Rear Diff going bad?

I have spent many hours on here trying to get to the bottom of what my truck is doing...and while I can say I am now well educated on how to diagnose a bad U joint among other things..I haven't found my answer so I am tossing this out to you guys for your opinions.

Truck is a 2015 SR5 (4wd, v6, around 55,000 miles) starting this weekend it has been intermittently been making a loud clunk coming from the rear end. With the clunk comes a slight sideways movement. The best way to describe it is if you have something heavy in the bed and it slides over and slams into the side of the bed. It does it mostly when I am turning and accelerating. But it did happen once when I was gassing to pass a car. Aside from that there is no consistency to it.

What are your thoughts on this?

 

A quick and easy check would be to drain and inspect the rear diff oil. If you have broken tooth in there somewhere, it will most likely be obvious upon inspecting the oil (small and or large metal fragments in the oil).

 

This. It makes enough sense from the described problems to check it.

I'd drain it into a clean container too, that way you can throw the fluid back in there (after filtering it real quick) if it does come out with notable metal in it. No sense putting $$ new fluid back into a bad diff just to move the truck around until a fix.

Let us know what you find out.

 

Sounds to me like a rear spring problem. Weak leaf spring or loose ubolts.

 

Definitely could be, we're known to have rear leaf spring breaking issues.

I misread the first post and presumed she had been under the truck for a visual already (and had replaced u-joints and looked around for any obvious issues). If that isn't the case, you should definitely start with the easiest thing first; get under the rear and look for something odd. Busted shock mounts, u-joints, leaf springs, shifted axle mounts, hanging exhaust pipe, etc.

 

This ^

 

Thanks guys! While I did a down one knee inspection, I have not crawled under the truck...I will do that at lunch and tell you what if anything I find.

I am thinking you guys may be on to it though..My drivers side leaf pack has always been noisy, apparently when the Toyota dealer did the add a leaf before I bought the truck they did not lube it when they installed it. I think my truck heard me say something about upgrading to a Dakar pack and is trying to rush the issue lol..

 

Doubt it is your differential...

 

Warranty it

 

There was a typo in the service manual regarding the u bolts holding the leaf springs to the axle. I believe it said they should be tightened to 37 foot pounds, when it should be 73. Get a torque wrench and tighten them to 85. I'm almost certain this will fix your issue - maybe the noise too.

 

There's potential that this could have broken the centering pin that aligns the rear end. Pay close attention to see if your truck goes down the road a little crooked - the way a dog often runs, at a slight angle. This will wear your tires unevenly. Switching over to Dakars will fix all this and more.

 

After crawling under it and poking and prodding and trying to shake every thing I could get my hands on I found nothing loose/worn looking. Nothing looked out of the ordinary except the leaf springs. There is no obvious damage but are they supposed to be this Flat? I don't remember them being this flat the last time I was under it. The bottom leaf is actually frowning a little on both the passenger and driver side. Maybe I beat them into submission on the trails and they gave up on me...

 

on a separate note is that a body armor bumper and if it is what winch did you stuff in there?

 

I always knew that number was 100x wrong in the manuals! Im not crazy after all, I always say 90 and send it.

 

Yep, body armor front and rear. A 9,000 lb Badlands from Harbor Freight, they were a lot smaller than others I found. Had to get a little creative with the mounting of the control box in order for the plug in for the actuator cable to be accessible by the pass thru. That would be eliminated by hooking up the remote, it is on my to do list.
I know a lot of folks turn their noses up at the Badlands but I have never had a problem with it.

 

I have body armor front and back also and just wanted ideas from other who have them on what they used

 

I am pretty sure the evidence on social media of all the times it has been off pavement this month alone would give the dealer ample reason to deny the claim.

 

Totally normal for stock leaf springs to be flat, or frown with any extra weight. That's what Dakars are for.

 

Transmission slipping maybe?
But if that was the case, why the sideways kick motion?
And a tranny with 55,000 slipping? I wouldn't think so.

@SinisterDexter did you buy the truck new?
If so, how hard are you on the truck when wheeling?

 

I don't think it is the tranny either but since I don't know what it is then I don't know what it isn't...I bought it new in 2015.

As for how hard I am on it?...well that is all subjective I have found. Comments on my ventures range from "have you lost your dang mind" to "I really think you could have made that hill" depending on the friend lol. I don't treat it as a rock crawler but I am prepping myself with continued challenges and the truck with mods for the Red Clay Rally this year.