Thread: D4 Rollover

Originally Posted by Jimmy Salsa

They stall quite easily when they get out of shape and the traction control can't work out what the hell is going on. It's one of LR's crazy engine protection mechanisms.

Could be to stop power going to wheels in certain scenarios. like pushing clutch on a manual trans to stop tipping backwards rollover. There have been times where I have had to select neutral quickly in my auto to stop front going over the back.

Originally Posted by Tombie

The engine does NOT shut down if rolling back... what has happened is in low range the box can lock up the TC in any gear and if it comes to a sudden stop can stall (just like any auto - take an Auto car out, speed up and anchor the brakes full bore - it can stall).

i did not know this. thanks for posting.



glad to hear mark is ok. im just waiting for the video to load

Originally Posted by SBD4

Glad you came out of it OK Mark - thank god for that tree! Scary stuff.

Do you remember how the brakes felt under foot? Just wondering if perhaps you lost brake boost at some point which would have made it very hard to stop. I understand that the brakes are designed to maintain boost pressure in the event that the engine stops. Not sure how many pumps that gives you though.

My experience of D3 brakes without engine running is they are very good, even after several hours, the vacuum is still held, (not sure how many brake applications it allows, I only use one), as I have a steep driveway and normally leave the car out there in summer and then just roll it in later, they are heavy to operate, as is the steering, but I've never had a problem.

In theory going backwards the braking would be slightly less efficient, due to being biased towards the front, on the other hand (I'm sounding like an economist now) going uphill would've avoided the classic disaster of a loose object rolling under the brake pedal.

I said above "the vacuum is still held", but obviously it has no vacuum, I meant it still has good brake force so that shows the master/slave piston ratio/sizing is correct.

Originally Posted by Jimmy Salsa

They stall quite easily when they get out of shape and the traction control can't work out what the hell is going on. It's one of LR's crazy engine protection mechanisms.

Care to provide some information to back that comment up...

Because it’s rubbish....

Default when ‘overwhelmed’ is to back off TC not turn off or stall.

As far as I can tell they only pulse the brakes and do not retard power and revs like Japanese 4wd's do. It's one of Land Rovers advantages in ETC over their Japanese rivals. Cheers

Originally Posted by Tombie

Care to provide some information to back that comment up...

Because it’s rubbish....

Default when ‘overwhelmed’ is to back off TC not turn off or stall.

What other information would you like other than the facts presented?

I'm not postulating or hypothesising about what happens with regards to the motor staling. I'm simply reporting to you my personal experience over many years of fairly rough offroading situations.

We have had this happen to us on many occasions. Most notably in more extreme offroading situations where traction control is struggling. The motor shuts down and stalls.

Admittedly we've probably tortured our vehicle more than most offroad and often pushed it past the limits that many others are happy to go to but we've certainly experienced the engine stalling many times.

I'm not sure what else you want to hear to convince you that it can and does happen on these vehicles.

I've attached a clip of it for you.

You can see that the traction control is chucking a hissy fit and isn't working properly. Engine stalls.

You ARE postulating as you have said the engine stalls as a protective measure which unless you have LR technical proof, is an assumption by you as to why it’s happening.

That stalled because it was in TC lock up and came to an abrupt halt...

It’s also a RR not a D4... different system and software.

Good video though!