Ok, here's what happened. I was out wheeling on new years day up a dry creekbed. I got all twisted up in some rocks and I heard a weird poping noise from the frontend of my 85 toy. I figured it was a birfield, probably cracked. I have a true trac in the front so I feathered the brake and made it through that section. I wanted to get to flat ground before investigating but to do so I had to pass over a huge rock. I got high centered on it and tried backing out, that is when I heard the Ker-Pow! There went the birfield, but the whole front end quit working. Even when I feathered the brake, no tire movement. I figured I had broken both birfields. So I operated on it this evening, only one broken passenger side birfield. That's odd, I thought, since neither tire would spin. So I pulled my thirdmember and my true trac seems to be ok. The question is, why didn't my one good axle pull???? The true trac sends power to both tires when one is in the air, why would it be different when on axle breaks??? Anyone had a similar experience?

Originally posted by 85toyboy
Ok, here's what happened. I was out wheeling on new years day up a dry creekbed. I got all twisted up in some rocks and I heard a weird poping noise from the frontend of my 85 toy. I figured it was a birfield, probably cracked. I have a true trac in the front so I feathered the brake and made it through that section. I wanted to get to flat ground before investigating but to do so I had to pass over a huge rock. I got high centered on it and tried backing out, that is when I heard the Ker-Pow! There went the birfield, but the whole front end quit working. Even when I feathered the brake, no tire movement. I figured I had broken both birfields. So I operated on it this evening, only one broken passenger side birfield. That's odd, I thought, since neither tire would spin. So I pulled my thirdmember and my true trac seems to be ok. The question is, why didn't my one good axle pull???? The true trac sends power to both tires when one is in the air, why would it be different when on axle breaks??? Anyone had a similar experience?

Sounds perfectly normal. The TrueTrac can work with up to a 3X torque difference between sides. So break a birfield and you 3 times 0 torque on the opposite side (as in zero). Easy test to do is drop the rear driveshaft, lock one front hub and try to move - not going to happen.

http://4crawler.cruiserpages.com/4x4/TrueTrac.shtml

With two good axles and one tire in the air, you can get on the brakes, add some torque to the lifted side which then transfers to the side with traction. Problem is the brake rotor is bolted on outside the birfield.

Thanks for the imput. I just emailed ya too :D So now that the third member is out, I'm wondering if I should just sell it and buy a full out locker instead? hmmm or will that just equal more broken birfields?

True trac up front is good for the reason that it will slip right. well now it slips. I got the exact same problem ALL THE TIME with my trutrac'd IFS. Especially when I'd get high centered and try and turn one wheel to get unstuck. Tried to unock one hub in snow and neither turned. I now swear on a true locker by the same people. It will continue to happen just FYI. I ran mine for 3-4 years that way. SUCKED

Hey on a side note yes you can actually trive your truck with a locker instead of three footing it, and if you want to sell me the locker and gears and carrier drop me a line. I want 4.88 and maybee a locker in my stock truck.

I'll probably keep the gears, they are Richmond 5.29's. I just need to pick up a full carrier locker or a carrier and lock rite.

lol the tru trak is a traction limiting device. birf broke and teh traction was limited. they dont send 100% power to both wheels.
of u want to have both wheels spin get a locker

Drew

i've run the true trac for about 2 years with great sucess. if you have low gears they work good.
0 broken birfs. so far...

it's just a show rig.

...

yo vova i am goin to las gatos soo we shoudl hook up.

Drew

Originally posted by WAX OFF
yo vova i am goin to las gatos soo we shoudl hook up.

Drew

when? we can meet for a :beer:

Originally posted by vova
i've run the true trac for about 2 years with great sucess. if you have low gears they work good.
0 broken birfs. so far... ha Vova i run a true trac allso when you are trying to ingage the frunt do you tap the brakes or just aply a constent pressure??

Originally posted by vova


when? we can meet for a :beer:

well i think in febuary. yeah all meet ya for a beer but i am only 18 :( so cant go to a bar

Drew

Originally posted by toy 4 rox
ha Vova i run a true trac allso when you are trying to ingage the frunt do you tap the brakes or just aply a constent pressure??

You need constant pressure to lock up the True Trac, at least until you have decent traction on both sides. I have some info on my TrueTrac page (http://4crawler.cruiserpages.com/4x4/TrueTrac.shtml#Impressions). A few keys I found to making it work are to get on the brakes before you start spinning (and lose momentum) and you need to apply approx. as much brake as it would take to hold you in place in the spot you are trying to climb, then use the throttle to overpower the brakes.

i have a trutrac up front, i bought that instead of a full locker, for price and for the fact of ice driving. it is nice on the snow with minimal pushing, it still does have some understeer.
i have a video, on tape, of my diff in action when i was hung up in these ruts. you can see it acting open and then i noticed and used the brake bias to hook it up. that bad boy got me right out though. i think you can use either the brake method or the WOT method to engage that thing, unless you have tire pickin's.
i also think the brake biasing would be easier if i had a crawler too, but it seems to be alright for whatever, like vova said.
after i get a crawler, i think i will get an electric hy-pinion though.
i think a switch would be better than the three pedal action.

Originally posted by gnob
i also think the brake biasing would be easier if i had a crawler too, but it seems to be alright for whatever, like vova said.
after i get a crawler, i think i will get an electric hy-pinion though.
i think a switch would be better than the three pedal action.

I found about 70:1 gearing was about the upper limit for decent brake biasing action, at least on steep terrain. Below that and you would bog the engine down before the TT locked up. At 100:1 and beyond, no need for 3 pedals, brake and gas are all you need, stay off the clutch.

Originally posted by 4CrawlR


I found about 70:1 gearing was about the upper limit for decent brake biasing action, at least on steep terrain. Below that and you would bog the engine down before the TT locked up. At 100:1 and beyond, no need for 3 pedals, brake and gas are all you need, stay off the clutch.

thats good to know, thanks man.

Originally posted by toy 4 rox
ha Vova i run a true trac allso when you are trying to ingage the frunt do you tap the brakes or just aply a constent pressure??

i hit the brakes just before i think i'll need both front tires to spin :) works great for me...

Originally posted by WAX OFF


well i think in febuary. yeah all meet ya for a beer but i am only 18 :( so cant go to a bar

Drew

swing by my house. i always have a few in the frig. :D