also an issue even on low mileage

 

[Jamie KC]

Bugger, thanks. Sounds like one for a garage to check out perhaps, as my current facilities at home don’t stretch too far. I’ll see if I have local 4x4 specialist.

 

[jackwhoo]

You don't need a 4x4 specialist to look at prop shaft support bearing any decent mechanic will do.

 

[jackwhoo]

Corrosion is biggest enemy

 

[Herts Hillhopper]

Just to be sure, you have not turned on the ELD switch behind the gear lever? (in normal use the green light on the switch should be off, or if a Cross model, the dial should be on the first, 'auto' setting, not the 'off road' position)

If it is on, or the dial in the off-road position, you will 'wind up' the 4x4 system because there's no central diff, and that manifests itself as various juddering sensations.

By the way, which engine? Is this in anyway an issue of dual mass flywheel problems (more generally on TwinAir it seems)

 

[Herts Hillhopper]

Corrosion is biggest enemy

to be fair, only really of the 4x4 under tray. The whole bodyshell is galvanised and the rear suspension beam on the 4x4 is a different design to the 2WD Panda and doesn't seem to suffer.

 

[Jamie KC]

Just to be sure, you have not turned on the ELD switch behind the gear lever? (in normal use the green light on the switch should be off, or if a Cross model, the dial should be on the first, 'auto' setting, not the 'off road' position)

If it is on, or the dial in the off-road position, you will 'wind up' the 4x4 system because there's no central diff, and that manifests itself as various juddering sensations.

By the way, which engine? Is this in anyway an issue of dual mass flywheel problems (more generally on TwinAir it seems)

It’s a 1.3 MJ, and doesn’t feel like a DMF issue. The knock is defo between the mid and the rear, and the sensation of it through the car bodywork points that way too.

ELD defo not on. Fell foul of that when test driving first couple of cars and initial thought something was wrong when it was engaged.

Anti corrosion measures good to know about on the 4x4, lot of water around here!

 

[Herts Hillhopper]

...
ELD defo not on. Fell foul of that when test driving first couple of cars...

Ah yes, didn't spot same as earlier conversation!

 

[Jamie KC]

Drove the Panda in to work today to test it out again. Bizarrely it didn’t really do it this time.

This journey was predominantly on narrow lanes, so lots of stop/start type driving at lower speeds, 16miles/30mins total. It did very gently manifest itself at about 20mins or so into the drive, but only a very subtle rhythmic knocking when coasting to a stop declutched at about 15mph. That was it. Again felt that it was very much occurring behind me.

The journey after collection was predominantly 50-70mph with more continuous driving, and began knocking more heavily after 30mins or so.

Is that symptomatic of discussed issues, or something else known to be a problem?

 

[Jamie KC]

Drove home round the houses to add 10 mins or so and got her clonking again. In the last 1/2 a mile the noise and feeling returned.

Obvious when pulling through 10-20mph in 2nd. Gentle rhythmic knock that increased until over 20 and disappeared. Same when slowing and coasting, decreased as got slower.

However when coasting I tried swerving around the lane. Whenever the front wheels were turned the knocking noise seemed to at least double in frequency.

What are you knowledgeable people thinking?

 

[Panda IIs]

Drove home round the houses to add 10 mins or so and got her clonking again. In the last 1/2 a mile the noise and feeling returned.

Obvious when pulling through 10-20mph in 2nd. Gentle rhythmic knock that increased until over 20 and disappeared. Same when slowing and coasting, decreased as got slower.

However when coasting I tried swerving around the lane. Whenever the front wheels were turned the knocking noise seemed to at least double in frequency.

What are you knowledgeable people thinking?

I'm thinking you need to get underneath and have a look at the propshaft bearing for starters. From other threads on here I believe you will see it has a bonded rubber layer. Start by looking for any obvious signs of the rubber debonding or "excessive" movement??

