OEM LSD from 80 GXL into FJ62 front diff ? (1 Viewer)

[Yspen]

I can get a LSD from a 80 series GXL ( Aussie Spec ) for free . Is it possible to fit it to my front diff of my 60 ?

I have a Aussie Locker in the rear and it is staying there but a LSD in front will be better than open diff . ( that is what I think - correct me if I am wrong )

2: how long does the clutches of the LSD last before needing replacement ?

3: Does a LSD in front affect steering at speed ( eg 50 mph on a gravel road in 4wd ) ?


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[Joe_E]

Not positive if it will fit or not but I can answer the second two questions...
Don't forget you only use the LSD and front rear period when you have the hubs locked and are in 4WD.
Cruising around in general puts no wear on the diff in the front as the hubs are full float and just spin freely.

EDIT- read again and saw you were actually wanting to do 50 in 4WD. I would think it would only be affected if your wheels were spinning doing 50. It should handle normal I would think.

 

[Tapage]

1. The Toyota LSD aren't the best LSD that I know .. but I thought in the front axle ( in a part time Cruiser ) with appropiate Oil and use it will last after rebuild maybe a couple of years ..

 

[tonkota]

Does that 80 series have an 8"ring gear like the FJ80 and FZJ80?

 

[Yspen]

Does that 80 series have an 8"ring gear like the FJ80 and FZJ80?

\

In the front yes but the rear is 9,5" .
I want to ensure that the REAR LSD from the 80 will be able to be dropped into the front diff of my FJ62 before I strip the diff to fit it .

Like Joe_E says - they only take wear when 4WD engaged so they should last a good couple of years .

 

[RockDoc]

Here's a page about putting an 80 series rear e-locker in the front of a 60 series, I would assume that an LSD would be similarly compatible, and likely doesn't require the long spline inner axle.

Toyota 80 Series Electric Locking Differentials Retrofit for an FJ60

 

[maat]

you should have originally swapd the rear stock lsd diff center to the front and put the front + locker in the rear

 

[Yspen]

Another reason for me to believe that it should be an easy fit is the fact that the ARB locker for 80 rear and 60 front is the same part.

 

[Yspen]

I have decided to first recon the LSD

Open the LSD casing and you see this : ( not all the clutch plates in position)

Remove the clutch shims , clutch plates and gear and the spring retainer on the spring remains

Remove the spring retainer and the spring can be seen

Spring and spacer with spider gears removed

Spider gears in position

The Thrust washer on far left of the picture with the clutch shims and clutch plates as found in LSD ( JB measured them to see which ones are still in spec )

Note in Manual re Thrust washer

See how the spring "lifts" the gear

Report by a Friend Gerrit Loubser - a differential fundi

The clutch pack in a friction type LSD consists of steel disks (called "clutch plates" in Toyota-speak; item 41385 on your parts book diagram) splined to the side gears and plates lined with friction material (called "thrust washers" by Toy, item 41361 on your parts book diagram) that are keyed to the differential case. There are four "thrust washers" and three "clutch plates" on each side.

According to the 80 Series workshop manual (RM184E), the thrust washers only need to be replaced if they are below the thickness limit (1.97mm to 2.05mm), are unevenly worn or have bare metal showing through the friction lining.

In a similar way the clutch plates need to be inspected and replaced if worn out of spec (1.97mm to 2.03mm). The manual also states that the clutch plates must be replaced as well, if the adjacent thrust washer(s) is(are) replaced.

There are also adjusting shims that are fitted in between the clutch packs and the differential case halves. These are available in different thicknesses, but are used to adjust side gear backlash, which needs to be within spec (0.02mm to 0.24mm), so I can't really see how it would be possible to add shims and still end up with a diff set up to be within spec.

The Toyota LSD depends on spring force to ensure preload. This is provided by a little compression coil spring (item 414658 on the diagram) that is installed in between the side gears in such a manner as to force them apart. The free length of this spring should be 38.0mm to 39.3mm according to the manual. If one is after maximizing the LSD's preload within standard specs, I think one should look at this spring carefully and replace it if it is on the short side. In fact, it would be great if it were possible to "blueprint" the LSD by finding and fitting a new spring at the top end of the spec band...

