Fulltime tcase / part time diffs.

[midnight]

Can you use a fulltime 4wd tcase in a 4wd that nevre had one?

Say a Rangie tcase, on say a Hilux.

Would the diffs be up to it? Or would they get transmission windup (???)

[bad_religion_au]

yep, although you'll have to keep your front hubs locked, or switch them out for driveplates.

[Beastmavster]

No harm in having part time diffs with a full time tcase. Just means the front output shaft is always turning but there's no drive to the wheels.


It's like running with the hubs unlocked and in 4wd on a normal tcase. Completely harmless.



It's only when you have drive to both ends potentially at different speeds (cornering, slight differences of tyre size) that you have driveline wind up.




You will get slightly worse fuel economy and slightly more bearing wear, but other than that there's no consequence.

[Daisy]

No harm in having part time diffs with a full time tcase. Just means the front output shaft is always turning but there's no drive to the wheels.


It's like running with the hubs unlocked and in 4wd on a normal tcase. Completely harmless.



It's only when you have drive to both ends potentially at different speeds (cornering, slight differences of tyre size) that you have driveline wind up.




You will get slightly worse fuel economy and slightly more bearing wear, but other than that there's no consequence.

full time t/case will probalby have a centre diff lock... if you run part time diffs.. the centre diff will slip giving all drive to the front via the unlocked hubs.

solution.. keep centre diff engaged. or get a part time kit to suit your t/case.

transmission wind up will happen if you lock the hubs with the centre diff engaged.

few ways to do it...

drive with centre diff on... and the hubs unlocked = 2wd - road use

drive with centre diff off and hubs on = 4wd with slippage between diffs - general 4x4 use (dirt roads etc)

drive with centre diff on and hubs on = full time 4x4 no slip between front and rear diffs - moderate to heavy 4x4 use (rocks, sand etc maximum traction)

Hope that helps.

[tweak'e]

mm.....to put it simplier.....if you fit a surf tranfer case into a hilux, simply keep the diffs locked and you will have part time 4x4 just like the surf and when you lock the centre diff you will have full time 4x4.

if you really want to, unlock the hubs and have rear wheel drive only, but what the point of that.....thats what you allready had before the change of transfer case.

[bad_religion_au]

disagree with the "no harm done" by running the front diff without the hubs locked. the end of the stub shaft isn't supported and can chew out the spindle.

[chimpboy]

If the "full time transfer case" has a diff, then lock the front diffs and drive that way all the time. But don't LOCK the centre diff while on hard surfaces.

You can't get wind-up if you have a differential; that's basically what a differential is for.

[midnight]

I think i should have explained a bit better.

I wish to make an AWD (Full time 4wd) 4wd for on road rallies and hill climbs.

But I want it all legal, which means diff swaps are out.


I dont want to be switching from 2---> 4wd all the time so the next best thing is AWD (Full time 4wd).

I was thinking of using a awd car setup, but that would involve swapping the front to IFS (Ugh ) which is out.


What about the Skyline GT-R. It has a tcase in it doesnt it?
Its hydraulically controlled, so that it detects wheel slip, and pushes a ram which engages the front drive.

Now does the Skyline have a seperate front diff? Or does it have the diff in the gearbox?

Yes the stuff will be customly made, but it wont be wildy custom.

[chimpboy]

No harm in having part time diffs with a full time tcase. Just means the front output shaft is always turning but there's no drive to the wheels.


It's like running with the hubs unlocked and in 4wd on a normal tcase. Completely harmless.



It's only when you have drive to both ends potentially at different speeds (cornering, slight differences of tyre size) that you have driveline wind up.

You will get slightly worse fuel economy and slightly more bearing wear, but other than that there's no consequence.

full time t/case will probalby have a centre diff lock... if you run part time diffs.. the centre diff will slip giving all drive to the front via the unlocked hubs.

solution.. keep centre diff engaged. or get a part time kit to suit your t/case.

transmission wind up will happen if you lock the hubs with the centre diff engaged.

few ways to do it...

drive with centre diff on... and the hubs unlocked = 2wd - road use

drive with centre diff off and hubs on = 4wd with slippage between diffs - general 4x4 use (dirt roads etc)

drive with centre diff on and hubs on = full time 4x4 no slip between front and rear diffs - moderate to heavy 4x4 use (rocks, sand etc maximum traction)

Hope that helps.

I think it would be clearer if you said "drive with centre diff LOCKED" or "centre diff UNLOCKED" rather than centre diff on/off. You can't really turn a diff on or off.

Really, if you have a centre diff that can be locked or unlocked, you should leave your front hubs engaged full-time.

Then, with the centre diff unlocked, you have an AWD vehicle, no risk of windup because there are three differentials allowing slip (front, rear, centre).

With the centre diff locked, you have a 4WD vehicle, with a risk of windup in the transmission, so no driving on hard surfaces this way.

[chimpboy]

I think i should have explained a bit better.

I wish to make an AWD (Full time 4wd) 4wd for on road rallies and hill climbs.

But I want it all legal, which means diff swaps are out.


I dont want to be switching from 2---> 4wd all the time so the next best thing is AWD (Full time 4wd).

I was thinking of using a awd car setup, but that would involve swapping the front to IFS (Ugh ) which is out.


What about the Skyline GT-R. It has a tcase in it doesnt it?
Its hydraulically controlled, so that it detects wheel slip, and pushes a ram which engages the front drive.

Now does the Skyline have a seperate front diff? Or does it have the diff in the gearbox?

Yes the stuff will be customly made, but it wont be wildy custom.

All you want is a centre diff on the t'case that can be locked or unlocked, this gets you AWD or can be locked for proper 4WD.

