4WD auto?

[The_Chemist]

I just found this thread when I was searching for "Front Differential Groan or noise".

My truck just had the rear differential rebuilt at 2,600 miles. The oil was like milk, but it never leaked. Link to my thrrad on the issue:.

Differential or Transmission Clunk

I picked up my Longhorn Tuesday night. So far I have less than 150 miles on it. Today driving home from work, I started hearing a clunk and can feel a slight jolt when starting and stopping in slow moving traffic (such as creeping your way up to a stop sign, waiting for your turn to go). I'm...

5thgenrams.com

After the rebuild, I noticed one of the rear wheels hops or scrubs over the dry pavement when in 2wd when making tight turns.

This prompted me to try 4wd Auto to see if the problem still exists when in that mode. I never tried 4wd auto before this.

When engaged, my front axle is very loud. It makes sort of a scraping or groaning noise. I also noticed that when making a tight turn in 4wd Auto, the noise becomes even louder, sounding like a tire is scraping the fender liner. I'm assuming there is some sort of mechanical defect?

 

[Rocket Pig Rebel]

I just found this thread when I was searching for "Front Differential Groan or noise".

My truck just had the rear differential rebuilt at 2,600 miles. The oil was like milk, but it never leaked. Link to my thrrad on the issue:.

Differential or Transmission Clunk

I picked up my Longhorn Tuesday night. So far I have less than 150 miles on it. Today driving home from work, I started hearing a clunk and can feel a slight jolt when starting and stopping in slow moving traffic (such as creeping your way up to a stop sign, waiting for your turn to go). I'm...

5thgenrams.com

After the rebuild, I noticed one of the rear wheels hops or scrubs over the dry pavement when in 2wd when making tight turns.

This prompted me to try 4wd Auto to see if the problem still exists when in that mode. I never tried 4wd auto before this.

When engaged, my front axle is very loud. It makes sort of a scraping or groaning noise. I also noticed that when making a tight turn in 4wd Auto, the noise becomes even louder, sounding like a tire is scraping the fender liner. I'm assuming there is some sort of mechanical defect?

I have the same issue. I am trying to find answers. The dealer tried another rebel on the lot and dismissed my concerns as normal 4wd noise because the other one does it too. That sounds like BS to me. I want to take it somewhere for a second opinion. This is the first new truck I have ever bought. got the extended warranty so I wouldn't have to worry. Its been back to the dealer 3 times.

 

[The_Chemist]

I have the same issue. I am trying to find answers. The dealer tried another rebel on the lot and dismissed my concerns as normal 4wd noise because the other one does it too. That sounds like BS to me. I want to take it somewhere for a second opinion. This is the first new truck I have ever bought. got the extended warranty so I wouldn't have to worry. Its been back to the dealer 3 times.

I have an extended warranty as well. I'm going to need it as my truck literally lives at the dealer.

Now it's got a bad transfer case output seal.

If you find anything out about the 4wd noise, please let me know..

 

[renzo2213]

I have the same issue. I am trying to find answers. The dealer tried another rebel on the lot and dismissed my concerns as normal 4wd noise because the other one does it too. That sounds like BS to me. I want to take it somewhere for a second opinion. This is the first new truck I have ever bought. got the extended warranty so I wouldn't have to worry. Its been back to the dealer 3 times.

Say you’re going to get in touch with a lawyer about the lemon law. Three strikes and they’re out


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[mike_ct]

I'm a fan of the 4-auto behavior, very well street mannered on wet roads, parking lots etc. In snow, can't really notice a difference in response between 4-auto and 4-lock modes.

there was a YouTube video of a guy in a 5th gen driving over some off-road berms to purposely create a offset tire-off-the-ground no traction condition. and it showed how the system operated in the different modes.

rocking those 22's!

 

[bloodline]

In 4wd auto the truck will not move forward through a turn without applying throttle and if you apply any throttle the rear wheels will begin to skip on the pavement. We tested this on the lot with multiple trucks. Basically put the truck in 4wd auto and try to make a 90 degree or more turn while letting the truck roll forward on its own. My truck will not proceed forward through the turn, but other trucks tested will.

Did you ever get any resolution? Diagnosis or repair?

 

[bloodline]

I purchased my truck eight days ago and it is currently at the dealership for this same issue. The truck definitely binds in 4WD auto. The 4WD auto and 4WD hi modes behave in exactly the same way. It's been driven by multiple people at the dealership and compared to other trucks on the lot, and there is something wrong. So far they have not been able to diagnose it. Have you had your truck looked at? If so did they find the issue?

On the other trucks we drove on the lot there was no noticeable difference between 2WD and 4WD auto on dry pavement.

I had the same problem and it ended up being a malfunctioning rear wheel sensor which was just replaced at the dealership.

