Ram 3500 issue

[TxGearhead]

2018 Ram 3500, Cummins, Aisin, 3.73.
I began noticing a few months ago that under very light braking...backing out of the garage and turning, I felt a jerking. I'm on the road and almost back home. It is very pronounced while pulling the 5th. Taking off from a stop and turning it acts like it's in 4 wheel drive. Sitting around the campground a couple weeks ago I mentioned it. One guy said his employer had a fleet of Rams that would do the same when in skid control and in 4x4. I turned skid control off and could tell no difference. Almost feels like a u-joint or posi trac differential clutches grabbing.
Anyone heard of this or experienced it? I'm due to visit my dealer when I get home and will get them to look.
Just rolled 50,000 miles.

[FishOnOne]

ShinerBock wrote:

Ram's 4wd system disengages the front axle completely when not in use unlike the Ford system which keeps the front axle spinning at all times, but locks the hubs when power to the wheels is needed.

Fords U joints/axles only turn in 4wd. That's the beauty of having locking hubs on the front axle. There is after market locking hub upgrades for a Ram.

[cummins2014]

mudfuel07 wrote:
My LB SRW 3500 does this in 4wd. It hops like crazy when I try to turn, don't notice it in 2wd. Don't know if it does in on pavement or not, never tried 4wd there. Taken it to the dealer a couple of times and they said it's normal. My SB never did it.

Every truck I’ve had if the hubs are locked and it’s in 4 wheel drive the front tires will grab or hop on dry pavement . That’s normal .

[mudfuel07]

My LB SRW 3500 does this in 4wd. It hops like crazy when I try to turn, don't notice it in 2wd. Don't know if it does in on pavement or not, never tried 4wd there. Taken it to the dealer a couple of times and they said it's normal. My SB never did it.

[cummins2014]

IdaD wrote:

cummins2014 wrote:

4x4ord wrote:

ShinerBock wrote:

4x4ord wrote:
Are you sure it is coming out of 4wd? Jack up one front wheel and see if it spins freely. Should Ram front hubs free wheel when in 2wd? (ie Does Ram use a auto lock hub like Ford or a constant locked hub like GM?)

Ram's 4wd system disengages the front axle completely when not in use unlike the Ford system which keeps the front axle spinning at all times, but locks the hubs when power to the wheels is needed.

The Ford transfer case does not transmit power in 2wd but the hubs Auto unlock as well. So with the Ford you can manually lock the hubs but you are still in 2wd until you shift the transfer case to 4 hi or 4 low. Chevy does not have hubs that disengage … the front axle and diff rotate in 2 wheel as well as 4 wheel drive? I think Ram is like Chevy but I don’t know?

I can't manually lock my hubs on my Ram ,but they are automatic locking , but no I don't believe they stay locked on my Ram . Nor do I believe my front driveline turns in 2hi. My old Superduty had automatic locking hubs , as well as manual. I suppose there is some need for manual hubs that are also automatic, but I never used the feature .

Auto hubs are great , I remember the days when we had to get out of the truck ,and lock the hubs, don't miss that. Many times not thinking we would need four wheel drive ,and needing it, and having to get out , and lock the hubs, wasn't terrible unless like the time I went thru some water on a mountain road ,and found my self stuck in a foot of water , you guessed it , I got wet getting out to to lock the hubs 🙂 If I knew as I started out on a hunt or whatever I would lock the hubs so I would be ready, now that's a thing of the past. We can shift into 4 wheel drive at any point now, so not sure what's the point of manual hubs ?? I am sure I will get enlightened on the need. 🙂

The hubs are always locked, but there's a center axle disconnect so your front driveline doesn't spin in 2wd. I prefer the old style manual hubs so none of the front driveline components spin in 2wd. It never took too much effort to plan ahead and not have to get out in the mud to lock the hubs.

No it wasn’t the effort or planning ahead , and I had locking hubs for years , but there were a couple times I got caught not thinking I’needed 4 wheel drive . No t’s just nice having auto hubs . As far as preferring manual hubs , for me I would have to have a reason for not wanting the front components to spin , and so far they haven’t given me a reason , have they you ?

