Steepish inclines and 'faulty' brakes???

[Sue]

Okay, this is a bit of a long story so please bear with me..

Several months ago I was on a steep incline (for those that know LCMP it was the hill on Rally Circuit), I was in second low range and as I started on the wombat holes at the top of the hill I realised that I didn't have enough grunt to get over them. I stopped the car, depressed the clutch (I know... I know!) and went to put the car into first gear. The car started to go backwards at a rapid speed (my most scary moment ever!!).. and despite trying to throw it into a gear (I tried both reverse and first) to gain some control it wouldn't go into gear and the car slid backwards some hundred metres or more. How I didn't roll over the edge I will never know as I had absolutely no control whatsoever. My hubby assumed that I had done something wrong and decided to get into my car and drive it to the top. But exactly the same thing happened to him. I was only eventually only able to stop by applying the hand brake - even this was iffy as by that stage quite a lot of speed had built up and it took some time for the hand brake to have any effect. Hubby was able to get the car into reverse after some time to gain control - needless to say I drove the car out the other way.

Now I had at that time had some problems with the TC and ABS lights lighting up and was waiting for some parts to arrive at Land Rover so they could replace the sensor. I went and saw them and explained to them on several occasions what had happened and the service guy (I wasn't able to speak to a mechanic) said he was sure it was probably related to the sensor they were replacing. The sensor was replaced and I thought that all was well.

This afternoon I drove to am area near home and was driving up a dirt steepish (but not unreasonably so) hill. Once again I decided towards the top of the hill that I would stop the car and put it into first gear to get some more momentum. I stopped the car, put it in first gear and as I released the clutch I started going backwards (very fast). Several times I stopped and tried to find a gear any gear - at this stage reverse was what I wanted so I could back to the bottom and try again. I was unable to get the car into any gear so I stopped and put the car into low range then I was able to reverse down the hill. At this time it occurred to me that the gear stick that selects whether you are in high or low range was in the neutral position. I hadn't touched this gearstick for weeks. I did some experimenting then and on a couple of occasions when I was stopped on an incline (nose up) and I tried to put the car into first gear the high/low gear stick moved to neutral - which in effect won't allow any gears to be selected. Is this making sense??

Has anyone else had a similar problem with this before.. I am rapidly losing confidence in using the car offroad. (and that makes me sad).. :o

[chook73]

Okay, this is a bit of a long story so please bear with me..

Several months ago I was on a steep incline (for those that know LCMP it was the hill on Rally Circuit), I was in second low range and as I started on the wombat holes at the top of the hill I realised that I didn't have enough grunt to get over them. I stopped the car, depressed the clutch (I know... I know!) and went to put the car into first gear. The car started to go backwards at a rapid speed (my most scary moment ever!!).. and despite trying to throw it into a gear (I tried both reverse and first) to gain some control it wouldn't go into gear and the car slid backwards some hundred metres or more. How I didn't roll over the edge I will never know as I had absolutely no control whatsoever. My hubby assumed that I had done something wrong and decided to get into my car and drive it to the top. But exactly the same thing happened to him. I was only eventually only able to stop by applying the hand brake - even this was iffy as by that stage quite a lot of speed had built up and it took some time for the hand brake to have any effect. Hubby was able to get the car into reverse after some time to gain control - needless to say I drove the car out the other way.

Now I had at that time had some problems with the TC and ABS lights lighting up and was waiting for some parts to arrive at Land Rover so they could replace the sensor. I went and saw them and explained to them on several occasions what had happened and the service guy (I wasn't able to speak to a mechanic) said he was sure it was probably related to the sensor they were replacing. The sensor was replaced and I thought that all was well.

This afternoon I drove to am area near home and was driving up a dirt steepish (but not unreasonably so) hill. Once again I decided towards the top of the hill that I would stop the car and put it into first gear to get some more momentum. I stopped the car, put it in first gear and as I released the clutch I started going backwards (very fast). Several times I stopped and tried to find a gear any gear - at this stage reverse was what I wanted so I could back to the bottom and try again. I was unable to get the car into any gear so I stopped and put the car into low range then I was able to reverse down the hill. At this time it occurred to me that the gear stick that selects whether you are in high or low range was in the neutral position. I hadn't touched this gearstick for weeks. I did some experimenting then and on a couple of occasions when I was stopped on an incline (nose up) and I tried to put the car into first gear the high/low gear stick moved to neutral - which in effect won't allow any gears to be selected. Is this making sense??

