Dodge tranny ques.

[Scott in MN]

After years of swearing that Dodge was the worst vehicle I just bought a builder Ram 2500 Cummins diesel. It was the Cummins that got me. Anyways, rumor has it that the weak link is the automatic trans. This thing has the tow package and some big coolers but I was considering synthetic trans fluid. Mopar calls for their AT+4 fluid but I was wondering if anyone has used the Alisyn Type 2 trans fluid in their Cummins auto trans? I know there are some diesel fans here any experience would be appreciated..Thanks, Scott

[jphii]

I talked to Jim(?) at Alisyn about using their stuff in my 06 2500 diesel. Problem is it's not certified and could cause a warranty issue. Dodge dealers are notorious for finding ways to weasel out of warranty claims.

[greyally]

Scott, I have a 3500 DODGE dually and just put a transmission in it. The tranny had about 180000 miles on it. I talked to a bunch of local transmission shops and the most common problem they found was it was a voltage problem comming of the computer. Low voltage is what got mine. when instalation of new tranny was installed it was doin the exact same thing. then the mechanic cleaned my battery and battery cables it automatically went to shifting like it should. Bottom line is keep your battery and battery cables clean and up to par. Theres also a single wire that goes to the computer that can also cause trans problems, again goin back to a loss of voltage problem.

[Scott in MN]

Joe, I see your point. I don't think Dodge would honor any warranty on mine because it has a salvage title, but if the fluid is not certified who knows if it will cause issues after a while.
Greyally, interesting, when I install my batteries I will be sure to clean the contact areas and use a sealant.

[STV_Keith]

Well, if warranty isn't a concern, skip the high dollar Mopar +3/+4 stuff and go with good 'ol Dexron 3 Mercon fluid. The +3/+4 is basically the same stuff with slip modifiers to make the trans shift smoother (read that as slip more). We had good luck with the Dexron 3 Mercon in DTT upgraded transmissions behind Cummins up through 800rwhp.

The synthetic equivalents just give more headroom before trans fluid temp becomes an issue. 210*F as measured in the trans pan or 250*F measured in the hot side cooler line with regular fluid...250*F in the pan or 280*F in the cooler line with synthetics is the max.

[Scott in MN]

I've always wondered what the difference was between mopar and dexron fluids.
So a mechanical breakdown is not imminent if dexron is used in a mopar--good to know. There is some crazy power being made by these diesels, I'm after mileage and reliability.....Thanks, Scott

[moparbarn]

i would stick with a fluid that meets the manufacturer's specs. the additives are there to allow slip and reduce the heat caused by it. modern automatic transmissions are designed with a certain amount of slip. mostly in the lockup clutch in the torque convertor. it is controlled by the computer. the lock up doesn't just turn off and on like it used to. the computer 'duty cycles' the control solenoid to allow slip in percentages for smoother operation, and motor effeciency. the slip is designed in for a reason, and the CORRECT fluid is NECESSARY for the trans to survive. doesn't have to be oem fluid, just the same spec/additive package. just a little something i have learned in 30 years at dealerships.

AIRWALK
gettin' old ain't for sissies

[STV_Keith]

I disagree. Everything the trans' did with +3/+4, they did better with dexron from a performance standpoint. As far as heat goes, more slip (with additive) = more heat, not the other way around.

I'm talking from hands-on, PERFORMANCE experience with trucks from stock to over 1000rwhp. You are not going to hurt anything except your warranty with Dexron. The dealers want you to buy that $20/gal stuff, so they will void your warranty if you don't have it in there and try a warranty claim.

Dexron held on to this (white truck - 740rwhp/1460tq back in 02): Video (http://www.dieseldynamics.com/videos/mm02/keith-jim.mpg) Right click and "save target as"

[moparbarn]

stv, the proper fliuds don't necessarily reduce heat by themselves. by allowing the clutches to slip easier/not chatter or try to grab, they let the trans work as it was designed to. working more effectivly, and not 'fighting' what the computer is telling it to do, reduces heat. the oem spec additives help allow the trans to follow the ecu's commands better. like i stated, you don't have to go to the dealer, the aftermarket makes suitable fluids. just make sure they meet oem specs is what i recommended. you say performance applications. most power programers/chips also affect trans operation. maybe not by directly comntrolling the trans ecu, but by the modified signals put out by the engine ecu. signals the trans uses to figure out what it needs to do, according to what the engine and drivers are doing. you add a chip, change the outputs from the engine ecu, and any other ecu that communicates with it will act differently, also. usually by allowing LESS SLIP, ie-firmer shifts. and shifting at a higher speed requires less slip to 'accept' the new load caused by the higher gear. i was refering to stock vehicles. when you add high performance, you basically throw the rule book out the window. not disagreeing with you or your experiences, just that we're talking apples and oranges here. in the long run, i have had better luck doing what the factory recommends for most stock applications. they do screw up, but the engineers make a lot of money for some reason:D .

