4.88 gears and 6 speed auto...questionSince

[KBalzuweit]

Since 4. 88 gears are the only option with an auto. What kind of rpm's will it be turning at 70mph??

 

[Wiredawg]

We could probably figure this out if we compare the 3500 CC w/ the 5500 CC.

I think I saw about 1950 RPM at 70mph on the 3500 w/ 4. 10s. Are the 19. 5 tires taller than the 17s? Find and compare the height of the 17s and the height of the 19. 5s This also assumes the gearing on the Aisen is the same for the two



My WAG is 2,200 to 2,400 rpm @ 70.



If someone ever gets one we can use the scientfic method of observation.

 

[klenger]

http://www.klenger.net/dodge/general-reference/gear-speed-calculator.xls



Plug in the correct numbers and have a ball.

 

[jelag]

Wiredawg.....

Our SWAG on the new 5500 we have on order was 2400-2500 @ 75... so we've got to be close...

On our F550, we had it like10 days and we pulled the rear end and changed the ring and pinion... found a different set that would fit... and work. . we had to modify the ring gear to accept the tooth wheel for the speedo and abs. . that truck now has 500K miles and we still have the factory ring and pinion set in the box with about 1000 miles on them... .

If its not what we want, we'll change it... .

 

[HBarlow]

Since 4. 88 gears are the only option with an auto. What kind of rpm's will it be turning at 70mph??

Karl,



I'm not sure that the 4. 88 is the only option. I forget the details now but I was thinking the 4500 comes standard with something like a 4. 4 depending on whether it was manual six speed or Aisin six speed automatic and the 4. 88 was an option.



Harvey

 

[KBalzuweit]

Karl,

I'm not sure that the 4. 88 is the only option. I forget the details now but I was thinking the 4500 comes standard with something like a 4. 4 depending on whether it was manual six speed or Aisin six speed automatic and the 4. 88 was an option.

Harvey

When I built one on Dodge.com if you selected the auto it showed only the 4. 88(it said "4. 44 Axle Ratio is not available with 6-Speed Automatic Transmission. "). From the calculations I have done @ 2000 rpm the speed will be 62. 3 mph. My 07 Mega at 2000 rpm (w/ 3. 73's) is 68. 5 mph. Now if you could get the 4. 44 gears it would be 68. 5 mph also.

I am having a tough time with rpm/speed of my mega so the 4. 88's are not an option for me. Heck anything over 70 in my mega and fuel economy drops off quickly!

 

[FATCAT]

That RMP calculater is nice.



The 4. 88 with 19. 5" wheels and the 6-speed manual G56 would be a screamer: 2400 RPMs at 65 mph. , max speed of 90mph.

 

[HBarlow]

When I built one on Dodge.com if you selected the auto it showed only the 4. 88(it said "4. 44 Axle Ratio is not available with 6-Speed Automatic Transmission. "). From the calculations I have done @ 2000 rpm the speed will be 62. 3 mph. My 07 Mega at 2000 rpm (w/ 3. 73's) is 68. 5 mph. Now if you could get the 4. 44 gears it would be 68. 5 mph also.



I am having a tough time with rpm/speed of my mega so the 4. 88's are not an option for me. Heck anything over 70 in my mega and fuel economy drops off quickly!

Karl:



I have an "08 Dodge Commercial" brochure I picked up recently from a big Dodge dealer over in Fort Wayne who has set up a Business Link facility to become an authorized cab and chassis dealer. The brochure, which seems to be very professionally done, shows that the standard axle ratio for trucks with Aisin automatics will be 4. 44 for 4500s and 4. 88 for 5500s. That makes sense to me and I hope it is correct. The same brochure indicates that with the manual G56 the 4500 will have 4. 10 gears and the 5500 will have a 4. 44. It also shows the "optional axle ratio" on a 4500 is 4. 88 and no option available for the 5500 chassis.



I suppose the brochure could be wrong and the website right but it is probably the website that is in error. The websites usually contain errors in my experience.



Harvey

 

[CUMMINZ]

I am sure the gear ratio from an engineering stand point,, you can't compare 4. 10s to 4. 88s considering whether the truck has 17s or 19. 5s. The truck's gear design would know if the truck had 19. 5s... They would then calculate the design of the r5ing gear/pinion for that rear end. ie: here is drive shaft/here is 19. 5 height tire/here is what ring gear matched with pinion. It comes out to 4. 44, etc.



