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14 bolt rear end build thread, shaved 15 bolt, ring gear turn...

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nvrstuk

nvrstuk

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D60gears here in a friends Dynatrack... should be named DynaCrack!! This on a well designed rig... he didnt know they could put D70 gears in back then...but he's having them put in now. Stock engine...no high rpm stuff.
 

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Apogee

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I think you'd be money ahead to sell your 9" housing and 35-spline axles to somebody who's willing to build a center section for it, then stick with the 14-bolt and beef it up. While you could certainly go D70(U), Sterling 10.25 or or something similar, none is going to be cheaper to build than the 14-bolt unless you're already sitting on a bunch of the parts.

FWIW, I saw a bunch of carnage this weekend at the Smith River Shootout down in Reedsport, OR, where the guys were blowing D80 R&P's, 2.5-ton toploader Rockwells, etc, but anything is possible when running high HP, high weight applications over crazy obstacles. Just blipping the throttle at the perfectly wrong time when landing from a jump can do it, as the D80 under the Sleep Thief can attest. He was out for the weekend since he couldn't find another R&P locally for a D80...you shouldn't ever have that problem with a 14-bolt, not that you're competing.
 
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nvrstuk

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My current rear is tentatively sold... so I'm hoping I'm on the right track :) thanks for your input as it sounds encouraging to hear from experienced wheelers that the 14 is the way to go.
 
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nvrstuk

nvrstuk

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Stock 14 bolt axles or aftermarket alloy??

That's my decision at this point... I haven't followed 14 bolts over the years...just don't know how TOUGH the axles are...

I've had a couple very experienced wheelers tell me they have literally hammered them for years and not had failures...with 42-47" tires...

Thoughts and feedback appreciated!!!

I mean it's nice to know that now I am at a stock width, that I could find (carry) spares cheaply. I know Detroits are almost guaranteed to blow when an axle blows...but since I need a selectable, has anyone heard of an ARB grenade when an axle blows?

But even more important, do I want to have to try to snake out a broken axle from deep inside an axle tube when wheeling with my wife on vacation??? not really :)

Really appreciate input and experience with 14 bolt axles...
 
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nvrstuk

nvrstuk

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sykanr0ng-- LOL.... maybe I should go back to L60x70x15's...I could just smoke 'em all day and not worry... like my buddies do in their "pretty" cars... I'm in a local Hot Rod club, small town, we all know each other and they never blow anything up... :) Like Yeller was saying...they don't understand the "torque equation"...
 
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nvrstuk

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Spline counts...
 

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Yeller

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I’ve had good luck with stock axle shafts, I’m still running them after 20 years. But I have seen them break, all though not often. And those that have just did Yukon chomo replacements, so far they have been happy. Oh and those that have with arb did have parts failure within the arb when they did but was replaced under warrantee was some small internal parts, they did not need a case replacement.

FYI the chart is deceiving. The 30 spline in the 14 is not the same depth or pressure angle and is actually slightly larger than 35 spline. Part of the survivability of the stock shafts is there shape, they have a very nice taper so they make great torsion bars and will twist quite far with out failure, I’ve watched them load up and unwind 1/3 of a turn repeatedly without failure.
 
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nvrstuk

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Here's a chart that touches on that a bit . For some reason last night this pic didnt post (didn't notice till this am) alongside the chart referenced above.

I appreciate the axle input' really do. Need to hear "real life-real wheeling" experiences...not just sales guys and charts for sure!

Thx Steve
 

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Yeller

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Here's a chart that touches on that a bit . For some reason last night this pic didnt post (didn't notice till this am) alongside the chart referenced above.

I appreciate the axle input' really do. Need to hear "real life-real wheeling" experiences...not just sales guys and charts for sure!

Thx Steve

YW :)

The reason I really like RCV for shafts is because they turn the entire shaft to minor diameter of the spline except for seal or bearing areas and it is all done on a radius. All of those things allow the axle to twist and if using 300m the cyclic rate is really impressive the number of cycles they will with stand without fatiquing, its not that 300m is so much stronger than normal chromo but it will survive maximum torsion more times, 10's of thousands more times. Guys running 40 spline axles (in racing conditions) have had issues breaking ring and pinions, the gears give up before the axle twists, getting the entire abuse of the shock load and no "cushion" from the axle twisting.

Its all a dance and your right we could still be running stock everything with G78-15's :p They would be fun for doing 4 wheel burnouts;D
 
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nvrstuk

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Laughing because a buddy gave me a set to light up a couple summers ago... I feel a bit more secure with COG about 12" off the ground compared to whatever mine is!!! Got a bit hairy even at 20 mph...

I have RCV's in the axle I'm pulling out as I'd heard nothing but good about them and they have some amazing machining on them... good info to know about the number of times 300M can cycle. Gordon tried to talk me into 300M's but my pocket said no... now 20 months later I'm selling them...
 