 

[Jamie KC]

I'm thinking you need to get underneath and have a look at the propshaft bearing for starters. From other threads on here I believe you will see it has a bonded rubber layer. Start by looking for any obvious signs of the rubber debonding or "excessive" movement??

Yeah I need to find the opportunity to get underneath for a gander.

Would there be any expectation that this would only manifest itself after car fully warmed up ie 30mins plus driving time and not do it when cold?

 

[Jamie KC]

Ah yes, didn't spot same as earlier conversation!

After drive home last night I can say it was similar to having ELD on when swerving left to right. Just this hot vs cold bit that is weird.

 

[Panda IIs]

Yeah I need to find the opportunity to get underneath for a gander.

Would there be any expectation that this would only manifest itself after car fully warmed up ie 30mins plus driving time and not do it when cold?

I don't think I would want to speculate; I have worked with/tested/designed rubber (elastomer) parts all my working life. It's feasible that things may loosen up as you do a few miles. The material itself will not soften due to increased heat per se but stiffnesses will change due to hysteresis effects. If it has begun to disbond this significantly changes the overall stiffness of the part (and therefore the design) the unbonded areas may slide/move around more readily if they get wet etc.

All speculation and the bearing itself may just have died! The metal parts may well behave differently with a few miles; turning the wheel may just add dynamic side loads which aggravate things plus the rear diff will be allowing for this turning so changing the loads on the propshaft subtly. All sorts could be going on - there may be a dead squirrel wrapped around the shaft?

 

[Panda IIs]

I don't think I would want to speculate; I have worked with/tested/designed rubber (elastomer) parts all my working life. It's feasible that things may loosen up as you do a few miles. The material itself will not soften due to increased heat per se but stiffnesses will change due to hysteresis effects. If it has begun to disbond this significantly changes the overall stiffness of the part (and therefore the design) the unbonded areas may slide/move around more readily if they get wet etc.

All speculation and the bearing itself may just have died! The metal parts may well behave differently with a few miles; turning the wheel may just add dynamic side loads which aggravate things plus the rear diff will be allowing for this turning so changing the loads on the propshaft subtly. All sorts could be going on - there may be a dead squirrel wrapped around the shaft?

Also; I believe there are some rubber bushes in the rear diff support(?) - I have a 2013 4x4 but its not on the drive at the moment so can't check.

If you take a step back to think about stuff that goes wrong on cars I'd hazard a guess that well over 50% of the time it involves some or other non-metallic part - belts, bushes, trim, wipers etc. So that's what I always do/look for first!

 

[Jamie KC]

Dead squirrel

 

[Herts Hillhopper]

Dead squirrel

My suggestion was going to be ‘look in the cage that protects the central joint of the propshaft’… the only time I’ve experienced the noise you describe is once that fills with snow then freezes overnight.

Clearly not snow in August, but mud or tangled grass would do it. Or a dead squirrel.

A failing bearing support tends to make a single clonk over ridged bumps, like speed bumps. The propshaft is always rotating when the car’s moving, but there should be very little drive connection beyond it into the rear diff unless the solenoid valve that engages 4x4 has operated. However, the rear diff will be turning as the rear wheels rotate, and during cornering have more going on inside. Maybe worth checking the rear diff oil level?

 

[Panda IIs]

My suggestion was going to be ‘look in the cage that protects the central joint of the propshaft’… the only time I’ve experienced the noise you describe is once that fills with snow then freezes overnight.

Clearly not snow in August, but mud or tangled grass would do it. Or a dead squirrel.

(For others: failing bearing support tends to make a single clonk over ridged bumps, like speed bumps)

Well I figured, even allowing for climate change, that a the balance of probability favoured road kill over snow in August?

 

[tomdee]

I had a similar problem with a knock at low speed that happened after the engine was warm, and all the mechanics involved, the problem was an axle shaft that had a dry CV joint with no grease inside the boot. The solution was to refill with grease. However the shaft will have to be replaced soon as it created a gap that creates a vibration at low speed.

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