AIRWALK
gettin' old ain't for sissies

[STV_Keith]

The "computer" doesn't have much to do with it for the first 3 gears. The 1-2 and 2-3 shifts are completely mechanical (spring/valve) in the valve body...the only thing computer controlled for these shifts is limit pressure or Governor pressure.

By allowing the clutches to slip, you allow more frictional heat (more time slipping vs. being coupled). More aggressive fluid can minimize this as the clutches come together.

As far at the ECU controlling the trans, we are talking about Dodges here, not Fords or Chevy's, and the Dodge 46/47/48RE transmissions are primarly mechanical being deriviates of the older 727TF trans.

Anyway, like I said, regardless of power, the Dexron III Mercon fluid only seems to help the transmissions over the slipperier +3 and +4 fluids (especially at $1/qt vs $5/qt). :) YMMV

[moparbarn]

by controlling pressure, you are varying to total pressure available to apply the clutch packs. directly related to amount of slip. and the torgue convertor clutch is computer controlled. the correct fluid won't affect slip or eliminate the heat produced by it. it will manage/allow the slip at a controlled rate, helping to manage the heat produced. they have friction modifiers that work with the clutchs to allow them to slip at the designed rate. different fluids can allow too much slip, more heat. or they can grab too much, causing chatter-the clutchs actually 'bounce' in and out of engagement. both not great for trans life or driveability. all of which is not much of a consideration in hp applications. line pressures are generally higher, limiting slip, and apply pressure is also higher, controlling chatter. in a STOCK situation, i would still use the recommended fluid. i worked for mitsubishi for 8 years. the same time they and chrysler corp. were in bed together. mitsubishi's were very fluid sensitive. chrysler used a lot of their technology in their trans' also. still does. the clutch material and the binders/glue used require the additives to function properly, and live long. again, in some respects i think we're discussing apples and oranges here. considering some of the applications, we're both right in some respects.or, we can agree to disagree:D :eek: :D :confused: .

AIRWALK
gettin' old ain't for sissies

[STV_Keith]

we can agree to disagree:D :eek: :D :confused: .

I guess I'll agree to disagree then...I have worked with stock and modified trucks and have NEVER had a problem with any of them related to running Dexron III Mercon.

[silverbullet02]

My response to the original question is, if you're gonna leave it stock, use stock type fluid and call it a day. Many of these trucks have gone abused and virtually untouched by lots and lots and lots of people who take 'em to walmart for service and go lots and lots and lots of miles trouble free. You hear about a lot of bad things, but that's all you hear about, you very rarely hear 'my truck is running great, put fuel in it and go every day with no problems', it's only the horror stories you hear, and if you compare the number of these trucks out there with no problems to the few that you do hear about problems, the percent is very small. Geez, that's a lot of typin! Have a great day!

Brian

Oh yeah, and the weak link the transmission, it's a week link in all of them *when modified. You go to a ford or a chevy or a dodge board, and you'll see the same trends over and over.

[moparbarn]

I've always wondered what the difference was between mopar and dexron fluids.
So a mechanical breakdown is not imminent if dexron is used in a mopar--good to know. There is some crazy power being made by these diesels, I'm after mileage and reliability.....Thanks, Scott
i remember going to chryslers at carlisle about 4 years ago. a guy had a white 4 wd 2500 cummins 24 valve on nitrous and propane. tail pipe the size of a water main. claimed he could put no more fuel to it, due to the stock ecu. dodge had threatened to sue if he opened and modified the oem ecu. claimed he had more power left on the table, because of lack of fuel. was running 4 wd to launch it. was breaking dana 70 rears and denny's driveshafts with 2 wd. still had to carry spare trans. he started breaking input shafts. even after cyrogenic treatment:eek: ! don't know how much power it had. he BURIED a 1200 hp/1400 tq. chip on the dyno! freakin' amazing. had time slips showing mid 11's at something like 115 mph. drove it from new england to the show. very stout trucks. carlisle's next weekend:D , guess where i'll be?

AIRWALK
gettin' old ain't for sissies

[Cobra1racer]

nothing like the old 727.

[STV_Keith]

47/48RE is basically a 727 with an overdrive on the back.

[catmando]

^^^I didn't know that. I had the 48RE on my 03 3500 srw. The only thing I didn't like about it was the long time it took to go into the next gear up. That had to create a lot of heat.

