RangeRovers.net Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
1,119 Posts
Discussion Starter #1
I have been trying to get to the bottom of an irritating problem on my 2006 Jaguar engined FFRR with 6-Speed ZF 6HP26 gearbox.

Under load especially in lower gears I can feel a vibration or harshness through the cars floorpan and seat etc. It is not apparent in "Overrun".

Having discussed with local Land Rover Specialist he feels its possibly the ZF 6HP26 as he is aware of several cars being fixed by their associated Main Dealer just up the road.

My question is this could harshness being produced by a ZF 6HP26 under load be cured by simply changing the oil, which may have become contaminated, or even the "Double Flush" oil change discussed elsewhere in this forum?

If not any ideas from the technical guys as to the likely cause/remedy for such a problem assuming it is the ZF 6HP26 causing the harshness under load.

Many thanks. :think:
 

·
Premium Member
2002-2005 Range Rover MkIII / L322
Joined
·
1,973 Posts
Vibration under load is often from prop shaft or equiv' joints. Have you had these checked out first? If they are Ok then I think you would be right to get an oil and filter change done.

I got mine done by TES Transmissions they are in Westbury, Wiltshire so not a massive distance from you. The guys there are very knowledgeable will happily discus various aspects of the trans' with you. They have a very clean and professional workshop, I certainly felt happy leaving the RR there and I'm usually fairly paranoid with things like that!
 

·
Registered
Joined
·
1,119 Posts
Discussion Starter #4
Thanks Dan I will get the Prop Shafts & Couplings checked but the Specialist though the car "Too Young" to have problems in this area.

Anybody got any other experience or ideas?
 

·
Registered
Joined
·
1,119 Posts
Discussion Starter #5
Received this direct from ZF - will keep you posted on further responses:

Gary,
I am looking into your problem of harshness / vibration, but need a few more details.
Please can you supply engine size and any previous problems with the transmission, if you have not owned the vehicle from new a VIN number would be helpful.
Have you a transmission fault light on and are there any fault codes.
Is the transmission fluid level correct and are the engine and transmission flashed (programmed) to the latest levels and adapts reset.

Kind Regards
Paul Loomes
Product Support Engineer.
Passenger Car Products
Customer Support
ZF Great Britain Ltd
Abbeyfield Road, Lenton, Nottingham, NG7 2SX.
Tel: 0115 986 9211 Direct: 0115 851 5511
Fax 0115 986 3038
[email protected]
[email protected]
[email protected]
http://www.zf-group.co.uk
 

·
LEGACY VENDOR
Joined
·
2,289 Posts
Torque converters are highly effective at isolating torsional vibrations from the engine to prevent them being passed down the driveline and ultimately being felt by the driver and passengers. In the quest for efficiency lock-up clutches were introduced in torque converters but this by-passed the excellent isolation properties of the TC necessitating spring/damper assemblies to be built into the lock-up clutches (similar to manual gearbox clutch friction plates).

To save weight & space, ZF removed the torsional vibration damper from the lock-up clutch of the 5HP24 transmission (used in ’02-’05 petrol L322s) and instead relied on their ‘controlled slip’ system to modulate the LUC pressures and prevent the transmission of torsional vibration once the converter was ‘locked’ (i.e. it was never fully locked). ZF carried over this system to the 6HP26 which was originally introduced in 2001 but only picked up by Jaguar for the L322 from 2006MY. These more recent transmissions not only offer better economy & performance as a result of increased ratio spread (6.04 in the case of the 6HP26/28, up from 4.44 in the 5HP24) but also by applying the lock-up clutch more frequently and in lower gears too.

In 2007 ZF introduced an ‘improved’ version of the 6HP26, called the 6HP28 – now used in the latest L322s – which, amongst other improvements, had a mechanical spring/damper assembly built into the lock-up clutch. It was advertised in the technical press at the time as “ZF’s new vibration-reducing torque converter”. ZF’s latest 8-speed transmission (8HP70) which has just been introduced by BMW has an even more sophisticated LUC torsional vibration spring/damper arrangement with a choice of three different systems depending on the application.

