stock front axle strength question

[cmhaah06]

I have the stock front axle, lockrite locker, 3.73's, warn manual jeep hubs and 33's. Is this too much for the stock axle? I dont have a lead foot. I wheel as slow as i can and very rarely spin the tires. I really like to crawl. What do you guys think?

 

[Anime]

The stock front axles are plenty strong, but what usually does them in is the lockers, not the gears or tires. People that wheel hard or do yahoo driving with a locker can bust a hub or axle every time.

If you crawl slow, and let the locker do the work rather than trying to solve everything by nailing the gas, and pick your obstacles so you're not constantly testing the strength limits of the axles and hubs, you can stay with the stock axles for a long time.

You might want to switch to 4.56 gears with those 33's. It should let you crawl even slower and get over stuff easier.

 

[rookieshooter]

The stock front axles are plenty strong, but what usually does them in is the lockers, not the gears or tires. People that wheel hard or do yahoo driving with a locker can bust a hub or axle every time.

If you crawl slow, and let the locker do the work rather than trying to solve everything by nailing the gas, and pick your obstacles so you're not constantly testing the strength limits of the axles and hubs, you can stay with the stock axles for a long time.

You might want to switch to 4.56 gears with those 33's. It should let you crawl even slower and get over stuff easier.

Like your way of thinking
Was out this morning doing a little rock crawling testing some new mods that I did.
Slow and easy.

 

[cmhaah06]

Cool. I wheel as slow as possible. I dont like breaking things everytime I go out. I am saving for a set of 4.88's, so a gear swap is on the list of things to do in the near future.

 

[IZwack]

Two more weak points of the front axle is the bearing caps and the axle housing itself - we've seen a few that have shattered.

 

[4x4junkie]

How'd the housings get shattered? Got pics?

 

[IZwack]

Oh that was for a 2nd gen - my bad, I didnt know this was about the 1st gens. I'll see if i can find pics anyway just for fun.

 

[IZwack]

I couldnt find the one i had in mind (totally cracked housing) but here is one that comes close:
http://www.explorerforum.com/forums/showpost.php?p=2394346&postcount=5

 

[Chief34]

I agree with the previous posts 100% and can attest to slow and easy approach... My dana 30 solid axle has held up nicely... you just have to be smart about your driving.... I did finally manage to break a passanger side axle shaft.... but it was only 35$ I know this isnt the stock ifs, but its the same principle... its actually a smaller ring and pinion.

One thought though... lower gears will help because your going slower, but the steeper you go the thinner the teeth are on your R&P, which makes them weaker, so there is a trade off. I would stick with 4.10's or 4.56's if you want to go taller. I never broke anything until I switched to 4.88's... I now have my prior 4.10's in there but I do plan on settling on 4.56's....

 

[4x4junkie]

Oh that was for a 2nd gen - my bad, I didnt know this was about the 1st gens. I'll see if i can find pics anyway just for fun.

Yeah I was gonna say in nearly 10 years of prowling the various boards, I haven't seen pics of an exploded D35 TTB housing (excepting those blown open by POS drop-plate liftkit brackets).
I have however seen a couple carrier bearing caps fail, though I've also seen this on many other axles too, so nothing really unique there.


On the ratio thing, I've heard conflicting theories on whether going deeper makes a set of gears weaker or not. Due to the hypoid offset, the teeth actually get longer (more spirally wound) on the pinion as it gets smaller, which may help offset the strength lost to the teeth being fewer in number (they are not "thinner" however).
Whatever the case may be, I again don't see very many people breaking the gears, even 5.13s. Unless you're gonna throw the power of a 300+HP V8 at it, I don't see much to worry about.

I've been rockin' mine for over 5 years now with 35x12.50s on it. Only time I ever broke anything was by doing something stupid with the throttle (I've actually had my D44 fail more often than the 35... Coincidence maybe, but the strength of the two axles are really not that far apart. The axle u-joints are what usually break, and they are the same on both).

 

[Chief34]

ok... its been a little while since I changed my R&P out but I believe your wrong....

From what I remember.... two things happen

1)the 4.88 has a WAY smaller pinion.
-the diameter of the pinion changes and it gets way smaller which actually makes
the "length" of the spiral shorter.... Weakens it majorly in Both areas.....

2)The ring gear Doesent change in diameter
-The "spiral" doesent get any longer or shorter, BUT the amount of teeth on the ring
gear goes up, therefore the teeth are Thinnner in order to fit them all on there. This
Weakens that majorly.

