GMC - DANA 44 - which gears to buy?- I wanna burnout!!
 

Hello,

I have just swapped my T5 with a 700r4. I am needing to swap my stock 3.54 rear gear for a 4.10.

Does anyone know the spline count for the GMC Dana 44 setup?

Thanks!!

Boucher'

Re: GMC - DANA 44 - which gears to buy?- I wanna burnout!!
 

Check out this thread: http://en.wikipedia.org/wiki/Dana_44

Re: GMC - DANA 44 - which gears to buy?- I wanna burnout!!
 

My 1960 GMC was custom ordered with Dana 44 3.90 gears when new. Years ago I swapped them to 3.08’s, and a few years later I switched from a TH350 to a Richmond 4 speed. With that swap I went to 4.09 gears. When I did the swap, I noticed Spicer Dana gears came in 4.09 and 4.10 with different tooth counts. I believe the two ratios may be for specific OEM housing applications. Yukon is also now marketing 4.11’s. These can be found at Summit racing. I went with genuine Spicer Dana gears as I read they were the quietest and most durable.

You’ll need to change carriers as the 3.90 ratio is the break.

Unfortunately all the web info I collected was a couple of computers ago and I no longer have the detail gear information.

Also I generally refer to my gears as 4.10’s, because discussing 4.09’s tends to confuse some people that I’m talking about an engine I don’t have.

Re: GMC - DANA 44 - which gears to buy?- I wanna burnout!!
 

I busted TWO Dana 44s in my 66 GMC Suburban with little to no effort. I had good luck with a posi but the spider gears are a weak link in these rears and you cant change the spiders without removing the ring gear. If your going to be hard on it I suggest a Chevy 12 bolt over the Dana 44. JMO...

Re: GMC - DANA 44 - which gears to buy?- I wanna burnout!!
 

The one in my '61 was 30-spline.
I put 3.42 gears on a late-model Jeep posi unit.

I've got another complete housing with an open dif, waiting for a future project.
Are those 3.54 gears OE or aftermarket?

-Brad

Re: GMC - DANA 44 - which gears to buy?- I wanna burnout!!
 

Do not know why you would change out to the 4.10, the first gear in your 700r4 is really low, it should burn rubber right now.......try it before going through the gear swap, send me the diameter of your rear tires, the engine that you run, and we will calculate speeds and usable torque to the ground so you can see how your burb will perform before you change the gears......Kieth

Re: GMC - DANA 44 - which gears to buy?- I wanna burnout!!
 

The gears are from the factory, 3.54

Kieth, first of all thanks for the spreadsheet. It is really useful. To answer your concern. I used your spreadsheet and came up with this.

I am comparing the new set up with my old setup (T5). With the 3.54 / T5 setup, I was turning 2300 rpm at 70 mph. With the 700R4 and 4.11 gears, I will turn 2300 rpm at 69 mph, so it is very close. I did like the highway setup with the T5, nice power on tap at 70 mph. It did not lug, it seemed to be at a sweet spot.

Also, look at the power ratio off the line (1st gear X rear ratio)

T5 - 3.76 x 3.54 = 13.3
700R- 3.06 x 3.54 = 10.8
700R with 4.11's- 3.06 x 4.11 = 12.6

The T5 in first launched really hard. Now looking at the 10.8 number, it sort of explains why it feels weak. The 4.11 gears get the power ratio close to that of the T5.

So... I am pricing a set of "thick" cut 4.11 and install.

We shall see!

Boucher'

Re: GMC - DANA 44 - which gears to buy?- I wanna burnout!!
 

GM recommends 4:10 in most applications of trucks, some were equipped with 3:73 like s-10's with smaller tires. My 700r4 with 3:73's and a 2oo hp inline does good unless loaded and going up hill. My 700r4 with 4:10s and warmed over V8 turns stop lights into go lights ( if you can see me through the smoke) both are running a 29" tall tire. The inliner gets 19 mpg the V8, 8 to 14 ish only because I have never burned a tank of gas without smoking the tires yet so Im guessing on the mpg's. Both are real world applications and based on 3 other trucks I own with 700r4, 4l60 and 4l80 I would guess that with your turbo inliner and tire size, 4:10's would be/feel/perform/get good mpg etc....perfect for what you are after. If you loose your job and your gas card, but still need to lock the 700r4 into 1st and chirp a little rubber on the way to return your beer cans then go with the 3:73's for fuel economy :)

Re: GMC - DANA 44 - which gears to buy?- I wanna burnout!!
 

haha, thanks

Re: GMC - DANA 44 - which gears to buy?- I wanna burnout!!
 

Great information, I did not realize the t5 was that low in 1st gear. One thing though, if you put your foot on the brake with the 700r4 you not only have the gearing of the 700r4 but the sharp rise in torque available with the torque converter.....that means more torque available and I bet she will smoke em with a heavy foot..........have fun Kieth :gmc2: