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CharlieL
Dodge Dakota
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8/16/2006
14:32:55
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 Subject: Tranny slipping while towing.
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I recently picked up an 04 Dakota ext. cab 2wd for towing a 3,500 lb travel trailer. 4.7, automatic (545RFE), factory tow package, 3.55 rear end (not limited slip), 11,000 miles, tires are 245/70R16 . I tow with a w/d & anti-sway hitch. When on the interstate I usually run O/D off (lots of hills in New Mexico). While going uphill, doing about 60-65 mph, the tranny will ‘downshift’ and rpm runs about 4,000 to maintain speed. The problem is that in this situation, (about half the time) it appears that the tranny will start to slip – rpm is maintained, speed decreases & engine noise will increase – sort of acts like pushing in the clutch on a standard while truck is under load. The only way to stop the “slipping” is to significantly decrease rpm and slow down substantially – which is not the preferred action while going uphill on a highway towing a load! Tranny fluid is full & no sign of burn. I haven’t changed tranny/rear-end fluid since purchase in early July. Any advice/ideas/suggestions would be appreciated…. Thanks!
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Kowalski
GenIII
8/16/2006
16:56:52
| RE: Tranny slipping while towing.
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Are you sure it's really slipping ? The 4.7 is a rev happy motor; especially when towing. Many of us who tow with the 4.7 auto leave the OD on - the 45RFE in my truck (very similar to your 545RFE) doesn't tend to hunt gears; shifting into OD only in low load situations. I pull a ton more than you in big NH hills - motor loves to rev - but no problem with slipping. It doesn't make sense that it would only slip half the time - if somethings wrong, it would likely slip all the time. You could just be oversensitive to the rpms.
Lead, follow, or get out of the way
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Obio3
Dodge Dakota
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8/16/2006
17:15:36
| RE: Tranny slipping while towing.
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I think your just hearing your fan cluch kicking in. As it picks up speed, it sounds liks the truck engine is. If it does this at times the fan cluch is not kicking in the there is something wrong. All so remembe when overdrive is out the trany has slippage, more so with a heavy load.All autos do this.
So many problems .... So little time
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CharlieL
Dodge Dakota
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8/16/2006
17:22:18
| RE: Tranny slipping while towing.
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Kowalski, thanks for the reply. Yep, I'm pretty sure the tranny is slipping - that's sure what it seems to be doing. When it happens, the rpm stays the same, the mph drops, & the engine sound increases - like pushing in the clutch on a standard, & if I give it more gas, the rpms increase without any increase in speed (in fact I continue to slow down). I really don't think I'm oversensitive to the rpms. It is a very noticeable effect & the tranny seems only to "re-engage" when I slow mph and rpms way down. I agree that it doesn't make sense that it slips about 1/2 the time, but then again not all hills are the same grade, either..... This is an oddity, that's why I'm seeking input.... I had no such problem with my 96 Dak (V6 auto) when pulling a 2,800 lb trailer - it was just underpowered!
BTW - Just double-double checked with dealer - they say from my VIN that tranny is 45RFE, not 545RFE.... my error.
Charlie.
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CharlieL
Dodge Dakota
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8/16/2006
17:27:24
| RE: Tranny slipping while towing.
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Obio3, I'm sure it's not the fan kicking in...... And you are telling me something I've never experienced before - that "when overdrive is out the trany has slippage, more so with a heavy load.All autos do this." Do you think that if I drive with o/d on that will eliminate/diminish any slippage? I've never had a similar issue with any other automatic pulling a heavy load...... 96 Dak V6 auto just slowed down - pulled my trailer up a +10% grade in Utah without any slippage. ....... Thanks for the input.
Charlie
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Kowalski
GenIII
8/16/2006
17:41:51
| RE: Tranny slipping while towing.
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Your speed can go down on a hill while the rpm stays the same - its working harder. For the motor to be louder at the same rpm, that could well be the fan clutch as Obio3 say. I've heard line pressure goes up slightly with the OD off though - that should mean less slippage not more. I think you'll find its the dealer wrong about your tranny - not you. My older '00 has the 45RFE; your '04 should have the 545RFE - basically the same tranny, with different programming. Some of the older jeeps got reprogrammed from the 4 speed version to the 5 speed version - the difference is more in the electronic programming than the tranny - I think there is something like 8 different gears technically possible with these planetary gear type transmissions.
Lead, follow, or get out of the way
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CharlieL
Dodge Dakota
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8/16/2006
18:06:08
| RE: Tranny slipping while towing.
