Sorry this is for once not Skoda related but VW caddy maxi but I believe its the same system as the Yeti. Son in law has one 2.0tdi 2011 plate and all drive is now being sent to rear wheels. Haldex unit has been fully serviced and oil changed as first thought it was the problem. Rear wheels were skipping and haldex not engaging properly. Now no drive to front wheels with all power to rear. Gearbox is currently out of vehicle. Clutch seems good with reasonable life left and drive shafts are solid.

Anyone come accross this. Can't find any info on this problem. Appologies again for posting on Yeti forum but we are desperate for an answer. Mechanic thinks maybe gearbox itself but hes not sure on haldex systems and trying to find a decent second hand gearbox is not easy.

Any help most appreciated.

Alasdair

Until someone more knowledgeable comes along, here's my 2 pence 😄. I wouldn't of thought it would be the Haldex at fault as it has 0 effect over what happens at the front end of the car. If anything goes wrong with the Haldex, you'll probably have 2 outcomes. 1, you'll have 0 power to the rear wheels because the pump has died or clutch plates are worn out. 2, you'll have 50% of the drive to the rear wheels all the time as you've experienced with the rear end skipping because the Haldex cannot disengage itself.

I'd probably point my attention to the Angle drive possibly which is bolted onto the gearbox and turns the drive 90 degrees to send the drive to the rear wheels. Maybe something funky has gone on inside which stops the front wheels getting drive but is still sending power to the back. Or like you say, maybe something within the gearbox. Neither of my suggestions make 100% of sense as I would've thought if something broke with the gearbox or angle drive, you'd get zero drive rather than rear drive only.

Hopefully someone with more knowledge will be along shortly to give you a much better answer 😁.

@Alisdair1 What you have described (no drive to front wheels) is a physical impossibility, the info is second or maybe 3rd hand so perhaps an error in communication, do you mean drive to the front wheels only which is feasible after someone has tried to resolve the rear wheel skipping problem which will have been precisely what Scott says.

The angle drive gearbox is driven from the RH front driveshaft, the front differential is a standard non LSD type, my Yeti would be a hoot in RWD only but the only way that could happen would be to cut through both front driveshafts (which would then flail around!), weld up the front differential and hotwire the Haldex pump.

I am dismayed that this mechanic who seemingly knows very little about the 4x4 transmission has removed the gearbox if it was indeed the gearbox and not the angle drive unit.

Was it the same mechanic who "fully serviced" the Haldex unit? I sincerely hope not.

Haldex seems to be working now. It was fully serviced and cleaned with new oil etc. It was skipping when driving and just wondering if thats caused damage to transfer box. I posted it on the general forum and got a diagram that shows power from gearbox via crown wheel to front diff etc. and then goes to front and rear. If theres power to the rear the gearbox I assume is still connected and supplying power to differential. As said son in law got a mechanic to take gearbox out but I havent seen it yet. Hopefully its a simple fix. Cars been off the road for a while now and he needs it for work. Will hopefully catch up with him today and get him to drain box and diff to see if theres any metal etc in there. Cant find any info on this. Its normally the rear that doesn't work due to haldex or controller.

Alasdair

19 minutes ago, J.R. said:

The angle drive gearbox is driven from the RH front driveshaft,

Having seen the diagram that @langers2k posted on the other thread I now realise the above is incorrect, I concur with his verdict that if the problem really is drive to the rear wheels only then the only plausible explanation will be the diff planetary gears having stripped.

I don't for one second believe this is the case as the graunching and screaming would be unmistakeable.

You should start by asking the mechanic or explaining to us if you already have how he (thinks he) knows that only the rear wheels are being driven.

3 minutes ago, J.R. said:

@Alisdair1 What you have described (no drive to front wheels) is a physical impossibility, the info is second or maybe 3rd hand so perhaps an error in communication, do you mean drive to the front wheels only which is feasible after someone has tried to resolve the rear wheel skipping problem which will have been precisely what Scott says.

The angle drive gearbox is driven from the RH front driveshaft, the front differential is a standard non LSD type, my Yeti would be a hoot in RWD only but the only way that could happen would be to cut through both front driveshafts (which would then flail around!), weld up the front differential and hotwire the Haldex pump.

