Differential Question

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68PowerWagon

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I am not very knowledge in how the drivetrain operates in & out of 4wd. When not in 4wd where does the drivetrain disconnect? At the transfer case? Seemed like many years ago it disconnect at the hubs. My ultimate question here, is there much less stress/heat on the front diff compared to the rear? If I end up re-gearing I was planning on upgrading to a larger capacity aluminum cover for the rear axle but possibly using the factory one back on the front. Not trying to cheap out, but I am already going to be putting down a lot of coin.
 
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R.L.K.

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What year and type Ram do you have Sir ?

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R.L.K.

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I am not very knowledge in how the drivetrain operates in & out of 4wd. When not in 4wd where does the drivetrain disconnect? At the transfer case? Seemed like many years ago it disconnect at the hubs. My ultimate question here, is there much less stress/heat on the front diff compared to the rear? If I end up re-gearing I was planning on upgrading to a larger capacity aluminum cover for the rear axle but possibly using the factory one back on the front. Not trying to cheap out, but I am already going to be putting down a lot of coin.
Do you have a 1500 or a 2500 4x4 ? They are totally different [emoji1360]

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olyelr

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I am not very knowledge in how the drivetrain operates in & out of 4wd. When not in 4wd where does the drivetrain disconnect? At the transfer case? Seemed like many years ago it disconnect at the hubs. My ultimate question here, is there much less stress/heat on the front diff compared to the rear? If I end up re-gearing I was planning on upgrading to a larger capacity aluminum cover for the rear axle but possibly using the factory one back on the front. Not trying to cheap out, but I am already going to be putting down a lot of coin.

The transfer case get locked in 4 hi/low when pulling the lever (or pushing the buttons), which also sends a signal to a CAD (center axle disconnect) on the front axle. This CAD is a little collar on the passenger side of the axle which connects the two piece shaft. This is the “modern” way to not have the front end completely locked up, without needing lockout hubs. The outer shafts and u-joints always spin when in 2wd, but not the driveshaft.

Just keep the factory diff covers.
 

Gr8bawana

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Interesting video
 
OP
OP
68PowerWagon

68PowerWagon

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Watch this before you spend money on diff covers- very informative.


That is VERY interesting & makes sense. I was looking at the BD Diff covers which look very similar to what Banks designed. Supposed to be designed to throw the oil back on the gears. I am going to look at them more closely now to see if I want to go that route. Not sure why (probably $$$) all HD Trucks don't have aluminum covers from the factory. Lighter truck, better heat dissipation.
 

U&A

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I also decided to keep my stock cover after seeing that video series.

I agree with his points.


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R.L.K.

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I also decided to keep my stock cover after seeing that video series.

I agree with his points.


Sent while firmly grasping my redline lubed RAM [emoji231]
Hey buddy [emoji112][emoji112]
You have a 3500 which I believe is the same basic set up as the OP .
On the OP he's asking for a description of the 4x4 system and your more than qualified to explain [emoji1360][emoji1360]

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U&A

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I am not very knowledge in how the drivetrain operates in & out of 4wd. When not in 4wd where does the drivetrain disconnect? At the transfer case? Seemed like many years ago it disconnect at the hubs. My ultimate question here, is there much less stress/heat on the front diff compared to the rear? If I end up re-gearing I was planning on upgrading to a larger capacity aluminum cover for the rear axle but possibly using the factory one back on the front. Not trying to cheap out, but I am already going to be putting down a lot of coin.

Here is my take based on lots of time figuring **** out.

I did NOT get this info from a book. It is MY interpretation. if someone disagrees please explain your reasoning.

Hang on.... need a whiskey [emoji2957]

Ok ok

Iv been back and forth with this with a mechanic and FCA as well as the guy that re-geared my truck.

Cut the ********* long stories. It HAS TO ..... HAS TO .... HAS TO disconnect from “power” at the transfer case.

If you jackthe back of your truck up (front tires still down) and put her in drive while in 2H. The driveshaft that goes to the front differential from the transfer case. DID NOT SPIN.

So in 2H the trucks POWER is not turning the driveshaft.

But.... your axles are still spinning while driving down the road. Because of this centrical force could turn the driveshaft a bit when driving.

