I am wondering if it is possible to get the 3.73 gears from the new trucks to work in older trucks? I have 4.10s and would like the shorter gears but don't want to drop down to 3.54s. Is this possible? Anybody checked into it or done it? Is the rear axle the same in the new trucks?

 

Sure. Just put 35" tires on it. Thats what I did.

 

Can't really get a 35" tire on a dually. That would be an easy option. Not only that but I probably wouldn't be able to tow a 5er as easy since it will sit up higher.

 

If I remember correctly the new trucks are no longer using Dana axles.

 

I have seen several 3500's with 35" tires. But they weren't towing.

 

Actually you can get up to a 38" tire on a dually before having to goto custom wheels. Superswamper and a couple other companies make a 36x11.00-16 for a dually. Also in size 37" and 38". For about $170 a tire

 

The 03's use an American Axle I think. It's the same one the ferd's use. I think the ring and pinion size are different between the two. So they won't fit. I also don't think any one sells a 3.73 gear for a D80. Otherwise, you could guarantee I'd have a set. That would be the perfect gear.

 

BigBlue, I agree. 3.73 to 3.90 would be perfect. I think that I may have achieved just that. The stock size tire for my truck is 215/85/16 and I just installed today 255/85/16. The stock diameter is 30.6" and the new tires are 33.4 Nearly 3" change in diameter. According to www.4lo.com my effective gear ratio is 3.78! ;D The tires fit just fine and are only .75" wider than stock. Still got about an inch between rear tires.

 

Just today installed the 255's? and updated your profile as well?<br><br>Might I say WOW.<br> :<br><br>phox

 

Well I try to keep my profile up to date. Not only that but since the bill was almost a grand....wanna make sure I give myself credit for them!

 

I have lots of F*rds at work. One day when I was looking for some parts for a F250 rear end I found a listing for 3:73 for Dana 80. I think it was for an F450 ambulance chassis. What really suprised me was a Dana 60 in an E350 with a Powerjoke.

 

I looked into this a while back. I called a few drivetrain shops in one of the four wheel drive magazines. Unless I misunderstood them, there are both 3.73 and 3.90 gears available. The biggest problem is that the 3.54 trucks use one carrier, and the 4.10 trucks use another carrier. I was told the lowest you can go without changing the carrier on a 3.54 truck is a 3.73 gear. If you want to go to a higher gear with a 4.10 truck, then the 3.90 is as high as you can go without changing the carrier. It has been a while since I called about this, but I'm 99% sure that info is right.<br><br>I've got 3.54s, and I want lower gears. Mainly so I can go with larger tires. I'm running 33's (285) now, and I wouldn't want to go much bigger without lower gears.

 

Yes, you can put 3.73s in a D80. I have a DanaSpicer part number for them at my shop.<br><br>List price is gonna freak you out though... ~$850.<br><br>I can get them for about $750.<br><br>I wonder what DC sells them for.