Again, this is what I remember.... just looking at the two side by side it was very evident when I installed the 4.88's that they were much more weak... I figured they would break and.... they did the first time out. I do have a supercharger though but I have never broke the 4.10's....

 

[Chief34]

these pics aren't great.... I wish I could find the pics I had of my gears, but check out the pinions.... That lil one is just asking to break lol... thats the 4.88 if you couldnt tell.

 

[rhauf]

^^ most of this is good advice.

do you have a rear locker?

i second the 4.10 or 4.56 gear option. (thats my next upgrade too)
just avoid gassing it through rough obstacles, or gassing it with you're wheels turned sharply (kills U joints), and wheel hop, and you should be fine. Driving style and skill determine when things break more than brute strength. if it breaks, then you know it's time to upgrade. also drive to match you're terrain. if you're on something smooth, soft and low traction (like dirt) you can gas it a lot and not worry about it.. if you're on high traction surfaces, such as rocks, thats when you're more likely to break stuff.

i'm running 33's with stock gears (not sure the ratio) but i know i need deeper gears in the front. so i'll go with 4.56's or whatever is the lowest i think i can get in there without compromise (or added expense). at the moment i'm running rear spool and open front. (i may switch to a lock-rites or something when i do the gears tho) oh.. here's a video
http://www.youtube.com/watch?v=UD_JBygDP4A

 

[RockRanger]

The stock front axles are plenty strong, but what usually does them in is the lockers, not the gears or tires. People that wheel hard or do yahoo driving with a locker can bust a hub or axle every time.

If you crawl slow, and let the locker do the work rather than trying to solve everything by nailing the gas, and pick your obstacles so you're not constantly testing the strength limits of the axles and hubs, you can stay with the stock axles for a long time.

You might want to switch to 4.56 gears with those 33's. It should let you crawl even slower and get over stuff easier.

What he said.

 

[4x4junkie]

2)The ring gear Doesent change in diameter
-The "spiral" doesent get any longer or shorter, BUT the amount of teeth on the ring
gear goes up, therefore the teeth are Thinnner in order to fit them all on there. This
Weakens that majorly.

Actually...

All of the following ratios have exactly 41 teeth on the ring gear:
3.73,
4.10,
4.56,
5.13.

Therefore the matching pinion teeth will also all have the same thickness, they just differ in number.
4.88 actually has 39 teeth on the ring gear, so they should be thicker than even the 3.73 teeth.

Even if everything you said were true, and everything I said wasn't, there's still this one fact left that no one seems to break them with any regularity. If yours broke as easy as you're implying, do you know if they were set up in the housing correctly? (a setup having an incorrect tooth contact pattern would make any ratio gearset very fragile).

Has anyone else here ever cleaned teeth off a HP D35 gearset? (not talkin' spiders, just the ring & pinion)

 

[Chief34]

....wasnt trying to rub you the wrong way, or get drawn into a debate...and i was just going off what i could remember. sounds like i was half right. The ring doesent change, ok.... but the pinion does get smaller. the set i installed was used and there could have already been something wrong with it, who knows? you can do whatever you want, buddy, believe me. I really dont care. I was just offering the OP my opinion on what I observed when I changed my gears....which was a couple years ago.
All I know is when you hold the 2 pinions in your hand... the little dinky one looks Way more weak. take it for what its worth.

 

[Chief34]

I thought about it and.... that sounded a bit hostile, lol. You bring up some very valid points.

I didnt do any researching on it and was just going off what I thought, from what I remember. I do however, remember saying "holy ___t" when I opened the ups box and saw that pinion. Boy its small.... I never claimed people were breaking them on a regular basis, though....

I personally am going to stick with 4.56's when I swap in full width axles. Once I get a doubler on there, i should be in great shape

 

[4x4junkie]

No problem man, I wasn't meaning to be argumentative (I did state those were theories I've read, and I've seen it myself the teeth do get a little more "spirally" as the head gets smaller), I was just pointing out that even if it's true they're weaker, people don't seem to break them very often before breaking an axle shaft first (some guys even running 38s w/5.13s on this axle), so I tend to look at it as a non-issue. I s'pose proper gear setup does become more critical as the pinions do get smaller.

I think deflection of the gears under load is actually the greater contributing factor toward failure of an otherwise properly setup R&P. The things that affect deflection the most are diameter of the pinion shaft itself, and the rigidity of the housing. Fortunately both of these remain constant regardless of ratio.