The only other ways that I can imagine to improve the preload are to increase the stiffness of this spring (by replacing it with an item made out of thicker wire or with fewer turns or with stiffer end details) or to sandwich curstom made spacers between the spring and the two spring retainers (the spring retainers are mounted between the side gears and the spring and are pinned to the spider, see items 41387 and 41388 in your parts book diagram). The latter will increase the amount that the spring is compressed during installation, which will increase the amount of pre-existing spring force (a.k.a. preload) just as if the spring had a stiffer characteristic to start off with. Higher preload will make it more difficult to rotate the two wheels at different speeds, even when one is lifted.

In situations where both wheels have some grip, but where the grip levels differ, the side thrust generated by the meshing of the side gears with the pinions will add to the force compressing the clutch packs together and limiting the relative rotation speed differences between wheels. This will work regardless of the magnitude of the preload; i.e. even on a worn LSD this effect should be present.

 

[Yspen]

Update on LSD

Cost so far is minimal : less than SAR60 ( that is $ 8 ) per clutch plate that needs replacing - and 6 will be used .

My mechanic sent met this report :

OK, here it goes.
The spring length can not be adjusted or different lengths available.
The length are 38.0-39.3mm and yours Bennie measured 39.30mm.
There are two adjusting shims on each side of the sun gears. these are fitted by the manufacturer and can not be order for spares, if how ever you need to adjust the backlash on the four pinion gears, you get two shims available. BUT, only when you change the factory washer !!!!!
Shim 90564-54001 ( 0.20mm )
Shim 90564-54002 ( 0.25mm )
I ordered two sizes of clutch plates. ( 2.0mm and 2.05mm )
the old ones measured between 1.95 to 2.0mm.
Before i replaced the old ones with new ones, the pinion ( planetry ) gears back lash measured between 0.38mm - 0.35mm on the one side,
and 0.45mm - 0.30mm on the other.
Backlash must be between 0.02mm to 0.24mm.
So to get closer to 0.02mm, the thicker the plates must be "or the thicker the shims." ?
I first started with the clutch plates 2.05mm with 0.25mm shim, and got no backlash.

then went for the 0.20mm, and still no backlash.

If i would use the 2.0mm clutch plates, i would have guess that the 0.20mm shim would have work. But im wrong.

The only time you use the adjusting shims, are when you replace the washer ( marked 2.35mm in Bennie's pic no 6 ), as the note said, this washer can not be order as a spare part, when you do replace this washer, you need to fit 8 of the clutch plates, instead of the 6 its fitted with. Then only you use the shims

But to get closer to the 0.02mm i stick to the 2.05mm clutch plates.
By not using any shim with the 2.05mm clutch plates, i measured back lash of 0.08mm on the one side, and 0.10mm on the other.
This im happy with.

SO, keep in mind, the thicker the shim or the clutches, does not mean that the LSD will work better, they only get the backlash to the best possible spec to get it work better. ( meaning ) the less the backlash, the closer the sun gear ( side gear ) get to the spring retainer and the spring, pushing harder on the clutches. This meaning, pre-mature slipping of the LSD will be minimal.

 

[ginericLC]

Are you using the 80 gears, if so make sure you match the ring and pinion in the rear.

 

[Yspen]

The LSD is from 80 GXL FF rear . Is it going into 60 front . Same ring gear .

 

[Yspen]

The LSD is fitted ( as per thread heading )

Have not had an opportunity to test off road .
On road : locked the hubs and drove in 2wd - I could feet the car wanting to pull straight in a turn. Lifting the wheels I could not turn them by hand - locking better than I thought it would .

 

[Cruzerman]

In the US, the 60s came with 3.73 gears and the 80 with 4.11 gears. Of course, this may not apply to SA.

 

[Yspen]

took some picture during fitment

Checking backlash on the different clutches

Back in the pinion carrier , tooth pattern re-checked ready to be fitted in axle

 

[bikersmurf]

took some picture during fitment

Checking backlash on the different clutches

Back in the pinion carrier , tooth pattern re-checked ready to be fitted in axle

How did this LSD work out for you? I’m considering picking one up for my FF 40 series rear axle. I’m don’t wheel enough to justify a locking diff.

Alternatively, I could put it in the front I suppose. I’ve got 60 series gears in the back and haven’t swapped the front to be the same ratio.