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Shatto
Dodge Dakota
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6/27/2006
03:26:47
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 Subject: Engine Braking with the Automatic Transm
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Message:
Automatic owners know that if the overdrive is disengaged, the downshift causes engine braking.
Problem is; if the slope is right, you'll keep picking up speed.
Cure;
Disengage the overdrive.
Select your speed.
Set your Cruise Control.
You will be delighted to discover the speed will be held.
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modain
GenIII
6/27/2006
13:15:50
|  RE: Engine Braking with the Automatic Transm
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Message:
That's pretty cool. I'll try that out on my Durango.
What's your left foot doing?
=========================================
2002 Graphite QC SLT Plus, 4.7L, NV3500, Superchips 3715, 3.92 LSD, loads o'fun...
2001 Patriot Blue Durango SLT, 4.7L, 45RFE, Superchips 3715, 3.55 Open (for now)
1999 Forest Green Dakota RC Sport, 2.5L, NV1500, 3.55 Open
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Graphite_Dak
Dodge Dakota
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6/27/2006
13:31:19
| RE: Engine Braking with the Automatic Transm
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Message:
I do notice that when using the Cruise Control when going downhill it WILL disengage the OD to slow you down on it's own.
Other than that, I wouldn't drive with the OD off at all times just to hold a rock steady speed. The gas mileage would suffer.
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DanK
Dodge Dakota
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6/27/2006
14:37:05
| RE: Engine Braking with the Automatic Transm
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Message:
The wife's 2000 Grand Cherokee (4.7, 545RFE and AWD) will automatically lock up the torque converter when using 2nd gear down a hill at about 35-40mph. Works great. Don't have to overwork those crappy Chrysler brakes.
My 2004 Dakota (4.7, 545RFE and 4x4) doesn't do that unless I use the cruise control method, as Shatto stated above.
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jerry
Dodge Dakota
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6/27/2006
17:53:18
| RE: Engine Braking with the Automatic Transm
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Message:
I put in in 2nd going down a hill too. I heard that it is not good for the engine to do this though, It was said that you may save money on brakes that way, but you will pay out for a ring job later. Myth or fact?
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Kowalski
GenIII
6/27/2006
18:31:42
| RE: Engine Braking with the Automatic Transm
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Message:
I think myth, this is common practice with a manual tranny. I do this on a long downhill run towing my boat; beats overheating the brakes...
Thanks for the tip, Shatto - I'll have to give that a try.
Lead, follow, or get out of the way
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DanK
Dodge Dakota
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6/27/2006
19:31:34
| RE: Engine Braking with the Automatic Transm
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Message:
Well Jerry. Whenever a lower gear is used to help control speed down a hill, whether manual or automatic transmission, it only makes good sense to keep a close eye on RPM so as not to force that engine to spin too fast.
These engines have rev limiters on them, but they only work if the engine is turning in response to a gas pedal input. Rev limiter is fairly useless when the engine is being spun by the transmission in a downhill run.
The general school of thought, though, is that brake rotors, pads, or shoes are much cheaper than any automatic transmission work. That's why downshifting some automatics is usually not recommended.
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toolfan
GenIII
6/27/2006
23:35:46
|  RE: Engine Braking with the Automatic Transm
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Message:
I'm shocked you guys have never done that on downhills before. i think its called compression braking. your just using the engine to slow you down cause the tires are only going to spin as fast as the engine.
its a great thing when you are dirt bike riding and have to go down a step hill, you just leave it in 1st gear with the clutch out.
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Josh
Dodge Dakota
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6/28/2006
08:38:17
| RE: Engine Braking with the Automatic Transm
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So many people who drive automatics think the lever stops at "D".
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Levey
Dodge Dakota
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6/29/2006
02:17:24
| RE: Engine Braking with the Automatic Transm
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Message:
Nowadays...most people who drive dont seem to think at all!
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shatto
Dodge Dakota
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6/30/2006
02:14:29
| RE: Engine Braking with the Automatic Transm
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Message:
Re: using 2nd to brake; I read somewhere, the reason race car drivers don't use the engine is brakes are cheaper.
Of course, we are talking long downhills, miles maybe, and loads.
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