Unknown part on my LJ70

[Saffe]

Hello everyone!!

I was inspecting the front and back differential (front one has almost 1/4 turn of allowance when I turn on the axle ). Anyone know what parts are so worn out?? I can still use the 2/4 without problem I guess?

But my main question is this:
I found a weird part on my rear differential which is connectect with a long lever to the rear brake system. I think it triggers a valve when the rear wheels go from the ground (hope I explained it good ). But I am not sure?



Thanks guys

EDIT: This weekend I went offroad and got stuck. A friend of me told me to use the (hand)brake to gain more tracktion in the rear LSD. Is this true?

 

[grantw]

That's exactly what it is.

The valves full name is Load Sensing Load Sensing Proportioning Valve (LSPV for short)

There is a good explanation here.

http://www.toyotavantech.com/forum/...-Sensing-Proportioning-Valve-and-Bypass-Valve

 

[Saffe]

Thanks a lot! anyone could answer my other question?

 

[Julian T]

I was inspecting the front and back differential (front one has almost 1/4 turn of allowance when I turn on the axle ). Anyone know what parts are so worn out?? I can still use the 2/4 without problem I guess?

That could be wear between pinion and crown gears (but not a 1/4 turn I think) or play on the spider gears (but not a 1/4 turn I think). possibly you have a lot of little wear adding up to a large movement when you take up the slack, pinion/spider/CV's.
Does your vehicle have manual locking front wheel hubs?

EDIT: This weekend I went offroad and got stuck. A friend of me told me to use the (hand)brake to gain more titration in the rear LSD. Is this true?

You don't say how you got stuck so I am assuming you got cross axle'd and had one or more wheels in the air.
The reason for applying the handbrake is to increase drag on the wheel with least resistance so that the wheel with traction will then be able to drive you out to where both wheels have traction (remember handbrake works on both rear wheels equally), I have never driven a vehicle off road that has LSD so how applying the hand brake would help I don't know as hand brake has no effect on differential, I believe for a LSD to work you need to use the engines power.
As I have only ever used open diffs or diffs with diff locks I have always made an assessment of the situation and then used the option with the least chance of damaging my vehicle,
usually steering wheel angle will help in the event that you get a wheel in the air, steer down hill so the vehicle moves to where you may have all wheels on the ground and can thus move, then try the obstacle from a different angle.

Hope this helps you and all I can suggest is keep playing and practising and you will get the hang of how your vehicle works, hopefully without doing too much damage to your wallet.

 

[Saffe]

Thanks for your reply Julian! I do have manual locking hubs in front. When I put the gearbox in 4x4 and unlock the front hubs there is no play on the front shaft. When I put the gearbox in 2x4 and lock the front hubs there is play on the front shaft. Both cases with wheels on the ground. 1/4th turn is maybe a bit exaggerated but I am sure I can turn it 45°.


Below you can see me, my LJ70 and how I got stuck. I miscalculated the depth of that puddle hehe. So here both right wheels slipped, both wheels with the least traction, I think (I am sure about the rear one).





I ended up waiting one hour for salvation by a defender...

cheers!

 

[Julian T]

Looking good lol, when you engage 4H/4L then you need to lock the front wheel hubs, and when in 2H unlock them, you can lock then while in 4H if you anticipate needing 4x4, apologies if you already know that.
The play on the front prop shaft when in 2x4 is likely the gearing in the transfer box taking up slack and as long as you have no excessive play with everything locked in 4x4 I don't think you have anything to worry about.

Your vehicle looks like it could be testing the water level

 

[Saffe]

Looking good lol, when you engage 4H/4L then you need to lock the front wheel hubs, and when in 2H unlock them, you can lock then while in 4H if you anticipate needing 4x4, apologies if you already know that.
The play on the front prop shaft when in 2x4 is likely the gearing in the transfer box taking up slack and as long as you have no excessive play with everything locked in 4x4 I don't think you have anything to worry about.

Your vehicle looks like it could be testing the water level

Yes I already knew that, I mostly let the front hubs locked, I only use the car for offroad. I only engage 4x4 when I see I could use it
Here in Belgium we don't have much testing ground, so testing the water level will wait (also for the snorkle).

 

[Chas]

View attachment 19075



salvation by a defender...

cheers!

Oh! the shame.

 

[roscoFJ73]

In theory the handbrake load wil activate the LSD ,but landcruiser LSD are notoriously weak and even after rebuild you are struggling to notice the difference. I seem to remember the diff sends about 14% to the wheel when LSD is activated , enough to stop the wheel dragging through mud and sand , but not really enough to give added traction.

 

[Saffe]

Alraight, thanks!
I am thinking about weld the back differential so I have a permanent lock. Or sound this as a bad idea?

 

[grantw]

If you drive it on the road it's a very bad idea. If it's only a weekend warriors that gets trailered to where you play then you could get away with it


Sent from my iPhone using Tapatalk

 

[clivehorridge]

IMO weld-locking the rear would not be a good idea, even if it's dedicated off-roader.

On even the slightest steer, you'll be inducing slip on one or both rear wheels, at a time when you need as much traction as possible.

On my 80, I've made the mistake of having the rear diff locked almost all the time and trust me, it's got me into bother that could have been avoided, especially if you're on wet sideslope grass or mud, the back end will likely let go, which could be a disaster if the sideslope is steep, and there's no safety net.

JMHO

 

[mrdelmonti]

I know a few people that have driven cars will welded rear diffs every day and there's only a couple things to worry about really.

You will need to be more careful in the wet.

It will skip and squeak at low speed in cars parks etc.

Your turning circle will increase a little.

Rear tyre wear will increase.

Other than that you're good to go. If you're still unsure as to how it will effect everyday driving then go and have a look on some drifting forums for a bit more info.

 

[Nekros]

Hi Chas,
If you are going to open the rear diff to weld it you may as well install an air locker or a mechanical locker! the air lockers are usually more expensive so depending on the budget a mech. locker may be better. I have Mech. lockers front and rear in my 84 FJ45 and she will go most anywhere with only three wheels on the ground!.

 

[Saffe]

Thanks! Do you have an idea how much such mechanical locker cost?