2nd Gen Non-Engine/Transmission Who has done a gear swap?

[Timbeaux38]

Do the carriers have to be swapped to change from 3. 54 to 4. 10's ?

 

[EBung]

Nope they should all be 4. 10 and down numerically.

 

[Nate]

Yeah 4. 10 and down use the same carrier.

 

[dodgeguy44]

If it's a Dana 80 the carriers are different, I just went thru this with my 3500.

 

[Clinton]

Wait a second... I thought the carrier split was at the 4. 10. That is, all gears numerically smaller had one carrier and the 4. 10 and all gears numerically higher had another carrier. I thought that was why it was such an expensive deal to go from one to the other. Is this wrong? Does that mean it is just a matter of ring and pinion swapping? Anybody wanna swap their 3. 54s for my 4. 10s?

 

[csutton7]

I'm with Clinton on this--seems when I did my swap back in '00 that was the case--different carrier for 4. 10 gears---chris

 

[B KIRK]

Dana does the split different between the D70 & D80.



The D80 uses a different series carrier between 3:54 & 4:10.

The split is 4:10 and numerically higher, (lower ratio).

And 3:54 and numerically lower, (higher ratio).

But the 3:73 is made in a thin ring gear for the 4:10 carrier, and a thick ring gear for the 3:54 carrier.



The D70 uses the same carrier for 4:10 & 3:54.

The split is 4:56 and numerically higher, (lower ratio).

And 4:10 and numerically lower, (higher ratio).

There is also a 4:30 gear that is made in a thin ring gear for the 4:56 carrier, and a thick ring gear for the 4:10 carrier.



So, a carrier change is needed in the Dana 80 for a 4:10 / 3:54 swap.

No carrier change is needed for a Dana 70 4:10 / 3:54 swap.



And every 2nd gen Dana 70 carrier I have changed, or swaped gears in have been 32 spline axle shafts, 1. 41 O. D.

I have heard of 35 spline, 1. 5 axle shafts, but not come across one yet.



The Dana 80 has 35 spline, 1. 5 axle shafts.



Edit:

Forgot to mention that the Dana 60F, (front), is the same as the Dana 70 for gear swaps.



Brad

 

[swmnkdinthervr]

Dana does the split different between the D70 & D80.



The D80 uses a different series carrier between 3:54 & 4:10.

The split is 4:10 and numerically higher, (lower ratio).

And 3:54 and numerically lower, (higher ratio).

But the 3:73 is made in a thick ring gear for the 4:10 carrier, and a thin ring gear for the 3:54 carrier.



The D70 uses the same carrier for 4:10 & 3:54.

The split is 4:56 and numerically higher, (lower ratio).

And 4:10 and numerically lower, (higher ratio).

There is also a 4:30 gear that is made in a thick ring gear for the 4:56 carrier, and a thin ring gear for the 4:10 carrier.



So, a carrier change is needed in the Dana 80 for a 4:10 / 3:54 swap.

No carrier change is needed for a Dana 70 4:10 / 3:54 swap.



And every 2nd gen Dana 70 carrier I have changed, or swaped gears in have been 32 spline axle shafts, 1. 41 O. D.

I have heard of 35 spline, 1. 5 axle shafts, but not come across one yet.



The Dana 80 has 35 spline, 1. 5 axle shafts.



Brad

OK... now that I'm thoroughly confussed how do I identify my axles... I'd like to swap for 3:73 or 3:54 (obviously from 4:10's) '99, 2500, Quad cab, long bed, 4x4, 5 spd... off the top of your head what would you guess I have?



TIA,

John

 

[csutton7]

manual transmission = Dana 80

 

[EBung]

Sorry I have the 60/70 combo and didnt research the 80 I'll shut up now.

 

[swmnkdinthervr]

manual transmission = Dana 80

Thanks... looks like the 3:73 is gonna be more affordable... know any good sources?

 

[B KIRK]

John, take a look at THIS chart.

Use your current tire size and gears to determine RPM's.

If stock size tires, should be 31".

They may not be what yours are, just use as a reference to show RPM change.

The change in RPM's from 4:10 to 3:73 isn't that much.

If you were to run a taller tire, you could accomplish almost the same RPM drop.

Would hardly be worth the cost to go the 3:73 gear change.

You have a 4X4 so both axles have to be done.



Brad

 

[Nate]

That chart is for a non OD transmission. OD transmission will be around 75% of those RPMs

 

[B KIRK]

They may not be what yours are, just use as a reference to show RPM change.

The chart was to show the difference in RPM's from going to different gears, or different size tires.

Plus the site the chart is on mentions:



"an overdrive transmission your RPM in overdrive will be 15% to 30% less than indicated. "



Brad

 

[Nate]

Here is a good applet that will finger out the RPMs. It seems quite accurate



http://www.reiderracing.com/rtech_engineRPM.htm

 

[DMannon]

I just got off the phone with West Coast Diferentials, http://www.differentials.com/ , and they said they can take me from 4. 10 to 3. 54 front and rear for $1400 parts and labor, but that I shouldn't drive any more than 30 miles at a time for the first 300 or so miles, otherwise I'd burn the gear set and it would howl.



Does that sound right? What happens with driving new trucks? If it's right, it's a little problem; their shop is 400 miles from me.



BTW, I have Dana 60/70 front/rear.

 

[Vaughn MacKenzie]

Here is a good applet that will finger out the RPM. It seems quite accurate



http://www.reiderracing.com/rtech_engineRPM.htm

If I remember right the OD ratios are:



NV4500 . 73

NV5600 . 72

Auto . 69



I don't know if the aplet uses these numbers or not but these should help determine exact RPM (not "RPMs") at X speed. The best tool is the tire calculator someone posted once, that was pretty nice.

 

[Bart]

I read were the change over is 4. 10 and down is one carrier. 4. 56 and up is another. Don't hold it to me. I just finished swapping complete diff assemblies with a gentleman from New Mexico. 18 hours a day for three days. Could have been shorter, but we found bad ball joints in the front of mine.

 

[csutton7]

the carriers change at 4:10--that is 4:10 and up is one carrier and anything below 4:10 is the another carrier---



price seems about right for CA---WCD is good and if you can ask for Eric Jorgenson(if he's still there)---



I do have another contact if you want(west of SAC around Vacaville) ---single guy operation who is very good also--D&D 707-449-6363---Don---tell him chris sutton sent you---chris

 

[bkroupa]

I swapped from 4. 10's to 3. 54's on mine , I found a complete rear axle at car-part.com & sold my old 4. 10 axle on ebay for about the same price. Total cost to swao was about $100

There is someone who makes 3. 73's for both the 3. 54 & 4. 10 Dana 80 carriers