Broken Axle

[Falcon]

Are these the rear-ends the ones designed for the Mexican F-150's? I had read that the Raptor had that rear end... because it was beefier... but wouldn't they put different guts in it?

Falcon

 

[SVTRay]

It's a 9.75, yours should be the same. The Raptor one is longer/wider, the tube is thicker, and the axle spline count is higher (can't remember 33 spline?). Generally these axles and assemblies are very stout and do great in just a regular F150 application. There must of been a bad batch made......

Thanks,

They looked like a 9.75 but wasn't 100% sure. Anyhow, I'm with you on these and that they may have been a bad batch because I can't recall the Lightning or Harley guys having an axle issue running supercharged 5.4Ls.

Now I'm talking mostly about your stock Raptors and not the GT500 swap.

 

[pirate air]

Are these the rear-ends the ones designed for the Mexican F-150's? I had read that the Raptor had that rear end... because it was beefier... but wouldn't they put different guts in it?

Falcon

Yes I think Ford uses the mexican style housing on these trucks. I don't think they are the exact same housing, due to the fact that the Raptors rear end is wider. As far as I know the mexican housing is stock length, but the axle tubing is thicker because the mexican F150s get over loaded often. So the Raptor probably has something very simular to the mexican housing. The Raptors axles shafts should be stronger then both the stock and mexican style axle assemblys because of a higher spline count. The e-locker should also be stronger in some aspects (not many) do to the higher spline count.

FWIW, I believe the front inner cv stub shafts also have a higher spline count (as well as bigger in daimeter, with stronger high angle alloy cv joints), but I don't remember what that count is.

Thanks,

They looked like a 9.75 but wasn't 100% sure. Anyhow, I'm with you on these and that they may have been a bad batch because I can't recall the Lightning or Harley guys having an axle issue running supercharged 5.4Ls.

Now I'm talking mostly about your stock Raptors and not the GT500 swap.

Raptorguy21's truck is pretty much stock engine wise from what i've read. Although he does use his Raptor like it should be. I've worked for a dealer for almost ten years now, I can't think of ONE failed axle shaft in a F150. Ford builds a stout axle assembly.

 

[SVTRay]

I've worked for a dealer for almost ten years now, I can't think of ONE failed axle shaft in a F150. Ford builds a stout axle assembly.

Yes sir, I know a lot of people with Lightnings and Harleys, and I'm also a member of several truck forums and have attended gtgs all over Texas and I never heard of one axle problem. And these trucks are all doing 6.2L or more. So I'm thinking these issues are a fluke or bad batch.

 

[frogslinger]

Hey tese things happen if you get weird loading on the axle... I snapped my Ram 1500's axle shaft when I hit a bump whilst cornering aggressively on the road...

 

[SVTRay]

Hey tese things happen if you get weird loading on the axle... I snapped my Ram 1500's axle shaft when I hit a bump whilst cornering aggressively on the road...

hum...make sense to me. I remember once owning a 63' Chevy truck which came stock with a limited slip rear end. The rear end would literally hop and bark the tires if I took a turn to sharp and fast.

 

[FSM06]

I thought it was intersesing that the gentleman on the live chat stated in Kaiser's thread that they were aware of the axle breakages and were looking into it.

FSM

 

[frogslinger]

Yeah...

The original post on the z talked about that SVT had sent engineers and new raptors to the site of the original axle breakage to try to replicate the problem.

 

[MarkT]

I was the one that broke the axle in Anza Borrego. I have a great deal of respect for Ford and the way they handled the entire problem.

Here (for the first time) is one of the actual Ford emails that was forwarded to me by Rancho Ford in Temecula, CA.

Just wanted to give you an update on the Raptor axle shaft. Received the parts, analysis found no defects and everything within design specifications. Our team is very grateful and amazed at the detail the customer put into his very detailed explanation of events leading up to the break. If you see him again, please thank him for us.

We have a Raptor at Borrego Springs right now trying to duplicate the customers conditions and break a shaft, we are also instrumenting another Raptor to follow up at Borrego to collect road load data of the events.

Thanks again for all your help.

So yes, Ford is aware of the issue I had and is doing everything they can to replicate the problem.

My opinion is that the Ford axle is a very strong and reliable piece of machinery.

I personally think the failure was a fluke contributed to by several factors that all came together at the wrong time in the wrong way.

Wet dirt or sand can provide an amazing amount of traction... even more than is available on pavement. My Raptor was hooked up in 2WD and accelerating hard in damp sand from a slow speed. This means the axle shaft was not rotating very fast. The amount of HP a shaft can handle goes up dramatically with shaft rpm. The 5.4 has a ton of torque at low rpm.

In any case, I think it was "one of those things". Had the sand not been wet. Had I been in 4WD. Had I not been accelerating so hard... Had my forward speed been a little higher... had the 5.4 not had as much torque at low rpm... who knows?

(the 6.2 could actually help... if it doesn't have as much low rpm torque as the 5.4 does... the extra 6.2 power kicks in at higher rpm so the axle rpm would be higher when the power hits and therefore the axle could handle considerably more load safely)

In any case, I am 100% satisfied with the way Ford handled the unfortunate situation. I don't believe I was "abusing" the truck in any way but they still could have denied warranty coverage because it happened off road... but instead... no hassle... Ford just fixed the truck in record time.

I think this incident speaks volumes about how Ford stands behind their quality products! And I'm not worried at all about breaking another axle... I've done a lot of off roading and sometimes stuff like this happens.

P.S. Shock load is what usually kills axles. I raced in an off road "stock class" for about two years where axle and transaxle failure was very common... usually happened after landing off a jump by applying power too soon in the air... many people upgraded and still broke parts. I never broke a stock axle or trans and usually finished in the top 3. Only one other guy had the same record of no breakage of the stock parts... He usually won.

My point is that it's important to avoid sudden shock loads. Spinning and suddenly grabbing traction. Wheel hop is very bad as well. You can break any axle if you shock it hard enough.

 

[Falcon]

Well said... concise, informative and points out that Ford makes the best truck in the world bar NONE. Good to know Ford is backing up the Raptor is style. Henry would be proud!

Falcon
"This is Ford country... on a quiet night, you can hear a Chevy rust"