transfercase diagram

[Hemi395]

Honestly I don't know why they chose to operate the system the way it is. It would really just be a simple software update to apply the clutch coil constantly when in 4lock/4lo. Although I have a feeling it's designed that way to prevent excessive clutch wear. At least Rams not the only one with that issue, both Ford and GM have used the BW transfer cases and operate in a similar way with their 4wd autos.

I think they designed it that way because it doesn't bind on pavement in any mode. They dumbed it down so anyone can drive it on any surface without damaging the 4wd system.

Wouldn't it possible to fix this with a tune?

 

[NYCruiser]

If it was a simple software fix wouldn't BW offer a fix? I don't think the clutch can take high-torque situations like fighting thru mud without overheating. Not to mention the strain on it if your truck is lifted with plus size tires.

 

[Hemi395]

If it was a simple software fix wouldn't BW offer a fix?

I would think so. Unless Ram specifically stated they don't want it to lock because they figure most people with 1500s won't tax their 4wd systems more than the occasional drive to work in inclement weather...

 

[Tach_tech]

I think they designed it that way because it doesn't bind on pavement in any mode. They dumbed it down so anyone can drive it on any surface without damaging the 4wd system.

Wouldn't it possible to fix this with a tune?

There's that too, every winter we always get people coming in complaining about that and they don't seem to like the answer that it's normal. So that probably has something to do with it as well.

 

[Tach_tech]

If it was a simple software fix wouldn't BW offer a fix? I don't think the clutch can take high-torque situations like fighting thru mud without overheating. Not to mention the strain on it if your truck is lifted with plus size tires.

I think the reason there isn't any fix for the issue is because technically speaking, it's not an issue. The system operates exactly how it was designed to. It's just misleading to market it as a true 4lock/4lo when it's more of a hybrid between a 4lock and AWD.

 

[PostalTwo]

I think the reason there isn't any fix for the issue is because technically speaking, it's not an issue. The system operates exactly how it was designed to. It's just misleading to market it as a true 4lock/4lo when it's more of a hybrid between a 4lock and AWD.

Well put totally agree is that a parameter that u as a tech can change?

 

[loveracing1988]

Well put totally agree is that a parameter that u as a tech can change?

That would be a negative. You guys can't even adjust the tire pressures on my 2500 anymore.

 

[Tach_tech]

Well put totally agree is that a parameter that u as a tech can change?

Nope, nothing I can do about it. Would have to be changed by engineering.

 

[Brandon-w]

Hey everyone. Did anyone come to any conclusions on this? I'm thinking of putting a multimeter on that clutch pack wire and seeing if voltage is variable as demand is put on the 4x4. If voltage changes why not put a one way blocking diode in and a rheostat or switch in to engage the clutch pack?

 

[Wild one]

Hey everyone. Did anyone come to any conclusions on this? I'm thinking of putting a multimeter on that clutch pack wire and seeing if voltage is variable as demand is put on the 4x4. If voltage changes why not put a one way blocking diode in and a rheostat or switch in to engage the clutch pack?

Check out the AflaOBD thread,somebody has successfully put the 44-45 T-case in and apparently has it operating properly.

 

[Brandon-w]

Check out the AflaOBD thread,somebody has successfully put the 44-45 T-case in and apparently has it operating properly.

My God the options Alfaobd gives a guy!! Where has this been my whole doge life lol. Still gonna test that wire tho more cusiosiy now! May have to switch to a 45!!
Thanks wild one
Good Info.

 

[Brandon-w]

Hey all. So I had a warm day to screw around with the t case today. It turns out that the clutches in the t case are controlled at a variable rate depending on engine load. So in 4x4 at idle there's zero voltage to the clutches as more throttle is applied it's slowly ramped up. I decided hey why not take a blocking diode and make an online wiring harness to go between the stock clutch supply line and add my own power. Curiosity was getting to me I must say. So I built the harness added my 12v power supply and tested. Unfortunately somehow even with the blocking diode in place the truck still knows its getting wrong clutch voltage. It threw a clutch voltage out of range high and a clutch overheat code. But now we know 100% this will not work now. View attachment 152132 View attachment 152131

 

[Brandon-w]

I made the harness in such a way it was easy to return back to almost stock. I like it better this way anyways as it's easier to change shift motors this way.
Looking at a t case swap now that I can't bypass this clutch garbage.

 

[chrisbh17]

Does the clutch talk on the CAN bus? That might be how the truck "knows" about the wrong voltage.

I think everyone's best bet is a 44-45 conversion. I regret getting my lifetime warranty because I won't change xfer cases so as not to void my coverage.

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[Brandon-w]

Yes I Beleive it Is on can bus, that's why I Beleive my blocking diode won't work. On a non canbus system it would just apply the clutches and not tell the pcm they're applied and we'd be good to go. I'm still on warranty but as a mechanic I do not trust dealerships. Usually breakdowns are an excuse to upgrade. I'm gonna see if I can find a 44-45 and I have the obd ****** coming for alfaobd. See what trouble I can find with this. Lol

 

[crash68]

Does the clutch talk on the CAN bus? That might be how the truck "knows" about the wrong voltage.

I'm guessing the output to the clutch is monitored for current flow, just like with headlights, taillights, etc.

Yes I Beleive it Is on can bus, that's why I Beleive my blocking diode won't work. On a non canbus system it would just apply the clutches and not tell the pcm they're applied and we'd be good to go.

Wonder if this will work: Measure the resistance of the clutch input and match it up to a resistor. Then use a relay to switch between the resistor and the 12V to lock the clutch.

 

[chrisbh17]

I'm also curious if there is proof that the clutch is partially engaged even without slip from the rear wheels.

Its been a question with differing answers... In 4-auto, is there at least a little torque going to the front driveshaft even without the rear wheels slipping?

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[Brandon-w]

I'm guessing the output to the clutch is monitored for current flow, just like with headlights, taillights, etc.


Wonder if this will work: Measure the resistance of the clutch input and match it up to a resistor. Then use a relay to switch between the resistor and the 12V to lock the clutch.

That is a very good idea!! I think I might try that next!! If I had an amp clamp I'd check amperage draw while clutch pack is on full engage more or less just to know tho.

 

[Brandon-w]

I'm also curious if there is proof that the clutch is partially engaged even without slip from the rear wheels.

Its been a question with differing answers... In 4-auto, is there at least a little torque going to the front driveshaft even without the rear wheels slipping?

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Just from sitting in my driveway on pure ice and in ruts I'm going to say even in 4lock you are getting zero transfer at all. I can have the tires spinning in gear and front tires have no torque to them whatsoever backs are locked and turning in unison. I don't seem to get any front wheel assist of any sort until 10-15% throttle. I do alot of deep snow driving (Usually over a foot) and I sometimes when I get rammy with the throttle I can actually feel it hook up and sometimes it'll pull the steering wheel. So the answer to your question this is my honest opinion is no the transfer case isn't putting anything to the wheels at low speeds, my voltage reading on the transfer case clutch packs also comfirms that at zero volts while idling in drive so they're not engaging. Almost any other truck with wheels turned full left or right will give you a feed back that you have torque transfer, these trucks give you nothing. Essentially it's a glorified awd setup only gives you torque when demanded.
Pretty $hitty system if you ask me. I miss the days of a t case shift lever and a light in the dash that only worked half the time lol!

 

[chrisbh17]

Good info, thanks!

One last question.... Do you know if your front driveshaft spins at all times, even in 2wd? Mine does but again "should it" is a bone of contention. Trying to determine if maybe my xfer case or front diff/axles might have issues

Thanks.

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