ping GG tranny questions

ouch. i just hate winding my cummins (either one) that tight. i dont like getting anywhere near redline.

cool, i can handle that. does it hurt to run in o/d so long as the tranny isnt hunting?

sweet, will have to get back to you when i know a little more about what im doing.

Reply to
Nathan W. Collier
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at what point (assuming flat ground)? i mean, towing a 400 pound atv on a

400 pound trailer obviously wouldnt hurt a toyota tranny in overdrive, much less one built for the cummins. is 1000 pounds the shift point (taking it out of overdrive)? 2000? 5000?

......sure wish i had gotten the 6 speed now. had i forseen just how much towing i would be doing (getting ready to purchase a slide in camper and will be pulling the 7x18 loaded with the toys every chance i get) i wouldnt have got the automatic in the .04.5.

Reply to
Nathan W. Collier

Maybe it's the "aww, shit" factor - you know, the one that says "One Aww Shit is louder than a bunch of attaboys"?

I cruise at about 65mph with my 12,000 lb fiver in overdrive until it starts hunting for a lower gear - and that takes a lot more than just the grade going up an overpass on the freeway. I have the fluids and filters on the tranny changed in accordance with the owner's manual recommendations and specifically ask the mechanic (not the service writer or manager) if he found anything "unusual, like shavings or chips" when he pulled the pan. Nothing bad has happened so far.

Greg '98 3500 QC 4x2 Cummins ISB, Auto, 3.54:1, Driftwood with Leather and all the heavy duty options. '89 Nu-Wa Champagne Edition, 34 foot Fifth Wheel.

Reply to
Greg Surratt

No, it would not. Unloaded, and with some light loading, my truck is able to climb hills without a thought at 1500RPM in OD. When I discovered this, I started manually killing OD.

Reply to
Max Dodge

Driving it like its a sports car does that. The Cummins Dodge is equipment, not a common commuter. Drive it like it cannot fail, and it will. Drive it with respect, like it can damage itself and anything in its path, and it'll perform for a lifetime.

Reply to
Max Dodge

Nate, the 48RE isn't the concern here... the concern is the 47RE in your '01. The 48RE has better fluid flow to the OD unit, more clutches in the OD pack, and MANY more clutches in the direct pack. Put a temp gauge in it, don't let it go over 180-190°F or so, and don't lug it in OD (below

1500-1600RPMs), just like you wouldn't do with a manual.

Dry your eyes, blow your nose, and cheer up... your automatic will handle your towing needs just fine... yep, even in the mighty mountains of the great northwest :)

Reply to
Tom Lawrence

4.10's or 3.73's?
Reply to
Tom Lawrence

youre pulling 12k on the 3.54 gears? how does it do? any mountain driving?

Reply to
Nathan W. Collier

if youre unloaded or loaded lightly, why the concern?

Reply to
Nathan W. Collier

sweet. do you feel that an automatic would also do "fine" in the '02 dually im searching for?

Reply to
Nathan W. Collier

....and just out of curiosity, how difficult would it be to retrofit a 48re into an '02?

Reply to
Nathan W. Collier

I'm a little less optimistic with the 47RE towing >8,000lbs. in OD, unless it's on flat ground - just because of the issues with the OD unit we've talked about previously.

As for retro-fitting a 48RE, it's not that difficult at all. Physically, they're identical. Electrically, I'm pretty sure the valve body connector and underlying electronics are the same. The only thing you'd have to work on would be adapting the wiring from the 47RE's park/neutral switch to the

48RE's transmission range sensor. Fortunately, the TRS has a separate output that mimics the P/N switch behavior, so that should just be a matter of obtaining the proper connector and splicing a wire.

If you can get a good-condition 48RE for cheap, then that would be the way to go. Otherwise, I'd just look at having the 47RE upgraded by a good transmission shop - one that's familiar with the Mopar trannies, and who can address the shortcomings when it comes to towing heavy.

Remember that most of the heat comes from the torque converter, and until very recently ('05 and up), Dodge still had a very anti-tow-friendly lockup strategy, and a barely adequate converter to boot. I can tell you that my beefed-up 48RE, with a better torque converter and electronic controller for improved lock-up, has pulled a 10K load effortlessly, up several 4-5% grades (one about 2 miles - the other about 6 miles), and I never saw over 160°F on the temp gauge - that was only when I hammered it from a stop to "see what she'd do", and the converter was slipping until 3rd gear. Any other time, and the needle never came off the 140°F peg.

Reply to
Tom Lawrence

Cummins lists lugging as more pedal but not more RPM. Since the truck weighs in at 7000+lbs, going up a hill in OD is not only pulling the RPM down, its creating more EGT, more strain, etc. All of that is unnecessary, since I have a direct ratio, so why not use it, and avoid all bad effects? My MPG rarely suffers with such a move. With no adverse effect, and a bunch of good things happening, its not worth the constant bragging rights.

Reply to
Max Dodge

can the 47re be upgraded to the same durability as the 48re?

does this include the '04.5?

Reply to
Nathan W. Collier

I bought the trailer in Benson, AZ right after I got the truck and towed it back home to Norfolk. Lowest speed I saw was about 40 mph north/east bound on the big hill going north out of Las Cruces, NM towards Alamogordo. Ditto for going westbound over Black's Mountain in North Carolina on I-40(?).

Caught the wife napping in Oklahoma, so I opened it up and it runs real nice at 85 with the trailer on the flats.

Most of the stuff since then has been up and down the east coast with a few trips to Tennessee. I get around 13-13.5 towing at 65 mph.

I'm happy with the combo, but intend to trade off both when I retire in a couple years and start my retirement with two fresh vehicles for full-timing.

Greg '98 3500 QC 4x2 Cummins ISB, Auto, 3.54:1, Driftwood with Leather and all the heavy duty options. '89 Nu-Wa Champagne Edition, 34 foot Fifth Wheel.

Reply to
Greg Surratt

Nate, these folks build as close to bullet proof as you can get.

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Roy

Reply to
Roy

And, of course, the obligatory counter-point to that:

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Reply to
Tom Lawrence

Certainly, you can only recommend what you have had good fortune with. My DTT was fantastic, never had a ats.

Roy

Reply to
Roy

IMHO, from my non-deisel towing, if you can do 85 mph, you can leave it in OD... now, at 60, I'd lock it out unless you were on flat ground and it wasn't taking a lot of throttle to maintain speed..

mac

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Reply to
mac davis

Nate.. to me (as one who's been wanting a ctd for years) the question would be "IS the transmission built for the Cummins?"... Or, it is a standard transmission that is the best that they have for the Cummins..

Sort of off topic.. we tow with a 5.9 gasser and our TT is only about 6,000 pounds or so, but we are very rarely in OD...

2 reasons for this: Unless we're on flat ground and at pretty good speed, (65+), it takes a lot more pedal pressure to maintain speed that it does in OD.. my guess is that more pedal pressure means less MPG, and more heat generated..

I sort of think of it like I would a 5 speed manual.. you can run it all day in

4th without hurting it, but sometimes being in 5th CAN hurt it..

We've played around with OD on trips and it seems like we get the same 8-9 MPG either way, so I'd rather be driving with OD locked out and not having to worry about the tranny.. YMMV

mac

Please remove splinters before emailing

Reply to
mac davis

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