Your $60 solution is to replace your transfer case with one from a lada niva, a divorced transfer with a lockable centre diff.

Jason

[largesuzy]

I think i should have explained a bit better.

I wish to make an AWD (Full time 4wd) 4wd for on road rallies and hill climbs.

But I want it all legal, which means diff swaps are out.


I dont want to be switching from 2---> 4wd all the time so the next best thing is AWD (Full time 4wd).

I was thinking of using a awd car setup, but that would involve swapping the front to IFS (Ugh ) which is out.


What about the Skyline GT-R. It has a tcase in it doesnt it?
Its hydraulically controlled, so that it detects wheel slip, and pushes a ram which engages the front drive.

Now does the Skyline have a seperate front diff? Or does it have the diff in the gearbox?

Yes the stuff will be customly made, but it wont be wildy custom.

the skylines have electronic clutches in the transfercse to allow slipage thats why you can pull out a fuse and make it 2wd

[midnight]

Thanks a heaps for that chimboy. Lada's arent much bigger (if any) then a Sierra anyways. (Oops, that wasnt meant to be told just yet )

I thought they had a hydro ram that pushes one clutch against another clutch thus providing 4wd @ Matt.

[midnight]

So the Lada tcase is fulltime 4wd, just not locked all the time which will allow slipage?

How much power and torque can they take? I intend to give this thing a hiding..........(Especially with 5000rpm+ starts)

[largesuzy]

Thanks a heaps for that chimboy. Lada's arent much bigger (if any) then a Sierra anyways. (Oops, that wasnt meant to be told just yet )

I thought they had a hydro ram that pushes one clutch against another clutch thus providing 4wd @ Matt.

i should read it better i meant the gts4 box but they are basically the same except for the clutches

[chimpboy]

So the Lada tcase is fulltime 4wd, just not locked all the time which will allow slipage?

How much power and torque can they take? I intend to give this thing a hiding..........(Especially with 5000rpm+ starts)

The lada transfer cases are reputed to be very hard to break. Apparently swapping in some non-russian bearings is a good idea. I have heard of people running them in pretty heavy rigs with no problems. But who can say? You could get one to experiment with pretty cheap.

And yes, they have a centre diff so there are two sticks: high/low, and centre diff locked/open.

When the centre diff is open you have AWD.

I've never used one, I just looked at them closely for a project once.... it never happened though.

nb the lada transfer case has a 1.2:1 high ratio, which means you get 20% lower gearing even in high range. Which either means you are going to have a lousy top end, or you are going to have gearing set up for 20% bigger tyres.

[midnight]

Thanks once again chimpboy.

That 20% lower ratio will be good, as it will provide slightly better acceleration.

Some non russian bearings?
What size are the flanges on it?
Are the diffs offset? Or centred?

[chimpboy]

Thanks once again chimpboy.

That 20% lower ratio will be good, as it will provide slightly better acceleration.

Some non russian bearings?
What size are the flanges on it?
Are the diffs offset? Or centred?

I think they are offset to the wrong side for a zuk, but I have heard of people running the transfer case rotated with no problems.

The whole service manual is here: http://www.lsdonline.co.za/ladaniva/

http://www.lsdonline.co.za/ladaniva/manuals.php

Might be suitable, might not... worth a look I reckon...

[Beastmavster]

The output would be your biggest problem.


Lada tcases are tough - the issue with them seems to be the coupler between the tcase and the gearbox whcih is made of rubber and a bastard to get balancing right. For your application thats a non issue.


20% reduction is for high range for a normal 1:1 high. If you're putting it into a sierra which already has pretty short reduction you will probably go taller about 20% instead - not really suited to you.


Of course.... if you have the money for the task some Vitara LSD centres with shorter gear ratio can compensate for both the gearing and provide even greater traction for racing and also slow offroad stuff. You'd just have to be careful about where and when you centre diff locked it.

[midnight]

Of course.... if you have the money for the task some Vitara LSD centres with shorter gear ratio can compensate for both the gearing and provide even greater traction for racing and also slow offroad stuff. You'd just have to be careful about where and when you centre diff locked it.

It wont be going offroad (I hope).

I wouldnt mind putting a Vit LSD into the diffs, If I can find 2 that is.

It will be a Hillclimb/road rally car.


Very off topic, Does anyone know how long the gearbox's roughly are on a 4AGZE?

[cooter]

from memory bout the same length as a corolla 5 speed

[midnight]

Also very offtopic.

Does anyone know how noisy Strengthened Helical cut gears are?
Whats the average price for them? $6000?

[hokey]

Of course.... if you have the money for the task some Vitara LSD centres with shorter gear ratio can compensate for both the gearing and provide even greater traction for racing and also slow offroad stuff. You'd just have to be careful about where and when you centre diff locked it.

It wont be going offroad (I hope).

I wouldnt mind putting a Vit LSD into the diffs, If I can find 2 that is.

It will be a Hillclimb/road rally car.


Very off topic, Does anyone know how long the gearbox's roughly are on a 4AGZE?

FWD or RWD? the rwd boxes are bout the same length as a corolla box but FWD are quite alot shorter as you would expect. very roghly the FWD would be around 500mm

[midnight]

Ummmmm Not to be rude hokey, but are you blind?

FWD's have no rear output, so it would be useless me putting in a tcase then.

[hokey]

hmmm good point. thought you might have been setting up some sort of AWD kinda thing with east west GZE Gearboxes in AE71 corolla are the ones you would use behind a gze so if you went to a wreckers and found one you could get a measure ment i suppose. (you prob already knew that though)