Truck with 3. 73s with 17 inchers would be done same way.



All that would be calculated by engineer and given to design folks and then manufacturer would build gears.



Either way the 4. 44/4. 88 would not be bad gear with auto. To pull 26k and greater you are going to need pretty good gear.

 

[Wiredawg]

KBalzuweit,



Us part time RVers have big concerns about RPMs of trucks @ 70 MPH, since we tow at that speed and run empty a lot at that speed. Here are some of the thoughts I'm going through as I decide if I want a 4500 or 5500:



I want to drive a 4500/5500 before purchasing. Right now, it seems production hasn't caught up with the ordering demand. I believe a 4500/5500 is (or should be) capable of achieving 15 to 17 mpg empty with the right gearing. I suppose the engineers design to operate at max GVWR and GCVWR in the top overdrive. With the electronics of the transmission and motor, the setup should be able to sense load and automaitically select the gear that achieves max economy. From my perspective, I would like 70 MPH @ 1900 rpm in top overdrive and drop down (lock out) to a lower gear when towing.



Just like right now w/ my 02 and 4. 10s. The sweet spot on my motor is 2,000 RPM, but 70 has me about 2,375 RPM. If I don't like the 4500/5500, I am considering a US Gear overdrive unit to give me better unloaded mileage. If I can get 1. 5 to 2 mpg it would not take long to pay the estimated $3k price tag. Right now I get avg 13. 5 mpg empty and 9. 2 towing 17K lb 5er.



Further, I estimate the price of a 4500 4X4 SLT QC w/ Aisen will be somewhere around $45K to $50K out the door, then another $5K to $8K to outfit a body. I realize we shouldn't be all that concerned about fuel mileage when we are talking about spending $60K for a truck to tow an $80K 5er, but it is not outside the realm of rising fuel prices to see $5/gal for diesel. I would put about 23K miles a year on this vehicle.



So, I'm hoping the folks who ordered their 4500/5500 will give us frequent report and see fuel numbers. I need the truck to get at least what my 3500 is now in fuel mileage.



Wiredawg

 

[KBalzuweit]

KBalzuweit,



Us part time RVers have big concerns about RPMs of trucks @ 70 MPH, since we tow at that speed and run empty a lot at that speed. Here are some of the thoughts I'm going through as I decide if I want a 4500 or 5500:



I want to drive a 4500/5500 before purchasing. Right now, it seems production hasn't caught up with the ordering demand. I believe a 4500/5500 is (or should be) capable of achieving 15 to 17 mpg empty with the right gearing. I suppose the engineers design to operate at max GVWR and GCVWR in the top overdrive. With the electronics of the transmission and motor, the setup should be able to sense load and automaitically select the gear that achieves max economy. From my perspective, I would like 70 MPH @ 1900 rpm in top overdrive and drop down (lock out) to a lower gear when towing.



Just like right now w/ my 02 and 4. 10s. The sweet spot on my motor is 2,000 RPM, but 70 has me about 2,375 RPM. If I don't like the 4500/5500, I am considering a US Gear overdrive unit to give me better unloaded mileage. If I can get 1. 5 to 2 mpg it would not take long to pay the estimated $3k price tag. Right now I get avg 13. 5 mpg empty and 9. 2 towing 17K lb 5er.



Further, I estimate the price of a 4500 4X4 SLT QC w/ Aisen will be somewhere around $45K to $50K out the door, then another $5K to $8K to outfit a body. I realize we shouldn't be all that concerned about fuel mileage when we are talking about spending $60K for a truck to tow an $80K 5er, but it is not outside the realm of rising fuel prices to see $5/gal for diesel. I would put about 23K miles a year on this vehicle.



So, I'm hoping the folks who ordered their 4500/5500 will give us frequent report and see fuel numbers. I need the truck to get at least what my 3500 is now in fuel mileage.



Wiredawg

I run 62-63mph towing and get 10. 5-12. 5mpg depending on what I am towing. Empty I run 70mph and get 18-19. 5mpg, I run 150-175,000 miles a year.



As far as a US Gear unit do some homework, I have found to many comments on problems. I also contacted a dealer of theres and they had just quit selling do to to many issues and warranty hassles (very reputable dealer, not some hack shop).



