Stub axle keeps braking

dsd · Post by **dsd** » Sat Nov 24, 2018 5:52 pm

I'm looking for help

I'm new to the go fast Bronco concept, I'm more of a rock crawler having two Broncos and an f150 with solid 3/4 axles, I've broken many axle shafts but in my pre runner bronco the stub axle keeps braking while on 4x4 due to the angle on the cut and turn beams and suspension travel just about every time I use the 4 wheel drive.

Does anyone know if there's a replacement like a RCV shaft I can order or am I destined to only drive it in two wheel drive?

I currently have a locker in the front

Thanks

Tchajagos · Post by **Tchajagos** » Sat Nov 24, 2018 8:23 pm

Rcv makes shafts for d44 ttb.

https://www.rcvperformance.com/ultimate ... style.html

Also, you have to clearance the center joint so it doesn’t bind.

A front locker and big tires it hard on the inner axles. A lot of people will run a limited slip to make it easier on the center joint. Even an open diff is ok in most gofast situations.

Tchajagos · Post by **Tchajagos** » Sat Nov 24, 2018 8:25 pm

Also, you should be cycling your suspension and setting up limit straps before the center joint binds up.

dsd · Post by **dsd** » Sun Nov 25, 2018 10:08 am

Thanks for the link Tchajagos
I will see if they sell the center stub only
When I cycle the suspension I don't get much travel before the axles get on a bind, when you say I need to clear the center joint did you meant to machine the joint or buy one that's already compensated to clear the u joint?
Thanks in advance

PaulW · Post by **PaulW** » Sun Nov 25, 2018 10:26 am

You can get a lot of travel if you custom grind the center joint. Usually done with a die grinder in a vice while measuring to get it uniform. If that does not meet your wheeling then upgrade to the larger joint and a modified beam with a bulge for the bigger joint. It be stronger, but axles will not be stronger and probably have less articulation. Try it and see.
BTW it is pretty rare to hear about a TTB setup properly having broken axles. Broken is an exclusive to class 3 racers not prerunners.

BDKW1 · Post by **BDKW1** » Sun Nov 25, 2018 11:33 am

dsd wrote:Thanks for the link Tchajagos
I will see if they sell the center stub only
When I cycle the suspension I don't get much travel before the axles get on a bind, when you say I need to clear the center joint did you meant to machine the joint or buy one that's already compensated to clear the u joint?
Thanks in advance

Yes they will sell the center axle separately. You will need the whole axle.

Or you can grind the yoke to look like the one above. If you compare that pic to yours it should give you a good idea of what to do.

dsd · Post by **dsd** » Sun Nov 25, 2018 11:58 am

Thanks a lot guys
I didn't want to weaken the axle further by cutting it but I will give it a try. I don't plan on going rock crawling with this bronco but I do plan on using it in all terrains like sand, snow, dirt and anywhere I get stuck at. Therefore I need to decide if I keep the locker or not and how much travel I can really get on this truck. I will post again once I fix it.

BDKW1 · Post by **BDKW1** » Sun Nov 25, 2018 12:01 pm

Top tip, tack weld the caps in the yokes.

Stan the Man · Post by **Stan the Man** » Mon Nov 26, 2018 2:10 pm

dsd wrote:Thanks a lot guys
I didn't want to weaken the axle further by cutting it but I will give it a try. I don't plan on going rock crawling with this bronco but I do plan on using it in all terrains like sand, snow, dirt and anywhere I get stuck at. Therefore I need to decide if I keep the locker or not and how much travel I can really get on this truck. I will post again once I fix it.

If you're strapped properly, clearance the D44 stub shaft like @tchajagos showed, and tack weld the cap in place, you'll be fine. I'm locked in the front with 18" travel, and haven't broken a stub shaft or joint yet. I have about 1/8" clearance between the stub and slip shafts at full droop.

You still might break a shaft in a high torque, off camber situation (rock crawling, hopping up a boulder, etc.). You can carry a lot of trail spares for the price of a RCV system.

dsd · Post by **dsd** » Tue Nov 27, 2018 12:07 pm

Thanks guys
I'm in the process of clearing the shafts I will keep you posted
Question such axle is better the bolted stub or the open

yikes · Post by **yikes** » Wed Nov 28, 2018 6:10 pm

Something else to look at - Breaking stubs and/or hubs can often be attributed to misalignment after the cut and turn, which will prevent the axle from sliding freely through it's travel from steering lock to lock. This is especially true when high degree camber/caster bushings are required to correct alignment. This was a problem I experienced with my set up.

dsd · Post by **dsd** » Thu Nov 29, 2018 8:43 am

I've already cleared and welded the yoke and another spare but this is taking longer than planned. The stub axle came out of the locker enough to damage the carrier with the splines and got stuck. I finely got it out but now I need to replace a bearing that got damaged as well.
I lost the spring that goes in between the axle shaft and the yoke and I don't know if anybody carries this anymore.
Yikes,
Besides not having the yoke cleared for the angle do you think the axle shaft may be sliding off the carrier or locker when turning or at full droop? The last time the axle broke is when I was turning on a flat surface. I also need to have the truck aligned by a shop as I only aligned my self to run straight in order to test it.

shockseals.com · Post by **shockseals.com** » Tue Jan 22, 2019 9:24 pm

The spring in the coupler is a fix to keep the stub in the carrier reducing load on c clip groove through the travel, not an oe part. Under high torque and traveling, splines dont work well for plunge and you are exceeding the strength of the C clip groove holding in the stub and thats why you get failures. I have broken 2 of them and then went to bolt in stub shaft. None of my joints bind but I often pull out heavy shit through bumps and turns which is worst csae scenario for the stub set up. I have an open diff so with a locker I would probably have broken more.

Stan the Man · Post by **Stan the Man** » Tue Jan 22, 2019 11:49 pm

You can pick up a spring at Home Depot (comes in a 4 pack and is baout $5). Just cut it to size, test fit, droop and rotate, cut, and test again. I think my spring came out to about 1.5" long. I have an e-locker in the front, but only use that at slow pace for rocks. I keep the diff open for the go-fast stuff.

Post by **SteveG** » Wed Jan 23, 2019 12:37 am

shockseals.com wrote:The spring in the coupler is a fix to keep the stub in the carrier reducing load on c clip groove through the travel, not an oe part. Under high torque and traveling, splines dont work well for plunge and you are exceeding the strength of the C clip groove holding in the stub and thats why you get failures. I have broken 2 of them and then went to bolt in stub shaft. None of my joints bind but I often pull out heavy shit through bumps and turns which is worst csae scenario for the stub set up. I have an open diff so with a locker I would probably have broken more.

Ditto. First, Mae sure nothing is binding due to geometry, installation errors, etc. After that, keep in mind it’s a weak link that, in our application, should be used sparingly and with a light foot.

PaulW · Post by **PaulW** » Wed Jan 23, 2019 8:34 am

Long ago we decided to not use the spring method and go with the original Ford design. That OEM design of course was eliminated by the Ford bean counters to save a trivial amount of dollars. The original Ford bolted diff is the real solution.
However, successful spring setups use a valve spring from a SBC. If you search on Pirate you can locate the best spring setup. And with the spring you need to weld the cap in place. And the resulting stress on the C-clip will still exist.
In any event correct lube on the splines is still needed.