Has anyone else had a similar problem with this before.. I am rapidly losing confidence in using the car offroad. (and that makes me sad).. :o

It sounds like you have a problem with the transfer case selector shaft, I had the same thing while it was under warranty and took it into landrover multiple times only to get "we cant seem to replicate the problem" to which I asked did they take it up a steep hill in low range? Of course they didnt, the workshop floor is flat.....:wasntme:

There is an adjustment that can be made by those "in the know" (to which I am not one) that allows the selector shaft to be held more firmly in place. Be careful however as too much adjustment will cause you not to be able to move it easily.

Once I finally found someone that knew how to adjust it (they are in Sydney) it was a five minute job and I have never looked back.

[Drover]

The transfer case gear select lever is sometimes difficult to get it to lock correctly into the new position.

It may require you to put the gear box into gear and while slightly releasing the clutch and then push the transfer case lever into the required position.

Regardless of the position of the transfer case, it will not inhibit you selecting gears, but will determine what if any drive you might get.

It sounds like the transfer case is either not being engaged correctly or just not engaging correctly.

[Sirocco]

I had the opposite problem with descents. The transfer box would jump out of gear sending us down the hill at a rapid rate with no engine braking.

This fault seems to have gone away, but I always get the passenger to hold the little lever in low, whilst I hover over the main (which has never jumped out). Not had the problem for a long time now, but yes, it is to do with the transfer box lever not engaging properly.

"dogging" it into gear works while you come off the clutch. Its fully manual so make sure its FIRMLY in, you don't have to be gentle with it.

G

[PAT303]

The best way to select low or high IMHO is to be moving at a snails pace and clunk the sucker in,if it clunks in you know it's in. Pat

[camel_landy]

The 'Official' line is:

Stop.
Leave the main gearbox in gear.
Move the transfer lever from Lo=>Hi or Hi=>Lo and maintain some pressure on the lever.
Bring the clutch up to the 'bite point' and then put the clutch back down again.
This simply aligns the gears in the transfer box so that when you put the clutch back down, the lever will shift that little bit further, fully engaging.

M

[Lagerfan]

The best way to select low or high IMHO is to be moving at a snails pace and clunk the sucker in,if it clunks in you know it's in. Pat

I'm with Pat, this gets me a much better success rate going into low. Coming out you go via neutral to get back to hi. I'm sure this method gets a mention in the manual somewhere.

[n plus one]

I'm with Pat, this gets me a much better success rate going into low. Coming out you go via neutral to get back to hi. I'm sure this method gets a mention in the manual somewhere.

Same - I always try to use rev matching and go hi - low (or vice versa) while still moving. I've only had the TC pop out of gear when I've done a lazy stationary change - CLs recommendation seems to work fine too, but I lore fee to keep things rolling along.

[BilboBoggles]

I reckon the transfer case lever is different on the PUMA than the other Land Rovers I've owned. for example on my TD5 the Lever moves forward and backwards, when forward it's in Low and when backwards it's in high, when central it's in Neutral. BUT on the 2 PUMA's I've owned the lever returns to the center. So when you push it forward it engages Low, but then the lever flops back to the Neutral position. It no longer seems a direct linkage, but some sort of floppy rubbery thing... Has anyone looked at how the PUMA high low range works, is it different to a older LT230 transfer case in the linkage area?

[n plus one]

I reckon the transfer case lever is different on the PUMA than the other Land Rovers I've owned. for example on my TD5 the Lever moves forward and backwards, when forward it's in Low and when backwards it's in high, when central it's in Neutral. BUT on the 2 PUMA's I've owned the lever returns to the center. So when you push it forward it engages Low, but then the lever flops back to the Neutral position. It no longer seems a direct linkage, but some sort of floppy rubbery thing... Has anyone looked at how the PUMA high low range works, is it different to a older LT230 transfer case in the linkage area?

FWIW, mine never returns to the neutral position - unless it hasn't correctly engaged.

[chook73]

I reckon the transfer case lever is different on the PUMA than the other Land Rovers I've owned. for example on my TD5 the Lever moves forward and backwards, when forward it's in Low and when backwards it's in high, when central it's in Neutral. BUT on the 2 PUMA's I've owned the lever returns to the center. So when you push it forward it engages Low, but then the lever flops back to the Neutral position. It no longer seems a direct linkage, but some sort of floppy rubbery thing... Has anyone looked at how the PUMA high low range works, is it different to a older LT230 transfer case in the linkage area?

