Rear axle Gear Ratios

[surfbeetle]

Finally talked my brother in law into buying a cummins. He wants a 4x4 3500 SRW with an automatic. Can this be ordered with a 3:73 rear end? The dodge website only allows for the 4:10. Also, what is the top speed for both rear ends? My 95 with the 4:10s only does 85 mph. He doesn't want to be stuck going that slow. Thanks

 

[Guest]

You can get both I just got an 04. 5 w/ auto and 3. 73's, @ 75 mph I am @ about 2200 RPM's

 

[klenger]

See http://www.klenger.net/dodge/general-reference/gear-speed-calculator.xls for all the numbers.

 

[crobertson1]

I think mine turns about 2600 rpms at 80. I've had it up to around 100 but was too busy to notice RPMs. I know it was revving pretty high though!

 

[R.M.THOMPSON]

Just traded my 03 with 3. 73's for a 04 with 4. 10's,what a differance !!!!!!!!!!!! I'll take the 4. 10's any day. The trans stays in the power band all the time and that very annoying overdrive shift that drops the engine to about 1200 rpms at 50 mph is gone forever. As far as the top speed I'm sure it will hit 100 before redline(3200),as well as 95 mph should be no problem at peak H. P. (2900) So whats the differance ,Ill never go that fast anyway. These observations have been unloaded ,wich is how I drive most of the time and in moderate traffic as well. This has had excellant early results as far as fuel mialage goes also,engine does not have to load as much to make swift take off's (not speed demon stuff either),Just an observation... and as far as highway mialage goes I would suspect it will fair worse than my 03 if a constant speed is required. I have found that a constant 1800 rpms is were the truck feels best and gets the best economy and by the way 2000 rpms was 70 mph on my 03 and 2000 rpms is about 62 with the 04's 4. 10's Hope this answers some of your questions.

Just read past my spelling like bugs on the windshield... ... ... ... ... ... ... ... ... ... Mark T.

 

[Bertram65]

4. 10s are the better choice with the automatic it works out to be very close to the 3. 73s with the 6 speed for a final ratio.

 

[jelag]

How is he going to work the truck... if he is going to work it like I do... than the 4. 10 is a must. . I pull 15 - 20K lbs(trailer weight) about 80% of the time with my 04 dually... . for that weight you need the 4. 10's to hold the engine in the power band, pulling those hills with the trailer... ... My travel trailer, weights about 12K and if I just pulled it I'd have the 3. 73's.



Jim

 

[Casey Balvert]

My truck with 4. 10 axle hits the governor at 105 MPH, almost 20 MPH faster than my 1997 truck with same ratio. Fast enough and I need the 4. 10 for the load I tow.

 

[XcumminsX]

Originally posted by Casey Balvert

My truck with 4. 10 axle hits the governor at 105 MPH, almost 20 MPH faster than my 1997 truck with same ratio. Fast enough and I need the 4. 10 for the load I tow.

WTF? what rpm's are you running at 105?

 

[surfbeetle]

Thanks for all of the info. My bro-in-law took his family down to the dealer last night, they will end up ordering an '05. His travel trailer weighs only around 9,000 lbs. I think that 3:73's would be fine based on all of your comments. The majority of the time, they will drive it around empty. Now about that Jake brake, I wonder if the 2005 with auto will be warranty approved for the Jake brake...

 

[RankRam]

surfbeetle "Now about that Jake brake, I wonder if the 2005 with auto will be warranty approved for the Jake brake... "



I highly doubt it!

 

[John - K5AWO]

RPM Deptartment:



I once followed a guy in a gas Suburban from Las Wages to Phoenix. He was going like he stole his rig. My 3500 w/4. 10s and 235R85-16s managed to keep up with him nearly all the way. Speedo indicated 93-95 all the time. The GPS showed 100+ occassionally.



What was neat was the hills, I would catch him there with the turbo singing a sweet song. On the downhill runs he out ran the rev limiter. Don't remember what the RPMs were now, but 3400+ comes to mind.



Betcha the tire circumference changed a tad at 90+ mph...

 

[klenger]

48RE and exhaust brake: I have heard that the hardware changes to the 48RE have been incorporated in the transmissions built within the last couple of months. Any truck with the newer transmission should be able to add an exhaust brake as soon as the software is available. This is just rumor, so don't quote me or make financial decisions based on this info.