October 13th, 2019, 11:41 AM
Squid is offline
Join Date: Oct 2003
Rep Power: 17
NOTE: While not complete, I found a very informative description of all the various differentials out there.
Here is an excerpt about the Trac Lok:
"Built by Dana Spicer for use in Spicer rearends, AMC rearends, and 1998 & older 10.25″ Ford rearends. The old design built up until about 1989 was weak. The 1990 and newer design is fairly strong and even rivals the Powr-Lok for impact durability, but the clutches do not provide as much lock-up force and tend to wear out in about 50,000 miles if used in the rear. Works better in the front of vehicles because itís not aggressive. The main selling points for this design are the fact that clutch chatter is almost non-existent, and it is very inexpensive. These two points make it a great unit for many applications and a very good value for the money. This unit makes a great front limited slip and works well for those who need a little extra traction but cannot tolerate clutch chatter. The Trac-Lok came factory installed in many models such as D28, D44, D60, AMC 20, AMC35, 10.25″ Ford. The problem with this unit is that it is not very aggressive and power transfer is minimal. Also, 1988 and earlier units tend to break fairly easily. (1piece case, 2 pinion gears, and 2 tab clutches). (factory)"
BREAKAWAY TORQUE TEST: (?)
Too lazy to check FSM, but is there a test to determine if clutches need replacement? like a torque spec to turn an axle and cause clutches to slip?
Found this on Jeep site (I suspect Paper Test is suggested because breakaway torque is extremely high)
DIAGNOSIS & TESTING
DANA 2-PINION TRAC-LOK
Drive vehicle to thoroughly warm up lubricant in rear axle. Place a piece of slick paper over a smooth formica board. Ensure formica board is on flat and level floor.
Drive vehicle over formica board until one rear wheel is
in the center of board and paper. Place a block of wood 2" high and a
minimum of 3" wide in front of one of the front wheels.
Open throttle gradually attempting to slowly drive vehicle
over block of wood. If paper slips out of position, reposition paper
and repeat test. If vehicle drives over block of wood, axle is
DANA 4-PINION POWER-LOK
With engine off and transmission in "N", raise one wheel
off ground. Block both front and rear wheels of opposite side. Install
adapter tool across 2 wheel studs and attach torque wrench to center
Observe torque required to continuously turn wheel
smoothly through several revolutions. Repeat test for opposite side.
If differential is okay, torque should be 40-200 ft. lbs. (54-272 N.
m). Disregard breakaway torque. Use rotating torque only.
Last edited by Squid; October 13th, 2019 at 11:52 AM.