Hi All

This weekend I was towing a car trailor with a vintage motor on the back, all told probably around 1.8 ton total weight.

During the tow, there were a few climbs as I live in a fairly hilly area, and I felt what can only be described as pulsing, or a hunting sensation from the drive. It wasn't hugely noticable (the wife couldn't tell from the passeenger seat) but I could feel it was there. After a 40 minute drive, on shut down there was a very slight smell coming from the car. I wouldn't call it clutch smell but it was along those lines...

Didn't happen so much when I over rode the auto box and told it what gear to use, but as is the way with the box it always reverts to Drive after 10-15 seconds...

Any thoughts on what this could be? Clutch slipping? gearbox issue? Or just a known characteristic of the gearbox when towing a heavy load?

No trailor this morning an no problems...

Thanks in advance
Brian
2012 4.4 V8 Westminster

Never had an issue towing a caravan circa 1500 kg. Might be worth trying to use sport selection on box next time. Could also be a trailer issue although your wife may have felt that. 2012 tdv8 Westminster arrived Jan 19 gone Dec 23

200 TDi discovery bobtail gone
RR classic v8 bobtail gone
300 tdi Discovery 3 dr gone

[quote="Westminster_Bri"]
Didn't happen so much when I over rode the auto box and told it what gear to use, but as is the way with the box it always reverts to Drive after 10-15 seconds...
/quote]

If you are using manual gear selection on the gearbox, then it shouldn't revert to auto on its own. When was the gearbox last serviced as IMO, with the smell you mention, low gearbox fluid level may be a possible cause. John
2008 Stornoway Grey 3.6 Tdv8 Vogue
2005 TD6 Java Black Vogue - Written off!!
GAP iiD BT
2003 Discovery TD5 Auto, Nanocom Evolution - gone to a new home!
MasseyFerguson 152 - No electronics!! - Sold

In drive the box reverts to auto after the 10-15 seconds if you don't select another gear, as OP says.


Westie,

Any chance you checked brakes for binding on the trailer and if it has an overrun brake it may have snatched a little. Particularly on the downhills. Cheers
Richard

(there are no such things as an ordinary FullFat, an ordinary cat or too many tools)
2011 TDV8 Vogue Santorini Black
Gap IIDBT

It was a hired trailer that went back this morning, but a binding brake on the trailer was something I had thought of...

Its the first time I have towed a car on trailer so don't really have any reference to know...

rjff wrote:

In drive the box reverts to auto after the 10-15 seconds if you don't select another gear, as OP says.

I've used mine to select lower gears for some engine braking and it has never done that. Maybe I've got a problem?  John
2008 Stornoway Grey 3.6 Tdv8 Vogue
2005 TD6 Java Black Vogue - Written off!!
GAP iiD BT
2003 Discovery TD5 Auto, Nanocom Evolution - gone to a new home!
MasseyFerguson 152 - No electronics!! - Sold

Ours is a 2003 model and I think it does the same. If the lever is moved over to 'Sport' mode and gear changes are made manually, I think that if the gear s are not changed within a certain time it does revert to Auto mode, although still in Sport mode.

(Could be wrong though!)

Normal Mode
Normal mode is automatically selected by the EAT ECU on power up. In this mode all automatic and adaptive modes are active. Normal mode uses gear shift and lock-up maps to allow vehicle operation which is a compromise between performance, fuel consumption and emissions. If the transmission is operated in sport or manual mode and the selector lever is moved to the 'D' position, normal mode is automatically resumed.

Sport Mode
The sport mode operates in high range only and provides enhanced acceleration and responsiveness. In sport mode the EAT ECU uses shift maps which allow the transmission to downshift more readily, hold gears for longer at higher engine speeds, and limits the transmission to 4th gear.
Sport mode is selected by moving the selector lever to the left into the 'M/S' position. When the sport mode is first selected, 'SPORT' is displayed in the message centre for 6 seconds and, if 5th gear is currently engaged, the EAT ECU downshifts to 4th.

Manual (Steptronic) Mode
Manual mode allows the transmission to operate as a semi-automatic 'Steptronic' unit. The driver can change up and down the five forward gears with the freedom of a manual transmission.
Shift maps are provided for manual mode to protect the engine at high engine speeds. The EAT ECU will automatically change up to a higher gear ratio to prevent engine overspeed and change down to a lower gear ratio to avoid engine labouring and stalling.

When kickdown is requested the EAT ECU downshifts at least 2 gears.

When the vehicle is stationary, to drive off the driver can select 1st gear in high range, or 1st, 2nd or 3rd gear in low range. Any other gear selection will be rejected by the EAT ECU.
When driving off, upshifts can be pre-selected by making + selections with the selector lever for the number of upshifts required. The EAT ECU then automatically performs a corresponding number of upshifts when the appropriate shift points are reached.
So,for example, when starting off in 1st gear, if three + selections are made in quick succession, the EAT ECU will automatically change up through the box to 4th gear as the vehicle accelerates, without any further selections being made.
In manual mode a low gear can be selected to provide engine braking for descending a slope without HDC or continuous use of the brake pedal. The driver can prepare for the end of the descent by moving the selector lever to D. The EAT ECUwill maintain the low gear and only revert to automatic shift control when the throttle is opened and vehicle speed increases.

Last edited by PaulTyrer on 20th Jan 2020 2:51pm. Edited 1 time in total

What mileage are you on?

I got this at about 120k. A gearbox megaflush sorted it.

PaulTyrer wrote:

. The EAT ECU will maintain the low gear and only revert to automatic shift control when the throttle is opened and vehicle speed increases.

That's probably why mine acted as I said as I was only using it for engine braking so didn't open the throttle until I was looking to increase speed at which point I would knock it into auto.  John
2008 Stornoway Grey 3.6 Tdv8 Vogue
2005 TD6 Java Black Vogue - Written off!!
GAP iiD BT
2003 Discovery TD5 Auto, Nanocom Evolution - gone to a new home!
MasseyFerguson 152 - No electronics!! - Sold

gilesharrison wrote:

What mileage are you on?

I got this at about 120k. A gearbox megaflush sorted it.

Mine was generally driving fine (not towing). Slight pulsing when towing horses, approx 2 tonnes. It gradually got worse, especially up hill. The car started to hunt for gears and there was a sense of clutch slipping.

I got it flushed. It took a bit of time to settle as the gearbox is adaptive. All great now. Cost about £350 all in but the sooner you do it, the less risk of long term damage to the gearbox or torque converter,

Search for 'gearbox judder'. There will be loads of info,

Change the oil and filter on the autobox, this problem should go away. Mine used to do this when going uphill, gearbox service sorted it.

Would strongly recommend seeking out a mega flush rather than just draining the oil pan and refilling. This only changes about half the transmission fluid. Mega flush removes all the old fluid, flushes decontaminantss out then refills with new fluid.

There's not that many places with the machines to do it, and it costs a bit more, but having had a Discovery 3 gearbox and torque converter ruined, I think it's worth doing it properly at the first sign or problems.