Differential gear swap

[White wondee]

Hey guys, currently my truck has 3:55 gears and they are terrible for towing with 35’s so I’m wanting to swap to 4:10’s. I can’t find a set that will fit my truck but I found a set out of a 94, my question is will the gears from the 94 axles fit in my 2000 axles? Thanks 

[LorenS]

Looks to me like they should fit.

https://www.randysworldwide.com/shop/zg-d70-411

 

If you want to replace some parts while you're in there, I suggest price checking East Coast Gear Supply. It's who I used for genuine DANA/SPICER parts.

[Andyba20]

Does the 94’ truck have a Dana 70u like your 2000, or a Dana 80?

[LorenS]

[Ironforger]

When I got my truck, it had 4:10's.  I switched out the gears (and carrier case) to 3:55.  I am quite happy with it now.

 

I'll give you a deal on my 4:10 carrier case. Your going to need it.

 

I'll throw in the ring and pinion gears for free. (They were singing, the axle shop that changed out my gears told me they looked worn out.)

 

My axle is dana 80.  Your is most likely dana 70.   My understanding (correct me if I'm wrong) is the 2nd gen dana 70 & 80 used the same gears & carrier. Interchangable.

 

PM me if interested

 

Jerry

[LorenS]

DANA 70 has 10.5" ring gear, DANA 80 is 11.25".

 

My humble advice is to stick with gears made for your axle, and that preferably aren't already worn out...

[Ironforger]

8 hours ago, LorenS said:

DANA 70 has 10.5" ring gear, DANA 80 is 11.25".

 

My humble advice is to stick with gears made for your axle, and that preferably aren't already worn out...

Thanks for clarifying Loren!  From what I understand, a manual trans determines if the truck got the dana 80:

 

3500 = Dana 80

2500 Auto = Dana 70

2500 Stick = Dana 80

 

 

If anyone needs a good used Dana 80 carrier for a 4:10 gear set, PM me.  Including the gears for free, but would not recommend using them as I was told they are worn out.

[LorenS]

6 hours ago, Ironforger said:

From what I understand, a manual trans determines if the truck got the dana 80

That's my understanding, as well - at least for 2000 and up.  That may be applicable to all 2nd Gens, I just don't know.
Of course these trucks are old enough now that it's worth checking EVERY axle; I'd love to put a DANA 80 in my auto 2001 simply because I like the gear-style limited slip diffs, and no one that I can find makes one for the Dana 70. 

[Silverwolf2691]

@LorenS, Eaton doesnt make a truetrac for a 70? Otherwise the factory limited slip is the same clutch pack style.. gear style didnt come factory until this past gen power wagon i think..

 

Just looked.. theres one for the 70HD but not a regular 70.. weird..

[wil440]

On 4/28/2022 at 11:32 PM, White wondee said:

Hey guys, currently my truck has 3:55 gears and they are terrible for towing with 35’s so I’m wanting to swap to 4:10’s. I can’t find a set that will fit my truck but I found a set out of a 94, my question is will the gears from the 94 axles fit in my 2000 axles? Thanks 

I have 3:55  and slightly smaller tyres at 33" and if I lock the trans out of OD my rpm is around 2250 at 60, tows nice, egt  low enough, could do with rpm being a little lower for me, 2100 would be nice

[Mopar1973Man]

Funny so far I notice my best MPG is between 2,000 to 2,500 RPMs. When it drops below 2,000 the efficiency drops. I cannot add timing to 1500 band because of bucking issues at about 30 MPH making city travel not fun.

Edited May 8, 2022 by Mopar1973Man