I am dismayed that this mechanic who seemingly knows very little about the 4x4 transmission has removed the gearbox if it was indeed the gearbox and not the angle drive unit.

Was it the same mechanic who "fully serviced" the Haldex unit? I sincerely hope not.

The drive is going to rear but not the front which I agree with you doesn't make any sense unless its a front drive shaft that has failed internaly. The rear wheel skipping was due to clogged filters etc in the Haldex. Luckily it wasn't the mechanic that serviced it. My son in law did it himself and hes pretty good and thorough. It was when they test drove the car after servicing haldex that they found no front drive and the gearbox was removed as they originally thought it was a clutch failure/gearbox failure. Will be speaking to him later on today so will get some more info.

Many thanks

Alasdair

I guess if the splines were stripped on one front driveshaft the diff housing would drive just that one shaft in free air and also the quill shaft to the bevel drive gearbox and rear axle.

Its beyond the realms of imagination that such an unknown event on this platform should happen immediately after the Haldex was serviced.

You reveal something else that is implausible, when you experience jerking from the Haldex it is undesired engagement of the clutch pack usually a commanded pre-emptive strategy, this requires the Haldex clutch pack to be loaded by the hydraulic actuator from pressurised oil from the pump, when the filter is blocked the fluid does not circulate and the clutch remains disengaged, its default state.

Failure of the pump or a blocked filter screen result in no drive at the rear axle not grabbing which in most cases is a feature of the system under certain conditions, I usually experience it when reversing on lock out of a supermarket parking space.

I look forward to hearing more information which hopefully will reveal something or bring some clarity.

As an aside can your son confirm that the volume of (hopefully Haldex) fluid that he drained was in the same ballpark as the volume that was used to refill it to the correct level and that the volume used to refill was close to the specified quantity, I cant recall if it is just over or just under 1 litre, 700ml rings a bell.

I have just been told that the van is getting dropped off here so will get more info and have a look myself. Will also make sure the haldex fluid level is correct. Son in law dropped it off and had to run so wil post once I speak to him

Now I know why I thought it was a Yeti, this thread is in the Yeti section.

If your son made the mistake that many garages have and also myself the Haldex level will be correct, for peace of mind check the differential oil level.

Quick update. Van is here and gearbox seems fine. Differential is still on van so can't check at moment. Mechanic was reccomended to my son in law but after speaking to him reckon the mechanic hasn't got a F***ing clue!! Said he would only replace geearbox if a new clutch and flywheel fitted but theres no play in DMF and cutch disk is only 1/4 worn so Son in law said don't bother and transported van to here. Son in law going to pop in one evening this week and we will have a proper look. Mechanic said drive to rear only and suggested gearbox. After looking at it if the gearbox had gone there would be no drive to anywhere. Might be a problem with diff but not sure how it could be. The only other thing would be perhaps a broken shaft cv joint etc or something inside the diff thats broken or stripped. Will post once we get into it. At least being a 4x4 and big chunky tyres its fairly easy to get under.

Many thanks so far

Alasdair

Its getting a bit confusing with the various threads but can you confirm who decided that there was no drive to the front wheels and for what reason please?

If it was the mechanic why did your son take the vehicle to him?

To test differential engage a gear, rotate one pinion flange, the other should rotate backwards, there should be no noise, catching and a constant low to moderate resistance.

Edited, you may need to prevent the gearbox input shaft from moving.

Then engage direct top gear (this might be 5th and not 6th) rotate the gearbox input shaft, both diff pinions should rotate together in the same direction, normally at the same speed but due to the resistance of the bevel drive the LH one may rotate faster, if it is the only one rotating then stop it by hand and the other should rotate.

Again there should be constant resistance, its difficult to describe how much, it depends on the gear selected, how old the diff is etc. You will feel if something is wrong, I'm sure there won't be.

I would like to know what led up to the (I believe) wrong decision to remove the gearbox, if it was the mechanic then what was he asked to investigate?

So many of these threads start out with a statement of fact that eventually is revealed to be the speculation of a mechanic who is beyond their understanding and want rid of the vehicle.

Edited 25 March, 20251 yr by J.R.

16 minutes ago, J.R. said:

Its getting a bit confusing with the various threads but can you confirm who decided that there was no drive to the front wheels and for what reason please?

If it was the mechanic why did your son take the vehicle to him?

Son in law serviced haldex as car was skipping and not driving well at all. Took for test drive and seemed ok and then suddenly no drive with no noise etc so assumed sudden clutch failure as its fairly high mileage. Didn't have time himself so took to mechanic who said that there was drive to rear but nothing to front so removed gearbox. Why I have no idea as he said there was drive to haldex. I personally would have checked front diff assembly/shafts etc which is still on car. Hence why he took van away from mechanic and wont be using him again!!. Had a look at gearbox this morning and selector is fine. seems to engage all gears and no play etc in input shaft. Clutch as said is 1/4 worn and DMF/release bearing all seem ok with no leaks form Gbox or clutch slave. Turned input shaft to gearbox and output shaft sockets turn so reckon gearbox is sound. Havent had a proper look at diff yet as I am up to my eyes with work as is my son in law. Hope to get a proper look in the next couple of days. Don't think he will be paying the so called mechanic either. Will post any findings as soon as I can

Alasdair

Thanks, still a mystery as to why there would have been no drive but that is the question to ponder as the drive to rear appears to be a red herring, if that were the case your son would not have experienced "no drive"

Maybe change the thread title or delete it and start a relevant one?

Could you ask your son under what conditions the lack of drive occurred, was he pulling away hard from a standstill on a loose surface to confirm that the 4x4 was functioning?

He should pay the mechanic if he instructed him to do the work he has done.

31 minutes ago, J.R. said:

He should pay the mechanic if he instructed him to do the work he has done.

Mechanic suggested to remove gearbox. Son in law said yes as he at that time trusted mechanic but also mentioned to mechanic it could be a diff problem as the gearbox/clutch gave him no trouble to that point. Mechanic said maybe diff but took gearbox out anyway without checking diff. He then said that he would only replace it if he replaced clutch,flywheel etc. which in my opinion have at least 50k left. I think the mechanic was making work for himself and obviously hadnt worked on a haldex system before. As said once we get a proper look and check the Diff will get back. Appologies for the lack of continuity in info as I am getting it second and third hand and also posting on the yeti forum. I wouldn't normally but we are needing help with this one. Once I get further info on what has been done or not done I will be back. Many thanks for the info re checking diff. Think the way to go is to remove diff from car and refit to gearbox out of car and check it from there on bench and see if anything is obvious.

Alasdair

Sounds like he needs to bite the bullet and take it to a Skoda/Audi/vw specialist with haldex experience, if it's not already in pieces.

@Prezafab A total lack of drive is not a Haldex problem.

@Alasdair1 I appreciate your position with the 2nd and 3rd hand info.

My speculation is that your son in law broke the clutch during the testing, not overheated, burned or worn out but a failure of the pressure plate (I exclude the drive plate because you would have seen that) that would result in a total loss of drive albeit you would normally notice the lack of pedal resistance.

I was trying to work out if the mechanic had jacked up the rear wheels whether with a tiny bit of torque transfer the front diff cage could rotate and spin the rear propshaft, the Haldex I dont think will engage if the front wheels don"t turn so it would only be the propshaft with little resistance, I asked myself maybe that is what the mechanic saw?

In my minds visualisation I decided that the differential crownwheel and quill drive to the bevel gearbox and propshaft could not turn if the LH and RH driveshaft planet gears were stationary, conceptualising is not my strong point so I jacked up the rear of my car to try it out.

DONT TRY THIS AT HOME CHILDREN 😀

I did it very carefully first in 6th gear (less chance of driving off the jack) and then very very carefully in 1st gear, the conclusion was definitive, if the rear wheels are off the ground the car will indeed drive forward in gear.

2 hours ago, Alasdair1 said:

Think the way to go is to remove diff from car and refit to gearbox out of car and check it from there on bench and see if anything is obvious.

Alasdair

Maybe my senile memory is not serving me correctly but I believe that the front differential is an integral part of the transmission assembly and you cannot remove the gearbox leaving it on place, you can however remove the transmission leaving the bevel drive transfer gearbox in place, I lifted both out as one unit, 68kg.

The more you post the more questions there seem to be, perhaps the Caddy transmission is different to the other VAG vehicles which I am certain be they FWD or 4x4 all have the differential within the transmission casing.

