csramsey640

I ran my truck heavy today, and its gonna be the norm from now on. I currently have 3.54's and I need better, just wondered if a 4.10 is night and day, or if I should go even deeper.

Please do not tell me about fuel economy, if I want to save my truck, I have no choice. Sorry but I have read countless threads and all that was mentioned was fuel mileage.

flashgordon

I have 4:10s and i wouldn't go any lower max speed pulling a load is 65 to 70, an thats with the go peddle down all the way, out on the flate!


Are you considering the lower gears becuse you can't get it moving or what?

csramsey640

well both. I started out on a mild grade comming outa the truck stop and stalled her out in 1st gear, when I finally did get going I had to rev her up pretty good, truck was rockin like a rookie after CDL school and I thought I was about to loose the clutch, when on the interstate (hilly) I dropped as low as 35mph and my average speed was between 55 and 60. 4th gear 90% of the time.

flashgordon

4:10 is probly the best solution! I was going to sugest the Gear Vender like i have witch would be grate to split the gears but can't be used be low 20 mph cus the tranny out put shaft is the pump for the over drive and pressure wont be there tell 20 also it isnt an under drive but an over drive unit!

US gear has and under drive unit that might work vary well for what you are doing but don't no much about them to coment much more.......maybe some on that has us on of theses unit will chine in!!

Underpsi

How much weight are you pulling? I never even use first in my truck its always second but sometimes I use 1st just to get rolling if i just wanna go real slow or something but never need to. I never pull weight with my truck but it does have 3:54's and has really great start-ability I imagine I could take well over 10000 pounds and still start off in first without using any fuel

csramsey640

Right around 26,000 lbs

hertz

Be careful PA is becoming more and more strict. I run a landcsaping business and they break my stones ALL THE TIME.

Underpsi

Wow! Thats alot of weight on the old girl. I see why you have the start-ability problem. Although I personally don't think the 4:10's will help out that much but could be wrong.

BlueOxD350

Go with the 4.10s
I ran 3.54s for the first 400,000 miles of hauling. Average load was around 26k, but she's seen as high as 34k when the bales were heavy. 4th gear, 55mph was all she'd give me.
Swapped over to 4.10s in a new-to-me Dana80 around 50,000 miles ago. 1st gear starts are cake - on an uphill is still a little tricky, but a quick slip of the clutch overcomes the forces of gravity. Highway manners are also improved - I push 4th gear to 50mph before grabbing O/D then roll a smooth 60-65 at medium throttle and 2100rpm.
Fuel economy under load is up from 8mpg (3.54s) to 11mpg (4.10s). Unloaded dropped from 21 to 18.
-Dan

brainfade

Mine's 4:10s. I haul a boat from time to time that's around 16K on the trailer. Handles it well but I don't go much over 55 with the boat on so can't say on top speed. No problem to get it moving though.

csramsey640

Thanks for the help. Ok so this leaves me a few options. 1. Ring and Pinion setup, 2. Different Rear end.

Ill be honest, I have never setup a Dana rear end. I have only ever done a few Ford 9" in the race cars, so I wont trust myself for many miles, or is it easier than it sounds?

2. If I swap in a new rear end, will a Dana 70 from a Dually work with my SRW's? since I dont have a dually bed, ill still be using my wheels.

3. Is the Dana 70 a diesel and dually option only? I have heard that usually a gasser 250 will have a D60 rear, unless its a SRW 350

Thanks

apwatson50

A dually rear axle supposedly has a wider WMS than a single wheel axle. I havn't personally measured either.

flashgordon

You realy should call up US GEAR and talk to them,,,,,it might cheeper then a gear change.....and you would get a low gear that us 4wd guy get with our t-case in 4 low.

Evan tho i'm not a fan of there, i do beleave that it a good product and it would be like haveing a 2 speed rear end and you could have a 1st and under to get the load moving from a dead stop with out torchering your clutch.

mhuppertz

You have guts to drive her in 5th under load. I think 4th with a Gear Vendor overdrive would get you the speed you need without OD problems under severe loads.
But that's big bucks....

wannadiesel

Correct. The wheels will stick out a little further, but the dually axle will work OK.