Dana 44 and road gears

[Hedgehog]

Most of my "getting there" mils will be on the road, the Interstate 10 to be exact. I really don't know what gearing my '75 has, but I always want to grab another gear or two when on pavement. .... and, I'm one of those that ALWAYS checks his mileage when filing up with gas. Yes, I know the word mileage and 360 powered Jeep don't go together, but I would like to get more than ~8.5 mpg. Does anybody know what "road gears" will fit in a Dana 44 ?

 

[IOPort51]

Diff Wizard

check this out.

 

[Torxhead]

Hedgehog, Do you know what rpms you are getting at 60 mph? What size tires are you using.

 

[Old Dog]

the diff. split is at 3:91, so depending on what gears you have now carrier changes might need to be made. Just something to keep in mind.

 

[Petescj]

Most of my "getting there" mils will be on the road, the Interstate 10 to be exact. I really don't know what gearing my '75 has, but I always want to grab another gear or two when on pavement. .... and, I'm one of those that ALWAYS checks his mileage when filing up with gas. Yes, I know the word mileage and 360 powered Jeep don't go together, but I would like to get more than ~8.5 mpg. Does anybody know what "road gears" will fit in a Dana 44 ?

Ahhhh , Interstate 10 . Fond memories of wide open desert and a the first 75mph speed limit. Finding the perfect gear ratio for a Cj is like finding the perfect woman , she just doesnt exist. There has to be compromize somewhere. Going by what I remember of your Cj it was on 35s and you dropped it to 31s. Your not looking for a rock crawling environment and in this case thats good. Lower gears at the exspense of gas mileage are generally used then.

If the previous owner geared the Cj for that purpose I can see why your getting the numbers you mentioned. 4.56 or 4.88 gears with 31s are going to leave you wanting an additional 2 gears from the Transmission for sure. Heres a chart that can help you get to where you want to be. The yellow end of the chart is gas mileage friendly and the red is all about power. See where you come in at by matching your Cj up to the rpms in the chart. They are at 65 mph. You should be able to double your 8.5 mpg with 31s no problem. I think 3.07 is the lowest for your 44 but you wont want to go that far anyway. You have to change carriers at 3.73 or 3.91 cant remeber which




I also recommend going in and physically looking at your gears to see what you have and what the previous owner left you. You never know what you'll find in there. Mine was like mud.

 

[Hedgehog]

Unfortunately my Tach. stops working at ~1200 RPMs. Another one is in the cards.

My Dana 44 doesn't have a drain plug so I needed to remove the cover to change the oil, inspect/clean and find out what I had for a diff. Unfortunately I was to green or ignorant to know what to look for as far as the gears are concerned. The cover will come off once again. This time I know what to look for on the gears. ..... darn I hate to redo work, but this is actually small work.

It is early though. I've filled the tank once more and will use a GPS for an accurate distance and to check the speedometer for true speed.

I'm not looking for silly MPG numbers, but 15 or 16 mpg would be good. The 360 has plenty of power to handle higher or is that lower gearing?

 

[Hedgehog]

Took the Jeep out on the Monday holiday. Used my GPS to keep track of distance driven and speed. Mileage was a little better than feared. Driving 40% highway (63 mph), 10% surface streets (45 mph) and 50% dirt road crawling along (15 mph) the Jeep hit exactly 11 mpg. Better than the 8.5 mpg of a few days ago.

A note on the speedometer. The odometer seems to be well within acceptable accuracy. The speedometer .... well the speedometer fills the hole in the dash nicely. Inaccurate doesn't even come close to what this thing is, inconsistent is probably a better word. Traveling at 55 mph (GPS) will show 44 one minute, 22 the next,
possibly 35 at other times. It is essentially unusable.

Other than that ..... The Jeep ran beautifully and I'm well pleased with the results of many months worth of work. I even adjusted the headlights, finally.

 

[Petescj]

Gotta find out where that extra mileage is at. If its in the gears it should be easy to either sell your axles or trade for higher gears. You could probably get a little more for yours if they have lower gears since thats what the majority of guys are looking for. I couldnt give away a set of narrow track axles with 3.54s here. Yours having a 44 and 30 along with being out West may make it a little tougher though.

 

[Hedgehog]

Even though I know more research is needed, I'm just in the beginning of this, I actually started this thread to see if anybody could tell me what gearing my carriers would take. I've got other sources, but thought I'd start here.

