Puke

I have read references to 4.10 and 3.55, can I assume we are talking about a particular type of rear end.???

Please update me on this if you know.
I have a 98.5 24valve. Would like to increase my fuel economy.
Don't care much about power, and I don't tow.

DODGE4X4

4.10's are for heavy pulling and in turn you get less mpg.
3.55's are a good all around gear and you should get better mpg.

Yes these gears are in you axles front and rear if you have a 4x4.

I am sure someone else will chime in and give you better advise on this.

By the way what does your truck have? You should be able to look in your glove box on it’s door for a sticker that should tell you what you have. That is where mine is.

billg

This is in reference to rear end gear ratio. A 4.10 means the drive shaft will turn 4.10 times to one turn of the wheels. For better fuel mileage you want that number to be as small as possible. In our case that will be around 3.55. You can see what you have as stated above and there should be a tag with the ratio stamped on it on the rear end.
You also want to keep the engine in the power band for best efficiency. Timing boxes like the Edge EZ can help with efficiency with the side effect of more power (if you can keep your foot out of it). The extra horsepower let’s you get to the higher gears faster and stay there longer. Which means you can go further on less fuel. This is a very simple explanation there is a lot more to this. Things like keeping the filters changed, type of fluids, tires, driving habits. If you have a boost gauge you can learn to keep the boost down without lugging the engine. You will be surprised how much that can help.
Hope this helps.

6cylinders

"Don't care much about power" ,,,You just ain't going to fit in around here! Sorry, couldn't resist, just joking.
Have you tried changing all your fluids to synthetic?
As mentioned above an Edge EZ will get you a little better MPG, if you can keep your foot out of it. Is the truck 2 or 4 wheel drive?
If you are 4 wheel drive you would have to change both differentials, if you have 4.10 and changing to 3.55.

Puke

I'm just a 2 wheel drive.

For the record.
Had I known the computer had ANYTHING at all to do with the transmission shifting points, I would have NEVER IN A MILLION YEARS bought an automatic. (Even though I live in traffic jam hell los angeles.) What's done is done. I just need to make the best of it. I'll be checking under my truck tomorrow for that 4.10 tag or 3.55 tag or whatever it is.

Mopar1973man

I will admit I got the 4.10 gears in my 02 CTD. I glad I did because of the hill climbing and trailer haulin' (firewood)...

The small loss of 2 MPG isn't to bad for the extra power to the ground.

Puke I was a Californian... Then I move to Idaho... Where the nearest freeway is over 200 miles away!

Puke

I just checked. My ratio is 3.55

I have a 24V 98 1/2 automatic 4 sp.

quad cab 2500SLT

2WD.

Where in Idaho are you 200 miles from a fwy.????

I grew up just south of there. Unless you are on the back side of the bitterroot range??? or someplace.
I have been tempted more than once to pick up and move to sun valley.

THanx for the posts.

Rattletrap1

In extreme cases the 4.10 is better suited to extreme towing. But then of course HaulininDixie prolly hauls more weight than anybody here on a regular basis with 3.55's.

The new ones come with 3.73's which is prolly perfect for all around use.

FWIW my 6 speed is running 2k rpm @ 70 mph in 6th, 65 mph @ 2500 rpm in 5th (or pretty close). That keeps the engine in it's zone when on the flat and pulling a grade (I have 3.55's).

RowJ

When I went looking for a used 2002 CTD, I found everything I wanted - but was an automatic. I settled for it, but the more I learn about them, the more comfortable I am.

Don't be to quick to look down on a computer controlled Tranny. They have been around for quite a while and Dodge has all the kinks worked out. I'm no tranny expert but I can tell you my stock version worked beautifully from 6500 lbs up to 9300 lbs.
And with a DTT upgrade - it's spectacular!

Unless you plan on very heavy towing - be glad you have the 3.55 rear end. Better fuel mileage and plenty of power. 2,000 rpm at 75 mph is perfect, IMHO.

I made the hill climb from LA to Barstow about a month ago - best test bed for checking out new mods I've ever seen. Wish I had a climb like that around here!
Good Luck

Rowland

Puke

"All the bugs worked out" in their auto. tranny software..... I'm not sure I believe that. At least for my 24V 98 1/2. It has been re-flashed twice since it was new. In my opinion, they just took my old problem and traded it for a new one. One which will cost me thousands of dollars over the life of my truck,,,,unfortunately, thousands of dollars THAT SHOULD NOT NEED TO BE EXTRACTED FROM ME>.

Does that mean they should be able to explain (to me and anybody else) why very often the miles per gallon decreases when they re-flash the software??? (You can find that on almost any dodge diesel chatboard). Especially in my case.

And also why that is supposed to be a good thing?? (I'm already sur4e they are going to explain to me why that is a good thing...soooner or later if I get to the bottom of it),.

Especially to those of us who do not tow.

I worked it out and that is a wasted 300 gallons of fuel per year (in my case).

I do not believe they are near as smart as some people think. I spent too much of my life overestimating the intelligence of whoever.
And believe me, I would sure like to think otherwise.
When I went in to talk to them about it, the official "cummins" dude at Glendale dodge wanted to
1) explain to me how he is an official dude schooled by "Cummins"
1 1/2) change my serpentine belt
2) change my fuel filter,
3) change my coolant
3 1/2) adjust my valves (like the clearances all of a sudden changed when they re-flashed my software....what an idiot).
4) ask me about selling me some mods to upgrade my miles per gallon.
4) GET MY DRIFT...THe last thing he even heard from me (which was the ONLY thing I told him) was that my mpg. was at one point before the re-flash, and another point after the re-flash. Everything else remained the same (except how ****** off I was at Dodge). Well, my shifting points did not remain the same, and I did tell him that.

The last thing that idiot wanted to do was actually troubleshoot a REAL PROBLEM that not just anybody can solve. Apparently, he wanted to be a "just anybody", and will forever be that in my book.

OK, I'm getting myself all ****** off just making this post. So I better log off.
Later,
Puke
Hope someone out there has some answers.
I wanted to adjust my valves one of these days, but I know I don't want to touch anything until the problem at hand is corrected. That way things won't get blurry.

RowJ

You raise some good points about dealerships. Like any service industry, they are only as good as the people you deal with.

You don't mention what mileage you do get? Are you unhappy with that or is it a loss of mileage since a reflash?

Have only been back to dealer twice, both times taped 3x5 card on steering wheel "PLEASE, Do not reflash-runs great as is". Can't prove it but believe reflashes have more to do with emissions than owners concerns. I would try to find or make a friend at the dealer who can get hold of the original factory flash, if possible.

On the other hand, if mileage was my primary concern, I would not be driving an automatic.

Puke

My miles per tank (my around town driving in Los Angeles) was at about 390 miles before the light would come on. Give or take 5 or 10 miles. I could always tell by my trip meter when the light was going to come on. (The whole life of the truck, the lowest in towno mileage it got was 370 miles on one tank a while back).

After the re-flash, it got 305 to 310, I may have made it to 315 a couple times. It was so different, at first I thought it was a mistake. So I let a couple tanks go through before I called them and

Puke

Oh,
My in town mileage was around 14 before, once in a while 15.
Now it is closer to 12,

On the freeway, I will get the standard 18 or 19 miles per gallon if I keep my foot out of it. (I have not done a freeway trip since my re-flash, about 15 tanks back. So I can't say if my freeway mileage is still the same)