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Question About Gear Sets for GM Dana-60/14-Bolt Diffs.

1-ton

1-ton

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This should be an easy one. When I am shopping for gears on the net for a set of pinion/gears for my 1991 V3500 Crew Cab (Dana-60 front/14-Bolt FF rear) all the adds say they are for a 1973 to 1988. I am guessing those gears will also fit the 1988 to 1991 V3500 1-Ton GM trucks as well?
 
Note: the install kits are different for the later (finned housing) 14 bolts, the pilot bearing outer dia changed size.
 
sweetk30 said:
how deep you going ?

i know a guy with 60/14ff install kits yukon and 5.38 14ff set all brand new .
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I am just going with a set of 4.88:1 ring/pinion set. Since my "street queen" Crew Cab is 90% street, and only used for light off-roading on maintained fire roads I am more concerned with gearing for the highway than off-road. I went to a web site that can do gearing calculations, and the best calculation with a set of 37" tall tires and an overdrive transmission (4L80E) is 4.88:1 for highway driving.
 
IMO, In a crew cab with OD trans, i would probably go with 5.13’s for 37’s. Unless its got a healthy motor, thats a really heavy truck.
 
almost all the guys on here have said for years if 35" or more and overdrive go 5.13 .

and if you do stock r-p to tire dia = rpm and then convert to match i have been told always go 1 more ratio deeper than what brings you back to stockish .

i plan on 35" tires and my 5.13 axles with a bbc and 70mph with 4l80 should be 2500 rpm . but i am building mine for a work truck .

just checked 5.13 and 37 = 150 rpm over the 4.88 . go deep . :waytogo:
 
muddybuddy said:
IMO, In a crew cab with OD trans, i would probably go with 5.13’s for 37’s. Unless its got a healthy motor, thats a really heavy truck.
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You have a point there. Even though the gear calculator shows that 4.88:1 is the perfect gear ratio for Interstate cruising, it does not take into account the weight of the vehicle or how much engine you have.
 
I'm putting 5.13s in my rig for the reasons mentioned above. Not enough of an RPM change to make that much of a difference, but enough gearing to help me get out of my own way. Also need to take into account TCC lockup which will drop rpm even more while cruising (most calculators/charts I've looked at didn't take this into account).
 
nvrenuf said:
Note: the install kits are different for the later (finned housing) 14 bolts, the pilot bearing outer dia changed size.
Click to expand...

I was looking at Pirate4X4, and they have a lot of detailed info on the 14-bolt. It shows a bearing master kit part number for 89 - up (the "up" means to the year 2000).
 
Chevman88 said:
Also need to take into account TCC lockup which will drop rpm even more while cruising (most calculators/charts I've looked at didn't take this into account).
Click to expand...
How can they do the calculation without assuming TCC is locked? Unlocked you have to know the torque through the converter and the characteristics of the converter (is that my cruising RPM going uphill or downhill, towing or empty?). I bet they are all just using the OD ratio of the trans straight up. Can there really still be confusion from 40 years ago that L/U is like another half gear? The truth is without lockup you were really not quite getting all the way into your gear.
 
1-ton said:
I am just going with a set of 4.88:1 ring/pinion set. Since my "street queen" Crew Cab is 90% street, and only used for light off-roading on maintained fire roads I am more concerned with gearing for the highway than off-road. I went to a web site that can do gearing calculations, and the best calculation with a set of 37" tall tires and an overdrive transmission (4L80E) is 4.88:1 for highway driving.
Click to expand...
I agree with 4.88 for your application.
 
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