 

[Stevenc150]

Do what u will in 4wd auto...imo should only use it for pouring rain/muddy/snowy conditions. For dry, use 2wd only.
4wd-auto works well on Dry on Fwd vehicles as the front axle "pulls" & steers so it never has a chance to bind with the rear. For a Rwd vehicle, no matter how much nerding they do...the rearend ends up pushing/binding with the front, especially in turns. Yes the manual says that it's ok...those engineers make recommendations and that's it; they never deal with the real-world repurcussions. I should know I'm a tooling engineer in a Tier 2 automotive facility...and I make likewise recommendations all the time.

 

[sessman]

I am looking at two 2021 Ram Rebels. One has the 4wd auto button (top left button) the other does not have the 4wd auto button (both are obviously 4x4).

Is this an option? Is it highly desirable? Thanks for the help!

 

[Scap]

I am looking at two 2021 Ram Rebels. One has the 4wd auto button (top left button) the other does not have the 4wd auto button (both are obviously 4x4).

Is this an option? Is it highly desirable? Thanks for the help!

Depends on what you plan to do with the truck. If you plan to off-road it, get the non-4A version. If it is mostly a street ride, the 4A version is adequate.

 

[SpeedyV]

Depends on what you plan to do with the truck. If you plan to off-road it, get the non-4A version. If it is mostly a street ride, the 4A version is adequate.

I would go just a step further and say if you plan to off-road it a lot, then skip the Auto 4WD option.

 

[sessman]

I would go just a step further and say if you plan to off-road it a lot, then skip the Auto 4WD option.

I live in Southern California so other than going to the snow occasionally in the winter it won't be going off-road. I'm getting a better deal on the "non auto 4wd" option but for those random rainy days with slick roads I think it might be nice to have ...

So confirming it IS an option then?

What would you suggest?

 

[downsc123]

I live in Southern California so other than going to the snow occasionally in the winter it won't be going off-road. I'm getting a better deal on the "non auto 4wd" option but for those random rainy days with slick roads I think it might be nice to have ...

So confirming it IS an option then?

What would you suggest?

The option title to get the 4 Auto is "Electronic Shift-On-Demand Transfer-Case"

 

[BigEarl62]

So I don’t know anything about 4WD. It started raining pretty bad here. With that said, there was wheel spin when I took off at the light. I didn’t punch it and it was on 2WD mode. When it’s heavy rain, am I suppose to put it on 4WD auto? What’s the high and low for? I believe low is when you have lots of weight and you need to get up at a slow speed.

Note that 4wd Low should be limited to 25 mph max per the manual in the US at least.

 

[Nels]

I live in Wisconsin where we have every kind of weather but hurricanes and tsunamis. I use auto 4wd in ice, slush, and snow. Almost never in just rain. IMHO it's likely not needed in SoCal. Good rubber on your wheels will be more than sufficient in rain. That said, if the truck has the Bridgestone Dueler HLs on it, you'll be wanting to replace those anyway.

 

[sessman]

Thanks, the pic has Goodyear wranglers shown, are those better? What's wrong with the Bridgestones?

I live in Wisconsin where we have every kind of weather but hurricanes and tsunamis. I use auto 4wd in ice, slush, and snow. Almost never in just rain. IMHO it's likely not needed in SoCal. Good rubber on your wheels will be more than sufficient in rain. That said, if the truck has the Bridgestone Dueler HLs on it, you'll be wanting to replace those anywthank,

 

[Nels]

Thanks, the pic has Goodyear wranglers shown, are those better? What's wrong with the Bridgestones?

The goodyear is the other tire that sometimes comes from the factory. Mine had the Bridgestones when i bought it with 24,000 miles. I just dont think they are a strong enough tire for a truck. The truck felt like it swayed all over the road. I was going bigger anyway and wanted something that could handle gravel roads and a stiffer sidewall for towing so i knew i was going to switch them. I drove them for 5 months through a winter waiting for the buy 3 get one for a $1 sale, but i did a lot of white knuckle driving. Had a flat from a rock puncture on gravel in the first month. They provide a smooth ride on straight roads but depending how you'll use your truck, not great performance.

 

[sessman]

The goodyear is the other tire that sometimes comes from the factory. Mine had the Bridgestones when i bought it with 24,000 miles. I just dont think they are a strong enough tire for a truck. The truck felt like it swayed all over the road. I was going bigger anyway and wanted something that could handle gravel roads and a stiffer sidewall for towing so i knew i was going to switch them. I drove them for 5 months through a winter waiting for the buy 3 get one for a $1 sale, but i did a lot of white knuckle driving. Had a flat from a rock puncture on gravel in the first month. They provide a smooth ride on straight roads but depending how you'll use your truck, not great performance.

Very interesting. Are the Goodyear's decent?

 

[Nels]

Very interesting. Are the Goodyear's decent?

I havent driven a goodyear for a long time so i guess i cant say. I used to get flats with goodyear wranglers on gravel roads so i went away from them.

 

[VectorZ]

I live in Alaska and would vastly prefer the 4WD auto.