Has anyone changed the rear gear and was a speedometer calibration box required. I am looking at changing the gear to 3:75 fro the 4:56 and on the earlier Vipers this required the box (on the 03 & up SRT Vipers the speed sensors in the wheels eliminated the need for the box) but could not determine if the RAM had the speed sensors.

Also, has anyone lowered the truck 2" in the front and 4" in the rear and if so what if any were the problems?

Thanks for the assistance,

FANGS

 

Are you sure you want to do that? My truck turns only 1600 rpms at 80 mph in 6th gear. With 3:75s you're engine is going to run too slow and bog down a lot at freeway speeds. If you're doing it for the mileage, any gains will be minimal at best. I got 17mpg from Utah to California and 15 mpg on the return trip. That ain't bad!

Do you have an automatic QC or a manual RC? Dodge went to the 4:56 gears in '05 RCs to relieve some of the strain on the clutch. 3:75s are going to make it even worse. It's your truck and your call but I think you're opening a can of worms. Something like a gear vender might be a better alternative.

If you do go through with it, the speedo should automatically adjust to the gear change. Go to http://srt10forum.com and ask the guys there. They have a lot of expertise on SRT-10s. They can also answer your questions about lowering your truck.

 

Thanks and from the advise on the SRT form I am going to wait and test.

 

I think you'll be glad you waited. I watched the posts on the other forum and like 9 Seconds said, the wheel size of the truck makes 4:10s about the same as the 3:07 in the Viper. The 4:56s are probably more like 3:55s in a car.

Good Luck and enjoy your truck. If you're like me, you haven't been able to wipe the silly grin off of your face since you got it.

 

I think 4.10's would be a good choice. 3.73's is a bit extreme. I'm planning to change my gears to 4.10's shortly. 4.56s is the same as 3.14's in 4th (OD). 4.10's will make the gearing 2.82 @4th gear. It will drop the RPMs by 250. And also tow the same. You don't haul or tow in 4th. I've done 2 Dana60's the past year. All came out great. But you need new gears and a new Trak-Lok carrier. Patience and a half day of work. You need special tools (yoke holder), inch/lbs torque wrench, ft/lbs torque wrench, 1 5/16 socket in 3/4 drive, bearing separator, 20ton press, and dial indicator. Dial all the numbers in and the rearend will purr better than the factory. I'm not sure but I think the carrier uses a 30 spline and c-clip.

 

big asp, are the 4:10s the only gears they put in them in 04? I bought mine used and haven't looked yet. Is there a tag on the diff to identify them? Just curious. I thought mine had 4:56 but now I'm not sure. I thought I saw on the dealers sale sheet 4:56.

Added... Just looked at the tag in the glove box. It says 4:10. So I guess that answers my question.

Stretch


[quote]ORIGINAL: big asp

Dodge went to the 4:56 gears in '05 RCs to relieve some of the strain on the clutch.

 

04's only had the 4.10 The 05's only have the 4.56 gears. The speedo will not change because the rear wheel speed sensor tone wheel is mounted behind the ring gear. Only a tire size change will affect the speedo.

 

Stingray's right on.

Don't know why anyone would want to switch 4:56s for 4:10s. Anyone who does should just swap with '04 owners because most of them want the 4:56s.