If you were me what would you do?

[tpruitt]

I am currently running 3. 54 gears on a truck that has 37 inch tires. The truck is way under geared and i am looking for ideas. I have posed in other places and have done a search and most of the responses came from the towing hauling sections. So should i go with 4. 88 which would be 4. 15 with a stock tire or should i go with a 4. 30 which is a 3. 66 with a stock tire. I do tow but not a whole lot. I will most likely be putting a Detroit locker in it as well.



Thanks for the advice

Trey

 

[Fireman]

I guess smaller tires are out of the question?



What about 4:56?



Fireman

 

[tpruitt]

They don't make that gear for the Dana 80 for some reason. i have some people looking into it but so far they have not found anyone who makes that gear for it. Thats what i was planning until they said those gears are not available. you can get a 4. 66 but that is not compatible with the Dana 60. It does not make much since to me but i guess it does to someone. i would have to say smaller tires are out of the question

 

[RCook]

I tow a 12K lb boat trailer - more air resistance than a big fifth wheel - with stock Michelin's and 3. 54 gears, long distance over lots of mountains.



It works fine, with only an EZ for power enhancement. It seems to me the gears which equate to 3. 66 would be the way to go - especially since you have a six-speed.



If I had 4. 10's I'd have to run slower on level stretches, and would have no advantage climbing hills - just shift at different points.

 

[Sled Puller]

Simple-up the power.

 

[y-knot]

I have been were you are now several times. I had to install 4. 56's in a 4x4 after installing new wheels and tires. The main thing to remember is this is going to be a very costly expense, and you only want to do it once. With your 37" tires I would go for the lowest gear (higher numerically) possible, which I suppose is the 4. 88's. For some reason, most on this forum and others are afraid of low gears. I don't think they get it, you buy a HD truck with a HD diesel for pulling, and then they order some lame gear like the 3. 54? I know most hide behind the "mileage thing", but the difference is nothing, and if 1-2 mpg is going to break you then you probably should have bought a Toyota. You are asking alot from your truck, it has 37" shoes and as to two. Do you and your truck a favor and go with the 4. 88. You already know how much the larger tires have affected the performance of the truck, so the decision should be fairly simple. The last 4x4 I had switched over, cost alittle over 2000. 00, and yours will be at least that. So plan this thing out now, if you are going to change differentials do the research and and get the one that is right for you. Plan on a front and rear bearing kit, they are not much so change them now. Also there are several good gear vendors in the 4x4 magazines, so give them a call and see what they have to say, what they recommend. the more you do now, the better the swap will go later. Also make sure you have a good drive line shop for the install, if you are not doing it yourself. Good luck and let us know how it went.

 

[TBeckman]

I agree with y-knot. Only pay for the job once, why be disappointed with the taller gears. Those tires and soon to be locker will rob power, so even if you have 4. 30's it won't feel like stock. 4. 88's are the way to go, especially if you wheel at all.

My blazer has 4. 56's and 42's, supposed to act like 3. 08's, which was a stock ratio on the truck, it acts nothing like that due to the tires and welded rear.

 

[Mtngoat]

I would definitley go with the 4. 88's.



Robin

 

[JyRO]

What I would do...

If you were me what would you do?

I'd put stock size tires on. Hey, you asked what I would do. As for what I would advise for you to do, I'd say most on here are right. The 4. 88's sound the best, but do the research. Liky y-knot says, do it once - its expensive the 1st time, do it right.



Rcook - Everybody I have ever heard from says that pulling a boat is much easier, because they have much less wind resistance than 5th wheels. Although since they bumper tow, I'd say you'd feel it back there pretty good.

I don't think they get it, you buy a HD truck with a HD diesel for pulling, and then they order some lame gear like the 3. 54? I know most hide behind the "mileage thing", but the difference is nothing, and if 1-2 mpg is going to break you then you probably should have bought a Toyota.

y-knot - I'm torn on this statement. I'll have to agree with you that an ETC with 3. 54's equipped with 265/75 R16 tires, is not nearly the tower as the same truck with 4. 10's. But when I ordered my truck, it didn't say, "NOTE - this truck if ordered with lame 3. 54's & 265/75 R16 tires, will not tow as good as you hope. " I think its a little uppity to say anyone is hiding behine the "mileage thing. " But, now with EZ & 275's, I would rather have 3. 54's towing any weight compared to having 4. 10's. Glad I got the 3. 54's. Oh yeah, I did buy a Toyota. That's good advice, thanks.



