Dana 44 and Ford 9", Matching gears Options

[Wild Willy]

I am working on a frame off restoration project. I have a 66 that has the 170 six cylinder in it. I bought a 70 Bronco Sport that had been rolled (lightly) for parts that has the 302. The 70 runs good but is a rust bucket. I have also obtained many other parts from a 73. I want to install the Dana 44 from the 73 on the frame of the 70 along with the 9" from that same Bronco. I will then take the body from the 66 and put it on the 70 frame. Here is my question: The 9" has a tag number WEM-E 9KB 3.50 8.7 605A and the Dana 44 has a tag number of 3.54 D3TA-KA 603368-3. Will these two gear combonations work together or do I need to match them? Where can I find more information on how to set up the differentials? I am clueless on this part of the build.

[Bully Bob]

Hay Wild W....,

I doubt that's a prob. but research it a bit more. (4:10's & 4:11's are often seen together)
---BUT ---
I wouldn't trust the tags.....
Mark the wheel and the pumpkin yoke...one revolution of the wheel should net you 3 1/2 turns of the yoke.
As I recall.., the other wheel needs to be on the ground., so as not to turn., to get a correct reading.

I would use which-ever 9" that has the large bearing....if in fact., one does.

HTH
B

BTW.., What are you going to do with the 170 c.u. I-6 ?

This post has been edited by Bully Bob: Nov 2 2009, 08:48 PM

[BUCKIN67]

I am working on a frame off restoration project. I have a 66 that has the 170 six cylinder in it. I bought a 70 Bronco Sport that had been rolled (lightly) for parts that has the 302. The 70 runs good but is a rust bucket. I have also obtained many other parts from a 73. I want to install the Dana 44 from the 73 on the frame of the 70 along with the 9" from that same Bronco. I will then take the body from the 66 and put it on the 70 frame. Here is my question: The 9" has a tag number WEM-E 9KB 3.50 8.7 605A and the Dana 44 has a tag number of 3.54 D3TA-KA 603368-3. Will these two gear combonations work together or do I need to match them? Where can I find more information on how to set up the differentials? I am clueless on this part of the build.

[BUCKIN67]

Hi there, I am sure that 3.54 (dana) and 3.50 (ford) are the same combo. The difference is dana and ford manuf. I would always suggest counting the teeth on the pinon and the ring gear and dividing the pinion into the ring # for ratio ID. I am certian if you had gotter them out of the 70 then they match and work together already obviously. If your putting the 66 body on the 70 frame isnt the diffs already in the 70 chassis? Also the 66 prob had a 4.10 and 4.11 combo for the tiny 170 eng. Id bet. You can look up my profile on here, Im a FORD motor co senior master technician and ASE master, have been a mechanic for 23 years and broncoing for bout 18. Yep, bully bob is also right bout that large bearing, the difference is 2800 lb or 3300 lb rear axle. The larger is much stronger and is easily identified by the size of the outer housing near the backing plates. just look where the leaf spring are bolted on and see how small it drops down to. I hope this helps ya some! GOD BLESS YA!!

[Wild Willy]

Thanks everyone for the helpful info.

[riggermortis]

anybody correct me if im wrong, but isnt the front sopposed to be just a little higher geared than the back so that it pulls just slightly, and thats why you cant drive on a hard surface or it will bind. right???

[Bully Bob]

Hay rig...,
Yes & no ....... the factory doesn't do this 'but' competition rigs do as it does help. (i.e. higher in the front)

I doubt the factory recommends 4x4'n on pavement even with equal gearing F&R....at least on the older rigs.

[S_bolt19]

typical rule of thumb is that if you are within 2-5% of each axle, you are good. A 4.11/4.10 combo is within less than .3% where a 3.50/3.54 is about 1.14%. Either way you are still fine. Now if you run a 3.50/4.10 combo (about 17% difference), you will see where it will trash just about everything connected to it.