Originally Posted by benullman
would a Scout Dana 44 trac-lock (crap-lock?) be rebuild the same way? Got one that needs new spiders in it.
This is great!
"Track Lock" is AMC's version of a 'Posi', like 'Posi-Trac' was GM's.
Even though they used the same differentials from the same companies, they gave them different 'Marketing' names.
The PROPER NAME IS 'LIMITED SLIP' for this type of differential.
The guy that 'Welded' the differential made it a 'Crap Lock' by removing the housings' ability to relieve 'Differential Stresses' from turning and one wheel turning faster than the other.
You don't need a 'Limited Slip' differential carrier to weld it up, any carrier will do.
The 'Limited Slip' part comes in because the clutches allow *Some* power to be transfered to the wheel WITH traction.
With an 'Open' differential, the power is transfered to the wheel with the LEAST traction,
Thats why an 'Open' differential just spins the wheel in the mud, while your tire on the gravel/pavement does NOTHING...
The 'Limited Slip' differential usually has some device or another that applies SOME of the engine torque to the wheel WITH traction so you don't get stuck as easily.
A good LSD (Limited Slip Differential) with 'Tight' clearances, or even preloaded a little (Springs on the clutch packs) will do VERY GOOD at adding power to both wheels, just not a 50/50 assignment of power.
I'm a little lost here...
If you are going to 'Weld' up the spider gears, why replace them?
Welding to connect axles together and the housing is what a 'Crap Lock' is, A 'Home Made' spool... Or so I thought...
The clutch type Dana Differentials used in Jeeps work quite well when properly maintained...
The clutches DO wear quite quickly (Lots of power going through them and they are SMALL),
But when they are working correctly, the really pull well...
When you weld up the spider gears to the drive gears, then weld all that to the diff carrier,
Both axles drives welded directly to the case, no side to side differential action at all anymore. You twist axles. Fact of life.
Differential in speeds of the tires as you go around corners, curves, ect.
When the housing is welded up to the axle drives, the tires have to slip traction on the pavement to unload the differential torque between wheels,
Or the axles have to twist, loading and unloading, taking and releasing the differential in torque/rotation between the tires.
A 'Posi' lets the differential in wheel speeds release, but still gives you SOME torque to the wheel with traction, instead of sending it all to the wheel that DOES NOT have traction like an 'Open' differential does.
If you are welding (Crap-Lock! I love that Description!
) you are connecting both axles directly to the drive shaft, no differential action at all.
There are three basic types of 'Posi' in use today,
The 'Clutch' type
shown in the thread (Obviously),
And clutches usually make them work for a while...
All depends on clearances for the clutch packs and if you add the proper 'Friction Modifier' to the gear lubricant...
A 'Forcing Cone' type
where just plain friction is used on larger 'Cone' shaped side drives, usually found in 60s and early 70s GM vehicles,
There is usually no rebuilding these, they haven't made parts for YEARS, and the bores for the cones are usually worn out to the point of uselessness.
I HATED these! When I was young, they were in the shop CONSTANTLY because the forcing cone would jam in the tapered bore and cause all sorts of driveability problems, broken axle shafts, ect.
And the 'Thorsen-Gleeson' type
that uses a series of spiral cut gears to deliver some power to the wheel with traction.
(These include 'True Track' differentials)
I LOVE these!
If they are set up correctly, you get about 30% to 40% of torque delivered to the wheel with traction without the 'Locking/Unlocking' you get with 'Lockers',
Operation is so smooth you won't know it's in there on the highway, no 'Pops, Clicks, Whine, Jerks' and no switching ends in traffic when you get on the throttle while turning!
No silly lube additives, and they last as long as the rest of the vehicle with no changing clutches, ect., Just service like it was an open diff and they are happy!