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Kowalski.... Of course my speed drops going up hill. However what seems to happen is that suddenly I lose power - engine noise increases, rpm stays about the same & mph drops, then to recover I have to slow way down & decrease rpms. The fan clutch could be the culprit for more engine noise. However, to me that wouldn't seem to explain why when I give it more gas, the rpms increase as if there is no load & I continue to slow down almost as if vehicle was put into neutral. - sort of like when speed governor kicks in. This is something that is very much noticeably different than the way my 96 V6 Dak acted pulling a load. Thanks for the clarification about 545 v 45RFE. I'm far from being an expert on that!
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Kowalski
GenIII
8/16/2006
18:14:33
| RE: Tranny slipping while towing.
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Still under warranty ?
Lead, follow, or get out of the way
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CharlieL
Dodge Dakota
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8/16/2006
18:33:44
| RE: Tranny slipping while towing.
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K.... Yep....still under factory warranty. I intend to take to dealer before heading off on my next planned trip. My concern, though, is duplicating the problem.... Maybe the tranny just needs adjustment?????
BTW - Lead, follow or get (the h...) out of the way is a saying many a Marine I've known has used... Are you former USMC?
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Obio3
Dodge Dakota
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8/16/2006
23:39:49
| RE: Tranny slipping while towing.
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CharlieL.... Try staging your truck. You will be surprised how much the RPMs will go up without moving. Compare that to your problem. In reality trying to fix a truck over the internet is very dificult. Otherwise if I drove your truck I might well agree with you.A dealer will test drive your truck empty and tell you he sees no problem. Your going to have to somehow get him on the road with the trailor and in the conditions that causes this to happen . Good luck.
So many priblems .... So little time
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CharlieL
Dodge Dakota
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8/17/2006
11:05:55
| RE: Tranny slipping while towing.
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Obio3..... I wholeheartedly agree about trying to fix a mechanical issue over the net! Without eyes, ears and hands-on, it's near impossible. I was hoping someone might have had a similar problem that I could take some hints from.
I'll take your advice about duplicating the problem with the dealer - The truck works great empty & accelerates uphill just fine without a load, so driving it empty would not duplicate what I'm experiencing.
Could you please explain what you mean by "staging"? I don't understand the term.
Thanks for your input.
Charlie
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Kowalski
GenIII
8/17/2006
15:25:30
| RE: Tranny slipping while towing.
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Nope, not a marine. Just don't care for those who don't belong in the left lane !
Unlike the other autos, there are no bands to adjust (or slip) in your tranny. Another way they might duplicate the problem would be on a dyno - if they have one; but most don't...
At least having the dealer look at the problem will show you reported it while still under warranty - so even if they say they can't find anything wrong, it would be a good idea to get that in writing.
Lead, follow, or get out of the way
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Obio3
Dodge Dakota
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8/19/2006
19:32:15
| RE: Tranny slipping while towing.
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Staging is simply sitting in one spot holding the brake and punching the gas pedal. Used for drag racing or any sort of speed run. I do not do it and do not recomend it. But to do at least a modest one will show you the slipage in an automatic.
So many problems .... So little time
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jayb
Dodge Dakota
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8/20/2006
23:41:17
| RE: Tranny slipping while towing.
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if it does slip, and its under warranty, just floor it while switching from reverse to drive. that way they have to replace it. if you bring it in, and say its slipping they will never fix the problem and say there is no problem with the way these shady dealers are.
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Kowalski
GenIII
8/21/2006
15:20:58
|  RE: Tranny slipping while towing.
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Dealers will likely know the type of damage caused by jayb's suggestion and deny that warranty claim, the sheared damage will obviously be from abuse...
Lead, follow, or get out of the way
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Dougo
Dodge Dakota
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8/21/2006
18:31:39
| RE: Tranny slipping while towing.
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I had the same problem this summer. I have a 2002 Quad cab with the 4.7. I pull a 17 foot trailer, max weight is about 3000 lbs. I have a transmission cooler installed on the truck. While climbing a long grade in the B.C. Mountains the transmission started to slip. I know it was slipping as the revs were increasing but the unit was slowing down. I pulled over right away and let the truck cool off. The rest of the trip I took it easy and when I returned home I had the transmission checked. The Dodge dealer said there was a high temp code from the transmission, but could not find any problems. They checked the pan for filings and found none. I had them change the oil and filters. When I bought the truck I made sure I did everything right to protect the transmissions when towing. I was very disappointed when the transmission started to slip. Still don't know if the problem will come back.
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jayb
Dodge Dakota
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8/22/2006
11:30:25
| RE: Tranny slipping while towing.
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thats why i like my 93 4x4. the auto can never make up its mine on what gear to stay in, but they seem to be more reliable than the newer electronics.
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