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5.38 gears for the 14FF

IIRC the bridge support for the pinion pilot bearing will interfear with the ring gear teeth with ratios that are numerically higher. I have had to machine certain Ford 9" cases when installing 6.50 gears in them in the same place just for that reason.
I'd be willing to bet that a 5.38 gear set could be made to work but I would not look for anything higher.
Tom
 
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Im trying to think of a good application when more than 5.13 would actually be a good thing....

maybe I'm koo-koo for cocoa puffs, but IMO if you need that much more gear, you should be spending your cash on a doubler, klune-v, atlas or some other upgrade. Im going 5.13s with my ff14 and D60... if 5.38s or 7.17s come out, I wont feel like I "messed up" by going to 5.13 cause its the right gear ratio for me. Not to mention that when they first come out and only 1 company is making them, imagine how much they will cost. ouch.

j

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Either that or a new motor...
I'm turning 44's with 4.10's...and it crawls...also..

I just bought 5.13's...that should be low enough.
I can't see 5.38's being worth the wait.
 
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Im trying to think of a good application when more than 5.13 would actually be a good thing....

j

[/ QUOTE ] My thought isn't crawl ratio its, just puting power to the ground in 4 or 2 hi. Crunching the numbers on my 5.13 gears with 39.5s its something like 3.23 gears with 31s. Plus all the weight of the tires. Of course thats on paper, I'm sure 5.13s will be decent with the 465 in hi. I have 5.13s so I wouldn't even consider trading up to 5.38s but liek I said if I could get 5.86s without weakening the 14 bolt I would.
 
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maybe I'm koo-koo for cocoa puffs, but IMO if you need that much more gear, you should be spending your cash on a doubler, klune-v, atlas or some other upgrade.

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Why? My tranny/transfer case are both flawless. Why would I pull out my rebuilt 4 speed, brand new drive sleeve/seals, and perfectly funtional 205 to replace it with some other combo of boxes when I can get more gear reduction with a ring and pinion change?

It's a trailer queen, it doesn't need nor do I want it to go 70 MPH. 5.38 is a step in the right direction. 7.17 would be better.
 
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Why would I pull out my rebuilt 4 speed, brand new... when I can get more gear reduction with a ring and pinion change?

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Because without an increase in ring gear diameter, a lower-ratio R&P set will have a smaller pinion. Smaller pinion means fewer teeth, fewer teeth means less gear engagement between the ring and the pinion, which means each individual tooth regularly sees more stress. Add a shock load, and you're running the risk of chunking/stripping the pinion.
At work, we see a lot more blown-up Eaton and Rockwell third members with 6.- and 7.- series gears than 3.- and 4.- series. A 3.55 pinion for an Eaton DS404 rear axle is around 5" diameter at the big end; a 7.17 pinion for the same rear is around 3" at the big end.

As was stated before, going from 5.13 to 5.38 just doesn't seem to be worth the $$$ and effort to re-gear two axles IMO. Of course I'm not a hardcore 'wheeler, so that probably has a lot to do with my opinion...
 
I have 4.10s now and I was going to go 5.13 to max out my gear. If 5.38 is going to be available, I'll wait.

I have 1 ton axles. I'm not worried about breaking a ring and pinion.
 
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I have 4.10s now and I was going to go 5.13 to max out my gear. If 5.38 is going to be available, I'll wait.

I have 1 ton axles. I'm not worried about breaking a ring and pinion.

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And I have 5.13s on the shelf, I won't purchase 5.38s if they come out. Cost for the extra little crawl ratio and power gain aren't worth it unless I was started fresh with some new axles.
 
The difference is minimal and only nets you 5% more gear. It is nice to see more options hitting the market. I would be leary of the pinion. There is now more torque on less surface. I am sure it is strong but the 14FF has a reputation to uphold.
 
[quoteWhy? My tranny/transfer case are both flawless. Why would I pull out my rebuilt 4 speed, brand new drive sleeve/seals, and perfectly funtional 205 to replace it with some other combo of boxes when I can get more gear reduction with a ring and pinion change?

It's a trailer queen, it doesn't need nor do I want it to go 70 MPH. 5.38 is a step in the right direction. 7.17 would be better.

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The trouble is you will never get a huge increase in crawl ratio by just swapping ring and pinion gears...........assuming you stay with a reasonable ratio in the 5.xx's and didn't have something like a 2.73 or 3.08 to begin with, I just wouldn't consider ratios in the 6.xx's or 7.xx's really practical for D60's and 14FF's because of strength issues.

Look at these crawl ratio examples for a th400/205 combo rig.

w/ 4.10's = 20:1
w/ 5.13's = 25:1

Maybe a noticable improvement but nothing extreme.

Now add a doubler to the same rig while keeping 4.10 gears and you have a 40:1 crawl ratio.

I'm not saying everyone needs a doubler......I don't think my rig needs one. In my experience ring and pinion swaps are typically more effective in making street driving better than have a huge impact on off-road crawl ratio.
 
What isnt being said...
I doubt the market they are looking at are the people who already have 5.13s. /forums/images/graemlins/rolleyes.gif
No one, or very few, would regear just for that.
But... if I was at 4.10s or something and wanted to go to the 5s... I would choose the 5.38s over the 5.13s. /forums/images/graemlins/thumb.gif
 
get some real gear ratio is all I have to say. TH400 and 205 is just nothing.

You left out that a doubler with 5.13 gears, the crawl ratio is about 51:1.

Or get a 465 and 241 /forums/images/graemlins/wink.gif.
465-241 4.10 gears: 73:1
465-241 5.13 gears: 92:1

465-205 4.10 gears: 52.5:1
465-205 5.13 gears: 66:1

Each number in the crawl ratio calculation has a good sized effect.
 
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get some real gear ratio is all I have to say. TH400 and 205 is just nothing.

You left out that a doubler with 5.13 gears, the crawl ratio is about 51:1.

Or get a 465 and 241 /forums/images/graemlins/wink.gif.
465-241 4.10 gears: 73:1
465-241 5.13 gears: 92:1

465-205 4.10 gears: 52.5:1
465-205 5.13 gears: 66:1

Each number in the crawl ratio calculation has a good sized effect.

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Still, my point is that a doubler, Klune-V, etc... will still have a much greater effect on crawl ratio no matter what combo you start with.

I'm not saying you should NOT install 5.13's......wish I had them instead of 4.10's, but since I started trailering my rig and therefore rarely drive it on the road, the 5.13 axle gears have dropped way down on my wish-list.
 
But then you leave out the torque converter on auto tranny's...sure the "calculated" ratio is higher than a manual setup, but you need more crawl ratio with a stick to get the same effect as someone with an auto and a higher ratio...i think that came out right... /forums/images/graemlins/dunno.gif
 
right now I have a 700R4 + np205 + 4.56s = 55:1 (yes, that includes the TC mult)

with 5.13s it'd be 62:1.... with 5.38s = 65:1. that measely difference isn't worth the cost is would be to go 5.38s since they will undoubtably cost more than your standard thick 5.13s will. On the other hand, leave the gearing at 4.56 and add a Klune-V and I'd have 148:1... or 166:1 with 5.13s... /forums/images/graemlins/laugh.gif

j
 
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