Rear END!!!

[TORQUE THIS]

Can my 4. 10 gears be changed over to a 3. 55. Will it have any effect on limited slip? Can I get the 3. 55 in a posi traction?

 

[Bob Wagner]

yes it can

check the archives another member is doing the same switch and he posted yesterday

 

[TORQUE THIS]

Thank You!!!!

 

[hdtrukn]

Just a thought

I am in the same boat,4. 10 gears.

Checked out a lot of options, overdrives/gear changes.

Decided to go with a taller tire.

My stock tire is a 215/85/16, I am going to a 235/85/16

Almost a inch difference, almost 4mph faster at 65mph or 140rpm

less.

Not sure what you could go to, I think your stock tire is 235/85/16

Just a thought

Scott

 

[CCBrady]

For what its worth, I don't think you would like the way your truck tows with 3. 55 gears! I just got home today from a trip up through Canada, the Jasper and upper Banff area, lots of Mtns. and running at about 2500+ RPMS the whole time I was in them. I don't think I got into O/D more than 10% of the time, even on the flats. Just not enough Rpms. I LOVE my truck, but it will get a new set of 4. 10 gears along with all of the other tricks and toys I am planning to put on it.

PS. SWorrall, to bad your on the wrong coast or I would trade rear ends with you in a heartbeat.

 

[Lsfarm]

Do you only tow??

For me I couldn't live with 4. 10 gears, even though I do tow a somewhat heavy load occasionally, [ about 10,500#, 17,700# gvcw].

The top speed and responsiveness on the freeway when not towing is too limited. Top speed with 4. 10 gears about 85mph.



Besides, I love to leave the traffic behind with the amazing torque and acceleration available at 2200 rpm = 80mph , punch it and I'm at 90 in seconds. .



I think that it is better for my trans to be towing with the OD locked out anyway, which leaves me the equivalent gearing of 4. 10 gears in overdrive. [top speed about 80 mph]



Just my driving style, maybe I need 4. 10 gears before my driving record points equals my age!!



Greg L

 

[KatDiesel]

Re: Do you only tow??

Originally posted by Lsfarm

The top speed and responsiveness on the freeway when not towing is too limited. Top speed with 4. 10 gears about 85mph.



Besides, I love to leave the traffic behind with the amazing torque and acceleration available at 2200 rpm = 80mph , punch it and I'm at 90 in seconds. .

Um 4. 10 geared trucks are not limited to 85mph. I can get the speedo to over 100mph (not corrected for slightly bigger tires) but never the less it would do a 100mph easy with the stock tires (265/75/16). I don't tow anything and wouldn't trade my 4. 10's for nuthin... ...

 

[Lsfarm]

RPM limited??

My above post was based on experience driving a '97 3500 with 5 speed.



This truck would only turn 85 mph flat out with both feet on the acc. pedal. The rpm indicated was 27-2800rpm



The 24 valve has a higher rpm limit, so I stand corrected; a 24 valve truck will exceed 85 mph, if you want to turn the RPM.



Doesn't the injection pump start defueling above 2700 rpm to limit horsepower and torque??



Anyway, personal preference for me is 2200 rpm = 80 mph.



Just my $. 02, some like blondes some like redheads!!



Greg L

 

[jjohnson1177]

3:54s are the way to go, with a six speed you can always drop it a gear if needed. I've had 4:10s and it was to much rpm on the highway.

 

[MCummings]

Call up Reider Racing, Check these posts for phone numbers, and info.

If you want to go to a 3. 55 ration,, You MAY want to try a 3. 23. the 3. 23 ratio is hard to get, but it is out there for the Dana 80. It is used in Trolleys that have the Dana 80.

The advantages of a 3. 23 would be RPM closer to the "power band" when towing (using 4th gear) and good MPG when Empty.



Here is my story of wanting to change rear-end ratio





https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=24900&highlight=Rear+end



MerrickNJr



P. S. I found these posts using the search word "Rear End"

 

[klenger]

I'm falling in love with the 4. 10's in my new truck. Tows great, and I rarely drive over 65 empty anyway.



Ken

 

[MikeR]

Comparing a 12v to a 24v in rpm range is like comparing apples to oranges. The governer limit on a stock 12v is alot lower than a 24v... not only that,but the newer trucks have a much TALLER tire and you can get a little more top-end speed out of the new 4. 10 combo. The 12v is more efficient at low rpm,the 24v is more efficient at high rpm. Driving a 12v with 4. 10's is nothing like driving a 24v with 4. 10's... in fact driving an older truck (94-99) with the stock size 215 tires and 3. 54's is within 100rpm of driving a new truck (00-02) with 235 and 4. 10's. Even the automatic trans guru says the 4. 10's will be a better choice.



