Hey guys how hard is the gear swap and what is the max MPH you can run with the 4:10's I have the 3:54 but can you go to a 3:73 or something? Also what will it do to the transmission shifting?

 

Jamie,<br><br>Its not as hard as it sounds. Generally, if you have the tools to do the work you will be able to do in a single day. <br>I went the other direction though, from 4.10 to 3.54.<br><br>Trail bearings make life easier to set up the bearing pre-load and I would not do another swap without them. They are priceless because the Dana 70 and 80 has the preload shims behind the bearing races. This means without trail bearings that slip off easily the races will have to be pressed on and off until you get the preload set right. Not only the preload, but the ring gear backlash as well. <br><br>I would use the factory Dodge Dana gears because I am certain the pinion gears are all marked with a number on the pinion head that will get you very close in the shim sizes you will need to set the pinion depth. This makes it easier as well.<br><br>Total time is less than 8 hours in the driveway and going very slow and careful. An experienced guy could knock it out even faster.<br><br>Carrier swaps are required on the Dana 80, but I dont know if they are on the Dana 70.<br><br>3.73 gears may be available for the 70. They are not for the 80.<br><br><br>Don~<br><br><br><br>

 

Jamie,<br><br>http://www.dodgeram.org/tech/specs/axle/rpm_vs_mph.htm<br><br>Try this link. It should tell you all of the speed versus RPM's for the different gear ratios. As far as the transmission shifting I have no clue.

 

i have the 4:10 in my 99 with a 5 speed running 305/70 16 tires. it maxes out at about 108 mph. even running the taller tires i wish i had the 3:54 gears

 

I max out at 100 mph at 3100 rpms. At 75 I am at 2500 rpm's. It would be nice to have different gears. I want my top end at about 130.

 

I can't believe you guys take your trucks that fast!!! Your roads must be better than ours here in Utah!!!

 

I think that the 3:73 would be the best gears if we could get em.

 

[quote author=Straight 6 link=board=7;threadid=13974;start=0#132183 date=1051371508]<br>I can't believe you guys take your trucks that fast!!! Your roads must be better than ours here in Utah!!!<br>[/quote]<br><br>not better roads just a few straightaways to open up on ;D

 

Yep, Texas is all road.

 

3.73:1 gears are available for both the Dana 70 and the Dana 80. I'm changing from 4.10 to 3.73. The trick with the Dana 80 rear end is the tone ring for the Rear Wheel Anti-Lock (RWAL) system. Since a new carrier to change (4.10 to anything lower is a gear split) ratios would mis-locate the tone ring, we need to use a &quot;thin set&quot; 3.73:1 ring gear and matching pinion in the rear. The gears are available from your favorite ring &amp; pinion supplier. If I remember correctly, front ring &amp; pinion were around $180 and rear were $250 or so.<br><br>I will also be going to a Detroit soft locker in the rear and Dana Powr-lok in the front. This is where you get into some money :-[<br><br>

 

OK im lost. Im not very educated on the rear end of my truck or the tranny. Could you fill me in on what I would need along with where to go and have it done? Do you know what will happen with my transmission shifting?

 

Here's a question. Wouldn't the thin ring gear set be to weak to hold the power that these things put out? I would love to have a 3.73 ratio but I plan on running like 1600lb.ft. of torque to the wheels later on down the road with 35&quot; tires. I don't want to worry about my rear end snapping with that kind of power.