I am looking into doing a tow and haul truck (one camper on the bed and the other in tow), so running empty I need to be able to run a decent speed and maintain some fuel economy. I also figure on the truck, bed, and sleeper to bring me to 60k or so. But if I can not operate it economically I do not want to spend 60k!

 

[KBalzuweit]

Karl:



I have an "08 Dodge Commercial" brochure I picked up recently from a big Dodge dealer over in Fort Wayne who has set up a Business Link facility to become an authorized cab and chassis dealer. The brochure, which seems to be very professionally done, shows that the standard axle ratio for trucks with Aisin automatics will be 4. 44 for 4500s and 4. 88 for 5500s. That makes sense to me and I hope it is correct. The same brochure indicates that with the manual G56 the 4500 will have 4. 10 gears and the 5500 will have a 4. 44. It also shows the "optional axle ratio" on a 4500 is 4. 88 and no option available for the 5500 chassis.



I suppose the brochure could be wrong and the website right but it is probably the website that is in error. The websites usually contain errors in my experience.



Harvey

I hope so, I am going to talk to a dealer on Monday and see what he can find for me. I will let you guys know.

 

[HBarlow]

... ... ... ... ... I am looking into doing a tow and haul truck (one camper on the bed and the other in tow), so running empty I need to be able to run a decent speed and maintain some fuel economy. I also figure on the truck, bed, and sleeper to bring me to 60k or so. But if I can not operate it economically I do not want to spend 60k!

Karl,



I ran into a fellow transporter up in Alberta, Canada a year or so ago that had a tow & haul rig. His was a retired Class 8 OTR Volvo tractor with a big standup sleeper and one of the drive axles removed. It had a professionally set up ramp and winch set up on back. He liked it. I think a late model used OTR tractor retired from a big fleet with good maintenance can be bought much cheaper than a new 4500/5500 series truck and will probably do a better job.



Another possibility would be a used Freightliner or International MDT. There are hundreds of late model International 4300s with DT 466 engines for sale every year. I guess Penske and other rental companies use them for rental straight trucks with 24' or 26' boxes on back and trade them every two or three years. They have relatively low mileage and are reasonably cheap to buy.



I'll be interested to read about your rig if you follow through on your idea.



Harvey

 

[KBalzuweit]

Karl,

I ran into a fellow transporter up in Alberta, Canada a year or so ago that had a tow & haul rig. His was a retired Class 8 OTR Volvo tractor with a big standup sleeper and one of the drive axles removed. It had a professionally set up ramp and winch set up on back. He liked it. I think a late model used OTR tractor retired from a big fleet with good maintenance can be bought much cheaper than a new 4500/5500 series truck and will probably do a better job.

Another possibility would be a used Freightliner or International MDT. There are hundreds of late model International 4300s with DT 466 engines for sale every year. I guess Penske and other rental companies use them for rental straight trucks with 24' or 26' boxes on back and trade them every two or three years. They have relatively low mileage and are reasonably cheap to buy.

I'll be interested to read about your rig if you follow through on your idea.

Harvey

Just trying to stay away from going over 26k. I want to stay non cdl and avoid ifta. I figure with the 4500 I can still pull a 10k trailer and should have no problem with the one on the bed. Hoping to then put a driver in my mega and then we can team drive back with the mega on the bed. This is just an "idea" for now, its really going to depend on how fast I heal and get back to work and how the rv industry looks after the 1st of the year. Heck I don't need a 60k rig sitting in the driveway with no work.

 

[Cattletrkr]

I'm looking at my proposal for a Sterling CONV55 (5500) that has the Aisin auto listed along with "4. 44 rear axle ratio. " Top speed of 96. 3mph. It says the 6. 7L is governed at 2900rpm.

Not sure it's 100% correct, but that's what I've got in front of me.

 

[HBarlow]

Just trying to stay away from going over 26k. I want to stay non cdl and avoid ifta. I figure with the 4500 I can still pull a 10k trailer and should have no problem with the one on the bed. Hoping to then put a driver in my mega and then we can team drive back with the mega on the bed. This is just an "idea" for now, its really going to depend on how fast I heal and get back to work and how the rv industry looks after the 1st of the year. Heck I don't need a 60k rig sitting in the driveway with no work.