[bigyella]

Guys, I drive one just like this! I also own a transmission shop! Dont worry about the fluid... Not a problem at all... If its red, it will work.. But a synthetic fluid, would decrease the temp some.. type f, if you can find it, would shorten the shifts some, because it has no friction modifiers. The dodge dealer would never no what fluid you used, unless you told them. They are not going to send it to a lab.. The 47RE/48RE... is just a computer controlled 727, with a overdrive unit on the back, although most of the parts will not interchange with a 727. The computer controls governor pressure witch controls shift timing of the 1-2 and the 2-3 shift. Then a solenoid is activated to shift to 4th.. The lock up (tcc) is also controlled by a solenoid. Someone said the tcc was a (pwm) duty cycle system. With slip built into the lock up.. NOT true, on this unit. It is either off, or on.. You slip the converter much on this thing, and you will be buying a trans. The converter, is the weakest link. All cummins trans, that come though here, get a billet converter... Hope this helps!:)

[moparbarn]

i agree with you on the 1 ton/3500 trannies, no duty cycle/percentage on lockup. i was referring to dakotas & 1/2 ton pu's. do know that the wrong fluids WILL affect those systems, they need the friction modifiers, to control the heat & amount of slip allowed. except for the wiring & computer issues, i'd rather have an old school 727 & a gearvendors od, like what's in my '73 charger.

[Reaction19]

i have a 99 3500 cummins in a dodge. love the engine tranny is crap did the tranny at 15000miles. did a full billet tranny with raybestos clutches and a good valvebody and billet triple disk converter. what a difference. and i only use the castrol atf+4 fluid in it. lots of boost and abuse and hasnt missed a beat in years. And i mean lots of abuse.

[STV_Keith]

Guys, I drive one just like this! I also own a transmission shop! Dont worry about the fluid... Not a problem at all... If its red, it will work.. But a synthetic fluid, would decrease the temp some.. type f, if you can find it, would shorten the shifts some, because it has no friction modifiers. The dodge dealer would never no what fluid you used, unless you told them. They are not going to send it to a lab.. The 47RE/48RE... is just a computer controlled 727, with a overdrive unit on the back, although most of the parts will not interchange with a 727. The computer controls governor pressure witch controls shift timing of the 1-2 and the 2-3 shift. Then a solenoid is activated to shift to 4th.. The lock up (tcc) is also controlled by a solenoid. Someone said the tcc was a (pwm) duty cycle system. With slip built into the lock up.. NOT true, on this unit. It is either off, or on.. You slip the converter much on this thing, and you will be buying a trans. The converter, is the weakest link. All cummins trans, that come though here, get a billet converter... Hope this helps!:)

LOL, after looking back, Bigyella pretty much sums up my posts 5, 8, 10, 16. :) Looks like the people IN the business at least, come to the same conclusions.

[STV_Keith]

i remember going to chryslers at carlisle about 4 years ago. a guy had a white 4 wd 2500 cummins 24 valve on nitrous and propane. tail pipe the size of a water main. claimed he could put no more fuel to it, due to the stock ecu. dodge had threatened to sue if he opened and modified the oem ecu. claimed he had more power left on the table, because of lack of fuel. was running 4 wd to launch it. was breaking dana 70 rears and denny's driveshafts with 2 wd. still had to carry spare trans. he started breaking input shafts. even after cyrogenic treatment:eek: ! don't know how much power it had. he BURIED a 1200 hp/1400 tq. chip on the dyno! freakin' amazing. had time slips showing mid 11's at something like 115 mph. drove it from new england to the show. very stout trucks. carlisle's next weekend:D , guess where i'll be?

AIRWALK
gettin' old ain't for sissies

HAHA! I'd love to see this dyno graph. You have it? How about the guys' name then? 1200hp diesel would make closer to 1800ft-lbs or more.

[moparbarn]

don't remember the guy's name, but he owns (owned?) a diesel shop in new england somewhere. different dyno crew there last year, don't know who will show up this year, but i'll see in a few weeks. the dyno sheet had 2 lines that went up at a steep angle, & left the page at about 2/3 across. no hp or tq number's were generated, he maxed the chip the had out. haven't seen him back since, & i don't miss a year....... like i said in my last post keith, 1 ton trannies - i agree with you on fluids:iagree:. the smaller ones, not so much :rolleyes:. it's still all good, if we ever meet, i'll buy the beer :cool:!

later,
robin

[Scott in MN]

Since the converter has been brought up I have a symptom that has occurred a couple of times now. When cruising in OD at approx. 60 mph there will be a slight shudder that happens only once. This has occurred twice now and I am suspecting the lock up on the converter. No codes show on the computer. Any ideas??? 04 ram cummins auto supposedly stock tranny.