Mechanic Says My Main Diff Has Excessive Wear 2021 Pete 389

I would get a second opinion from a driveshaft shop. Find a good reputable shop near you that specialises just in drivetrain and have them take a look at it. Also, I would drain the oil or And takeoff the drain plug and inspect it for shavings. Excessive backlash will always cause shavings. Judging by the mileage it is way too soon for differential testing go bad even with 90,000 lb loads, unless you have a Light duty differential and Drive in the mountains. The differentials are Built to last over 1,000,000 miles with proper maintenance

 

Pull your drain plug and check your oil for any silver glitter check your magnet for excessive shavings. If looks good and no excessive shavings on your plug fill it back up and run it.
My money would be on you had a false diagnosis.

 

95k is no big deal. Those diffs should have no problem with that.

 

I hate to say it, but, 205K on that truck you probably just needed a good clutch adjustment. Those forks on that transmission are very close to the pressure plate. When it gets out of adjustment, the back of the forks hit the fingers on the pressure plate. Finding a reputable mechanic is a tough job. There are still quite a few out here, but you need to really know your mechanic. Or learn a few things on your own it will save you a ton of money in the end.

 

Mileage and weight is not normally an issue. Getting stuck in a mud hole and running the engine at high RPM can smoke the power divider and or differential spider gears in short order. I have seen local vocational trucks with a 1/4 turn slop on the input yoke. They said it is not broke do not fix it. Amazing how long some of those run.
I would get on out of there and check the things the others said.

 

Well, to have to adjust a clutch every 50,000 and then it be totally gone at 205,000. I agree something was definitely wrong.

 

How is he measuring? What exactly is he saying has too much play? If all they are doing is turning the yoke back and forth, there is a fair amount of "play" there as you are spinning againsts several gear sets, 2 differential sets and pinion and crown. I have see guys get worried about it before when nothing is wrong. Check yours with another truck. Like mentioned, check the drain plug and oil for excessive metal and get a second opinion.