I have a drivetrain setup issue

[USSkoval]

4.88s??....1ton runing gear??? In a weekend warrior road truck that will see little offroad and towing a light boat?
Come on guys. He is not running the Rubicon or towing a house.

4.88 will put the guy over 3000 RPM in drive @65mph Not exactly great for a "Weekend road truck" Plus it will suck fuel like crazy.
1 ton running gear is way over kill.
Keep the 10 bolts and run 4.10 or 4.56 max. either one will be fine for his uses.
If the truck is more road use and fuel milage is a concern go with 4.10
4.10 will put him a little over 1900 RPM @65 in overdrive which will keep the 700r4 happy. In drive 2500rpm @ 65 which is in the middle of the powerband for towing.

I run 3.73's and I only have 33's. The motor is too low in the powerband at freeway speeds and the 700r4 does NOT like it. This is in my Burb and with no load. 4.10's would not improve it enough and keep in mind I'm only running 33's and not 35's. 4.56's would be ideal here and fuel mileage on the highway may actually improve a hair, though possibly at the expense of low speed mileage (slightly). Right now I actually get a little better mileage around town than I do on the highway, because the gearing just lugs the motor down too much.

 

[4xcrazy]

i have a TBI 350/700r4 trans/np241 t-case and a 14bff with 35" tires and 4.10 gears.


i WISH i had 4.56's.

4.10's do fine for around town, mainly because it doesn't need OD, and even on the highway the trans does alot of "searching" between OD and 3rd.

been in a friends truck with similar setup, but has 4.56's and it seems pretty decent for the daily driver type use, and decent pull for towing as well.


my opinion, 4.56's are perfect for the weekender, occasional use, and towing will be fine with them as well.

 

[Stomis]

I honestly have to disagree with alot of whats being said here. Alot of 1/2 ton and Most 3/4 ton and 1ton trucks (IE trucks that will actually get used for loads and work) post 80's fuel crunch era were fitted with 3.73's and 4.10's and came stock with 31 in tires.

When a truck comes under geared stock that doesn't mean you make your calculations for over sized tires based on those gears. For a rig with an OD in my eyes you should base your gearing off of 3.73s as a base for 31in tires and adjust properly.

As for the statements on keeping a 10bolt rear for towing I think thats a terrible idea. I've read stories on guys blowing out 10b cause they hit the gas a little hard on a gravel driveway. And I personally know someone that blew out a 10b in a late 90's truck towing 2 quads... I mean come on why stick with that rear when you could get a 14b with the gears you want in it cheaper than regearing the 10b?

 

[blueblazes44]

I am no expert but I do run 44s on a 10 bolt locked rear end in a 200' mud pit at wot. I experienced no problems with the 20 yr. old axles until the steering stops fell out causing the front u joints to spread and break the ears off the axle. No problems with rear at all but I do run chromemoly at all corners and have had no breaks. I will probably have to step up to 14 bolt since I replaced a warm 383 with a hot 496. jmo

 

[Stomis]

I am no expert but I do run 44s on a 10 bolt locked rear end in a 200' mud pit at wot. I experienced no problems with the 20 yr. old axles until the steering stops fell out causing the front u joints to spread and break the ears off the axle. No problems with rear at all but I do run chromemoly at all corners and have had no breaks. I will probably have to step up to 14 bolt since I replaced a warm 383 with a hot 496. jmo

Yeah but things act much differently in mud. Plus its pretty agreed upon that running tires that big on half ton axles is a pretty bad idea. I mean if it works for you eh alright I guess your just spinning through mud anyway but for situations where tires are gonna grab, bad idea.

By no means am I saying a rear tenbolt is a bad axle. Hell theres plenty of G body guys that put 500hp launches down on them successfully and for a long time but something about them just looses their strength factor when you up tire size...

 

[Blue85]

I mean come on why stick with that rear when you could get a 14b with the gears you want in it cheaper than regearing the 10b?

