Hey guys. I have a dually that breaks something on the rear axle every hook. Latest break was it sheared the axle bolts at the hub AND broke the splines off the shaft. Is there chromoly shafts available?

 

Sterling is out. Had a bent pinion shaft and broke ring gear teeth

 

You say with each hook, truck pulls I assume. My thoughts, your planted with no wheel spin, something is going to break. What is the tire combination and ratio in the rear end? Air pressure? When has your break occurred, start, mid, end?

 

The last break was because of the transmission I'm pretty sure. I burnt 2nd gear so I programmed it to shift from 1st to 3rd and then lock the converter at 50 percent throttle . I was full mash at the shift and it banged into 3rd and locked same time. 90 feet and it broke a dana 80 shaft. It usually breaks on the far end when the sled gets heavy and full power. I run street pressure of about 65psi.

 

Front end stays light when the boost comes on. 35 inch procomp all terains with 410's

 

The truck looks planted with not much wheel spin. I'm no expert but a friend of mine pulled for many years, to bad he expired a few years ago or I could ask him.

Hopping is bad as well as no wheel spin or a down shift at the end of a pull. Can you run a Super Single in the rear? Locker in the front? She is laying over on the right front, you could address that also within the rules of course.

I would want to come out of the hole with wheel spin either by gearing or tires, she will hook in the first 50 feet where you take advantage and get the sled up to speed.

I know the guys around here block the frame, it is not locked, just allows 1 inch of travel like a bump stop.

 

Thats a shot of the start. I can't hold it on the line to build boost so it comes out soft then lights 20 feet out so. Full spool in the front. I'm new to pulling and I'm willing to listen to all advice. I been winning most of the pulls around here but it breaks at the end alot.

 

Not allowed or can't? You have to have a full head of steam coming out of the hole. Stall change in the converter maybe. Is this a street mod class? So many sanctions with different rules.

What is the end like, spinning out or are you down shifting?

 

I can't hold it. The brakes won't hold it. Creeps. 2 different front brake setups up front and multiple rear axles and now has a dodge cab and chassis dana 80 with big brakes. The stall is a 2600 from suncoast. Street mod class. Not much enforcing any rules around here. Just for fun really.

 

I would up the stall and figure out a way (not knowing your set up) to unlock the converter before the end of the run where you stop. Smaller tire or lower gear perhaps but you need a full head of steam coming out of the hole or with in 20 ft of the start. Seems to me, lol what do I know, the sled weight is transferring faster than your lighting the turbo and getting up to speed.

 

I can program the tranny to do whatever needed. It's a pcs controller. I have chromoly shafts coming in next week and a new Kevlar 2nd gear band coming tomorrow. There is a pull next weekend I think. I'll get it together and we if anything changes. I'm putting weight in the bed which I know contributes to the breakage. Truck only weights 7300 without the added weight

 

You need the weight as far to front as you can over the front axle. Not sure what engine we are dealing with but my 6.0L is a 2200 stall from SunCoast for the strip, not bad for the street so you would be even higher to pull.

Move what weight you can to the front. You could also use a tie down shock on the left front to help slow it down from transferring to the right.

 

It's a 5.9 12v. I do need to move the weight but I'm borrowing some front my brother in law and I'm waiting to build a hanger for way I but my own. But I keep spending money on repairs and upgrades so I haven't bought any yet

 

I'm not a puller, or much of a diesel guy, though I did own a 96 f350 7.3L.

For line holding, what kind of brake booster were you running? Stock vacuum or hydroboost? I ask because there were factory F-superduties with hydroboost brakes all the way back to 87. They are far superior to the vacuum brakes. Last I checked, Rock auto had NIB motorcraft hydroboosters for sale.

I know guys running hydroboost that can lock up their 40" tires on pavement

 

It's been a while and I've learned some since my last confession.
I took the old truck drag racing and to a few more pulls. Drag racing is way easier on parts. Heat seems to be the only enemy.

On the street in 4 high I can hold the boost back to a little over 20lbs. 2wd or 4low and it creeps. The Chevy brakes I have on the front seem to be way stronger then the old ford setup. But 4low and even with a 2600 stall speed it's hard to hold it back.
I did end up getting some weights for the front hanger but haven't used them at a pull yet. The last pull I went to I had the drag race tune in the tranny and it got into overdrive and locked the convrtor. It snuffed the flame and fell short.