Dying front diff in my 2006?

[SlowBuild]

Sorry, I realized I was covering this in two threads. Here’s where I asked about my mismatched axles and wear:

Does someone know what these should look like cleaned up?

Once I got my axles out (I removed the diff too - I'll reassemble it all once the diff is rebuilt) I could see they don't match. The ps appears aftermarket. I see no markings and I haven't cleaned it out yet but the boot says 'Interparts'. The ds is stamped 'REMFG VGA16' and I assume it's a reman oem part.

I was planning to reboot & repack both sides but I'm wondering if it's worth the time to redo the aftermarket one (assuming that's what it is). To my untrained eye the ds assembly (remfg) looks in pretty good shape. Very minor pitting on one bearing that I can barely see, a bit of wear on the inboard splines, and some irregularities on the basket cutouts. However, it has no dustshield at either end. The ps assembly (aftermarket?) has a dustshield at the inner end where it meets the diff and a dustshield along with a gasket or bushing (but very detiorated) at the outer end where it meets the knuckle. The ds assembly is missing both.

Any thoughts on this? I'd like to replace the aftermarket axle assembly with a rebuilt one from CVJ, and just reboot the remfg assembly. I'd maybe reboot the aftermarket one as well just to keep as an emergency spare, depending on its condition once I clean it up.

Does the ds look like a good candidate for a reboot? Should it have dustshield? Does anyone know if I can get them individually or have part numbers? Have I correctly identified them as aftermarket and reman oem?

Photos:

Two shafts. PS (aftermarket) on left, ds (reman) on right:

View attachment 1548976

View attachment 1548974

Ds stamp:

View attachment 1548979

Page 6 of this thread:

CV Boots Replaced with directions

 

[SlowBuild]

My new front diff will come tomorrow. I had a look at my old one. I wonder if it’s been rebuilt.

The axle tube looks to me like factory finish, shiny. The diff housing also looks like factory black cast. The spot of blue paint near the pinion flange makes me wonder if it’s a reman. The housing cover is a different finish from the housing (silver, not black). And loads of red fipg.

Opened up:

There’s ‘mud’ inside that looks like pulverized metal. It’s dark graphite color here inside the cover:

And also here inside the housing it shows up lighter against the black, a little harder to see:

 

[SlowBuild]

There’s also blue paint on the ring gear. Reman?:

The outer edges of the teeth are worn, especially in the valleys:

Maybe that’s where the ‘mud’ is made.

Looking in past the right axle seal I can see wear on the shallow teeth closest to me. I’m not sure what this ring is:

Nothing appears to be broken but there’s definitely wear.

 

[SlowBuild]

I can’t post the video here but when I turn the pinion flange or the ring gear by hand it makes a grinding sound. Maybe I had more life in this but it feels like it was slowly chewing itself up.

 

[2001LC]

Post video in youtube then here!

 

[78f150tx]

Thanks for taking time to post all the photos. Can't wait to see pics of the new diff. Are you planing to do the install yourself or take it to a local shop?

 

[SlowBuild]

It think sounds more crunchy in person....

 

[SlowBuild]

And here’s what the squeal sounded like before I took it out:

 

[2001LC]

Are the lower teeth in the second to last picture scored?

Was the gear lube very low?

 

[SlowBuild]

I think the lines on the face of the teeth are from the machining/manufacturing process. They feel smooth but do catch the light. I could be wrong. But I do see a nick in the end of at least three separate teeth at the top/apex:

Also, looking at the spot that has been marked with paint, there is some indication of uneven wear:

Short answer:
Fluid was likely low for up to a few hundred miles, but not extraordinarily low.

Long answer (recap):
I bought this truck in May about 8k miles ago before a long road trip. I took it to a shop to have fluids replaced. They told me diff fluid looked really bad. Then, within the last 500 miles, I went to the dealership to diagnose a sudden front end grind and a small leak that had developed a few hundred miles earlier but that I hadn’t gotten around to investigating. They told me there was a leaking axle seal, diff drain plug had a ton of metal, and that there was ‘dye’ in the fluid (implying someone was previously chasing a leak). I don’t know what to make of this. If P.O. had used dye, it would have been drained at least once by then. Anyway, they changed axle seal and refilled diff for the cost of a timing belt job (I know, I’m an idiot). They told me I need a new diff. Fluid drip stopped, grinding sound softened, but the squeal began. My own investigation informed me that the new axle seal was still weeping, along with pinion seal. Also, pinion flange was loose and my cv axles had worn splines and one was aftermarket. Now we’re moved into our new house so I have time to learn this and to try and tackle the rest of it myself.

 

[2001LC]

If they fixed the seals, they (Dealer) own you a reseal.

The sound when you're spinning the gear didn't sound that bad, sound was consistent (in video).

I noticed in your squeal video, that it was raining. Did you ever hear squeal when it was dry out and/or you did wash the rig, for say three days or more?

