Differential Hot to the touch and seeping oil around fill? Need help with this one

See title. I have been hearing a light rumble/ground from the rear for a couple of days but haven’t crawled under until now. Thought it was the parking brake dragging but now I realize it could be this. Not even visibly dripping so I don’t think it would have lost too much fluid. Next step is to drain the oil, but also looking for other suggestions

 

Check the level first before draining to see if you can even touch it through the fil hole.. Measure what comes out to get an idea on how much its been low.

 

This is the color I got out of the top. Not sure what to think… it’s

$29 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 from 30K miles ago. Oil coming out the top when warm which makes me think full

 

I would put the rear diff on jack stands. Put the trans in neutral with the park brake off and check for pinion play. Grab a hold of the pinion and try to move it up and down. It should not have any play. Next rotate the pinion back and forth slightly, to see if pinion to ring hear play is excessive. There should be a small amount. Next, I would rotate the pinion and feel if there is any roughness in the assembly. It should spin smoothly with resistance from the weight of the wheels and axles. Next, remove the fill plug and see if the there is oil just under the opening of the plug hole. If there is, then the fluid level is alright. Next you can drain the fluid and filter the fluid through a cloth or heavy duty paper towel. Look for metal in the filter media. Also look for heavy metal sheen in the fluid. If everything checks out then refill and see if the noise continues or worsens.


It is normal for a diffential to be hot to the touch after driving a while. And it isn't uncommon for the plugs to sweat fluid. The noise, if it is from the diff is something that may or may not be an issue of concern.

 

Did you perhaps fail to put the washer back when buttoning it up after fluid change ?

 

Verified that the washer is on there, and there was fluid behind the plug when I took it off. But that was a good thought!

 

vent clogged ?

 

I can't really see the seeping, so I'm not sure there is an issue except maybe snug up the plug a little. Better yet: check it when it's -cold- and install a new fill-plug gasket when you put it back together. If it seeps a little when it's cold, wait until it's a drip and install the plug. Spray the area with brake-kleen and monitor it. Don't remove the drain plug until you verify the fill-plug will come out. If there are major issues with the diff: the magnetic drain plug will indicate it. (A little metallic fuzz is normal.)

Warm/hot diff is normal: That's why it requires 75W90 oil.

 

Vent looked pretty clear but I blew it out just in case. I’m thinking I’m just dealing with a very slight seep like Speed mentioned. I did do something a little stupid a few weeks back when I pulled the parking brake to the max in a bit of a panic. Could I have pulled it out of adjustment and that’s the noise I’m hearing?

 

I don’t see your leak?
That looks like old gear oil with road grim.
Likes it’s been there awhile.

Gear oil sticks around.
I usually take Brake/Carb cleaner and spay the diff off after I refill.
And I do torque the drain plug.

 

Does that truck have zerk fittings on the u joints ?

 

I should have taken a picture when I first crawled under there. I had already wiped the grime and spot of oil around from the fill but I agree on that it wasnt very much oil on the diff. Which makes me feel a little better

 

It does, but only on the forward ones. They probably need to be serviced again as I did it at the 90k change of fluids

 

I thought it may have rear also.

 

Park it on a slight incline, (in your driveway if you can) put it in neutral and slowly apply the parking brake when it picks up a little speed and see how long it takes to start to slow the truck down. Listen for the noise you're hearing. For reference, I have the foot-pedal type and it starts to apply about 1/3 of the way down. It's fully on and stops the truck before it's all the way down. The parking brake is 100% mechanical, so I can't see how a panic-application would throw it all out of kilter.

 

If they are on the rear I haven’t been able to locate them. From what I read Toyota did away with the rear zerks prior to my truck year and then got rid of the fronts shortly after mine was made

 

10-4

 

While trying to diagnose the noise I tried doing something similar on flat ground and dropping it into neutral once the truck was rolling good. The brake stops the truck pretty hard at the 3rd click on the handle

 

I hear a low pitch coming from mine when I open the power sliding window.

 

Sounds about right. The "handle" parking brake on my son's 2005 has far less travel than my pedal one for full application. I think the true test on my truck is that a full/hard application of the pedal at speed will lock the rear brakes right up before getting all the way to the floor/end-of-travel. IMO: that's the standard.