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What's going to break first?

ak68

Sr. Member
Joined
Oct 24, 2004
Messages
453
I'll be getting my bronco back on the road soon and I had a question for all. Here's the setup. 393W, NV3550, dana 20, custom driveshafts, small bearing 9 inch with 28 spline axles and an auburn LS unit and a stock dana 44 with discs. I have 3.50 gears with 33 inch BFG ATs. I'm planning on doing a gear change to 4.56. I'll drive it 80+% on road with light offraod. I don't plan on beating on it. Should I upgrade components to help prevent breakage and if so what first? Thanks!
 

mkaenel

Bronco Guru
Joined
Jan 3, 2006
Messages
1,545
Loc.
La Costa, CA
Just wait for something to break and then fix it unless you have a ton of money to burn unnecessarily.

Thats what I do.
 

Gummi Bear

Bronco Guru
Joined
Jul 8, 2003
Messages
3,647
You're putting a lot of power to the ground. You'll be able to break parts pretty much at will.

Start saving up for upgrades.
 

broncnaz

Bronco Guru
Joined
May 22, 2003
Messages
24,341
axle shafts will probably go first. followed by ujoints and other things you wouldnt think would break. Throw your plan for not beating on it out the window that 393 will do with ease what would be beating with a 302.
 
OP
OP
A

ak68

Sr. Member
Joined
Oct 24, 2004
Messages
453
And the winner is!

The pocketbook or wallet wins my vote for the first thing to break :D
Thanks for the answers.
 

Madgyver

Bronco Madman
Joined
Jul 30, 2001
Messages
14,678
crawln68 said:
Axle shaft, u-joints or output shaft would be my guess.
Just what I was thinking.....



Here's one..... From a dead stop, rev it up 3000rpm, in 1st gear on dry pavement, now pop the clutch.
If anything will break it will be one of the three. My vote would be the stock dana20 rear output shaft..

Don't ask how I know this...;D
 

theshadow

Sr. Member
Joined
Jun 30, 2006
Messages
358
Good to see a fellow Alaskan!

Hey good to see another Alaskan on here! Dont really have much to add in the way of advice that hasnt already been said; i would say axles. I run 28 spline as well but im running a 5.0L. Whats even better than paying the price for the parts is the shipping eh?
 

trailpsycho

Bronco Guru
Joined
Dec 11, 2003
Messages
4,856
If your going to regear to 4.56s, you should upgrade to a 31 spline traction unit and go with 31 spline alloy axles. Complete off-road or Randy's R&P both have great prices. COR also has the best prices I was able to find on the Yukon D44 chromolly axles and superjoints. You will also need a new crrier upfront with the 4.56s...might want to consider a selectable locker at least for the front axle...lots of stuff eventually get into up in AK, might as well do it right...you have already gone pretty far with everything else in your truck...upgrading the axles will mean that you can dependably put it through the paces without too much concern. If you will be running it much in the winter there, you may want to look at a selectable for the rear too (ARBs are strong and would work nicely). Several good options, but you are looking at about $3K in parts for gears, install kits, selectable lockers, axle shafts and U-joints) (give or take, plus install)...not cheap, but definitely a good investment....at least consider upgrading the rear to 31 spline chromollys when you regear the rear. Good luck with your choices.

John
 

SpareParts

Bronco Guru
Joined
Nov 13, 2004
Messages
5,592
With the torque from the 393, I would rethink the gear selection. I would run it for a little with the 3:50's. on the street I be you'll be plenty happy with the power. You'll probably get better economy, I shure with building a big motor your not worried about it.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,835
Front axle U-joint when backing up in reverse. It will take out the ears and require a new inner and outer stub axles.
 
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