The 5.29 Mega Thread!!

THANK YOU Chris for this!! You have inspired me to work on this tomorrow. I’ll let everyone on my progress

 

Gear dummy here, I'm about to buy a Nitro 5.29 package.... here's the dummy part: what's the difference between the 5.29 package and the 5.29 - 8.75?

 

5.29 is the gear ratio. 8.75 is the diff size. Here's a chart to help you tell which rear diff you have.

 

DUDE. This chart is perfect! This is my first time dabbling with gearing in any vehicle. I've watched enough episodes of Roadkill and Hot Rod Garage to bite the bullet, but they don't feature Tacos, obviously. Last thing I want is to gut everything to realize I ordered the wrong part.

 

Chris,

1) I checked the front Diff fluid and it was just below the top of the filler plug, although it was warm, not cold. I think that means when cold the fluid level would be a bit lower. I also noticed that only the lower area of the diff was damp with oil, it’s dry everywhere else

2) I followed the breather tube down from the top until it enters the top of the diff. Seemed to all be connected.

3) what is the ADD tube?

Thought I’d include a pic showing the filler and drain plugs both of which are dry



Here’s a pic of the backside,notice weeping around the two bolts

 

Ok, looks like either the drain plug is leaking. Maybe needs a new crush washer and torqued to 30ft#'s. Or the housing isn't sealed good in the area it's leaking at. Since the back side is wet, I'd lean more toward the housing. That temp sensor doesn't appear wet, but sometimes that isn't sealed all the way.

The ADD tube is the extension that goes from the main body of the diff to the passenger side CV axle. You'll see 4 external torx bolts (e14) connecting it to the diff with the ADD actuator attached to it.

 

I'd spray all the fluid down with brake clean and wipe thoroughly to pinpoint where the leak is coming from.

 

Great idea!

 

Updates?

 

Sure thing! I separated the diff breathers. With @Texoma suggestions I used brake cleaner to clean up the diff and the breather area and then waited few days and saw that there had been no fluid leaking anywhere - so far so good.

I then ran it in 4wd with both lockers engaged climbing a minor hill and checked again - again no leaks.

a week later I checked and the diff is dry


Here’s the same view from the drivers side:

All dry around the diff!

now for the bad news:

The front diff is now leaking a bit...

 

That "leak" on the breather could just be vapor/mist. Those lines are so small ID that a bubble of oil can get trapped and push its way up too.

 

Great! I’ll just keep on the watch list. Hopefully it doesn’t grow

 

@socalexpeditions

Looks like mostly 85w-140

 

I need to swap over to 85w-140 and see if that helps get rid of my noise some. Currently running

$30 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90.

 

I’ve ran 85w-140 since my regear and haven’t had any noise

 

Man, that must be nice. I doubt it’ll help, but it’s worth a shot.

 

My truck at 75mph off throttle sounds like a Boeing haha. Gears are fine though, wear is perfect. Just a nitro thing

 

My Yukons do the same, plus some noise in the 30’s.

 

Mine noise is exhaust drone

 

So, long time lurker to the thread. Finally pulled the trigger on some 5.29 first off I have a 2018 OR w/auto and 33” tires. Running straight on factory gears was just horrible. If anyone says it’s not bad they are lying. Don’t trust them. Needless to say I went with the 5.29 over the 4.88 because I do plan on going 35” tires but pulling a offroad trailer they just made sense. I’m still in the break in period, so haven’t got to try the trailer out but initial review. They are night and day compared to the stock, mileage is around 15, so I do expect that to remain. Shift points are so much better, no more hunting for the gear and I can finally run 6th again. So if anyone is thinking of the 5.29 over 4.88. If you are running bigger than facotry sized just get the damn 5.29