This is the adjustment I was talking about in my first post, a five minute job and it stays in place.

[Ancient Mariner]

The adjustment is done with a 6mm allen key top rear of TC held in with Loctite
assuming same as earlier models

AM

[Blknight.aus]

first up the Tcase jumped out of gear. that usually happens when the linkages are fouled or not aligned correctly if you have selected your range properly and the lever has "locked" into position. normally it will happen as the transmission torques around in the tunnel as you power on and off. dealing with this has been talked about above.

the reason you couldnt stop.

you have ABS. unless all 4 wheels stop at the same time its designed to stop you from sliding giving you steerability, in the kind of situation you were in if you value locking up the wheels to try and skid to a halt over the steerability and traction that ABS retains for you (Static Friction VS dynamic friction) the only quick choice you have is to simply turn the ignition off. The killer here is that if you do this while panicing you may turn it too far and lock the steering wheel. As for the faulty sensor one sensor giving a dud reading doesnt stop the system from working but it DOES throw up the system fault light. The ABS will still work on the wheels that are giving good data. Of course if you've lost grip laterally, all bets are off, good luck.

The non legal solution is to replace the ABS master fuse with a Fuse and a remote switch that you can turn off on demand.

In the TD5's you could disable ABS/TC by rapidly pumping the brakes with the accessories on but the engine off. so if you were approaching a spot where you thought you would rather go it without the ABS/TC you had a way of disabling it prior to entering or attempting the obstacle. It might work with the ford but I doubt it.

Whats really going to kill you is trying to do the stall start in the normal as taught manner because, on paper, you cant stall the ford its got "stall control"


FWIW. The way I teach the Tcase change is.

If moving (and safe to do so)

bring the vehicle to a near halt, depress the clutch, select netural on the gearbox, select neutral then low (2 actions) on the Tcase, select the appropriate gear for the speed you are doing (usually first/reverse, occasionally second if you have picked up speed) maintain effort on the Tcase lever as you lift up on the clutch.

If stopped.

Select neutral on the gearbox, select Low on the Tcase, depress the clutch, put the main gear box in your desired gear, maintain effort on the tcase lever and ease up the clutch (release the applicable brake as requried)

[benji]

Someone please tell me if I'm wrong; but the pumas run the lt230q transfer case?

If this is the case, the locking mechanism holds it in low and high range with a ball detend, to which you can adjust the load on the spring which affects the amount it is held in. It was a very common complaint to landrover that the transfer case lever was hard to move, and I've read on the defender td5 landrover reduced the pressure on the spring - but maybe too much.

Sent from my GT-I9305T using AULRO mobile app

[Blknight.aus]

correct lt230Q, turned and tilted...

the turn might also account for the offset on the linkages that helps pop it out of low but thats just WAG and speculation, I havent had an issue with it in the ones I've driven.


IME the reason why the lever was hard to move in most cases was because the linkages had siezed up.

[Ancient Mariner]

The whole lot is a stick in a bucket of bolts:mad:.Why I converted to 2 separate sticks a bit agricultural but works :D

[Blknight.aus]

The whole lot is a stick in a bucket of bolts:mad:.Why I converted to 2 separate sticks a bit agricultural but works :D

Throw a couple of gears, bearings and a shaft or two and I believe you have the basic design spec bried for the landrover gearbox.

[Ancient Mariner]

You forgot the oil leaks:D

[Sue]

Thank you everyone!

I'll definitely go and get my mechanic to look at the transfer case selector shaft! I hope that is the problem and that I can get it sorted as I am now wary about any hill climbs which in time will ruin any sense of fun I get from a 4wd day out.. it's just not enjoyable wondering at which moment you're going to be careening downhill out of control.. :eek:

And just for the record, at no time was I trying to change the gears from low ot high and vice versa.. the lever has simply jumped out of place on it's own. I am wondering if that might have something to do with the angle the car is on as it's never happened on flat ground before.

