new gears or new differential??

hi there,

during the next weeks the "pinion-nut recall" will be completed on my truck .
since the will take off the complete differential with its bearings etc this seems to be the best moment for regearing or putting in a true trac or sth like this cause i don´t have to pay any labor costs - only the parts.

i have a 2wd crew cab with 3.21 gear ratio and the open diff. i use my truck for onroad drinvin 99,99% of the time. the gears work pretty fine for me up to now (33" oem tires).

for the near future i am thinking about a BL plus leveling kit which might end in putting on some 34" or 35" tires.

this is my dilemma: what should i do?

1. regear? if so, which ratio would be the best for my use (no offroad and as good as no towing or hauling - yet)? which manufacturer do you recommend - motive gears?
2. throw in a true trac or sth. like that? what would be the best for my use? a locker would be a overkill i guess but i wanna have the maximum traction without any loss of comfort or safety, e.g. in turns.

what would you guys recommend? i would be VERY grateful for your help and advices which parts to buy. over here in germany it is pretty hard to figure out (e.g. which gear manufacturer to buy).
if you could help me finding good deals on parts i might be able to change both?!

thank you soooooo much in advance!!

If you aren't going bigger than 35s, do a 4.10 swap with an LSD


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4.10 sounds pretty high to me. how much rpms are this gonna be at 60mph. right no i have 1400-1500 at 60mph (with mds).

I went from 3.55 to 4.10s with stock 33" tires. Gained a lot of acceleration even at 50 mph for passing, lost .5 mpg overall and about 2 mpgs at 70 mph+. But if your going to do a 2 " front end level with 35" tires then you would def want at least the 4.10s. Im at about 1700-1800 rpms at 60 mph.

I would get Motive 4.10s, Auburn LSD and an install kit from MOES for about 750 all in and call it a good day.

Hope this helps.

Differentials

4.10s without a doubt with tires 33" and bigger. When I went from 3.55s to 4.10s I actually gained nearly 1.5 MPG with the same driving style and keeping the cruise set 70 max.

You might check with your dealership about installing after market parts that you bring in, especially if you are wanting to mix their installation with warranty work they will be doing. Some dealerships don't like to do that.
Jay

Pull Ya said:

You might check with your dealership about installing after market parts that you bring in, especially if you are wanting to mix their installation with warranty work they will be doing. Some dealerships don't like to do that.
Jay

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Exactly! Mine wouldn't even install an aftermarket rear differential cover while doing the recall so, you better check with your dealer before you buy any parts expecting to save on labor costs.

TylerB said:

4.10s without a doubt with tires 33" and bigger. When I went from 3.55s to 4.10s I actually gained nearly 1.5 MPG with the same driving style and keeping the cruise set 70 max.

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wow that sounds good. up to now i was ok with my 3.21 on 33´s. it sounds like 4.10 will be a noticeable difference, right?
i thought about 3.92 as a golden middleway solution - especially since 4.10 sounded always very high to me.
so, would you really recommend 4.10 for a daily driver without going offroad or towing?
what is better: auburn lsd or a true trac? from what i read the true trac is maintenance free - the auburn doesn´t seem to be so. is that right?

i will ask them if it´s ok for them if i bring the parts in.

I have an 09' and purchased a TruTrac with 4.10's from Matt (http://www.moesperformance.com/); it just makes sense to knock them both out at the same time. Coming from 3.55's on 20's, the initial feel was actually "boggy" until about 100mi +/- where it just woke up (break in period?). Where I feel it the most, 4.10's, is acceleration from complete stop and the TruTrac keeps me grounded. Definitely worth the while As far as I know, the only major difference between the lsd's are whether one requires maintenance or not (clutches, cones, etc). I did not lose mpg, actually gained 1-2mpg.

If you go with the Motive gears, having spoke to them directly, they recommend 85w-140 GL5+ rated gear oil (non-synthetic). Supposedly synthetic gear oil under 80w-140 is too thin and doesn't lubricate to their liking.

is there a chart or sth like that which shos the differences in rpms with different gears?
i am really thinking about the swap but i just can´t decide wi´hich size to go with.
i use it on road only with minimal towing or hauling. new tires might be a 34" or max a 35" tire - let´s plan with the 34" for this question.

4.10s without a doubt at the minimum, but if it were me, I'd do 4.56s with anything taller than 33".

FWIW I run 4.10s with 30.5" tall tires and it's almost exactly equivalent to 4.56s with 33" tires. Anything to help to get these heavy trucks moving, especially with taller tires.

I'm also going to re gear soon. right now im running 38s and i am planning to go with 4.56 is this what i should be running? thanks for any help

ok guys, it seems like i´ll be getting the 275/65 r20 (34") tires - cooper zeon ltz. would you recommend regearing to 3.55 oder 3.92?

right now i have 3.21 which is actually fine and i don´t want the rpms to go sky high which might cause some drone inside the cab due to my FM super 44.

oh one more thing: i am planning on getting a vararam soon as well as a ne TB (85 or 87mm). might that maybe do the trick and make the regear unncessary/an equivalent to it?

ok guys.... ia m about to pull the trigger on a true trac. regarding gears: i don´t think that a 3.92 ratio is the right way for my - i don´t haul, tow, go offroad or do drag racing.
cause of that i am thinking about 3..5 max. bit i donßt know if this is worth the money?!?!
is there a difference in the quality of the manufacturers of gears?

let me know what you think.

Don't bother with 3.55s. Do 3.92s at the minimum, preferably 4.10s with 33" or bigger tires otherwise it'll lug the engine and hurt fuel mileage.

TylerB said:

Don't bother with 3.55s. Do 3.92s at the minimum, preferably 4.10s with 33" or bigger tires otherwise it'll lug the engine and hurt fuel mileage.

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i thought the high rpms would lug the engine?!? do u notice the difference in response only at kick-down/WOT or during normal driving, too?
what manufacturers do you recommend - in terms of durability? motive gears?

Motive gears are good and affordable.

I have 3.55s on stock rims, do not go 3.55. If you are going to do it go 4.10s. I am about to spend $2,000 to swap for 4.10s, lsd and larger cover. Acceleration is not the only consideration. The 4.10s will help with shifts, and the tranny searching for a gear and bogging in some cases. It will feel more responsive and less weighted down, IMHO.

^^^ Is "weighted down" even a phrase?! My English needs some work...

You got the right idea David, it makes the truck feel a lot lighter than it really is. These trucks with the 5/6 speed should never have come with 3.21s or 3.55s to begin with, too much of a granny gear for the way overdriven trans.

The 4.10s will improve the feel of the truck entirely not just off the line. The truck will no longer need to drop a gear to make it up an overpass or if you're trying to pass a little touch of the pedal and the truck will accelerate nicely.