Perhaps you are particularly sensitive to these driveline torsional vibrations? On overrun, the lock-up clutch is automatically disengaged unless ‘manual’ mode is selected to provide enhanced overrun braking. You mentioned that the vibration seems to disappear on overrun. Does it come back again if you select manual mode and gradually downsequence through the gears as you come to rest?

Phil
 

·
Registered
Joined
·
1,119 Posts
Discussion Starter #7
RRPhil said:
Torque converters are highly effective at isolating torsional vibrations from the engine to prevent them being passed down the driveline and ultimately being felt by the driver and passengers. In the quest for efficiency lock-up clutches were introduced in torque converters but this by-passed the excellent isolation properties of the TC necessitating spring/damper assemblies to be built into the lock-up clutches (similar to manual gearbox clutch friction plates).

To save weight & space, ZF removed the torsional vibration damper from the lock-up clutch of the 5HP24 transmission (used in ’02-’05 petrol L322s) and instead relied on their ‘controlled slip’ system to modulate the LUC pressures and prevent the transmission of torsional vibration once the converter was ‘locked’ (i.e. it was never fully locked). ZF carried over this system to the 6HP26 which was originally introduced in 2001 but only picked up by Jaguar for the L322 from 2006MY. These more recent transmissions not only offer better economy & performance as a result of increased ratio spread (6.04 in the case of the 6HP26/28, up from 4.44 in the 5HP24) but also by applying the lock-up clutch more frequently and in lower gears too.

In 2007 ZF introduced an ‘improved’ version of the 6HP26, called the 6HP28 – now used in the latest L322s – which, amongst other improvements, had a mechanical spring/damper assembly built into the lock-up clutch. It was advertised in the technical press at the time as “ZF’s new vibration-reducing torque converter”. ZF’s latest 8-speed transmission (8HP70) which has just been introduced by BMW has an even more sophisticated LUC torsional vibration spring/damper arrangement with a choice of three different systems depending on the application.

Perhaps you are particularly sensitive to these driveline torsional vibrations? On overrun, the lock-up clutch is automatically disengaged unless ‘manual’ mode is selected to provide enhanced overrun braking. You mentioned that the vibration seems to disappear on overrun. Does it come back again if you select manual mode and gradually downsequence through the gears as you come to rest?

Phil
Will check this soon Phil - Many thanks that all sounds very "Linked" to my problem!
 

·
Registered
Joined
·
1,119 Posts
Discussion Starter #8
Update re ZF correspondance:

Gary,

I have since spoken with one of our Car Field Engineers, what is the mileage of your vehicle. He also asks when you feel the harshness / vibration do you a surge on the tacho.


Kind Regards
Paul Loomes
Product Support Engineer.
Passenger Car Products
Customer Support
ZF Great Britain Ltd
Abbeyfield Road, Lenton, Nottingham, NG7 2SX.
Tel: 0115 986 9211 Direct: 0115 851 5511
Fax 0115 986 3038
[email protected]
[email protected]
[email protected]
http://www.zf-group.co.uk

Paul,

The Mileage is just 50k.

The harshness is most obvious under acceleration or going up a hill but it’s there in the background most times the foot is on the pedal.

I do get minor Throttle hunting/surge at low revs especially when engine cold(ish) and going up an incline.

Regards

Gary
 

·
Registered
Joined
·
1,119 Posts
Discussion Starter #9
Further Update/Advice:

Gary,
It is possible that it is a diff problem, this can be checked by driving at 35-50mph, noise with foot on the pedal, no noise foot off the pedal.
Otherwise transmission oil degradation is possible but is normally seen on higher mileage vehicles.
A double flush and refill in this case would solve the problem, but this is an expensive operation so all other possibilities in the drivetrain should be ruled out beforehand.
It is very important that the correct fluid is used (ZFlifegaurdfluid6) and the correct fill process is used.

Kind Regards
Paul Loomes
 

·
Registered
Joined
·
1,119 Posts
Discussion Starter #10
further update:

Gary,
It will be worth checking the diff if the test suggests it is the diff. A Land Rover dealer or a transmission specialist should be able to quote how much for the flush and refil. ZFGB do not offer this service.

