Gen 1: Locking Centre Diff (or lack of) Workarounds

[Snuggles]

Well, I learned some interesting things at least.

To help me understand more - if we are in 4H the transfer case is “locked” 1:1. What about 4Low?

Also, not to be obstinate, but this discussion makes it sound like all transfer cases are locked by default. If so, then why do Landcruisers have a fancy diff-lock button? And even the highly desirable “triple lock” from the factory with F, R, and t-case locks?

 

[FordTechOne]

Well, I learned some interesting things at least.

To help me understand more - if we are in 4H the transfer case is “locked” 1:1. What about 4Low?

Yes, same. Locked 1:1 in 4Low as well.

Also, not to be obstinate, but this discussion makes it sound like all transfer cases are locked by default. If so, then why do Landcruisers have a fancy diff-lock button? And even the highly desirable “triple lock” from the factory with F, R, and t-case locks?

There are multiple types of transfer cases based on use case. Some use a center differential to provide full-time 4WD; those vehicles typically do not have a 2WD selection; they’re permanent 4WD. The center differential lock engages the front and rear axles 1:1 for off-road use.

The Gen2+ Raptor uses a Torque-On Demand Transfer case with a 2WD mode for normal operation. In 4Hi and 4Low, the front and rear axles are mechanically locked together. In 4A, the transfer case uses a wet clutch to apply torque to the front axle as necessary.

 

[Gumby]

The Gen2+ Raptor In 4A, the transfer case uses a wet clutch to apply torque to the front axle as necessary.

is this only gen2? or dose it apply to gen 3 also?

 

[FordTechOne]

is this only gen2? or dose it apply to gen 3 also?

Yep, Gen 3 is the same.

 

[Snuggles]

Yes, same. Locked 1:1 in 4Low as well.

There are multiple types of transfer cases based on use case. Some use a center differential to provide full-time 4WD; those vehicles typically do not have a 2WD selection; they’re permanent 4WD. The center differential lock engages the front and rear axles 1:1 for off-road use.

The Gen2+ Raptor uses a Torque-On Demand Transfer case with a 2WD mode for normal operation. In 4Hi and 4Low, the front and rear axles are mechanically locked together. In 4A, the transfer case uses a wet clutch to apply torque to the front axle as necessary.

What about Gen 1? (This is what I have, so if particular interest to me

 

[FordTechOne]

What about Gen 1? (This is what I have, so if particular interest to me

Gen 1 locks 1:1 in 4H and 4L as well. But it does not have a full-time 4A mode.

 

[CruiserClass]

Well, I learned some interesting things at least.

To help me understand more - if we are in 4H the transfer case is “locked” 1:1. What about 4Low?

Also, not to be obstinate, but this discussion makes it sound like all transfer cases are locked by default. If so, then why do Landcruisers have a fancy diff-lock button? And even the highly desirable “triple lock” from the factory with F, R, and t-case locks?

It's due to the center differential, not the transfer case. Center diff lets you use full time 4wd, which requires that you let the front tires spin at a different rate than the back tires in some circumstances. Without a center diff or other way to allow that slippage in the drive line you'll either bind up the drive line or you'll drag a tire for a bit. Neither is good. Some 4wd systems use a clutched transfer case that allows slippage when in "full time" and then mechanically locks for off road/4hi/whatever label. Some just add extra friction to the clutch, which isn't truly locked and can cause overheating in some situations. Ask Chevy...

 

[Mineratron]

Yes I read the wandering, blabbering OP.

Again, you clearly don't understand much, if anything about these trucks. Center diff... Talking AWD torque split... Good luck, there's a reason nobody else is bothering to reply anymore.

Geez peace!

 

[Mineratron]

@McCarthy It is obvious English isn't his first language. but he can't really learn anything if we just dismiss him. not to mention I still haven't got my A+ grade.

Correct... scottish!

 

[Mineratron]

Sorry to keep you waiting... had family over visiting and not had time to come back on. Catching up with forum stuff as they've all left and I've got a TPMS issue on the mrs Edge. Not going to reply to all the points, just quoting the most relevant/rude/abusive ones... and multi quote is beyond my expertise along with 4x4 systems.

I'll pick the main points and threads up below and try to stay concise...

First up - I got it wrong, based on my understanding of the 4x4 system on the truck.

Its not the same as what I'm used to with switchable 2WD/4WD and locking centre diff (Mitsubishi Super Select II) Read a few of the replies and sussed out that I'd got something wrong. Took myself back to school and now realise that there is no centre diff on the Raptor and that 4H is locked at 50:50 in a transfer case setup.

Locking the rear diff should've helped the situation as eluded to... would've kept 50:50 in the rear and whatever in the front.

However it was clear to me now that I was then and the other times beached and didn't realise it.

There is no damage to the 4x4 system from all the sends... all working fine and the rear wheels must've been turning and I didn't notice.

I must be getting beached more than I thought and I must be struggling to getting my head round it after many years driving the matchbox (Puddlejumper as we'd say... Hermione is her name, a mug blood to some but a bloody good magician to others )... which despite its smaller stature and 30.6" tyres rides higher with its 2" lift than the stock Gen 1 Raptor with its 35" tyres. It doesn't have the power of the Raptor but it does get about well... torn on which one to drive tomorrow.

I will work on my driving in the boat to avoid getting beached... the one where I got stuck in the post; bad lines (marshall/trip leader's Jeep was overheating, had to get off the dunes ), late in the drive, tired from the airport run and entertaining, checked up slightly to point left for the kids as it came over the radio to look at the camel bones. A fairly innocuous stuck. It had been bugging me for a while though... but it turns out ground clearance is really the issue, not the 4WD setup.

I will also work on the Mrs (technically is her truck) regarding Stage 3 suspension kits... big boat needs more ground clearance. PERIOD! (as you would say ) Fox 3.0, UCAs, bump stops and Deavers looks like the best option locally.

Sand boards - useful if out yourself but if in a convoy and rope/winch is an option, just pull it. People's time is more precious and over here, its far to hot most of the time for doing any unnecessary digging.

Think that's it... I've been on various forums for over 20yrs so happy to take abuse for posting something dumb (especially with a low post count / rep). Also happy and big enough to put my hand up when I've wet myself. I don't hold anything against anyone up till now...

Set myself up a bit with the post and the pinching fingers gesture emoji... but I came on here for a better answer than the bookface groups... which I got and then some... which is what I intended.

Mineratron - professional engineer (should know the systems better ) 9yrs in the sand, 4x4 noob when i arrived here in the UAE. Level 3 (current grade - side/cross cresting OK, assisted recoveries) in the Pajero, probably lower in the Raptor as still getting used to it. Out every other weekend in the dunes on the bikes, dirt/desert level experienced/trip lead on two wheels.

Bear with me... I'm keen to learn, willing to share and I love this truck. Getting handy with Forscan, done plenty on the truck and fixed my mate's Gen 1 Roush yesterday (PATS programming, MyKey disabled, DTCs read/cleared and adaptive table resets, along with other troubleshooting). Got plugs, wires and coils to go along with breather valve. Coolant change, Method 305 refurb and whatever comes up... will post it here to share the experience. Take it easy.