When out this Monday I basically idled all day in 3rd gear and the Jeep hardlt ever needed to be shifted into 2nd. Naturally on the steeper hills a litle gas and a gear shift was needed.

 

[73CJ]

After years of doing the math to convert the actual speed to the speedo reading I went digital.

Now it does not matter what tires I'm running its easy to re calibrate with the push of a button.

I got a nordskog OEM style. Dakota digital still makes one.

It's really nice to know how fast you are really going.

 

[Hedgehog]

I did a little searching for your guages. Does yours have nothing but digital information or does it look like it's stock, but better behing the pretty face?

 

[73CJ]

They are all digital. 5-7/16" diameter.

 

[Hedgehog]

Space ship looking, high tech. kinda cool.

So I now have some data to go with, an Auto Meter tach. was installed and the speed was determined by my GPS.

@ 65 mph, 31" tires, engine turning ~2800 RPM, means most likely 4.10 gears.

It is amazing what a small exhaust change can make. The PO installed a dual exhaust that exited straight out the back with a square tip. Looked very cool and had a mean sound. Unfortunately the exhaust was pulled right back up into the cab. So the tip was removed and a bend put on to make the exhaust exit behind the rear wheel. Man what a difference in sound and perceived engine RPM. The CJ no longer feels like a hot rod and I'm no longer reaching for another gear all the time. The difference is unbelievably impressive.

 

[Posi]

My Dana 44 doesn't have a drain plug so I needed to remove the cover to change the oil, inspect/clean and find out what I had for a diff. The cover will come off once again ..... darn I hate to redo work, but this is actually small work.

If you have fresh fluid and you rather not dump it you could also check the gear ratio by raising one wheel off of the ground and mark the tire at the 6:00 position, then mark the driveshaft. Turn the tire exactly 2 full turns. Count the number of times the driveshaft turns.

2-3/4 turns of the driveshaft = 2.73, just past 3 turns = 3.08, 3-1/3 = 3.31, just past 3-1/2 = 3.55, 3-3/4 = 3.73, just past 4 = 4.10 or 4.11.


If it's locked raise both wheels off of the ground and turn both wheels exactly 1 full turn. Everything else is the same as above.


Hope this helps.

 

[Hedgehog]

Yep, I have seen that method as well. About the only moving part of the Jeep I haven't seen is the front diff.

This weekend a gasket for the front diff. was purchased. I will pull the cover this coming weekend or possibly this week. Now that I know where to find the information the numbers wil be checked to confirm what the Differential Calculators say I have. By the way, tach readings were taken at 35, 40, 45 and 50. The results were very consistent with a ~4.10 (granted it could be 4.11, but most were in the 4.089-4.095 area) gearing.

What I'd really like to know is will a 4.10 carrier work with 3.73 or 3.54 gears.

 

[Petescj]

What I'd really like to know is will a 4.10 carrier work with 3.73 or 3.54 gears.

Yes.

 

[Hedgehog]

That would be great! My local Jeep guy has several sets of used gears that I can purchase at a very reasonable price. Naturally most guys want to go the other way, where I want road gears, they want crawler gears. I bet a nice trade would be possible. It's been said that Diff. work is difficult and exacting, so I asked Rob and he said that with the skills I've shown it would be no problem for me to get it done myself. .... cool, a real confidence builder.

 

[Hedgehog]

Petescj - You've been around this area, It's fairly flat gound with a lot of Interstate between here and about anywhere else and the added fact that the 360 has plenty of power, 3.54's (debating on the factory stock 3.73's) should be good enough for my needs. Exceptionally slow speeds aren't necessary around here. As I wrote before, with the current set up all day can be spent trolling along at idle in high gear.

 

[Posi]

What I'd really like to know is will a 4.10 carrier work with 3.73 or 3.54 gears.

No, the 44 carrier break is 3.73 and down / 3.92 and up
The 30 is 3.54 down / 3.73 and up

 

[Petescj]

No, the 44 carrier break is 3.73 and down / 3.92 and up
The 30 is 3.54 down / 3.73 and up

Forgot he's got the Dana 44 . Your correct.

Also Im so used to the 80s most everything you hear is 2.72 and 3.31. 3.54 is the correct answer for the Dana 30 and AMC20 .

Sorry 0 for 2. Thanks Posi.
That said with only 31 in tires 3.54s would be plenty. I remember when they raised the speed limits out there. The relatively flat stretches were one of the big reasons. If you dont see yourself moving up in tire size from the 31s the smaller carrier with 3.54s sounds good. And your right , it should be easy to trade them off.