17 hours ago, J.R. said:

Maybe my senile memory is not serving me correctly but I believe that the front differential is an integral part of the transmission assembly and you cannot remove the gearbox leaving it on place, you can however remove the transmission leaving the bevel drive transfer gearbox in place, I lifted both out as one unit, 68kg.

The more you post the more questions there seem to be, perhaps the Caddy transmission is different to the other VAG vehicles which I am certain be they FWD or 4x4 all have the differential within the transmission casing.

I think your correct. I assumed the unit that was left on van that supplies power to rear and also drivers side wheel was diff but I think its the bevel drive unit and as you said the diff is in the gearbox itself

Still to get van in shed.

Alasdair

Just had another look at gearbox on bench and it looks like it may be a gearbox fault after all. If I turn input shaft the bevel drive gear turns and theres good resistance if I try to stop it by hand. The other side where the passenger side shaft fits does turn but has no resisistance at all. I am not sure if I am correct but it looks as though the power is managing to get to the drivers side drive shaft and bevel drive unit which supplies the rear prop but nothing to the passenger side which would perhaps explain lack of front wheel drive but power to rear. I assume something has gone bang or stripped inside box or diff.

Alasdair

Unless there is an LSD fitted, which appears to be unlikely on a Yeti, all drive will go to the unloaded driveshaft.

To test the differential, you will need to apply an equal load to both front driveshafts when you turn the input shaft.

Many thanks for the replies. The gearbox is out and reckon will take to a specialist to see if they can help. Something doesnt feel right. Feels slightly rattly and uneven when turning. Bevel drive for prop/haldex turns when input shaft is turned and has complete resistance when trying to stop it turning so should be driving constantly which as said would explain power to rear but front drive is the problem. As said maybe time to take to a specialist to get it checked out.

Alasdair

What you have described is absolutely correct, the bevel drive gear is driven directly from the crownwheel, you need to refit the quill shaft and test the planet gears in the way I described, turning one alone without any significant resistance is normal.

Don't take it to a transmission specialist, you have been taken for enough money already, if you give them a perfectly functioning transmission saying that its faulty but you dont know where they could profit from the situation, doing something like that in my country earns the moniker "pigeon" - a willing victim, someone whose naiveté or ignorance is to be exploited.

To repeat:

21 minutes ago, Alasdair1 said:

Bevel drive for prop/haldex turns when input shaft is turned and has complete resistance when trying to stop it turning

Completely normal

21 minutes ago, Alasdair1 said:

so should be driving constantly which as said would explain power to rear but front drive is the problem.

You do not know that (lack of) front drive is a problem, that is what a mechanic who knows little or nothing about the system has said and what you have wrongly deduced from testing the differential incorrectly, refit the quill drive and do the testing as I described.

The only thing you know from your sons first hand report is that all drive was lost, if there was power to the rear the vehicle would not have lost all drive, I think looking at the clutch might take you straight to the resolution, that and asking your SIL to describe exactly the circumstances when drive was lost.

Edited 26 March, 20251 yr by J.R.

13 minutes ago, J.R. said:

What you have described is absolutely correct, the bevel drive gear is driven directly from the crownwheel, you need to refit the quill shaft and test the planet gears in the way I described, turning one alone without any significant resistance is normal.

Don't take it to a transmission specialist, you have been taken for enough money already, if you give them a perfectly functioning transmission saying that its faulty but you dont know where they could profit from the situation, doing something like that in my country earns the moniker "pigeon" - a willing victim, someone whose naiveté or ignorance is to be exploited.

To repeat:

Completely normal

You do not know that (lack of) front drive is a problem, that is what a mechanic who knows little or nothing about the system has said and what you have wrongly deduced from testing the differential incorrectly, refit the quill drive and do the testing as I described.

The only thing you know from your sons first hand report is that all drive was lost, if there was power to the rear the vehicle would not have lost all drive, I think looking at the clutch might take you straight to the resolution, that and asking your SIL to describe exactly the circumstances when drive was lost.

Many thanks. Will be speaking to him in the next couple of days. I will either refit gearbox or remove rear drive unit and connect on bench. Its difficult to get to internal spline on passenger side of gearbox due to it being deep into box. Clutch plate/disc seem good with disc only worn 25% and no play in DMF. Will ask him exactly what the scenario was when it failed.

Alasdair