 

[bwell]

It's hard to say what ultimately caused the failure other than multiple issue, and then a few missteps. When you had the dealer install the new pinion seal they should have been up front with you and said that it wouldn't fix the leak there. The tech should have known with the amount of play you described, the factory "crush" pinion spacer likely got hot and warped when low on fluid. They really aren't very heavy duty considering the load they can be subjected too.

I destroyed my front ring gear about a year and a half ago and rebuilt it my self with a solid pinion spacer from JT's.

Ultimately I contributed the diff failure to the pinion spacer in mine and what I was doing with it.

 

[SlowBuild]

When you had the dealer install the new pinion seal ...

The dealer replaced right axle seal, I’m not even sure they looked at pinion seal or the pinion flange, which I now realize would have been the obvious thing to do. They were not interested in diagnostics. They told me I probably needed a new diff before they even looked at it. I feel better doing the work myself, even if I have to study how before I begin each project.

If they fixed the seals, they (Dealer) own you a reseal.

I agree they do, but seeing how the pinion flange was loose and pinion seal was also leaky, I think there was more going on than just the leaky seal. I didn’t see much benefit to having them fix the seal, I don’t trust this dealership too well and in future I’ll drive the extra 45 min to the next closest one. Maybe I can negotiate to have them put this all back together for me if I run into trouble, but I’d kind of rather do it myself.

I suspect there may have been issues from P.O. that were unresolved and which maybe contributed to this. When I bought the truck the rack was shot, the water pump was leaking, and the charcoal canister was throwing evap codes. All this was cleaned up and hidden by the Lexus dealership that sold it to me; I wouldn’t be shocked if there were more surprises. They reassured me their service department had looked it over and it was in excellent condition. It had been serviced at their dealership the previous six years. It looked good to me and I believed them. (Again, I know I’m an idiot. My wife is continually reminding me.) At this point I’m just looking forward. It’s a learning experience for me, an opportunity to save this truck, and I hope once these issues are all resolved I’ll have a reliable cruiser for years to come. More due diligence before I buy my next one.

I noticed in your squeal video, that it was raining. Did you ever hear squeal when it was dry out and/or you did wash the rig, for say three days or more?

The squeal was consistent, occurring when accelerating, especially when coming out of a turn as in the video. I think that day was the first it had rained in the week or so since the squeal began. It began right when I got it back from the dealership with the new axle seal and fresh full diff oil. Prior to that, I could hear a grinding noise under no load (when I’d lift my right foot) that lessened as I’d brake. The grinding remained after the squeal began but was quieter. I suspect there was old fluid run for a long time, and then it was low for a bit. I don’t think there are any broken teeth but I think they had begun to wear each other down.

 

[SlowBuild]

The sound when you're spinning the gear didn't sound that bad, sound was consistent (in video).

I guess it doesn’t sound so bad in the video, but it feels really gritty. Here’s another I took just now turning the pinion flange. Again, it sounds a little crusty and here you can see better how rough it feels.

 

[SlowBuild]

Here’s another of the loose flange still on the truck:

 

[SlowBuild]

A previous one driving. The squeal is easy to hear intermittently throughout, the grind is harder to hear. I think it’s most clear around 1:50, 2:17, and 2:30. I don’t have videos prior to the axle seal repair and fluid change when the grind was much louder.

 

[abuck99]

Find a good driveline shop, or a competent cruiser shop who understands gear installs and have them go through it and get it right. Youve already got it out of the truck- so your cost to set up wil be nominal. Especially setting the backlash correctly is a critical job for long term durability. If your diff has been rebuilt, it may very well have been set up incorrectly.-

If you dont have a trustworthy shop near you, you could send it to Zuk at gearinstalls.com. He is a Toyota diff/gear specialist that has a very good reputation. ( you can find Zuk here on mud @gearinstalls.com )


Edit 10/26: I just read back a few pages and noticed you ordered new-everything- and youre not trying to fix this diff. Sounds like you’ll basically have a brand new front end.

 

[SlowBuild]

This just came in the mail today from JT. Stock gears with TJM locker, already built.

I’ll try to hang it myself if I can figure out how. It’s just a few bolts but it’s HEAVY! Any suggestions?

 

[2001LC]

I heard it in last video, not good.

I used a floor jack under main body of diff. Then put a small wheeled thingy under DS axle tube.
See #190 Scored a 06 LC (untouched Jewell restoration)

 

[SlowBuild]

Thank you @2001LC ! That write up is very helpful, I will use it as a guide to supplement the FSM. I've been following your Black Knight build and I appreciate the time you take to illustrate your process and your demonstration of 'best practice' for us who need to know.

It looks like you raised the diff with the axle tube attached and connected the mounting bolts front and back then came in afterward with the crossmember and the final mounting bracket while still supporting the diff. Is this correct? I removed the diff with the crossmember attached and I'm hoping not to put it back up that way - it's hard to balance!

Also, I saw that you like Mobil 1 oils, do you recommend their gear oil for differentials? When I ordered the new diff, I asked JT if they had a preferred oil to use, but they do not.