Dana 71/61

89cumminstd

89cumminstd

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I recently swapped from a 727 to getrag on my 89, and I'm just not happy with the way the 5 speed works with the 3.07 ratio. Some people say you can regear them some say you can't, whats the truth? Could I put 3.55s in this axle with a locker? Or am I gonna have to swap them out for some 60/70's?
 
its possible. youll have to run a 4:56 and up carrier to get the pinion offset required, i had to machine either my front or rear carrier or both to get backlash correct. so yea its possiable but a real PITA. i went 4:10, 3:55 has bigger pinion so might not be as bad.
 
I ran the 3.08's for several years in my '90 model with an NV4500. I hated the 4-3 shift that had to be done to avoid the high EGT's once we hit the mountains.

I later swapped in an NV5600 and I absolutely loved the gears. Talk about mileage, she was barely running in 6th. We 'twin sticked' the NP205 so I could shift into low without 4x4. When the heavy pulling/hauling came up, I usually went to low range to take off and split the gears from 3-4 shift.

Well, I wanted to run 35's on 'er so I knew a gear change was in order. Instead of fighting the custom C&C dually dana 70, (I took a 70B and machined the 71 carrier to fit the 3.08's in it), I found a 4.10 C&C drum brake dana 80 fairly reasonable. We completed the swap and now I hate the 4.10 gears. They are perfect for local runs and pulling/hauling the heavy stuff, but, they are horrible for the long hauls. Mileage went way down as well and even with 35's, the rpms are high.

Looks like a swap to 3.54's is in my future for the dana 80.

IMO, if you are going to keep stock diameter tires, I'd keep the 3.08's and spend the money on either a G56 or NV5600 swap. Even with a gear swap to 3.54's, which my son has with a getrag, you will not be happy.
 
Thanks for the replies I wish I could do a g56 swap right now but I just got all the getrag and new clutch all in. one day I will was it hard putting a nv5600 in? Junkyard dog, whats all required with putting 4.10s in? I never do any highway driving so I think that's my best bet right now
 
4:56 and up carrier for the off set plus little machine work on the carriers to be able to shove the carrier over far enough to achieve correct backlash. i have a power lock carrier in rear i robbed from a ditch witch axle and a Randys R & P trac-loc in the front.Had to shorten one rear axle shaft due to hitting center pin. It was a days work on the lift and i had all parts. I've also got some new dana 4:10's i'll sell if your interested. PM me
 
was it hard putting a nv5600 in?
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No, not that I remember. You'll need the flywheel housing and starter from a second gen, I believe???

We also went with a South Bend Dual Disk.

The 'ol 205 bolted right up. Had to fab up some xfer case linkage and have the drive shafts shortened and lengthened.

It has been the best addition I have made to the truck.
 
If going with a 6 speed I'd go with a G56. The NV5600 has basically no rebuildable parts available for it. Where as the G56 is a relatively new transmission, and you can get most, if not all the parts to do a total rebuild on it.

Check out this thread for what's involved with a G56 swap....

http://www.cumminsforum.com/forum/89-93-powertrain/1239601-getrag-g56-conversion-finished.html

And this one...

http://www.cumminsforum.com/forum/89-93-powertrain/270795-g56-swap.html

Good info on Fuller 6 speed, NV5600, G56 and ZF6 trannies....

http://www.cumminsforum.com/forum/general-diesel-discussion/316884-fuller-6-speeds-versus-nv5600-g56-zf6.html
 
Danas

Is it possible that a 1989 that came with the 727 no overdrive has a dana 70 rear? The truck was parted together before I bought it I have no clue what year the drivetrain is. It looks to me like the rear has a 70 stamped on it can u put 3.08s in a 70? I attached a pic of it u may need to stand on your head to see it. I can't find any markings on the front tho I looked on the pumpkin and axle tubes.
 

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89cumminstd said:
Is it possible that a 1989 that came with the 727 no overdrive has a dana 70 rear? The truck was parted together before I bought it I have no clue what year the drivetrain is. It looks to me like the rear has a 70 stamped on it can u put 3.08s in a 70? I attached a pic of it u may need to stand on your head to see it. I can't find any markings on the front tho I looked on the pumpkin and axle tubes.
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The 89 I had for parts had a Dana 61 in it. Had a 61 cast right into the housing. looks like a newer 70 if the truck is a Frankenstien's monster it just might have a 3:55 geared 70 in it.
 
gorilla550 said:
The 89 I had for parts had a Dana 61 in it. Had a 61 cast right into the housing. looks like a newer 70 if the truck is a Frankenstien's monster it just might have a 3:55 geared 70 in it.
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Which part of housing for the 60? I can't see any numbers, it is 3.08s unfortunately and it's pretty miserable with a 5 speed getrag for daily driving. This is why I'm trying to figure out what I have so I can regear. Will the 71's have a 71 cast into them? It looks to say 70 pretty clear in the pic but is there a major difference between the two cosmetically?
 
