Mechanic Says My Main Diff Has Excessive Wear 2021 Pete 389

This a dealer or just a repair shop?

 

Just??? WOW might be a certified repair shop.

 

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Up and Down play is normal apparently... and (rotational) play should only be a certain spec. I would imagine the up and down (lateral) play is what he was referring to. There are some diffs that do exhibit this characteristic and is no cause for concern. Rotational Play is minor too, I mean I have worked for a fleet where they sent everything (didnt really repair it) and it never blew up, you cant really damage it anymore unless shrapnel gets into the spider gears and chews them further. Its usually replaced with a whole new or rebuilt setup so the core is sent back if still good but really everything should be replaced... Wheel Bearings, Seals, gaskets, etc... when you pull it to replace & it gets a good cleaning of all its scunge! Keep the oil level up and current and send it!

 

Someone correct me if I’m wrong, doesn’t the yoke have shims ? On my former Pete, it had 402 rears, I had a slight vibration and my drivetrain specialist checked for excessive play, he shows me the shims that go behind the yoke, he said to remove certain shim by size and it would tighten up the yoke slightly more. I did as he requested and vibration went away.

 

Yes they do have shims on the outside bearing retainer on some. And yes they can be addressed that way, but you would want to know what created the issue to begin with. If it's just break-in wear then the specs on assembly should differ as well to compensate having to shim it twice. I dont trust robots to assemble a differential to a precise increment unless all the parts went together perfectly, but time will tell how good or bad that will get.

 

If it has excessive play you would feel and hear it every time you shift or start from a stop.. I’d get a second opinion. Normally we change gear oil in differentials every 500 k if you’re worried change it early and you’ll have your answer.

 

That's way too soon to need a rear unless it's been seriously abused. Get a second opinion from a reputable driveline shop.

 

I would ask.. Does the seal leak where this "play" exists?