Because that $150 14b will need $100 in brakes, $450 in wheels and $100 in front 8-lug conversion. Granted, regearing is only "cheap" if you or a friend will be setting up the gearset.

The front end needs new gears either way, so that's a wash.

The EASIEST solution is to find a set of 4.10 10-bolts. But these are hard to come by.

A 14Bff is total overkill here.

 

[Stomis]

Because that $150 14b will need $100 in brakes, $450 in wheels and $100 in front 8-lug conversion. Granted, regearing is only "cheap" if you or a friend will be setting up the gearset.

The front end needs new gears either way, so that's a wash.

The EASIEST solution is to find a set of 4.10 10-bolts. But these are hard to come by.

A 14Bff is total overkill here.

I really dont agree. Is a 14bff in its own right overkill, yes. But is a better axle than a 10b, No. This is a perfectly good application for say a SF or even a ford 9in (O noes I'm switchin up the brands here ).

I think your prices are a little over though...

$100 brakes
$250 wheels
$100 for front 8 lug

So thats $450 for the whole rear axle, ready to rock.

Gears would be $180, $100 for the install kit, and upwards of $350-500 for a shop to install them. Gotta remember most people arent too savvy on gear setup. The good amount of us on here are a rare breed

I mean jeeze I know how to setup gears. I know exactly the proper procedure using the real tools to get pinion depth dead nuts on the first time and have proven to myself I can do it no problem on more than one occasion BUT they still scare me.

 

[4xcrazy]

for what he plans on using his rig for, i personally believe the 14bSF would be the better option for him, not too sure how many there are though with at least a 4.10 ratio in them, let alone a 4.56 setup.



all i was saying in my previous post, and was trying to give personal experience advice, is that i HAVE 4.10 gears, and honestly it's still not enough, it does lug the motor pretty decently in OD on the highway unless i'm doing like 80+mph.

right now i can EASILY run around town, even on the higher speed limited sections of streets of 45-50mph and keep it in 3rd with no seemingly over rev'ing of the motor.

i personally COULD go with 4.88's, but i really didn't want to go with anything too agressive with rpm changes and whatnot.

 

[Stomis]

for what he plans on using his rig for, i personally believe the 14bSF would be the better option for him, not too sure how many there are though with at least a 4.10 ratio in them, let alone a 4.56 setup.



all i was saying in my previous post, and was trying to give personal experience advice, is that i HAVE 4.10 gears, and honestly it's still not enough, it does lug the motor pretty decently in OD on the highway unless i'm doing like 80+mph.

right now i can EASILY run around town, even on the higher speed limited sections of streets of 45-50mph and keep it in 3rd with no seemingly over rev'ing of the motor.

i personally COULD go with 4.88's, but i really didn't want to go with anything too agressive with rpm changes and whatnot.

Yep thats why I recommend the 4.56s OR the 4.88's. I wouldnt go any higher of a ratio than the 4.56's.

 

[Blue85]

for what he plans on using his rig for, i personally believe the 14bSF would be the better option for him, not too sure how many there are though with at least a 4.10 ratio in them, let alone a 4.56 setup.



all i was saying in my previous post, and was trying to give personal experience advice, is that i HAVE 4.10 gears, and honestly it's still not enough, it does lug the motor pretty decently in OD on the highway unless i'm doing like 80+mph.

right now i can EASILY run around town, even on the higher speed limited sections of streets of 45-50mph and keep it in 3rd with no seemingly over rev'ing of the motor.

i personally COULD go with 4.88's, but i really didn't want to go with anything too agressive with rpm changes and whatnot.

I totally agree on the 14b s/f, assuming he is OK with converting it to 6-lug, moving the spring perches or making the jump to 8-lug. 4.10 was not uncommon, but I think 4.56 was pretty rare. I don't think they ever came with 4.88. I think 4.56 is best for 35's, but I get good results at all speeds with 4.10's in mine, so I wanted to add that experience.