I don't have my old housing or I would check to see what was cast into it. I'd say you have a 71 if you are positive it is 3.08's. The trouble I went through to get my 3.08's into a 70B C&C dually rear would not be tackled by the meek.

They will not fit without custom machine work.
 
Geez what a pita, this truck is lucky I love it I guess I'll be on the look out for a 70/60 soon. Or a 6 speed whichever pops up first when I have the money. Is there a big difference when you twin stick the 205s for a 2 low?
 
Is there a big difference when you twin stick the 205s for a 2 low?
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The 'ol 205 should have about a 2:1 reduction (1.98:1 IIRC). With my NV5600 and the 3.08's, I would stay in low range until 45-50MPH. Pretty much the same when the NV4500 was in place.

Just unlock your hubs, throw it in low range, and drive it around. Same deal as the twin stick.

As stated before, the best thing I could have ever changed on my 'ol 90 model to date was installing the six speed. I'm thinking pretty strongly about just re-installing the 70B we fixed up with the 3.08's. I like the fact of having the dana 80 with the strength and hub centric wheels, but, I really don't need it and a complete rear end swap is way easier than the gear change for me.
 
Bodacious said:
The 'ol 205 should have about a 2:1 reduction (1.98:1 IIRC). With my NV5600 and the 3.08's, I would stay in low range until 45-50MPH. Pretty much the same when the NV4500 was in place.

Just unlock your hubs, throw it in low range, and drive it around. Same deal as the twin stick.

As stated before, the best thing I could have ever changed on my 'ol 90 model to date was installing the six speed. I'm thinking pretty strongly about just re-installing the 70B we fixed up with the 3.08's. I like the fact of having the dana 80 with the strength and hub centric wheels, but, I really don't need it and a complete rear end swap is way easier than the gear change for me.
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So the twin stick is just a waste of
Time and money? Is there any other perks to them besides 2 lo? I did a little research on these axles, apparently there was never a 71 but only a 61. The rears in these non o/d trucks are a dana 70U-2A I can read that on mine, which apparently has an offset pinion to handle the 3.08 gears. The pinion being off set is this able to be regeared?
 
Bodacious said:
I ran the 3.08's for several years in my '90 model with an NV4500. I hated the 4-3 shift that had to be done to avoid the high EGT's once we hit the mountains.

I later swapped in an NV5600 and I absolutely loved the gears. Talk about mileage, she was barely running in 6th. We 'twin sticked' the NP205 so I could shift into low without 4x4. When the heavy pulling/hauling came up, I usually went to low range to take off and split the gears from 3-4 shift.

Well, I wanted to run 35's on 'er so I knew a gear change was in order. Instead of fighting the custom C&C dually dana 70, (I took a 70B and machined the 71 carrier to fit the 3.08's in it), I found a 4.10 C&C drum brake dana 80 fairly reasonable. We completed the swap and now I hate the 4.10 gears. They are perfect for local runs and pulling/hauling the heavy stuff, but, they are horrible for the long hauls. Mileage went way down as well and even with 35's, the rpms are high.

Looks like a swap to 3.54's is in my future for the dana 80.

IMO, if you are going to keep stock diameter tires, I'd keep the 3.08's and spend the money on either a G56 or NV5600 swap. Even with a gear swap to 3.54's, which my son has with a getrag, you will not be happy.
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Is your truck a single wheel? How is the stance with the dana 80 in?
 
How is the stance with the dana 80 in?
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We installed a chassis Cab dual wheeled rear with drum brakes. I'm not sure what you mean by 'stance'??

So the twin stick is just a waste of
Time and money?
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Well I guess it could be depending on how you look at it. For us, it was a blessing with the 3.08's. At one time I regularly grossed over 30k lbs moving my equipment from job to job. Being able to go to low range without stopping was a must. You can't go to low range while moving and the hubs unlocked. lol, I guess you can but your gonna get some rake.
 
So there's no way I could possibly put a locker In this? I drove it In 4 lo with the hubs unlocked it was great and would be great for towing I'm gonna look into twin sticks
 
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