jcutler Posted December 6, 2022 Share Posted December 6, 2022 I have a 2018 Mack LR64 the differental lock light comes on by itself and has now destroyed the rear rear end locker. Has any had this issue before? If so is it electrical or mechanical? Quote Link to comment https://www.bigmacktrucks.com/topic/70833-differential-lock-light/ Share on other sites More sharing options...
Mackpro Posted December 6, 2022 Share Posted December 6, 2022 I’ve been hearing lots of complaints of the inter-wheel lock not unlocking after you hit the switch to unlock them . And of course the carrier explodes. All my dump truck buddies took the air lines off the carriers for the inter wheel locks. Mack has a recall/campaign for software update on the dash cluster to keep the alarm going when it’s locked in . The recall was for GU and GRs . PI0889 is the recall number. My old dealership had 7 at one time with exploded carriers. The actual actuator is air powered . There is a sending unit that screws into the housing that tells if it’s engaged. This is not to be confused with the regular power divider. Quote Link to comment https://www.bigmacktrucks.com/topic/70833-differential-lock-light/#findComment-517574 Share on other sites More sharing options...
fjh Posted December 6, 2022 Share Posted December 6, 2022 Drivers will love having that lock busser going while driving in the snow and up logging roads I'm sure! Are these Mack carriers blowing or meritor? Quote Link to comment https://www.bigmacktrucks.com/topic/70833-differential-lock-light/#findComment-517581 Share on other sites More sharing options...
Mackpro Posted December 6, 2022 Share Posted December 6, 2022 20 minutes ago, fjh said: Drivers will love having that lock busser going while driving in the snow and up logging roads I'm sure! Are these Mack carriers blowing or meritor? It’s the newer Mack carriers. Quote Link to comment https://www.bigmacktrucks.com/topic/70833-differential-lock-light/#findComment-517583 Share on other sites More sharing options...
fjh Posted December 6, 2022 Share Posted December 6, 2022 10 minutes ago, Mackpro said: It’s the newer Mack carriers. Ya we had a guy trade his unit back in because he kept blowing diffs bought Meritor second time around no issues since to my knowledge! point is its not totally a driver issue for the most part same job same hill! Yup you got to know when and when not to use diff lock! In some cases you got very little choice! Quote Link to comment https://www.bigmacktrucks.com/topic/70833-differential-lock-light/#findComment-517584 Share on other sites More sharing options...
Mackpro Posted December 7, 2022 Share Posted December 7, 2022 Mack re-introduced the inter-wheel diff lock a few years back probably because they were loosing sales to Meritor. They lock in abs function great . It’s the unlocking is the issue. We have them on some of our CXU’s . Sometimes you have to drive in a figure 8 on a gravel parking lot to get them to unlock . Quote Link to comment https://www.bigmacktrucks.com/topic/70833-differential-lock-light/#findComment-517592 Share on other sites More sharing options...
Mackpro Posted December 7, 2022 Share Posted December 7, 2022 11 hours ago, jcutler said: I have a 2018 Mack LR64 the differental lock light comes on by itself and has now destroyed the rear rear end locker. Has any had this issue before? If so is it electrical or mechanical? I forgot to add . The Diff lock switch is electric and sends voltage to the solenoid pack back on the frame rail . This sends air to the diff lock actuators on the carriers Quote Link to comment https://www.bigmacktrucks.com/topic/70833-differential-lock-light/#findComment-517621 Share on other sites More sharing options...
Mackpro Posted December 7, 2022 Share Posted December 7, 2022 Quote Link to comment https://www.bigmacktrucks.com/topic/70833-differential-lock-light/#findComment-517623 Share on other sites More sharing options...
fjh Posted December 7, 2022 Share Posted December 7, 2022 the set up is the same for meritor diff correct? Sounds like a design flaw in the lock its self! Quote Link to comment https://www.bigmacktrucks.com/topic/70833-differential-lock-light/#findComment-517652 Share on other sites More sharing options...
Mackpro Posted December 7, 2022 Share Posted December 7, 2022 First problem was when activated the dash would beep once to let you know it engaged. The light showing it was engaged was on the switch. Drivers forget they engaged it and take off down the road and Kaboom. The software update made the buzzer stay on while it was engaged this help the problem. The second problem was getting it to disengage. I believe once the air was let off the spring pushed the plunger to unlock it . The spring is not that strong. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/70833-differential-lock-light/#findComment-517657 Share on other sites More sharing options...
Cpitt32 Posted December 16, 2023 Share Posted December 16, 2023 On 12/7/2022 at 8:30 AM, Mackpro said: First problem was when activated the dash would beep once to let you know it engaged. The light showing it was engaged was on the switch. Drivers forget they engaged it and take off down the road and Kaboom. The software update made the buzzer stay on while it was engaged this help the problem. The second problem was getting it to disengage. I believe once the air was let off the spring pushed the plunger to unlock it . The spring is not that strong. Hey Mackpro... I recently bought a 2014 CXU613 and I was wondering if the buzzer constantly stays on while locked... I thought that it just wasn't engaging and thought I had a problem... Let me know if this is how it should be... Thanks... Quote Link to comment https://www.bigmacktrucks.com/topic/70833-differential-lock-light/#findComment-543531 Share on other sites More sharing options...
Mackpro Posted December 18, 2023 Share Posted December 18, 2023 Yes , if the dash cluster software update was done It should buzz when the diff lock is engaged. Quote Link to comment https://www.bigmacktrucks.com/topic/70833-differential-lock-light/#findComment-543677 Share on other sites More sharing options...
timmer62 Posted January 11, 2024 Share Posted January 11, 2024 I have a 2022 Granite that also has intermittent diff lock alarm. Mack recall service was done, and still get the alarm coming on intermittently. When this happens, the diff lock was on earlier in the day, then turned off, then the alarm comes on itself shortly thereafter (anywhere from 10-45 minutes later). Driver quickly pulls over, engages and disengages the diff lock, and continues on. Checked the solenoid (both electrically and pneumatically) to confirm that air was not inadvertently actuating the diff lock to due an electrical short or failed valve and found no issues. I have considered changing the spring that retracts the plunger (and unlocks the diff) once the air pressure is turned off, and am very curious about Mackpro's comment on the spring. Mackpro, is there a stronger spring available? Is this a common issue? Quote Link to comment https://www.bigmacktrucks.com/topic/70833-differential-lock-light/#findComment-544916 Share on other sites More sharing options...
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