[Grit_dog]

TxGearhead wrote:
You have a point. Manual says 75w-90. Guess I will go with that and see if it helps.
Thanks for your input.

So you've inspected the front axle u-joints and verified it's not them?
Your original post says "feels like in 4wd", which to me involves the front axle, not the rear. With a little see-sawing of the steering wheel.
A posi locking up in the rear is easy to diagnose, you can see, hear and feel it coming from the back of the truck.

Totally possible you have an issue with the rear diff/fluid. Just not following how you went from front to rear without saying you verified the front isn't binding up?

[Grit_dog]

IdaD wrote:


The hubs are always locked, but there's a center axle disconnect so your front driveline doesn't spin in 2wd. I prefer the old style manual hubs so none of the front driveline components spin in 2wd. It never took too much effort to plan ahead and not have to get out in the mud to lock the hubs.

Bingo. So much confusion, that just a cursory peek at and a little turning of axles/driveshafts would explain very matter of factly...

[IdaD]

cummins2014 wrote:

4x4ord wrote:

ShinerBock wrote:

4x4ord wrote:
Are you sure it is coming out of 4wd? Jack up one front wheel and see if it spins freely. Should Ram front hubs free wheel when in 2wd? (ie Does Ram use a auto lock hub like Ford or a constant locked hub like GM?)

Ram's 4wd system disengages the front axle completely when not in use unlike the Ford system which keeps the front axle spinning at all times, but locks the hubs when power to the wheels is needed.

The Ford transfer case does not transmit power in 2wd but the hubs Auto unlock as well. So with the Ford you can manually lock the hubs but you are still in 2wd until you shift the transfer case to 4 hi or 4 low. Chevy does not have hubs that disengage … the front axle and diff rotate in 2 wheel as well as 4 wheel drive? I think Ram is like Chevy but I don’t know?

I can't manually lock my hubs on my Ram ,but they are automatic locking , but no I don't believe they stay locked on my Ram . Nor do I believe my front driveline turns in 2hi. My old Superduty had automatic locking hubs , as well as manual. I suppose there is some need for manual hubs that are also automatic, but I never used the feature .

Auto hubs are great , I remember the days when we had to get out of the truck ,and lock the hubs, don't miss that. Many times not thinking we would need four wheel drive ,and needing it, and having to get out , and lock the hubs, wasn't terrible unless like the time I went thru some water on a mountain road ,and found my self stuck in a foot of water , you guessed it , I got wet getting out to to lock the hubs 🙂 If I knew as I started out on a hunt or whatever I would lock the hubs so I would be ready, now that's a thing of the past. We can shift into 4 wheel drive at any point now, so not sure what's the point of manual hubs ?? I am sure I will get enlightened on the need. 🙂

The hubs are always locked, but there's a center axle disconnect so your front driveline doesn't spin in 2wd. I prefer the old style manual hubs so none of the front driveline components spin in 2wd. It never took too much effort to plan ahead and not have to get out in the mud to lock the hubs.

[cummins2014]

4x4ord wrote:

ShinerBock wrote:

4x4ord wrote:
Are you sure it is coming out of 4wd? Jack up one front wheel and see if it spins freely. Should Ram front hubs free wheel when in 2wd? (ie Does Ram use a auto lock hub like Ford or a constant locked hub like GM?)

Ram's 4wd system disengages the front axle completely when not in use unlike the Ford system which keeps the front axle spinning at all times, but locks the hubs when power to the wheels is needed.

The Ford transfer case does not transmit power in 2wd but the hubs Auto unlock as well. So with the Ford you can manually lock the hubs but you are still in 2wd until you shift the transfer case to 4 hi or 4 low. Chevy does not have hubs that disengage … the front axle and diff rotate in 2 wheel as well as 4 wheel drive? I think Ram is like Chevy but I don’t know?

I can't manually lock my hubs on my Ram ,but they are automatic locking , but no I don't believe they stay locked on my Ram . Nor do I believe my front driveline turns in 2hi. My old Superduty had automatic locking hubs , as well as manual. I suppose there is some need for manual hubs that are also automatic, but I never used the feature .