And thank you Blacknight for the info.. it confirms that what I was trying to do what correct.. except it didn't really have an effect and I suspect that is because the front brakes I believe apply about 70% to the rear's 30% and with the cars nose in the air and all the pressure on the rear brakes they really didn't have a chance at halting the car quickly. Does that make sense or am I talking dribble?.. :)

[Samblers]

.. except it didn't really have an effect and I suspect that is because the front brakes I believe apply about 70% to the rear's 30% and with the cars nose in the air and all the pressure on the rear brakes they really didn't have a chance at halting the car quickly. Does that make sense or am I talking dribble?.. :)

If the centre diff is locked would this not tend to balance out the performance of the brakes anyway? Was the centre diff locked when you were doing all of this?

[Sue]

If the centre diff is locked would this not tend to balance out the performance of the brakes anyway? Was the centre diff locked when you were doing all of this?

I discussed this with my hubby.. as I was under the impression that it was but he insists that the front wheels were locked and sliding while the rear wheels were turning.. hence the jury is out on whether it was locked or not.

It was not locked yesterday, there was no need to lock it as the track was not difficult or rough etc. :)

[wrinklearthur]

A couple of things.
Was the center diff lock engaged?

I discussed this with my hubby.. as I was under the impression that it was but he insists that the front wheels were locked and sliding while the rear wheels were turning.. hence the jury is out on whether it was locked or not.
It was not locked yesterday, there was no need to lock it as the track was not difficult or rough etc.
If the track is steep enough to warrant the lower gears or low range being used, then do lock the center diff as well.

ABS has caused a bit of grief with a few vehicle's I have heard about that have been reversing down the steep stuff and the ABS does it's thing.

My purposed fix, but I haven't done this yet, so I invite comment about this.

Find the wire going to the center diff lock light and feed it to the coil of a normally closed relay with the contacts cut into the ABS wire coming from the fuse box.
So CDL light on, relay opens and there is no ABS as the power to ABS is cut by the opening of those normally closed relay contacts.
.

[n plus one]

It was not locked yesterday, there was no need to lock it as the track was not difficult or rough etc. :)

As per the above, this is not a good idea - if it's steep enough for low range the lock your centre diff. With the exception of steep driveway/trailer manoeuvring the best way to think of the centre diff lock is like a 2wd Jap truck's lever - I.e. If they'd be in 4wd, you should have your centre diff locked.

Beyond the drivability issues that not locking can create, it will also reduce your TC life dramatically....

Edit: not saying this is the main issue you're having - but it's relevant to your first 'incident'.

[Blknight.aus]

Thank you everyone!

I'll definitely go and get my mechanic to look at the transfer case selector shaft! I hope that is the problem and that I can get it sorted as I am now wary about any hill climbs which in time will ruin any sense of fun I get from a 4wd day out.. it's just not enjoyable wondering at which moment you're going to be careening downhill out of control.. :eek:

And just for the record, at no time was I trying to change the gears from low ot high and vice versa.. the lever has simply jumped out of place on it's own. I am wondering if that might have something to do with the angle the car is on as it's never happened on flat ground before.

And thank you Blacknight for the info.. it confirms that what I was trying to do what correct.. except it didn't really have an effect and I suspect that is because the front brakes I believe apply about 70% to the rear's 30% and with the cars nose in the air and all the pressure on the rear brakes they really didn't have a chance at halting the car quickly. Does that make sense or am I talking dribble?.. :)


no you're about on the money.

you do need to be careful with the CDL selection, its also biased towards a centeral position (not designed that way but they do tend to do it because of the layout of the linkages and the boots on the lever) if its jumping out of range then its also just as likely to throw out of CDL when you're not expecting it.

The brake bias distribution problem VS weight distribution on hills is well known and most real 4x4's get around it by transferring brake torque through the driveline. (in part this is why when I teach beginner off road driving that for each obstacle you must pick the gear you need before you get there and just before you enter the obstacle you hook your clutch foot under the clutch)

[mools]

A couple of things.
Was the center diff lock engaged?

If the track is steep enough to warrant the lower gears or low range being used, then do lock the center diff as well.

ABS has caused a bit of grief with a few vehicle's I have heard about that have been reversing down the steep stuff and the ABS does it's thing.

My purposed fix, but I haven't done this yet, so I invite comment about this.

Find the wire going to the center diff lock light and feed it to the coil of a normally closed relay with the contacts cut into the ABS wire coming from the fuse box.
So CDL light on, relay opens and there is no ABS as the power to ABS is cut by the opening of those normally closed relay contacts.
.

My understanding is that you won't have TC if you disable ABS, which will probably mean you'll find yourself reversing back down more slopes.