You can spin the front driveshaft by hand when in 2h and parked

Your front diff is open. When in 2H you axles spin with the wheels at the same speed. But because the diff is open they spin separate.

There is an “axle disconnect” on your passenger side front axle. Looks like a big plastic electric solenoid on the back of the axle that moves a fork shaped arm in and out moving a splined sleeve that will slide over that 2pc axle.

This means only half of your passenger side axle is spinning with the wheel while in 2H.

When 4x4 is engaged it simultaneously moves that splined sleeve on you 2 pc axle to essentially Making the passenger side a “one pc” now .....at the same time it puts power to the driveshaft for the front diff with the transfer case.

The 2 pc axle for safety reasons.

The HD transfer case has NO clutches. Its is direct chain drive. It is ALWAYS best to do any transfer case switch while moving SLOWLY. But not stopped.... because of the direct drive.

2H to 4H is usually easy to do when moving. But 4L is tricky because you need to be in “N” on your transmission when doing the move.

I always try to roll JUST fast enough to slip the trans into “N” and once that is done push it into 4L. ..... all while still rolling

If you are stopped all of the switches “can” be a struggle. Especially 4L. Don’t even try it.

Hope this helps.




Sent while firmly grasping my redline lubed RAM [emoji231]
 
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McBroom

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Here is my take based on lots of time figuring **** out.

I did NOT get this info from a book. It is MY interpretation. if someone disagrees please explain your reasoning.

Hang on.... need a whiskey [emoji2957]

Ok ok

Iv been back and forth with this with a mechanic and FCA as well as the guy that re-geared my truck.

Cut the ********* long stories. It HAS TO ..... HAS TO .... HAS TO disconnect from “power” at the transfer case.

If you jackthe back of your truck up (front tires still down) and put her in drive while in 2H. The driveshaft that goes to the front differential from the transfer case. DID NOT SPIN.

So in 2H the trucks POWER is not turning the driveshaft.

But.... your axles are still spinning while driving down the road. Because of this centrical force could turn the driveshaft a bit when driving.

You can spin the front driveshaft by hand when in 2h and parked

Your front diff is open. When in 2H you axles spin with the wheels at the same speed. But because the diff is open they spin separate.

There is an “axle disconnect” on your passenger side front axle. Looks like a big plastic electric solenoid on the back of the axle that moves a fork shaped arm in and out moving a splined sleeve that will slide over that 2pc axle.

This means only half of your passenger side axle is spinning with the wheel while in 2H.

When 4x4 is engaged it simultaneously moves that splined sleeve on you 2 pc axle to essentially Making the passenger side a “one pc” now .....at the same time it puts power to the driveshaft for the front diff with the transfer case.

The 2 pc axle for safety reasons.

The HD transfer case has NO clutches. Its is direct chain drive. It is ALWAYS best to do any transfer case switch while moving SLOWLY. But not stopped.... because of the direct drive.

2H to 4H is usually easy to do when moving. But 4L is tricky because you need to be in “N” on your transmission when doing the move.

I always try to roll JUST fast enough to slip the trans into “N” and once that is done push it into 4L. ..... all while still rolling

If you are stopped all of the switches “can” be a struggle. Especially 4L. Don’t even try it.

Hope this helps.




Sent while firmly grasping my redline lubed RAM [emoji231]

^^^very well said ^^^
Your the man!!!


- The Blue Mule
 

olyelr

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Another neat little fact. When you loose abs signal (a cut wire, disconnected wire connection etc), 4wd will no longer work. Even with the manual tcase.
 
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U&A

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Another neat little fact. When you loose abs signal (a cut wire, disconnected wire connection etc), 4wd will no longer work. Even with the manual tcase.

Must be related to the fact that our speedometer uses the ABS somehow to read wheel speed.


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olyelr

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Must be related to the fact that our speedometer uses the ABS somehow to read wheel speed.


Sent while firmly grasping my redline lubed RAM [emoji231]

Im thinking its that for some reason the electronically actuated collar for the CAD does not operate when there is an ABS signal issue. But for the life of me I can not figure out why the hell they would do that. I mean wtf.

I found that out when we broke my friends abs wire right out of the hub bearing. He didnt have 4wd right after that. So I tested it on mine by unplugging the wire connector on my front drivers side bearing... same ****, no 4wd.
 

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