Blackdiamond (Gup-C build-up)

[mudmaster]

Time to sell it.....

[blackdiamond]

Approximately how many miles on the 4:88s?

Approximately how many miles on the rear diff gear oil?

What type of gear oil is in it?

Does the pinion angle effect lubrication of the outer pinion bearing?

Gnarls.

I'd guess the differential is under 40k and I don't think the angle is extreme enough to be a significant issue though it could be a factor.  I have properly torqued the gear oil from time to time. I typically have run a blend.

[blackdiamond]

Time to sell it.....

I've honestly considered as a general concept. No plan to replace it and that doesn't feel quite right.

[blackdiamond]

I was tentatively planning to take tomorrow off to have Carl "supervise" me pulling the differential since I need to know what the issue is. Work got overwhelming today and Carl thinks he can get to it in the next day or two so off to work in go.

[swilson]

I hope you find it.

I had a drive line vibe pop up this week.  Only at 65 mph, only when decelerating.  Mine was a rear t-case flange coming loose.  The staked nut had come loose 1/4 turn

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[blackdiamond]

Things were taken apart yesterday and the voicemail report was that a lot of crap had gone through the bearings. Nothing catastrophic, but I'd be getting all near bearings including wheel bearings (one was bad and the other on the way out) and a clean housing. Sounds like neglect may be the primary cause.  That's what happens when life happens.

[blackdiamond]

The big issue is a bent housing. Thankfully, the shop is setup to handle it.

[swilson]

Glad you're getting it sorted out.

What's the cost to straighten the housing vs just buying a more robust housing?

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[blackdiamond]

Glad you're getting it sorted out.

What's the cost to straighten the housing vs just buying a more robust housing?

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Sounds like $200-$300 plus it saves having to setup a new one. It's already straightened.

[blackdiamond]

Here's a few pictures with my Sequoia tires on the rear trying to isolate the tires from being the issue.

[blackdiamond]

Here's some before and after pictures of the housing along with the setup Carl used to fix it.

Pardon the photo quality as my method to resize them is clearly not ideal.

[swilson]

That's quite the setup to straighten housings!

[blackdiamond]

That's quite the setup to straighten housings!

He sent me a little video that shows another pieces that he slides onto the outside end of the alignment shaft that just fits over it and is also sized to match the housing mating surface so that he can verify the alignment.  If you're not familiar with Carl Jantz check out Jantz Engineering and his Super Jeep on YouTube.  I setup my phone contact to say "Mad Scientist".

When I was in his shop he showed me a failed attempt at installing a Dana 44 ring & pinion in a Toyota carrier.  After not being able to get a pattern he discovered that he overlooked the fact the hypoid distances for the two setups are about 1/4 inch different.  He does a lot of different kits/setups to allow larger gears to go in housings.  A big one is D70 gears into D60 housings.

[blackdiamond]

In retrospect, I think it's probably been bent for quite some time and then got worse over time to the point that I couldn't ignore it. I'm really curious to see how it feels once it's back together.

[Gnarly4X]

Hey b....

I am very happy to read that your way-to-long-time of frustration of a phantom vibration is over.

I'm curious what the "Mad Scientist" would say about early Toyota axles. 

It's been my understanding since my early days of owning my first 1986 Toyota Longbed, that Toyota axles, and drive train in general, are high quality, beefy, and very well designed.

I had my first 1986 Longbed front end about 10 feet in the air in Mexico on the beach at about 55 MPH... accidentally! .. bent the tie rod.

I've had my 1985 shortbed in the air, dune jumping, in the Glamis sand dunes... no evidence of damage.  Fortunately, my girlfriend was wearing her sports bra.

I only experienced one axle failure, in Maob, I stupidly backed up while the steering was hard turned, and broke my stock birf.

I can't recall any specific times of discussion on axle failures on Toyota axle housings due to being bent? 

BUT... obviously it happens.

Gnarls.

[toyodaaddict]

Have you considered adding a truss? I hear they are more susceptible to bending again after being straightened. The ruff stuff trusses look pretty nice.

[blackdiamond]

Have you considered adding a truss? I hear they are more susceptible to bending again after being straightened. The ruff stuff trusses look pretty nice.

