Any body know where I can buy a 391 Differential assembly for my 2003 U320?
391 Differential March 22, 2022, 10:59:06 am Any body know where I can buy a 391 Differential assembly for my 2003 U320? Quote Selected
Re: 391 Differential Reply #1 – March 22, 2022, 11:04:40 am Might give these people a call.Rebuilt Truck Differentials Spicer, Eaton, Rockwell, Meritor, Mack & More Quote Selected
Re: 391 Differential Reply #2 – March 22, 2022, 11:51:24 am Quote from: luckiedave – March 22, 2022, 10:59:06 amAny body know where I can buy a 391 Differential assembly for my 2003 U320?Do you care to share with the group why a 2003 model coach needs a differential assembly? Quote Selected 1 Likes
Re: 391 Differential Reply #3 – March 22, 2022, 11:58:27 am A third member or the entire assembly? Why?Pierce Quote Selected
Re: 391 Differential Reply #4 – March 22, 2022, 01:11:09 pm Just saw that you are located down in the Lufkin area. You may try C & C Truck Parts Inc - Auto Parts Store in Kilgore as they are in Kilgore which isn't that far away from your location. If anyone in this area has one or know where one is located Tim will know.Mike Quote Selected
Re: 391 Differential Reply #5 – March 22, 2022, 01:11:36 pm Best I can tell it's got a broken tooth on ring gear or pinion Quote Selected
Re: 391 Differential Reply #6 – March 22, 2022, 01:23:38 pm What symptoms are you having?Mike Quote Selected
Re: 391 Differential Reply #7 – March 22, 2022, 01:27:02 pm Quote from: Pamela & Mike – March 22, 2022, 01:23:38 pmWhat symptoms are you having?MikeNoise start's slowly and gets faster and louder as you increase speed and changes as you get off and on throttle Quote Selected
Re: 391 Differential Reply #8 – March 22, 2022, 01:33:21 pm Have you checked the U joints to see if they are dry? Look real close at the driveshaft to make sure that the balance weight hasn't came off. Just trying to eliminate the simple stuff before you get into the BIG $.Mike Quote Selected
Re: 391 Differential Reply #9 – March 22, 2022, 01:34:37 pm Quote from: Pamela & Mike – March 22, 2022, 01:33:21 pmHave you checked the U joints to see if they are dry? Look real close at the driveshaft to make sure that the balance weight hasn't came off. Just trying to eliminate the simple stuff before you get into the BIG $.MikeYes I have, I changed unjoints driveshaft looks good Quote Selected
Re: 391 Differential Reply #10 – March 22, 2022, 01:44:10 pm That is sure sounding like you may have a ring gear problem. Have you pulled the plug and got a sample of rear end grease to see if there is any grindings in there? Those just don't go bad often as little load as they have on them compared to what would be on that gear in other applications.Mike Quote Selected
Re: 391 Differential Reply #11 – March 22, 2022, 02:01:09 pm Quote from: Pamela & Mike – March 22, 2022, 01:44:10 pmThat is sure sounding like you may have a ring gear problem. Have you pulled the plug and got a sample of rear end grease to see if there is any grindings in there? Those just don't go bad often as little load as they have on them compared to what would be on that gear in other Quote from: Pamela & Mike – March 22, 2022, 01:44:10 pmThat is sure sounding like you may have a ring gear problem. Have you pulled the plug and got a sample of rear end grease to see if there is any grindings in there? Those just don't go bad often as little load as they have on them compared to what would be on that gear in other applications.MikeMikeNo metal on the magnetic drain plug. With only 68k miles I can't believe it myself.I borrowed a device from a mechanic friend made by Steel Man it's a wireless chassis sound reader with probes placed where you want on suspension then test drive and handheld monitor enables you to listen to each probe individually and the one I placed on third member revealed the sound I was hearing Quote Selected
Re: 391 Differential Reply #12 – March 22, 2022, 02:05:21 pm Be nice to get one side off the ground and rotate pinion by hand and check free play. I understand the ring and pinions are different in the coaches to make them more quiet. Could possibly do by removing one axle. There are several junk yards with coaches in Tennessee area, I would probably be looking there myself. Doubt the diffs have been removed, but who knows.Scott Quote Selected 2 Likes
Re: 391 Differential Reply #13 – March 22, 2022, 02:10:08 pm The sound coming from the differential as you describe it is as Mike says, ring and pinion out of sync. usually from worn carrier bearings. The only parts needed are the ring and pinion, pinion bearings and carrier bearings. Try to lift up on the pinion yoke and see if the pinion bearings might be the only cause. I have bought the gears, bearings and seals from Fleet Pride and rebuilt the diff. on my cranes a couple of times. Not rocket science just need tools.FleetPride | Heavy Duty Parts and Service Quote Selected
Re: 391 Differential Reply #14 – March 22, 2022, 02:20:39 pm Thanks for all the advice was hoping to find a Reman and just swap out if I can't I'll try to pull it out my self and have it rebuilt Quote Selected
Re: 391 Differential Reply #15 – March 22, 2022, 02:50:19 pm Check pinion bearing and back lash . Quote Selected
Re: 391 Differential Reply #16 – March 22, 2022, 03:36:49 pm Google will find the rebuilts for you.... Quote Selected
Re: 391 Differential Reply #17 – March 22, 2022, 04:49:41 pm Quote from: luckiedave – March 22, 2022, 02:20:39 pmThanks for all the advice was hoping to find a Reman and just swap out if I can't I'll try to pull it out my self and have it rebuiltWondering if you would have a choice with a reman being coach quality having highly polished gears. Quote Selected 1 Likes
Re: 391 Differential Reply #18 – March 22, 2022, 04:53:02 pm Sorry I had to bail out and go to the Dr. I think Chuck is on the right track in that the pinion bearing has loosened due to wear or heat cycles. All you may need is to reset the thrust with a dial indicator and go again. If I was to go that far though I would put new bearings in as you are right there with the labor and no need to risk over the cost of the bearing.Mike Quote Selected 2 Likes
Re: 391 Differential Reply #19 – March 22, 2022, 05:06:02 pm Quote from: Pamela & Mike – March 22, 2022, 04:53:02 pmSorry I had to bail out and go to the Dr. I think Chuck is on the right track in that the pinion bearing has loosened due to wear or heat cycles. All you may need is to reset the thrust with a dial indicator and go again. If I was to go that far though I would put new bearings in as you are right there with the labor and no need to risk over the cost of the bearing.MikeAbsolutely agree. If there is no damage yet, there is no reason to spend a ton of money on some other issues. Fix and run what you brung. BUT if this was my coach it definitely would be time for a locker. No need on the 2003 since they have traction control.Scott Quote Selected 2 Likes
Topic: 391 Differential