4.56 gears failure

[AlexJet]

I have Nitro 4.56 gears in my truck for 1,5 years with only ~ 20'000km (12'500mi) on them. Installed by professional mechanic at the shop which is doing gears installs for years. I've added ARB locker when changed gears, so they are on strong carrier.

Nitro set failed after only 7-8 month of regular not off-road use. At that time they were at ~11'000km (7'000mi).

I was driving on the parking lot and had to drive over the carb as someone has parked and blocked the exit from the lot. I've heard a "bang" noise switching from "D" to "R" from the rear while making a 3-point turn on the carb. I went to the shop I've done the install and asked them to take a look. They took the 3rd member and found out that gears are worn out as they've been wheeled for over 100'000km (60'000mi). This was way too much for the mileage I had. Simple answer was to contact Nitro and claim it under the warranty as the gears were less then a year old. Things like that happen rarely, but they do and the shop I've been dealing with never had any issues with typical cases of gear warranty. They never deal with Nitro, but usually do with Motive, Richmond, Precision. Motive
even sending a new set of gears without looking at faulty ones. Ok, so we contacted the Nitro and were getting responses that it's installer problem, not their. I was in need for the truck so I continued talking to Nitro as the shop too, but I drove the truck around carefully. At some point I stoped by another off-road shop dealing with gears and asked them to take a look as independent consultant. They did took it apart and checked. It cost me $150 for the labor, but I wanted to see problem. They their findings were that gears still have "acceptable" pattern and there is no installing problem with them, they just worn out to the point when replacement required. On the question and my answer on the mileage they were shocked as they thought gears are at 200'000km (130'000mi) range. I tried to negotiate with Nitro again for warranty, but they refused to accept it, even alternative shop said my set must of been defective from the factory.
At current time, my gears worn at the point that I'm afraid I'm going to sheer them on highway and I need replacement. I don't want to deal with Nitro as they do not care of the customers and not favor the warranty at all. Problem is both shops are having trouble locating the right gear set for me. I know that some of you guys put Yukon 4.56 gears on the rear axle. Could you verify the right gear set and part numbers as some suppliers saying 8" Toyota V6 will fit and some saying that they would not. I'm also getting confused of allot of different information what is Toyota V6 and what is Toyota Turbo. Which one is 7.5" and which is 8".
If some one has the answer for my issue, please post it up as I don't want to order a wrong set.

[medic83]

Should have gone with Yukon or Sierra!! If I were you, I would just swap out the both front and rear with Yukon or Sierra. You're right.... re gearing and puting in front and rear lockers should have made your truck's diffs much stronger, this is unacceptable....I would be done with nitro and send them your old R&P's along with your date of purchase or install.... Ur gears shouldnt wear out at this point...they should break if anything (hard use)

[AlexJet]

I have V6 and front is disconnected 99% of the time. So far front didn't gave me any issues. For cash issues, I was thinking to swap only rear ones as they are about to blow out any time now.
Phil, I know you went with 4.88s from Yukon, but do you remember the right part for 4.56, as I remember you were choosing either 4.56 or 4.88. Can you confirm the right 4.56 part number?

[medic83]

Originally Posted by AlexJet

I have V6 and front is disconnected 99% of the time. So far front didn't gave me any issues. For cash issues, I was thinking to swap only rear ones as they are about to blow out any time now.
Phil, I know you went with 4.88s from Yukon, but do you remember the right part for 4.56, as I remember you were choosing either 4.56 or 4.88. Can you confirm the right 4.56 part number?

Yikes...I dont know. Ray (dapitbull) just got oem toyota 4.56's... Maybe you can go with those.

[AlexJet]

Those must be expensive....

[daPitbull]

Yup, they're $$$. You can buy the gears from Toyota, but they're $800 for the rear, $800 for the fronts. Toy Connections made a mistake and ordered 4.88s Sierra's. They had the OEM 4.56s in the shop and swapped those in for me since they made a mistake.

[bulldog]

Allpro at one point got Toy 4.56 gears in from overseas for the front.