At this point I'm relying on the guy doing the work. If he thought it needed one I'm positive that he would recommend and install it.  I think the likelihood of a repeat depends on how/where it bent and the condition after being bent back.

[blackdiamond]

New puzzle:

During the ring and pinion setup Carl noted something curious. He verified that the carrier is flat so the ring gear would be expected to rotate in a flat plane, but when rotating the pinion to verify the pattern he noted that there's play on one side and tight on the opposite. Think of the pinion rotation as being 0, 90, 180, and 270.  At 0 it's tight (almost can't turn the pinion by hand, at 180 he estimates 0.005 to 0.008 play, and it's "normal" at 90 and 270. The ring gear doesn't even turn a full revolution so it seems like it would be a pinion issue.  What would cause a pinion to not rotate in a consistent plane relative to the ring gear?

New gears are on the way.

[liveoak]

driving around with a bent housing is the most likely cause. I think I have a similar issue, also explains why my ARB locker always leaks, even after installing a new one. I wish I had a Carl around here.

[mudmaster]

I never had this issue??

[swilson]

Bent 3rd member.  Had the same thing this winter, after my ring gear bolts backed out and caused all kinds of damage, they rebuilt the 3rd with new bearings, gears, ARB, but they couldn't get the setup right.  Finally switched to a fresh 3rd member with the same guts and the setup was perfect

[blackdiamond]

Bent 3rd member.  Had the same thing this winter, after my ring gear bolts backed out and caused all kinds of damage, they rebuilt the 3rd with new bearings, gears, ARB, but they couldn't get the setup right.  Finally switched to a fresh 3rd member with the same guts and the setup was perfect

A bent 3rd member could cause the pinion angle to be different than intended resulting in a poor pattern, but because the pinion rides on two bearings it should still rotate straight relative to the bearings and maintain the same contact all the way around.

[LittleSteve]

New puzzle:

During the ring and pinion setup Carl noted something curious. He verified that the carrier is flat so the ring gear would be expected to rotate in a flat plane, but when rotating the pinion to verify the pattern he noted that there's play on one side and tight on the opposite. Think of the pinion rotation as being 0, 90, 180, and 270.  At 0 it's tight (almost can't turn the pinion by hand, at 180 he estimates 0.005 to 0.008 play, and it's "normal" at 90 and 270. The ring gear doesn't even turn a full revolution so it seems like it would be a pinion issue.  What would cause a pinion to not rotate in a consistent plane relative to the ring gear?

New gears are on the way.

Suspect a bent pinion. Check on a flat table or on rollers. Fit new gears etc, check the "bent" one to make sure, just so you know.

[blackdiamond]

Suspect a bent pinion. Check on a flat table or on rollers. Fit new gears etc, check the "bent" one to make sure, just so you know.

How does one bend a pinion?  It fits the problem and is what Carl thinks.

[LittleSteve]

How does one bend a pinion?  It fits the problem and is what Carl thinks.

Is it new?

[swilson]

A bent 3rd member could cause the pinion angle to be different than intended resulting in a poor pattern, but because the pinion rides on two bearings it should still rotate straight relative to the bearings and maintain the same contact all the way around.

I hear what you're saying.  Just repeating what the installer had told me.  Said as he would rotate the pinion (new) it would get tight at one point in the rotation.  Couldn't solve it until he tried a new 3rd housing

[blackdiamond]

Is it new?

It was installed in the 3rd around 2002. I doubt that installer wouldn't have caught this issue since he was super picky.

[blackdiamond]

I hear what you're saying.  Just repeating what the installer had told me.  Said as he would rotate the pinion (new) it would get tight at one point in the rotation.  Couldn't solve it until he tried a new 3rd housing

I passed this along and it gave him a couple of ideas for other things that he can check.

[Gnarly4X]

...  Couldn't solve it until he tried a new 3rd housing

One of these?

https://www.marlincrawler.com/differential/housings/3rd-member-housing

Gnarls.

[blackdiamond]

The fun continues.  The new ring & pinion gears arrived and the report on the old ones is that one tooth had a burr and three had cracks.