Auto hubs are great , I remember the days when we had to get out of the truck ,and lock the hubs, don't miss that. Many times not thinking we would need four wheel drive ,and needing it, and having to get out , and lock the hubs, wasn't terrible unless like the time I went thru some water on a mountain road ,and found my self stuck in a foot of water , you guessed it , I got wet getting out to to lock the hubs 🙂 If I knew as I started out on a hunt or whatever I would lock the hubs so I would be ready, now that's a thing of the past. We can shift into 4 wheel drive at any point now, so not sure what's the point of manual hubs ?? I am sure I will get enlightened on the need. 🙂

[Grit_dog]

4x4ord wrote:

ShinerBock wrote:

4x4ord wrote:
Are you sure it is coming out of 4wd? Jack up one front wheel and see if it spins freely. Should Ram front hubs free wheel when in 2wd? (ie Does Ram use a auto lock hub like Ford or a constant locked hub like GM?)

Ram's 4wd system disengages the front axle completely when not in use unlike the Ford system which keeps the front axle spinning at all times, but locks the hubs when power to the wheels is needed.

The Ford transfer case does not transmit power in 2wd but the hubs Auto unlock as well. So with the Ford you can manually lock the hubs but you are still in 2wd until you shift the transfer case to 4 hi or 4 low. Chevy does not have hubs that disengage … the front axle and diff rotate in 2 wheel as well as 4 wheel drive? I think Ram is like Chevy but I don’t know?

Shiner, you’re a little off here.
Newer Rams, in 2wd, driveshaft doesn’t spin, axle u joints do.
Super duty’s, nothing spins except the wheel bearings if hubs unlocked and in 2wd.

[Grit_dog]

Cummins12V98 wrote:
For my DRW my frame and axle guy said OE spec of 1/4” toe is WAYYYYY too much. Set to 1/64” toe and all your outer edge “stepping” woes will go away.

Rotate front tires ONLY by moving tires side to side leaving rotation the same. Tires need to be separated from rims to do so.

Never understood the keeping the rotation the same. All treads feather as they wear and changing rotation if side to side or keeping same rotation if front to back corrects this.

Now, flipping tire on rim will correct inside or outside wear as the outside is now in, but that is a separate condition and just blindly sticking to a rotation “pattern” without reading what the tires are doing is not maximizing the tire life or ride quality.

[4x4ord]

ShinerBock wrote:

4x4ord wrote:
Are you sure it is coming out of 4wd? Jack up one front wheel and see if it spins freely. Should Ram front hubs free wheel when in 2wd? (ie Does Ram use a auto lock hub like Ford or a constant locked hub like GM?)

Ram's 4wd system disengages the front axle completely when not in use unlike the Ford system which keeps the front axle spinning at all times, but locks the hubs when power to the wheels is needed.

The Ford transfer case does not transmit power in 2wd but the hubs Auto unlock as well. So with the Ford you can manually lock the hubs but you are still in 2wd until you shift the transfer case to 4 hi or 4 low. Chevy does not have hubs that disengage … the front axle and diff rotate in 2 wheel as well as 4 wheel drive? I think Ram is like Chevy but I don’t know?

[ShinerBock]

4x4ord wrote:
Are you sure it is coming out of 4wd? Jack up one front wheel and see if it spins freely. Should Ram front hubs free wheel when in 2wd? (ie Does Ram use a auto lock hub like Ford or a constant locked hub like GM?)

Ram's 4wd system disengages the front axle completely when not in use unlike the Ford system which keeps the front axle spinning at all times, but locks the hubs when power to the wheels is needed.

[4x4ord]

Are you sure it is coming out of 4wd? Jack up one front wheel and see if it spins freely. Should Ram front hubs free wheel when in 2wd? (ie Does Ram use a auto lock hub like Ford or a constant locked hub like GM?)

[TxGearhead]

You have a point. Manual says 75w-90. Guess I will go with that and see if it helps.
Thanks for your input.

[Cummins12V98]

TxGearhead wrote:
I bought 5 quarts of Valvoline full synthetic 75w-140 gear oil. Will let the dealer change it when I'm there next week for a oil change.

I would return it. That’s wayyyyy too heavy. Look in your manual.

I use AMZ/OIL SevereGear 75-110 because I tow 35k combined. The Dana axles used the heavy spec towing heavy.