| From | Message |
mike p
Dodge Dakota
7/30/2001
23:01:06
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 Subject: Diff. Gearing
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Message:
This is sort of a dumb question,
if I replace the REAR Diff. gearing from 3.92.1
to 4.10.1 do I also replace the front Diff. too?
I have a '99 DAK 4x4 , I think I should , but am
not sure .
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J. C. Brandon
Dodge Dakota
7/31/2001
00:28:41
|  RE: Diff. Gearing
IP: Logged
Message:
Yes.
Some folks will say there's an advantage to having a slightly different ratio so that the front "pulls more." But I've never seen an engineer or other reliable expert recommend that. And no 4x4 comes from the factory with different ratios.
Remember, the diff ratio describes how many revolutions the driveshaft makes for each single revolution of the tires. Currently both front and rear driveshafts are turning 3.92 times each time the wheels make one revolution (in a straight line, when all wheels have equal traction.) If you have different front and rear gear ratios something will have to give. Most likely it will be traction at one of the axles. So you'll be breaking traction. You don't want that.
What are you trying to accomplish with a gear ratio change?
-J.
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mike P
Dodge Dakota
7/31/2001
10:40:56
|  RE: Diff. Gearing
IP: Logged
Message:
I am lifting my truck W/ a 3" suspension
and 2" body lift , then installing 32" tires
now I've been told that the truck will work
ok with the 3.92's & 32" tires, but would work
much better with 4.10's , thus the reason for
the gear change :)
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kota4bye
Dodge Dakota
7/31/2001
12:12:47
| RE: Diff. Gearing
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Message:
Spend your money on more performance mods. Going from 31's to 32's is only going to change a couple hundred rpm's at most. I'm running a 3.55 with 32's. I would prefer to have a 3.92 now, but if I spend the money for gears they'll be at least 4.10's maybe 4.56's with 35's.
In short, I couldn't justify $800 to regear because of a tire diameter increase of an inch.
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J. C. Brandon
Dodge Dakota
7/31/2001
12:29:16
| RE: Diff. Gearing
IP: Logged
Message:
What motor and transmission do you have? What size tires are you running now? Do you pull a trailer?
I have the 4.7 liter with an automatic, 31" inch tires, and 3.55 gears. My truck climbs and accelerates more than adequately both on and off-road. I don't pull a trailer.
A smaller engine might not have enough torque and would require lower gearing with 32s. Likewise a manual transmission, as it does not benefit from the torque multiplication of an automatic.
You could budget for the gear change but wait a while before doing it. Drive the truck for a bit after you change to the bigger tires. If it needs the gear change, you'll know it. If not, spend the money on something else. Remember that the larger tires will give inaccurate speedometer readings so factor that into your decision. That is, if fuel mileage, engine wear, and top speed are factors in your decision process they will be affected by the new speedo readings.
-J.
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mike P
Dodge Dakota
7/31/2001
13:46:38
| RE: Diff. Gearing
IP: Logged
Message:
I have a '99 Dak CC 4x4 , it has a 3.9L V-6,
with a automatic OD tranny , right now I
am runnung 31x10.5 15 tires W/3.92.1 gearing,
No I don't pull a trailer .
I will be installing 180 degree T-Stat, Brass
contact cap/rotar, cold air intake, JBA headers,
autolite plugs, JBA power cables, and later on
48mm flometrics TB and Accel ignition Sys.
I already installed a Dynomax "super turbo"
single in single out cat-back exhaust
So your saying that I shouldn't change the gearing
the 3.92.1 will be ok?
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J. C. Brandon
Dodge Dakota
7/31/2001
18:39:01
| RE: Diff. Gearing
IP: Logged
Message:
I'm saying don't commit to the gear change until you are sure you need it; after the tire change. You may not need it with 32s.
Are those the biggest tires that will fit with your lift plans? Seems like a lot of money and work for just 1/2 inch of ultimate ground clearance.
If I were going to lift my truck, I would go with the biggest tires that fit. That would probably mean bigger wheels and new gears. Lifting a truck for better off-road performance quickly gets to be an expensive project.
That's why my truck is at the stock height. But I don't let that confine me to pavement. These trucks are amazingly capable, if you drive with care. I often get to watch guys in modified Jeeps bark tires and scrape paint on an obstacle and then watch me motor sedately on through. With the air conditioning on. Then I get to drive home at 80 mph with the CD player on. I like being able to say "I drove through there in a stock truck."
cheers,
-J.
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mike P
Dodge Dakota
7/31/2001
20:41:48
| RE: Diff. Gearing
IP: Logged
Message:
Thanks for the Info.
BTW / I really don't do a hell of alot off -
roading, maybe 2/3 times a year. I just want to lift my truck cause I like the look.
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Eric
Dodge Dakota
JOIN HERE
10/24/2005
15:45:13
| rotars
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Message:
I have a cracked rotar on my 2002 dodge dakota 4x4 quad cab truck. To change the rotar, do I simply take off the brake system, take off the old rotar to change it? Or I is there something else that needs to be done? My truck is a V8 4.6 Ltr. and is AWD. I've already had my rotars turned once, so they need to be changed.
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Brian22
Dodge Dakota
JOIN HERE
10/24/2005
15:57:52
| RE: Diff. Gearing
IP: Logged
Message:
To pull the rotor off.. should just unbolt the caliper and it should come right off...
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