Paul Loomes

PAUL,

OK but I can find no record of Diff problems with the 2006 Jaguar Model RR as they specifically addressed this issue for the new model and added a flexible coupling at transfer case end of the shaft.

What else could go wrong or effect the diff?

Many thanks

Gary
 

·
Registered
Joined
·
1,119 Posts
Discussion Starter #12
update:

Paul,

I forgot to mention that I “May” have a slight coolant leak as the level seems to reduce by about ½ pint over a couple of weeks. Could this potential leak be contaminating the gearbox oil leading the slight grinding/harshness?

I just read some of ZF Trouble Shooting Guide JLR 13 38 10_2E and it seems to be a possibility?

Regards

Gary
 

·
Registered
2002-2005 Range Rover MkIII / L322
Joined
·
203 Posts
This is quite interesting. I bought an '03 4.4V8 Range Rover in March this year with 70K on the clock. Full LRSH. Before we took delivery the car was checked out by Harwoods in Basingstoke and they found an oil leak on the gearbox.

The dealer (Kempshott Cars - would recommend highly!) , give him his due, sent the car off to 3D Transmissions in Reading where to the dealers surprise they fitted a reconditioned Auto Box (This is the 5 Speed ZF unit).

The car was fine except occassionally it would not engage going into reverse, then would 'bang' in, or give tremendous 'slip' (ie revving the engine in reverse gave no drive in reverse).

We took the car back to Reading 2 weeks ago and got the car back last week (It was a hairline crack in the valve block and they have replaced it with another reconditioned gearbox).

Since it has been returned the gear changes are now smooth (I havent driven it yet as I work in Paris), but my wife is now saying that there is a vibration and droning noise at around 30mph....

We are going to take it into TES Transmissions this week for them to check it out.

The gearbox place in Reading suggested it might have been the propshaft not done up securely, but this has been checked by a local mechanic, although he did report one of the bolts being a bit loose.

P38Spares have suggested it might be the rubber couplings worn, but why would this only start now?

The front diff / propshaft has been replaced in April by Ottons of Salisbury (we are near Devizes), so the front is all good.

Is it possible that with the gearbox being removed twice within a period of 4 months the propshaft couplings could be damaged or the propshaft gone out of balance?

I am making the assumption that as it is a recon box and a new torque converter (fitted with the first recon box in March) that it is not a problem with the gearbox.
 

·
Premium Member
2002-2005 Range Rover MkIII / L322
Joined
·
1,973 Posts
Hi,

I see you're going to be using TES Transmissions, I've used them for my gearbox oil and filter change. I found them to be really helpful, they did the work on time and for a reasonable cost. On top of that they were very polite and kept the car clean.

You'll be in the area so if you fancy meeting up for a beer or popping over for a coffee to discuss RR issues give me a shout!

I had a very bad experience with Ottons when I tried to get my Diff replaced there, and vibration after the diff recall is common if it's not been aligned correctly.

Regards,

Dan
 

·
Registered
2002-2005 Range Rover MkIII / L322
Joined
·
203 Posts
Well we finally got the gearbox vibration problem sorted! A full recondition by TES Transmissions!

The car went in for an MOT back in April when we discovered that the car had not been serviced for 2 years! (my comments re Kempshott Cars - strike them from the records!!), some problems with the suspension sensors / valves and rear brake drums / shoes etc etc.
Anyway, vibration on gearbox was still occurring, so it went into TES Transmissions. They initially thought it was the torque converter, so fitted a brand new (not recon) unit, no difference, so it was a full stripdown and rebuild.

They found that the valve block had some faults (this was supposed to have been done by 3D Transmissions in Reading...), also the clutches were badly worn (again, supposed to have been a recondition by 3D transmissions..).

Anyway, TES have done an excellent job, car is now running better than it has ever done and fuel consumption has decreased!!

One point they did mention is that if you are having Torque converter issues, you will see the rev counter 'twitching' which is caused by the gears not locking out.
 
1 - 15 of 15 Posts
Top