-Mike

 

[JJW_ND]

If any of you with 3. 54 have any plan of turning up the power even a little, skip the gear change. All problems go away. Even a good running STOCK HO 6sp with 3. 54 tows 14K worth of trailer all day at speeds at of above speed limit.



If you plan on stay stock (power wise) forever and need more power, lower gears or smaller tires will help. Those that never drive over 65 would probobly do fine with 4:10.



jjw

ND

 

[Roger rodbolt]

3.54's Yes!

I've owned one CTD with 4. 10 gears and auto. It towed and drove okay at 55mph and was tolerable at 65mph in overdrive. Don't intend to own another because it's very simple to adjust the Cummins torque to a lower rpm and increase both the torque and hp. Me thinks... why have an overdrive and then gear so low that direct drive is not useable? 3. 54 gears with a manual trans in direct drive (4th with a 5sp. )and 33" tires will tach about 2350 at 65mph. 30" 245/75-16 tires tach about 2600 in direct at the same speed, but still are useful where road conditions dictate slower towing. I rarely shift out of overdrive when towing on good road unless traffic gets in the way. At around 325hp with proper torque curve the mountains will submit!! Auto trans do have a greater ratio overdrive and the lock up clutch in the torque covertor is highly stressed with tall gears and heavy loads but if I could choose my gears with a manual I go with 3. 23's, JMHO

 

[tgbol]

I have the 3. 55's and to me most of the time they are too low. I think my truck would like 1800rpm at 70 instead of 2200. Mine is a 4x4 with a 2-low kit. Even with 7000 lb trailer from CA to Utah I never needed to drop down below 5 th unless I got caught behind a Ford.

 

[JJMiller]

2 quick questions--

While we're on the topic:



(1) None of the 4x4 crowd seems to talk about changing their gearing. Is it that much of a pain to swap out fronts and rears? Or is it just not worth the added expense?



(2) Are they 3. 55s or 3. 54s? I've seen it both ways. On my charts (now outdated) that I printed off from the dodge website when I was ordering my truck in 4/00, it lists the 3. 55 and 3. 92 for the 1500 models, and the 3. 54 and 4. 10 for the 2500 and 3500s. Is this correct? If so, why do some use 3. 55 instead of 3. 54?



--J

 

[tgbol]

JJ

First off is it 3. 54 or 3. 55? You be the judge! Most gear sets at that ratio are 39 teeth on the ring gear and 11 on the pinion. when you work it out you get 3. 54545454545454 so if you stop at 2 decimal points it is 3. 54 if you round it off it is 3. 55.

The expense of changing ratios in a 4x4 is usually a little more than double because of the extra labor to do the front axle. Also the transfer case has a reduction gear around 2. 7 in it.

Alot of people are modifyiong their trucks with a 2-low kit that allow us to use the reduction with out locking in the front axle.

 

[Big_Daddy_T]

gear change

I am a youngin and bought this truck to pull my toys. I decided early on when she broke 100k I would build her into a serious offroader. I started bombing early to be ready for the meats and the winch when she reached her 3rd birthday. I am of the opinion that off the road its diesel or nothing( small footnote: stay away from the bottomless mud). I am changing my running gear to a 4. 10 and going to a streetable locker as soon as funds permit. If anyone has already done this input would be very welcome.

 

[Big White Beast]

Changed mine.....

I found someone wanting the 4:10 rear end so I swapped them for their 3:54. I am kind of dissapointed in the extremes. The 4:10 had me screaming down the freeway. In Kalifornia average speeds are 75 (Read: I'm above average ) Now the 3:54 has me lugging around town. Wish I wasn't so cheap. I should have just bought a set in the 3:73 range. Might still do it. Gonna spend a lot on DTT's stuff and want to give it the best chance I can to survive.



For me the gear change had absolutely no effect on mileage. What I saved taking off with the 4:10's I lost on the freeway and vice versa. All of my driving is a mix here so the 3:73's might be a good alternative.



Don't know about prices but here's another link. Going to call today.



http://lightruck.com/index.htm



Garrett

 

[DHawthorne]

I too will be looking at a lower ratio for my truck as soon as I get

a fifth wheel. I'm going to US Gear and get the underdrive unit. I still want the mileage when running light and the power of the lower ratio when towing. Check it out at USGear.com. It more expensive than changing the rear, but when you change it you got want you got if you known what I mean.



Dave