Rear locker won't disengage.
02-11-2010, 06:44 AM
#11
JK Newbie
Rear dog clutch
Hi all,
I have a problem with the rear dog clutch. I have approx 4000 miles, and my rear lockers sometimes didn’t disengage. It happened sometimes after 10 miles, sometimes after 2 miles and then it didn’t switch off at all. I took it to the authorized service of Daimler-Chrysler in Prague where they at first made a very dilettantish repair. They put back the dog clutch with a screwdriver and they did not repair anything, no solve cause. The defect happened immediately again. I returned car to the repair shop but they told me that it is necessary to exchange the whole diff, they give me back the old one. I shall have to pay the repair since I don't have the original tyres and wheels !!!
I collected my repaired Jeep Wrangler Rubicon and an exchanged spare part. I could not resist testing at first the "old" differential basket with a dog clutch. Having put it under 12V DC voltage, the clutch connects as disconnects reliably. The disconnection occurs at about decrease of the controlling voltage down to 2-3V depending on the basket position. Hence, the hysteresis of the connection process is considerable. Due to a remanent magnetism of the basket, the clutch patches together which is caused by a low voltage but on "the table" it always disconnects. The condition of dog clutch was, of course, perfect. The cogs were as new, we both know it. No wear and tear, overload, different stress or shocks (see the repair list), no foreign material in the basket.
The same can be said about pinions, their shafts and, of course, also other differential parts. It seemed to me that axial spring was quite weak; it has got lots of work with disconnection of both parts of the clutch. It is, prolly, the production fault of this set. It took me less than 10 minutes to dismantle the basket set (2 screws, 2 pins in the axle of pinions and disassembly). The assembly was even quicker. Your mechanist could easily see the clutch condition already during my first complaint.
What should I think about the carried out identification of the defect and its repair now? Did not I spend CZK 31,000 (approx USD 2 000 ) preliminarily?
I guess your answer - there is a guarantee on the repair, when it happens again within 6 months, we shall repair it free; if it happens after 6 months and within 2 years you will only pay for work.
In my opinion the defect is in the switch of a dog clutch; the spring setting apart both parts of the dog clutch isn’t strong enough to overcome the strength of control switch which guards the real position of dog clutch.
Many regards from snowy Prague, the Czech Republic!
I have a problem with the rear dog clutch. I have approx 4000 miles, and my rear lockers sometimes didn’t disengage. It happened sometimes after 10 miles, sometimes after 2 miles and then it didn’t switch off at all. I took it to the authorized service of Daimler-Chrysler in Prague where they at first made a very dilettantish repair. They put back the dog clutch with a screwdriver and they did not repair anything, no solve cause. The defect happened immediately again. I returned car to the repair shop but they told me that it is necessary to exchange the whole diff, they give me back the old one. I shall have to pay the repair since I don't have the original tyres and wheels !!!
I collected my repaired Jeep Wrangler Rubicon and an exchanged spare part. I could not resist testing at first the "old" differential basket with a dog clutch. Having put it under 12V DC voltage, the clutch connects as disconnects reliably. The disconnection occurs at about decrease of the controlling voltage down to 2-3V depending on the basket position. Hence, the hysteresis of the connection process is considerable. Due to a remanent magnetism of the basket, the clutch patches together which is caused by a low voltage but on "the table" it always disconnects. The condition of dog clutch was, of course, perfect. The cogs were as new, we both know it. No wear and tear, overload, different stress or shocks (see the repair list), no foreign material in the basket.
The same can be said about pinions, their shafts and, of course, also other differential parts. It seemed to me that axial spring was quite weak; it has got lots of work with disconnection of both parts of the clutch. It is, prolly, the production fault of this set. It took me less than 10 minutes to dismantle the basket set (2 screws, 2 pins in the axle of pinions and disassembly). The assembly was even quicker. Your mechanist could easily see the clutch condition already during my first complaint.
What should I think about the carried out identification of the defect and its repair now? Did not I spend CZK 31,000 (approx USD 2 000 ) preliminarily?
I guess your answer - there is a guarantee on the repair, when it happens again within 6 months, we shall repair it free; if it happens after 6 months and within 2 years you will only pay for work.
In my opinion the defect is in the switch of a dog clutch; the spring setting apart both parts of the dog clutch isn’t strong enough to overcome the strength of control switch which guards the real position of dog clutch.
Many regards from snowy Prague, the Czech Republic!