Alex, BTW didn't you have an issue with your front gears a year or so back, where you had to tighten the pinion bolt on the diff?

[AlexJet]

Originally Posted by bulldog

Allpro at one point got Toy 4.56 gears in from overseas for the front.

Alex, BTW didn't you have an issue with your front gears a year or so back, where you had to tighten the pinion bolt on the diff?

Yes, I had, but the problem there is that bolt lost tightness. After re-tightening it, no issues so far. Now on the back is completely different issue.

Interesting fact, Yukon Gears listed 9.5" Land Cruiser for the rear. I don't think this is right.

http://www.yukongear.com/DiffList.as...iser&Side=Rear

http://www.yukongear.com/ProductDeta...px?ProdID=4314

[medic83]

You should be able to find the rear gears in any brand.... the rear is the toy 8" and everyone makes gears for that. DO SOME SEARCHIN MAN CMON!!!

http://shop.ebay.com/?_from=R40&_trk...All-Categories

[AlexJet]

Originally Posted by medic83

You should be able to find the rear gears in any brand.... the rear is the toy 8" and everyone makes gears for that. DO SOME SEARCHIN MAN CMON!!!

http://shop.ebay.com/?_from=R40&_trk...All-Categories

I've done and I have some information saying that Toyota V6 will fit the rear housing, others saying Land Cruiser one and the other find is that only Nitto or Iceland Toyota ones. Some information saying that some other R&P may fit with some custom work. What I'm trying to do is to get things orginized in my head and see what actually works.

I found in your post that you used YG-TV6-488 for the back and YG-TLCF-488R-CS (3.91 up). Not counting the teath numbering 4.56 and 4.88 must have same overall fitting. This means, at least from my point of view, that Toyota V6 fit the back while Land Cruiser fit front. Was it bolt-on install for the rear? I saw you used some overhaul kit for the front.

[medic83]

I used 4.88 gears Alex. My gears could only be used if I changed the carrier( USING ARB's front and rear)

[AlexJet]

I have ARB rear too. So basically if you fit 4.88 from Toyota V6 without modification or new diff, then I should in theory fit 4.56 Yukon...

[shabaka]

front is a reverse-cut 8" clamshell for IFS (...NOT LandCruiser)
rear is same turbo/v6 8" as always

yukon rear from Randy's is YG TV6-456
as stated no 4.56 for the front from Yukon only Nitro

do you have the solid pinion spacer? ...i missed it if you do

[daPitbull]

Sierra's have 456 for the front too

[medic83]

Originally Posted by AlexJet

I have ARB rear too. So basically if you fit 4.88 from Toyota V6 without modification or new diff, then I should in theory fit 4.56 Yukon...

I ve no clue what you mean.

Shabaka stated the part number for rear Yukon 4.56... that is Yukons part num that is the same everywhere. Sierra also makes a 4.56. Make sure you get solid pinion spacer too.

Not really sure what problem you are having Alex or what you are asking, but its pretty simple... if your rear is bad... replace it with either Toy OEM gears, Sierra Gears, or Yukon. You said ur front is fine so and you didnt want to swap that right now. So Im not sure why you are asking about the front or whatever. Your rear axle is the same as turbo v6...toy 8" no elocker. Sorry man...Just dont know what the hell ur asking

[shabaka]

Originally Posted by daPitbull

Sierra's have 456 for the front too

...are you sure???
i can't see any FJ Cruisr/Tacoma/4Runner part numbers
where did you hear about these

that's great if gears are becoming more available

[medic83]

I heard that they do

[bulldog]

Check my regaer and locker thread, as on the front you have different thickness gears and carriers. Rear should not be an issue. DO watch for the yoke though on the pinion.

[AlexJet]

I've ordered YG TV6-456 From Randy's with install kit.

[zimm17]

I was just going to suggest Randy's ring and pinion and his Yukon gears. They were awesome in my F250 and held up to a modded diesel, 4.30 gears, and 37" tires with lockers.