- JyRO

 

[tpruitt]

looks like i will go with the 4. 88. i will let you all know how they turn out. Thanks for all the good information



Trey

 

[MCummings]

I love my 3. 54's in my 2wd truck, and even in my 4x4. With 36" tires on my 4x4, it's a little sluggish off the line, but top-end is killer (pun intended?) and wheel speed is greeat, but of course, I have 560RWHP behind that gearing to make this work. I bet it would be piggy if used with near stock HP.



With your 6-speed, I would be just nhappy with a 3. 54 and 38" tires. Just use first gear (which would be like 2nd in a stock truck?) and then you'll have a great O. D. , or use Direct when on the highway. I would save the $2,000 for power adders, instead of gears, but, it's your money.



Just My $. 02



Merrick

 

[tpruitt]

Well i bit the bullet today and ordered the gears. I have talked to many people over the last weeks and have gotten some good advice. With this being said i went with 4. 30's. I really wanted the 4. 56 but they don't make them. The 4. 88 would have been nice around town but on the interstate i would be turning 2300 rpm's. It is not the Gas mileage that i was worried about its the noise. The truck is screaming now at 2300 and i thing that i would have gotten old quickly. I got everything that i need including the master install kit and Detroit locker for $1415 from Reider racing. The Ring and Pinion are all Dana parts which is another plus as well. I will keep you all updated and will let you know how it turns out.



Thanks for all the good advice.



Trey

 

[robobx]

I know an axle builder that lives in Asheboro, much cheaper than most (in the $200 per axle range) and he does gears for a Jeep dealer. sets up lots of 30s, 44s and 60s. and has his own DC install tools. He did my 5. 13s and electrac in my wrangler.

I'm sure he'd be happy to set up your gears, he just bought himself an 03', so he's loving the Cummins.





and I'll think you'll be thrilled with the 4. 30s

 

[tpruitt]

Thanks for the Info. One of the guys that works for us use to own a 4wd shop and he has done so many gear changes. He is also the one that made the winch mount and the coil spacers for me. I am going to get him to show me how to do it right so maybe i can do it the next time i need to change gears. Now I will need to find some one to buy my 3. 54's and limited Slip. I hope i made the right choice on gears but from what all the diff shops said i think that i have. I cant wait for the Detroit. it will be nice to have something that pull both tires.

 

[NVR FNSH]

tpruitt,

I think you made the right decision with the 4. 30s. I turn 2000rpm at 66mph with my 6pd/4. 10s/315s (35") combo and I don't even try 75mph because it's too darn annoying to be turning 2300rpm for any length of time. The best I've gotten is 17mpg and that was 500 miles of I-5 at 66mph



However, my combo is awesome when towing my 36ft 5th wheel. I wish I could have got 3. 73 or 3. 92 R&Ps... ...



Brian

 

[tpruitt]

Brian looks like you and i will be about the same when it comes down to it. After the calculations if you were running a 265 tire to start with you gear now with the 315 would be a 3. 65 which is the same as me but with a 37 inch tire. From what you said about your RPM i am even more glad that i got the 4. 30's i would have been out of the torque range with the 4. 88. Thanks for the info



Trey

 

[NVR FNSH]

What brand tires are you running now?



Brian

 

[willyslover]

off topic... sorry



Brian are you going to Brown valley next weekend ? I am...

[still want the headlight ?]

 

[tpruitt]

37/12. 5 r16 super swamper ssr

 

[RollOver_Pete]

A detroit will be a handfull in the snow/ice/rain. Low side finder every time. I've got detroits in f&r of my Jeep. . and love them. You'll end up re-learning how to drive on the highway... . or you'll end up in a ditch. Would'nt a ARB or L/S be better for what you need, with all of the highway driving you do?