Personally I've never really had an issue with reversing down and ABS. Reverse in low range being pretty slow, if you need to go slower just try not to lock up the brakes.

I have a TD5 so can choose to disengage TC if required, as BLK night said, although I very rarely do so.


Ian.

[n plus one]

I think there's a risk that two seperate issues might be being conflated - might be better to try and isolate the issues in order to figure out what's going on. i suggest you get the 'jumping out if gear' issue sorted and then go and have another play with the brakes. This way you'll be able to determine if the brake issue was just related to the vehicle 'getting away from you' (due to the loss of an engaged gear) or whether something else is going on (and if something else is going on you'll have your gears to control it in any event).

Without trying to sound like a know it all, my Puma has done plenty of loose steep stuff with stops involved (for a number if reasons, including my bad driving practices!) and I've never had the kind of braking issue you've described - which makes me think you've either a) got a genuine issue with your brakes/ABS or b) it may be the initial loss of control leading to a speed condition that is uncontrollable while travelling in reverse with a (possibly (and not surprisingly) panicky) braking response.

Just some thoughts.

[wrinklearthur]

My understanding is that you won't have TC if you disable ABS, which will probably mean you'll find yourself reversing back down more slopes. -------

Thanks Ian

I must admit that the Traction Control ( TC ) function in the later Land Rovers was forgotten when I made the suggestion to disable the ABS, as I have only ABS on my model, a 1997 SE7 Discovery.

Does the TC function safely in reverse in a vehicle fitted with Traction Control?

If in TC equipped Land Rovers, that relay that I proposed, is switched not by the CDL light, but by the reverse light switch instead, would reversing then be safer with both TC and the ABS off?
.

[Blknight.aus]

TC and ABS work both forwards and backwards.

ABS can cause an unwanted gain in speed on descents because of the following.

1 wheel locks, the brakes release on that wheel. In theory this means that it regains grip and the brakes reapply effectively. In some circumstances the loss of braking transfers the braking effort to other wheels which are right on the margin of traction, these now slip on the surface and lock up causing ABS to release the brakes on them. This cycle repeats and compounds as you gain speed on the loose surface. (its 1/2 of the same principle as why it takes an ABS vehicle longer distance to stop on a pea gravel road than a non ABS vehicle with the brakes locked)

TC shouldnt come into effect when executing a stall recovery as you are descending using the engine to retard wheel spin not applying power.

and yes, TC, ABS,HDC, Hill start Assist (some versions) and a lot of other brake related acronyms all rely on the same box of hudroelctramechanical mayhem to work, pulling the master fuse for it (or the fuses related to the controlling ecu/sensors power supply) fits into the catagory of "Bad Idea, if you wanted to drive like you didnt have it whyd you buy a vehicle with it?"

[Sue]

A couple of things.
Was the center diff lock engaged?

If the track is steep enough to warrant the lower gears or low range being used, then do lock the center diff as well.

ABS has caused a bit of grief with a few vehicle's I have heard about that have been reversing down the steep stuff and the ABS does it's thing.
.

And that makes perfect sense, except this track was not steep enough to warrant using low range. I was in normal high and only changed to low to reverse down once I realised I had no gears. :)

The centre diff lock seems to often jump out of place, so when it is needed it is always applied - however the car seems to just pop it out quite often. I know I'm not the only person to have this problem as I've had a few people tell me that theirs does the same thing also. So as for the original question that was asked about the first incident.. yes the centre diff lock was applied.. but I'm suspecting it dropped out on the way up the hill. :)




you do need to be careful with the CDL selection, its also biased towards a centeral position (not designed that way but they do tend to do it because of the layout of the linkages and the boots on the lever) if its jumping out of range then its also just as likely to throw out of CDL when you're not expecting it.



Yep that's exactly what it is doing.

[Sue]

TC and ABS work both forwards and backwards.

ABS can cause an unwanted gain in speed on descents because of the following.

1 wheel locks, the brakes release on that wheel. In theory this means that it regains grip and the brakes reapply effectively. In some circumstances the loss of braking transfers the braking effort to other wheels which are right on the margin of traction, these now slip on the surface and lock up causing ABS to release the brakes on them. This cycle repeats and compounds as you gain speed on the loose surface. (its 1/2 of the same principle as why it takes an ABS vehicle longer distance to stop on a pea gravel road than a non ABS vehicle with the brakes locked)



That is actually a very scary thought! :eek::eek::eek: