Heavy steering.

[scooby]

Just wondering if anyone has any advice for a recent development on my Wife's 120. Last week I suddenly discovered that the steering was quite heavy at the extent of the left and right hand turn. If you turn to full lock either way, then let go of the wheel, the steering dosn't really straighten even a small amount as you drive forward. There are no vibrations or wobbles. I'm suspecting the power steering pump, but just wondered if anyone has any other suggestions, or has experienced similar? I have checked the oil level and that's O.K. and I think I have ascertained that the vehicle is in 2wd although, probably, because of my age, I found the user manual not terribly helpful.

I did post this query initially in the 100 Series section of this Forum in error but just to be sure, the details of the vehicle are as shown below in a part of the V5. Thanks in advance for any help and/or advice that anyone can give.

 

[Trevor]

It may well be that the UJ is corroded and sticking in the column itself. If you look at where the column joins the steering rack and follow it up you will see the UJ. It's this section that is known for this, a royal pain in the proverbial to change too and you must ensure you are spline perfect in refitting.

It's very important that the position of the steering wheel and steering rack is maintained even when the old part is removed, you open up a whole can of worms to recalibrate the steering position if you are a spline or two out. Best to apply the steering lock and mark the steering rack with the position of the steering shaft before you start.

Roughtrax supply a Genuine Toyota replacement for this HERE

 

[Shayne]

Old school permanent 4x4 worked the way you describe , and wore through tyres like they were made of chocolate,

I'm fairly sure yours doesn't .

I'm not familiar with the 120 series but i think it very likely you have permanent 4x4 with limited slip differential so drive goes to the wheel with the least traction allowing wheels to run at different speeds while cornering .

The 2 axle X button is your centre diff and will indeed make cornering more difficult hence its for situations when you need more grip .

My 80 series is modified so i can use the low gear option without engaging the centre diff which can be useful when say trying to maneuver with a heavy trailer and I'd not be surprised to learn the more modern 120 gives that option as standard .

I have no idea about the steering but i will mention again lower ball joints .

 

[GeekOKent]

How do you mean 2wd? Looking at the EPC for GKAEYW - it's the base 120, unless your transfer case is busted or someone added free wheeling hubs along the way, you are permanent 4wd.

For the power steering, I guess you did the basic checks etc already, flush the fluid make sure no leaks or air etc ? Also, I guess you are raising this as an issue because it's changed behaviour recently ?

 

[scooby]

It may well be the the UJ corroded and sticking in the column itself. If you look at where the column joins the steering rack and follow it up you will see the UJ. It's this section that is known for this, a royal pain in the proverbial to change too and you must ensure you are spline perfect in refitting.

It's very important that the position of the steering wheel and steering rack is maintained even when the old part is removed, you open up a whole can of worms to recalibrate the steering position if you are a spline or two out. Best to apply the steering lock and mark the steering rack with the position of the steering shaft before you start.

Roughtrax supply a Genuine Toyota replacement for this HERE

Thank you very much for that detailed info. @Trevor. It is very much appreciated. The vehicle is actually booked in for it's MOT next Monday and they have said that they will investigate the steering issue but if you don't mind I will show them your comments (incognito of course) because it sounds like a possible cause of the problem. And thank you for the link for the shaft, again many thanks for your help.

 

[scooby]

Old school permanent 4x4 worked the way you describe , and wore through tyres like they were made of chocolate,

I'm fairly sure yours doesn't .

I'm not familiar with the 120 series but i think it very likely you have permanent 4x4 with limited slip differential so drive goes to the wheel with the least traction allowing wheels to run at different speeds while cornering .

The 2 axle X button is your centre diff and will indeed make cornering more difficult hence its for situations when you need more grip .

My 80 series is modified so i can use the low gear option without engaging the centre diff which can be useful when say trying to maneuver with a heavy trailer and I'd not be surprised to learn the more modern 120 gives that option as standard .

I have no idea about the steering but i will mention again lower ball joints .

Thank you again @Shayne, I really do appreciate the time that you have spent trying to help me. I had wondered about limited slip diffs. but TBH I have no experience of those. The diffs on tractors are normal diffs with the drive going to the half shaft with the least resistance unless you lock the diff. up in which case steering, depending on what surface you are on, can be either challenging or completely useless because both half shafts, and hence both wheels on the relevant axle will turn at exactly the same speed.

 

[scooby]

How do you mean 2wd? Looking at the EPC for GKAEYW - it's the base 120, unless your transfer case is busted or someone added free wheeling hubs along the way, you are permanent 4wd.

For the power steering, I guess you did the basic checks etc already, flush the fluid make sure no leaks or air etc ? Also, I guess you are raising this as an issue because it's changed behaviour recently ?

Thank you very much for your help @GeekOKent. It is very much appreciated.
I have always assumed that the vehicle is in 2wd unless steps are taken to change that. There are no free wheeling hubs fitted. When you say that the vehicle is in permanent 4wd do you mean that it has permanent drive to both axles because there is a centre coupling that sends drive to both the front and rear axles ? And yes, it has changed behaviour recently.

 

[Shayne]

Go to your nearest bowling green and do some figure of 8 doughnuts and you will see the evidence that all four wheels spin .

Remember the Audi Quattro won just about every race it qualified to enter into when it was released in 1980 ?

It was permanent 4x4 , no difflocks that no other car could compete with . Subaru is another example .

Because your Landcruiser can get to places no Subaru will ever see you have a centre difflock for those occasions when all wheel drive is not quite enough .

 

[scooby]

Sorry @Shayne but I think we disagree about all this. Firstly, I don't need to go to my nearest bowling green, I can ride round our fields if I want to. I have owned a few Land Rovers, Series 2, 2A and 3. And when you put those in "4wd" it just sends the drive to the front axle in addition to sending it to the rear axle as normal. Yes, there is a high and low option on the box but that affects the speed of the drive shaft out of the gearbox. Same with the Subaru pickup that I owned. Putting it in "4wd" meant that drive was sent to the front axle as well as the rear.

But once those front axles have drive they behave in exactly the same was as the rear axle i.e. it is only 2wd in each case. If you want true 4wd then there has to be a mechanism to lock the differentials in each of the axles so that each half shaft is powered and of course at the same speed. But. if you do this, which we can do on our tractors, the wheels are powered at the same speed which means that steering is virtually impossible unless the vehicle is on slippery/frosty/muddy ground.
When you steer a vehicle in a straight line the wheels revolve at the same speed. As soon as you turn the steering mechanism to go in any direction other than straight ahead the wheels on both axles, whether they are being driven or not, revolve at different speeds.

 

[Trevor]

The LC4 and LC5 variants have ATRAC, IIRC under 2K revs and ATRAC pulses the ABS on the slipping wheel on an axle to try and send power to the other wheel. Worked well in some muddy conditions at Lincomb but not great in really thick claggy stuff.

Engage centre diff for slippy or snow conditions to ensure power gets to both axles. Wet grass on a slope will defeat anything regardless of brand

 

[Shayne]

Off-road vehicle four-wheel drive systems explained - Farmers Weekly

Flick through the marketing bumf for a new four-wheel-drive vehicle and it will generally give little indication as to the type of off-road running gear

www.fwi.co.uk

 

[karl2000]

There were a few 120s that were part time 4wd drive, but yours aint one of them! Theres a thread on here somewhere....

 

[scooby]

The LC4 and LC5 variants have ATRAC, IIRC under 2K revs and ATRAC pulses the ABS on the slipping wheel on an axle to try and send power to the other wheel. Worked well in some muddy conditions at Lincomb but not great in really thick claggy stuff.

Engage centre diff for slippy or snow conditions to ensure power gets to both axles. Wet grass on a slope will defeat anything regardless of brand

Thank you @Trevor, that was very helpful. I hadn't realised this sort of technology existed.

 

[scooby]

http://[URL]https://www.fwi.co.uk/machinery/4x4s/off-road-vehicle-four-wheel-drive-systems-explained

[/URL]

Thanks again @Shayne, that article has taught me a lot. I don't take the Farmers Weekly any more and so I didn't see it. The whole "4wd" system in road vehicles can be quite a sophisticated matter so it seems. My experience with 4wd drive, as you will have guessed, is with tractors etc. and works by being able to physically lock the diff. on an axle so that both half shafts on that particular axle have equal power going through them.

 

[scooby]

There were a few 120s that were part time 4wd drive, but yours aint one of them! Theres a thread on here somewhere....

Thank you @karl2000. So are you able to tell me, in detail, what the drive system is on our Cruiser please ?

 

[karl2000]

Full time 4wd

 

[Shayne]

It quite astonishing the UK spec Landcruiser 80 didn't get a mention in that 4x4 explained link with it being permanent 4wd , a hi/low box and having 3 optional difflocks .

I've driven them old tractors with the blunt mechanical 4x4 lever which was only good for reversing yourself out of a ditch or bog , with little wheels on the front and huge wheel on the back the system really wasn't any good for anything else .

 

[scooby]

Full time 4wd

Thank you @karl2000. I never knew that. But can you tell me what the switch with the image of front and rear axles that is positioned to the right of the heated seat switches does and the LNH lever does please ? I have always assumed that the switch powers up the drive to the front axle and the lever gives a choice of normal or low speed out of the gearbox.

 

[scooby]

It quite astonishing the UK spec Landcruiser 80 didn't get a mention in that 4x4 explained link with it being permanent 4wd , a hi/low box and having 3 optional difflocks .

I've driven them old tractors with the blunt mechanical 4x4 lever which was only good for reversing yourself out of a ditch or bog , with little wheels on the front and huge wheel on the back the system really wasn't any good for anything else .

If you start to reverse a tractor out of a ditch or bog the first thing you will do is fill the treads with whatever you are stuck in. Tractor tyres are treaded in such a way that they are self-sleaning when going forward and are exceptionally useful when ploughing or other jobs that requires extra traction because of ground conditions. I have never seen a tractor with a lever for engaging the diff. lock. It is always a pedal which you usually engage wit the right foot. One thing that you shouldn't do of course is to stamp on the diff. lock pedal when one wheel is spinning and the other is stationary. That's one way to chew a diff. up good and proper.

 

[Trevor]

Thank you @karl2000. I never knew that. But can you tell me what the switch with the image of front and rear axles that is positioned to the right of the heated seat switches does and the LNH lever does please ? I have always assumed that the switch powers up the drive to the front axle and the lever gives a choice of normal or low speed out of the gearbox.

View attachment 336770

That is your centre diff lock button. Only ever use on loose surfaces but good practice to "exercise" every now and again to keep the actuator from seizing.