94 Caravan AWD Not Engaging
tebo77
02-13-2011, 05:36 PM
Our 94 Grand Caravan AWD is not engaging when the front wheels slip. It also makes a whining noise while backing up, don't know if that's related. What could cause this? PTU? Greatly appreciate any help!
mikefaster
02-26-2011, 06:27 AM
The PTU (which is the transfer case) has a ring and pinion and it is a direct drive type of unit...
There is a sprag on the driveshaft that DOES NOT allow to rear wheels to spin WITH the front wheels when going in REVERSE... The drives shaft just freewheels in reverse... Because of the crude method, Chrysler had to do that or else people would be breaking things and wear out tires all the time...
Whining at idle or when driving? Sounds like a tranny pump whine... So you may need a transmission soon... They sell bearing kits for the PTU because once you break on of the gears, they are not orderable... Changing the bearings will prolong it's life for sure... Then use full synethic gear lube for lubrication...
Cost: VERY friggin' expensive...
There is a sprag on the driveshaft that DOES NOT allow to rear wheels to spin WITH the front wheels when going in REVERSE... The drives shaft just freewheels in reverse... Because of the crude method, Chrysler had to do that or else people would be breaking things and wear out tires all the time...
Whining at idle or when driving? Sounds like a tranny pump whine... So you may need a transmission soon... They sell bearing kits for the PTU because once you break on of the gears, they are not orderable... Changing the bearings will prolong it's life for sure... Then use full synethic gear lube for lubrication...
Cost: VERY friggin' expensive...
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