I understand your concern about IFTA. That magic number of 26k has a powerful effect on transportation. But you'll probably need a CDL to do what you are considering.



After a year or so as a transporter I started pulling for a company that pulls a lot of heavy triple axle 5ers. I was worried about getting busted on a scale with only an operator's license so I visited my local DPS office at home. I found it very easy to obtain a CDL class A. I read the free booklet, paid the fee, took all the exams on a computer terminal, then borrowed a tandem axle dual wheel flat bed gooseneck trailer with a GVWR of 20k, hooked it to my little Dodge dually, and took the practical exam. All in one day. I don't have an air brake endorsement because I couldn't borrow a truck with air brakes but also passed the air brake endorsement exams. I thought later I could have probably showed my new Class A license to rent a Penske box truck, some have air brakes, and taken the practical test with that. The clerk at the truck rental office would probably not have noticed that I didn't have an air brake endorsement on my license.



I know what you mean about waiting to see what the RV industry looks like after the first of the year. When both of us spend a day posting on the TDR like today its clear there are no trailer loads. This is the first time in just under three years I've been transporting that I returned from a haul and have no load and don't know when one will be available. I'm sitting around this weekend contemplating going back to being retired again. Maybe its time for me to quit.



Harvey

 

[KBalzuweit]

But you'll probably need a CDL to do what you are considering.



I know what you mean about waiting to see what the RV industry looks like after the first of the year. When both of us spend a day posting on the TDR like today its clear there are no trailer loads. This is the first time in just under three years I've been transporting that I returned from a haul and have no load and don't know when one will be available. I'm sitting around this weekend contemplating going back to being retired again. Maybe its time for me to quit.



Harvey

Well as long as I stay under 26k gross combined (16k truck and 10k max trailer) I can stay non cdl. I wish it was that easy for the cdl in IL. I have to go take and pass the written first, then make an appointment (2 month wait) to take the road test. A CDL A driver has to bring the truck and trailer there and wait with me to take the road test (they want to verify I did not tow it illegally). The other problem is I don't know anyone that has a trailer and I tried a couple places local to where I will take the test and no rentals.



I wish I could say I could quit and be retired like you said, but I am far from that point right now. Anyway what ever you decide I hope it works out for you and enjoy. Myself I am hoping the doc tells me tomorrow that my collar bone is healing and no surgery, I am going stir crazy sitting in the house and not being able to drive (right collar bone so shifting is not an option). Maybe a change is in my future too(freight or cars), I guess I will wait and see how the industry goes.



Karl



Edit: Got in to the Doc today, plate and some screws Friday. Guess no driving for a bit longer now.

 

[HBarlow]

Karl,



I thought about what you were saying about buying a Ram 4500 c&c, setting it up as a tow and haul, and staying under 26k. You are right. Actually that's not a bad idea now that I think about it. The GVWR of a 4500 is listed as 16,500 and you would probably only be towing a trailer with GVWR of 6k or 8k so the combo should work. I expect that the new Ram 4500/5500 trucks are going to sell like fresh popcorn at a movie theater as soon as they are delivered.



What happened to your collar bone? Were you in a crash?



I hung around the terminal in Topeka today watching the Amish horse-drawn buggies clop by. No calls except for two transporters with other companies looking for a job. Obviously no work at their companies. I saw only a trickle of trailers moving out of Topeka today. I'm on top of the list for a load but no idea when one might be offered.



Harvey

 

[KBalzuweit]

What happened to your collar bone? Were you in a crash?

I crashed on my ATV. Was out riding with my 9 year old and I did not make all the way up a hill and came down backwards and ended up getting tossed off. Thanks to my 9 year old (he got me up and rode me back on his ATV) I made it back to the parking lot were someone drove me to the hospital.



Hope you get a load soon,

Karl

 

[HBarlow]

Karl,



I'm sorry to hear of your mishap but glad it wasn't an accident in your truck with a trailer loaded. Best wishes on a full and speedy recovery. I guess if you had to be injured you "picked" a good time to do it. Our industry appears very slow right now.



If I don't get a load in another day or two I'm taking off on a "leave of absence. " I don't want to quit because I've become addicted to the road and addicted to being busy, needing to go somewhere, do something everyday. I'm afraid I will be severely bored and restless if I quit and would regret it. I think my company will be happy to have me on vacation but available if and when we get busy again.



Harvey