Yeller

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LOL. I bet it was fun:p ran equivalent size on my gmc for a while. Was instant rev limiter every time I leaned on it. Was just about undrivable wet. Running 255’s now much better planted.
 

Apogee

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I was talking to Kyle Falls at the NW Off-Road Rage event last month, and he runs a pretty cool gray 4-runner skinned buggy on 2.5 ton Rocks with relatively small 43" TSL SX stickies, and has managed to break some axles (front and rear steer). That said, he was joking (I think) about switching back to his 14-bolt, because he never broke a 14-bolt axle...but he really wanted to add rear steer. He runs a relatively mild LS/auto/ATLAS combo and chooses his lines more than some others I've seen, so I'm sure that helps keep the rig together at the end of the day.
 

Yeller

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Lots of rock bouncers say the hot ticket 14b with Rockwell outers.

I’ve been beating on the Rockwell’s in my buggy for a couple of decades, never broke and axle, but it’s not been from a lack of effort trying;D it gets driven when I want to drive like a drunk 2 year old with reckless abandon, it’s long over due for some massive carnage but so far hanging in there.
 

Dirtroadjunkie

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"it gets driven when I want to drive like a drunk 2 year old with reckless abandon".
That's a classic quote right there!
 

ntsqd

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My understanding of the genesis of 300M is that they took the 4340M alloy formula and tweaked it to respond better to reversing torsion. That is why it's various strength numbers are so similar to 4340. and it is why racing torsion bars are made from it when street duty bars are made from something like 1050. It is also why when I was asked what alloy to use on the first production high strength replacement D20 output shaft for EB's I said "300M" with no hesitation.

Brian, Have you really looked at those 14bff axle tubes? Reach down just past the stub spindle to get an idea of the wall thickness. It does have a mild taper or the bent (!!!) one that I cut up did. It is not DOM tube, the weld seam was quite apparent on the inside. Imagine the tooling it takes to roll sheet stock that thick into a tube that (relatively) small.

I used a section of that axle tube to create the housing for the swing-away tire carrier bearings in Patch's rear bumper. That was some of the most difficult to machine steel that I've ever encountered. The chip came off stringy like it was 316SS, but no 316 ever rapidly dulled a carbide insert lathe tool like that stuff did.

AFAIC going 14bff and cutting off the stub spindles to go semi-float is the very bad wrong move. Run those SA Ind 5x5.5 wheel hubs if you need to keep that bolt pattern.
 
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nvrstuk

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TS- I put together the mass buy from Chuck decades ago for that run of 300M D20 output shafts...I killed 4 D20 cases, stock output shaft, low range gear set, you name it...but I couldn't kill the 300M output shaft! lol

OK, I'm going with the stock axles... I'll find some spares and pack them in the Mtrhome. I'm dang lucky I got the 14 bolt WMS to match what I had so I have the option of not having to go with custom axles... :)

If I put 2 sets of stock axles in the scrap bin I'll step up to 300M. Sounds like it won't be a problem tho...

I run 8 x 6.5" pattern.

If that 1/2" housing material is "rolled", I want to see that equipment in person...
 

Yeller

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"If that 1/2" housing material is "rolled", I want to see that equipment in person..."

I've toured lots of pipe/tubing mills. Its impressive, the rolling, welding, and annealing process is quite intriguing. I could spend hours watching that equipment work.
 

68rockcrawler

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Stock 14 bolt axles or aftermarket alloy??

That's my decision at this point... I haven't followed 14 bolts over the years...just don't know how TOUGH the axles are...

I've had a couple very experienced wheelers tell me they have literally hammered them for years and not had failures...with 42-47" tires...

Thoughts and feedback appreciated!!!

I mean it's nice to know that now I am at a stock width, that I could find (carry) spares cheaply. I know Detroits are almost guaranteed to blow when an axle blows...but since I need a selectable, has anyone heard of an ARB grenade when an axle blows?

But even more important, do I want to have to try to snake out a broken axle from deep inside an axle tube when wheeling with my wife on vacation??? not really :)

Really appreciate input and experience with 14 bolt axles...

I broke a stock 14 bolt shaft with a tired 5.0. I blame it on driving a T-18 manual in the rocks and not feathering the throttle and clutch just perfectly to get up out of a hole. I didn't beat on it, but who knows what the previous owner did with it. Maybe it's just a fluke. I put another stock shaft back in because I had it laying around.
 
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nvrstuk

nvrstuk

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Thx 68Rockcrawler...I just got off the phone with the shop that will be doing some machining for me and he builds custom Heeps and "bigger" rigs. He said over the past 5 yrs they've broken 4 stock axles. They (6 different rigs) all run stock 14 bolt axles and the smallest tire in their group is a 42" sticky. They have never broken one while bouncing or hammering the pedal, only when totally bound up in rocks and when the doublers are in and in low, low gear. Trying to just throttle out and "pop". Never grenaded unless "bound" up as he put it.

My decision is made...I'll try stock.
 
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