Torque Convertor or Something Else?

[D90]

I was hoping someone might be able to steer me in the right direction with an issue I have been noticing with me V8 D3.
When cruising for instance down a hill or just when I have my foot off the accelerator I have been noticing the revs seem to be oscillating around 1600-200rpm. You can feel I slight jerkiness which I'm guessing is from the engine braking.
If I have it in sport mode it seems to be fine. I have never had any problems under hard acceleration such as it skipping gears or clunky changes etc.
It has had a steel pan fitted but I'm not 100% sure how long ago that was.
Has anyone else had similar symptoms?
Thanks

[TerryO]

I'd be interested in finding out what causes this as my D3 does it occasionally as well and just like yours if it is put into sport mode it stops.

[Redback]

Try accelerating slowly then back off slightly and use a trailing throttle around 60 to 70kph, do that a few times, if you get a slight vibration or shudder, it's the torque converter.

A cheap way to diagnose this would be to get a gearbox oil change, not a flush just an oil and filter change and get some Dr Tranny and Lubegard ATF Protectant and have that put in when you change the oil, if that fixes the problem then yes it will be the torque converter, this will give you time to save for an overhaul of the box, only if you have the shudder/vibration though.

Here ya go,

http://www.lubegard.com/~/C-230/Dr.+Tranny+Instant+Shudder+Fixx


Also read this
http://www.aulro.com/afvb/d3-d4-rrs/125041-disco-3-4-automatic-transmission-faq.html

Baz.

[PhilipA]

While I have no experience with d3 , petrol engines with injection usually cut off the injectors at1500rpm , if you are going down a hill on closed throttle at about 1500rpm , it is quite normal for the injectors to disengage and reengage as the revs go over or under1500 rpm.
This causes the revs to rise a couple of hundred.
Quite normal. In fact the bloke who bought my RRC which I had fitted a Thor manifold to which increased torque , pad me asking if there was something wrong with the auto.
Nothing wrong. It's the engine saving fuel.
Regards Philip A

[D90]

Thanks guys. I don't have any shudder or vibration it's more of the slight acceleration/deceleration as the engine ossilatates revs. I wouldn't call it a shudder.
It's sounds a bit like what PhilipA has mentioned... Apart from the fuel saving bit :rolleyes:
Thanks guys.

Sent from my LG-D855 using AULRO mobile app

[Epic pooh]

On one or two occasions late last year mine did exactly what you describe D90. It only did it when cold and like you, no vibration or suchlike. I used my IIDtool to reset gearbox adaption and it hasn't done it since. Interestingly I was having rough shifts into 6th for a while there and I charged the batteries intensively and the rough shifting is gone ... go figure ...

[PeterOZ]

the 60 to 70km/h is interesting, not sure I'd call my a shudder as such, more of a noise that sounds like something resonating. Perhaps very mild shudder.

Now I pointed this out to the LR dealer at least 3 times when it was under warranty and under lease, they claimed to not be able to hear or replicate the issue.

They did fit the steel pan and do a flush/service.

Of late is seems to be louder though.

Occassionally I'll get the clunk but no skipping gears that I can tell.

It will be going back to MR in June for service and also trans service.