Well it all started when I took the top off and got to cocky and was trying to race people in my ’79 bronco. It has enough get up to have some fun in 2Hi, so I wanted to know how well it would do in 4Lo. (This is the point in the story where some people already know what happened) Anyways I slammed it in 4L and the light had just turned green half a second before, so I don’t ease into it, I put that petal down as hard as I can and *clank* I just hear the driveshaft flying around below the truck and people in the parking lot clapping and laughing.

Thinking I snapped a u-joint I yell “Danny turn the hubs!” and pulled into a parking lot, a parking lot with less people laughing.

Long story short, I had too much fun and snapped the pinion off inside the yoke.
Carnage pics: http://www.scooterunderwood.com/pictures/bronco/pinion/

I’m looking to get some Yukon gears from Jeff’s bronco graveyard and I was wondering if their ‘Gear install kit’ is going to cover everything I need. (Mostly just concerned about that warped piece where the pinion exits.)

Would traction bars have prevented this? Or was I F’ed as soon as a romped on that petal?

Right now I’m trying to decide if I should just replace it with the same gears that are in there (I think its 3.50) or going with something that would make my gear ratio “like stock” with the 35” tires I’m running. What do you think?

BTW Arnt u-joints designed to snap before your pinion?

-scooter

 

you are very lucky that flying propeller shaft didn't destroy anything else underneath
when it was flailing about.

 

i snapped an axle jackin round like that once! there just not built for it , there mud truck's! probaly should'nt have put in lo, increased tourqe makes s**t break, oop's

 

So you put it into 4lo on dry pavement and romped the gas? Why would you do such a thing? Of course you were going to break something, have fun but use your head, sounds like a costly f**k up.

 

One of the things I'm really wondering is would a pair of traction bars have prevented this? i.e. did i raise the pinion angle too far and snap it that way, or was the 'jackass' factor all there is to blame

 

i personally dont think traction bars would have changed anything , yes they do help but i think it was that lo gear+heavy foot on pavement that did you in

 

Traction bars would have made it worse. A 4 wheel drive system is designed to give you traction. When it is engaged it relys on wheel slip to keep things from breaking. the wheel slip is provided from the loose ground your on. In other words- never engage a 4x4 system on dry pavement(which is designed to give the best traction for mass transit use). Read any owners manual and they will tell you the same thing.


All that said.......................been there,done that,hehehehehe

I always looked at the bright side, now you can build it stronger. Make it all you can afford it to be, good luck.

 

I wasnt thinking so much about the traction it would have given me as much as the less axel-wrap i would have had on those big leaf springs ...

So do you think i should just replace the ring and pinion with the same ratio that is in there or switch it up for the front and rear to get me back to a "stock ratio"?

 

Dude if you like your 35's and plan to keep them, and you have the money-hell yea throw gears in it. You already have to do one end anyway. Might as well get an awesome upgrade in the process.

Incidentally, I had a friend do that in a 79 with a 460. He blew the pinion gear THROUGH the case, and it was flippin and floppin around under the truck. Parts and fluid everywhere within a 20 ft raduis. It was cool. He happened to have another nine in. laying at the house with the same gear.

As for the u joint question, I'd buy that brand again!

A set of 4:10's would be an awesome upgrade, but I bet your wallet won't like how thirsty your truck is.

 

As stated above, it depends on what you want.......an offroader or a daily driver.
Unless, you can afford the gas or have a daily driver or like me- you can't afford the gas but you can't afford the new payments and you only live 2 miles from work anyway. If I had the money I'd upgrade to what I wanted it to be in the end since I was there anyway. If you want it to eventually be a trail truck, go reduction front and rear. If ya wanna keep it close to stock(might wanna get rid of it in the future) put the factory ratios back in it. There again if your anything like me, you won't plan on selling it at all and start the bad@$$ off road build up. Up to you man?!?!?!? Good luck.