Rear LSD

[Bat21]

I decided to test how 'limited' my rear LSD was today, my 80 is a early 92 JDM import.

After jacking one rear wheel off the ground, I selected D and let my foot off the brake. At this point the lifted wheel just span with very little attempt to move my truck. I engaged the center diff and tried again, sure enough she tried to drive off the jack, so at least I know the center diff works.

Is this the norm or should my truck have made an attempt to move without the center diff locked?

If this is normal, I suspect that I may be on the lookout for a UK spec rear axle. Are all rear diff ratios the same and can the locker be actuated via a simple on/off switch if wired correctly?

 

[joinerman]

Think auto & manuals have different ratio's

 

[Bat21]

I should have said "are all auto box rear diff ratios the same"?

 

[joinerman]

There you have me, i'm not sure.

 

[Andrew Prince]

Yes, I'm pretty sure they are. Ratios for autos are 4.1 as standard AFAIK, manuals are 3.7 or something like that.

 

[Bat21]

I have just found this.

As my coding is K295 it looks like mine has a 9.5" ring gear a ratio of 4.10 and 4 spiders.

Would someone with a UK spec Auto with rear diff lock have a look at their axle code, it is stamped on the VIN plate which is located in the engine bay passenger side bulkhead... go on get a torch and get out there now

Edit, just typed this reply before I saw Andrews post.

 

[Andrew Prince]

I think the axle code with lockers is K294 and without is K292. Someone with a torch will be along to confirm soon

 

[Paul_Humphreys]

The Axle codes will not be the same as one is locked and one is LSD. But from knowing people with LSD in Toyotas, they do not work after about 5 years!! One thing to try is full the diff with ATF and run it for a week. Drain and look at the colour. It will bring all the "muck" out. This sometimes sorts them. If not get a ARB locker!! Unless you can pick up a pair of uk spec axles!

Paul

 

[Bat21]

The Axle codes will not be the same as one is locked and one is LSD.

It is the last number in the axle code that denotes what sort of diff (open/LSD/Locker) you have

But from knowing people with LSD in Toyotas, they do not work after about 5 years!! One thing to try is full the diff with ATF and run it for a week. Drain and look at the colour. It will bring all the "muck" out. This sometimes sorts them. If not get a ARB locker!! Unless you can pick up a pair of uk spec axles!
Paul

Might be worth a try with the ATF trick.

The problem with the ARB lockers is they are air operated (I think) and it would mean sorting onboard air etc

I've just had a thought, my mate owns this place and is a guru rebuilding LSDs....

 

[Paul_Humphreys]

I have heard of them But thy the ATF route, but the cost of rebuilding would cost more than a ARB, but seeing as you know a man that can it might not.

Paul

 

[Andrew Prince]

Paul,
I would second Paul's advice - the LSD's are not great. There is a guy on LCCSA who spent a fair amount refurbing his LSD with OEM shims and plates and had it all assembled by a Toy expert and.... it still wasn't wonderful. After spending a decent chunk of cash on it, a month or 2 later the guy bought an OEM diff-lock and replaced the LSD.
So it's decision time - do you spend "some" money getting the LSD to function reasonably well, or do you put the money towards a locker?

My experience of looking out for replacement axles has been that they go for real money - because of the lockers, they are popular with people looking to build hardcore off-roaders so there is a bit of demand for them. Coupled with the cost, you have to consider the (possibly different) diff gearing, different brake size (presume your current axles/brakes are based on 15" rims?) and at the end of the day you're going to have an axle/diff/locker that is more than 12 years old and in unknown mechanical condition. Even a discounted Rubie diff-lock actuator will set you back the best part of £400 so getting your 2nd hand axle might not be the low cost solution if anything doesn't work as you'd hoped...

The ARB option is quite pricey, especially after you've thrown in the cost of the air system, fitting etc BUT at least you'll have a functioning new locker from day 1 and you'll not have the same risk of unknown additional cost to get the thing working. You could get your diff refurbished at the same time (solid pinion spacer etc) and you'd have a diff pretty much as good as new. The on-board air system could also be quite handy for pumping up tyres if you're charging around North Africa (as I know you do) and you could potentially run air tools off it if you added an air tank.

Cheers,