2nd Gen Non-Engine/Transmission DANA 70 and 80 demensions

[Bug Out]

Quick story. I bought a 97 Dodge 2500 2wd QC gasser for work( I have a 2012 3500 CTD 4x4 CC LB for towing) and changed out the rear axle. The old was a D70 with pinion howl like mad. The seller thought he sold me a D70, but when I put it in, it turned out to be a D80/3;54 gears. Cool. Got 3x what I needed. Anyhow, what I need to know is the center line dimension of axle to the universal yoke for both rear ends. The universal joints/yokes were the same, but it seemed like I could barely get the drive shaft back in place as if the 80 was longer,taking more room toward the transmission then the 70 did.



If I remember correctly from my teenager wrenching days, as the axles goes up under a load, the transmission yoke slips out????? Or does it go inwards toward the trans???? What I dont want to happen is bottom out the drive shaft yoke into the transmission housing etc etc. .



Thanks for any help in advance. I goggled it with no luck and nothing here either. . I probably used the wrong words or something. .

 

[cerberusiam]

No, as the suspenion compresses the slip joint goes together. If you bounce it to hard and it will bend the drive shaft. The D80 is a larger ring gear so the diff is longer. You need to resize your drive shaft.

 

[Bug Out]

Thats what I was afraid of... Thanks. .

 

[cerberusiam]

IIRC, the drive shaft needs shortened 1. 5 inches to give adequate travel on the slip joint. Sholud be raltively easy for a drive line shop to do that. Congats on the beefy diff.

 

[JLeake]

Bug Out- I suggest that you replace the seals on the Dana 80 at a minumum. Lost the pinion seal on my buddies 3500 DRW on a trip, they are a bear to change (torque value is basically all you can get on the nut). If it was mine, I would go through the whole diff to ascertain the condition before placing it in your truck. Cheap insurance to do before you start to use it. The yoke nut as I recall needs a modified socket to remove the nut, I did ours on a belt sander by hand at the race track. The tools required are not the ones you usually have around.