3:54 TO 3:73or 4:10

[Fuzz]

I have 3. 54 gears in differential. Shoulda ordered 4. 10

What the possibility of changing them?Expensive?

Any comments appreciated,either way.

It's a Y2K 3500 4x4,6spd



Thanks

 

[RonaldLarson]

You're looking at 2-3 K to change both ends if you are four wheel drive. I'm curious as to why you want to change. Do you haul very heavy loads all the time? If not, stick with the 3. 54's. Better mileage and lower engine speed. Put a Vanaaken box on it and you may not need the ratio change, from my experience.

Ron

 

[CUMINNTSTRKN]

Fuzz



i grew up in castle rock, i moved out in 1990 what a great place. it was before my junior year.



as far as switching i would be curious why you want to. if you don't pull loaded all the time i would leave it. if you want 4. 10's downshift one gear and poof instant 4. 10's. you might try bombing your truck a little you won't beleive the difference. with my mods i have. i have to get over 11k#'s behind me over a 6% grade before i have to grab 5th. the cummins has great low end. unless your putting 40" tires on it or something i would leave it.



if you do end up switching i would recommend finding good shop to do the trade. i'm not sure if your carrier will accept 3. 73 or 4. 10's.



Jim

 

[Fuzz]

I am a little overloaded(GCVW) when pulling 5er and thougt it might be an option. . Seems like I'm in 5th a lot to keep RPM's where they belong. It is bone stock so maybe try a Fueling Box.

Can't really afford to trade trucks,so guess I'll stay with the 3. 54's.

Appreciate the comments. . That helps the decision.

Fuzz

 

[MikeR]

Fuzz,



Once I got rid of my stock size tires I also regret getting my 3. 54's. Shoulda went 4. 10's,but it's way too expensive for me to switch now.

A while ago I was wondering if anyone made a 3. 73 for our Dodges since one is available for the Ford Dana 80. A guy from a driveline shop emailed me and informed me that the 3. 73's is available and that this is the highest gear you can install in the same carrier that the 3. 54 comes in. To switch to 4. 10's you also have to get the different carrier,lots more $$$. When all my other projects are done,I will switch to 3. 73's.



-Mike

 

[Diesel Dan]

Sorry to be the devil's advocat but my oppinions are much different.

1. you will love the switch to 4. 10 (i did)



2. the carrier will accept 4. 10 (mine did) on a dana 70. tried to go to 4. 56 but would require new carrier.



3 cost was $1250 at a local off-road shop not known for great prices just great work.



don't give up on this mod just yet

Diesel Dan



fyi i gained apx 225 rpms on the freeway

 

[Archive]

Originally posted by Diesel Dan

Sorry to be the devil's advocat but

DD... you are not alone!



I have repeatedly stated that I am a believer in 4. 10s. It is widely known, and published by Cummins, that these 24 valve motors have "sweet spots". For economy, it is 1800-200rpm. For towing, it is 2000-2200rpm.



Power is not a question if you are going to BOMB... the question to me is what speed do I want to tow these loads at. It is scary to me to see people talk about towing 13000lb loads at speeds in excess of 75mph. Hopefully, when they have a blowout or some other problem, they won't take an innocent person with them.



Which gears put you in the above "sweet spot"? Those are the ones I would choose. IMHO.

 

[JJW_ND]

3.54 Gets the job done!

We added 4 new HO6sp all 3. 54 to our fleet which has several older 99 & 2000 5sp 3. 54. At 70 mph with stock 245 tire the tach shows 2100. With one of the new trucks that came with 265 tires, it runs 2000 at 70. This would be the slowest we drive even when pulling.



NO TRAFFFIC, NO HILLS, NO TREES, long straight roads.



If you want to run at higher RPMS, 5th (direct) is always there.



We gross 20K with our combinations and the new 6sps will run all day at 2200 - 2400 in 6th and 3. 54. Takes bigger hills then are state has to shift out of 6th. We will be putting on larger tires to tach even lower.



Any problems with lack of power are most likely not related to gear ratio... they are related to "good" running trucks vs poor one. We have had some poor ones. BTW, Ours are all stock and have to stay that way. When these trucks are running good like they should, another gear above 6th or a higher speed 3. 30 yet would even work, especailly empty.



It is nice have several trucks from each year. You really know how they should run.



jjw

ND

 

[Archive]

Re: 3.54 Gets the job done!

Originally posted by JJW_ND

At 70 mph with stock 245 tire the tach shows 2100. With one of the new trucks that came with 265 tires, it runs 2000 at 70. This would be the slowest we drive even when pulling.





It is nice have several trucks from each year. You really know how they should run.



jjw

ND

Yikes! That seems awfully dangerous to yourself and others. Flash your lights as you approach... I will be glad to pull over!



I have never questioned the power of the Cummins with either gearing. I do question running at 2200rpm all day, considering the above rpm/speed data, as a safety issue.

 

[Barry]

I had a 2000/3500 6 speed with the 354s. I kept it 7 months and sold it. My 2001 with 410s pulls!. There is a company in the northwest that has the Ring Gear and Pinion sets in 373 and 390 that will bolt into your existing carrier. Quoted me $350 per set plus shipping. Brand new. I think it is Randy's Gear Service... ... ... we have batted this around a number of times and probably this won't be the last... ... ... ... .