Are the Sterling 10.25" and 10.5" differentials interchangeable? I'm not talking about the entire axle assembly, just the differential casing itself. I want to install the ring gear from my 10.24 two-pinion diff to a later 10.5" three-pinion diff. Will the ring gear physically fit onto the later differential casing?

 

I have not tried it, but my understanding is yes it will.

 

Thanks for the input, Dave. At one point you talked about switching from a locking differential back to a positrac unit. Why did you do that? What differences did you notice between the two in day-to-day driving? I'm looking at either putting a PowerTrax unit in my 3-pinion setup, or going with the OEM 2-pinion PowerLok differential.

 

What I had for a locking diferential was a Lock Rite locker.
It worked great for plowing snow and driving off road.
Driving on the very steep hills around here on dry pavemant and trying to make sharp turns was interesting with the tires doing a lot of chirping.

But I also have a dump bed.
When I loaded the truck up with 3 or 4 or 5 tons, driving around the area became very difficult. The more torque you applied to the Lock Rite the harder it locked.
With a load over the rear axle, driving up a hill and turning the truck became almost impossible. Turn the front wheels either way as far as you wanted, but with the rear end locked the truck went in a straight line. The only way to turn was to hit the clutch and coast back turning the front of the truck the way you wanted to go.
Then you pulled up as far as you could till you had to repeat the process. This is hard to do in town traffic and the start stop start stop start stop just to get around the corner was very hard on the driveline with the loaded truck.
I had to replace the bolts that hold the rear axles to the hubs about every month, I sheared them all off a couple of times on one side or the other.
Next thing that happened was when driving empty the locker started to release and then catch again going around corners on dry pavement. Sounded like the rear axle was chopped off by a train. Not a bang, it was a BANG!!
A couple of days of that and then as I was driving one day and for no reason it really went BANG, the rear wheels locked up for a couple of seconds then it started to freewheel. Bang again and it was back to normal kinda. Drove straight to my driveline guys shop. We pulled the punkin out and it looked like a fragmentation grenade went off inside the housing. Ring gear and pinion both were missing a lot of teeth, every bearing in the housing was trashed. Lock Rite looked like drill press shavings. 1500 dollars later I drove out the shop door with a limited slip from Spicer as I remember.
I liked it so much that I put one in my front axle as well when I rebuilt it.
Now when I am in the snow or mud and it starts to spin, I nail the throttle and it hooks up and all four tires start to dig.

I will now tell anyone, if you are driving around empty or if you are towing a load a locker is OK.
If you are putting a load on the truck and driving on dry pavement you are asking for expensive trouble.

Looking back on it, I have no idea how I never broke an axle. I guess it was because I kept shearing off the bolts which must have been designed to be the weak point. They were lots cheaper to replace than an axle shaft would have been.

I know someone will pipe in with I never should have had 5 tons on the truck, but I really think the same thing would have happened if I was only hauling 1000 pounds, it would have just taken longer.

Now you know why I say the Sterling axle is bullet proof, it can even withstand a grenade on the inside of the housing. I have been testing the limits for 20 years, I have not found the limit yet.
Biggest thing I have pulled was a loaded semi that weighed 74,000 pounds out of the middle of the interstate when he blew his driveline going up a hill. Should have seen the look on the drivers face when I hooked up to him and pulled his rig up the hill to the top to get it off the road. I do wish I would have had a camera and someone to take the picture, I bet that would have been a cool picture with the black smoke rolling out the stacks and white smoke off all four tires till I got him rolling. After it was moving the rest was easy.

 

You shouldn't be overloading your truck like that Dave

When you have two wheels trying to turn at the same time something is going to let go.

Even with a open diff my truck refuses to steer in a corner when loaded because of momentum plus tire scrub.

I was going to put a locker into my truck until Dave was saying he had problems with his truck. I put 6000-7000lb loads of gravel on my F-450 and the roads here are very twisty and 10% grades I'am not going to take a chance decending a steep grade with the corners and not beable to steer.

 

Dave, do you have the Spicer part number for the rear unit? Tried looking on the webpage - not too informative. Apparently, Spicer makes three types of limited slip differential - PowerLok, TrakLok and Hydra-Lok. Having a heckuva time trying to find applications for the Sterling diff's.

 

I did not get the paperwork on the unit.
I have a driveline guy that does all my repairs and upgrades.
With the kind of stuff I am doing I am more than willing to have everything in top notch shape.
I am also willing to pay a professional to do it right the first time.
How many transmissions have you ever seen getting rebuilt that you would eat out of?
Bead blast the outside, steam degreaser washing unit that does the inside and every last dirt particle scraped out of the inside before it starts back together in the clean room.
Painted before it goes back in the truck.
Plus he is a Timken and Spicer stocking dealer so he usually has all the parts in stock.
I tell him what I want, he tells me how long it will take and what it will cost.

I will try to stop in and get the info from him on what we installed.
I can tell you it has clutches instead of gear to gear lockup, and he set it up tight for me so the clutches don't slip very easy. Both rear tires have to spin for me to be stuck in two wheel drive. Since I put the one in the front axle, I have to spin all four tires before I am stuck in 4x4.


Kenworth why are you hauling such small loads on a 450?
You should be able to get at least 6 tons on that truck easy.

 

I make more money hauling the smaller loads I charge 50 dollars per hour its oh darn I have to make 2 trips to haul you 3 yards 100 dollars please

There is too many idiots on the road nowwadays to run around too overloaded the days are gone of getting away with hauling with a overloaded 1 ton.