Unlocked...
Blown front locker!
- Thread starter Jordan345
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^ I agree. If this is the original gear set that had been running since 2001 it would've been setup by Toyota. Installing the new locker shouldn't have been as difficult or involved as a new locker and new gears since the original ring gear was just moved to the new carrier. The pinion depth wouldn't have needed to be changed since it was already setup with the Toyota diff and ring gear that came out. I guess my point is this should be a easier install for someone doing the work themselves and especially for a certified mechanic. Good the hear the locker isn't damaged. Hopefully you / they can thoroughly clean it to make sure all chunks, metal shavings and debris are clear. Is your mechanic covering the cost of the new gears and setup labor for you?
Is it possible the old gear set was worn and couldn't handle the stress at full lock with the new TJM engaged?
Is it possible the old gear set was worn and couldn't handle the stress at full lock with the new TJM engaged?
That's what I was just thinking. I feel like I'd want to see that my diff was set up as if new even if I was just putting in a locker. Why not make sure it's all set perfectly while you're in there?
The preload would have changed over time due to normal wear on the gears. Even thousandths of an inch could have some effect. I would think that it's a good idea to set the gears up again even if you're just installing a new locker.
- Thread starter
- #26
beneficial feedback on that guys, thanks. The gears were not set up since it was basically a drop in locker in an existing setup. Now that new gears are on their way, the gears will have to be setup properly.
I can't see how the old gear set would have been worn enough to allow it to happen.. looking at the teeth, they look pristine and now uniform wear. Again, this is what my mechanic indicated, so I could be fed some b.s..
The mechanic will not be paying for the new gears, but labour will be free since its a friend (who runs the shop). I don't know if there is a way to prove the actual cause with complete certainty. at this point, i'm not going to let a couple hundred bucks come between friends.. Even if a mistake were made and the mechanic is not indicating such, i'm sure the lesson will learned and rectified second time around.
I can't see how the old gear set would have been worn enough to allow it to happen.. looking at the teeth, they look pristine and now uniform wear. Again, this is what my mechanic indicated, so I could be fed some b.s..
The mechanic will not be paying for the new gears, but labour will be free since its a friend (who runs the shop). I don't know if there is a way to prove the actual cause with complete certainty. at this point, i'm not going to let a couple hundred bucks come between friends.. Even if a mistake were made and the mechanic is not indicating such, i'm sure the lesson will learned and rectified second time around.
How does one install a new ARB locker without re-doing carrier bearing preload and backlash set-up?
>.
yes...maybe a loaded question too 
I guess that doesn't make much sense, once everything comes out, it has to go back in. Incorrect preload and a much stronger carrier maybe?
yes...maybe a loaded question too
I'm wondering the same thing. Somebody fire away!
Ok...I'm not a diff set-up guy. Now that we have that out of the way ...I've watched a few get set-up. I could be dead wrong but your diff blow up woes smell of improper installation and set-up within the 3rd member. So the ARB has its own carrier. And it probably, magically, isn't the exact same/identical width as the OEM carrier that came out; hence shims.
I don't understand how an ARB locker assembly could be properly installed without due consideration to carrier bearing preload set-up and backlash adjustment. So if the installer indeed just swapped the two ring/carrier assemblies out/in without any further check and adjustment of the aforementioned...I see this as more than coincidental.
The ring suffered considerably more damage than the pinion. And although its difficult to ascertain what exactly did occur it doesn't seem to be a stretch to concur the ring gear flexed...causing substantially more damage than what the pinion suffered. If the carrier preload and/or backlash wasn't set correctly it could induce just enough flex/play, under even a light load, to cause the very damage you incurred.
I could be way out on a limb...just a guess.
...I've watched a few get set-up. I could be dead wrong but your diff blow up woes smell of improper installation and set-up within the 3rd member. So the ARB has its own carrier. And it probably, magically, isn't the exact same/identical width as the OEM carrier that came out; hence shims. I don't understand how an ARB locker assembly could be properly installed without due consideration to carrier bearing preload set-up and backlash adjustment. So if the installer indeed just swapped the two ring/carrier assemblies out/in without any further check and adjustment of the aforementioned...I see this as more than coincidental.
The ring suffered considerably more damage than the pinion. And although its difficult to ascertain what exactly did occur it doesn't seem to be a stretch to concur the ring gear flexed...causing substantially more damage than what the pinion suffered. If the carrier preload and/or backlash wasn't set correctly it could induce just enough flex/play, under even a light load, to cause the very damage you incurred.
I could be way out on a limb...just a guess.
I am no expert either but I have successfully replaced a couple differentials myself.
Backlash is the amount of depth the pinion sits on the ring gear. In this case the installer probably didn't have to manipulate anything involving the pinion depth or pinion bearing pre-load. The old Toyota carrier was in for years and ran fine - so backlash in theory should've been correct. Swapping the old ring gear over the the new same size carrier should've resulted in the pinion sitting in the same place on the ring gear (as far as depth is concerned).
There is also a carrier bearing pre-load which determines how tightly the carrier sits in the axle housing basically. I guess you could think of the two bearing pre-loads (pinion and carrier) as front and back and side to side tolerances for play or movement. You need just enough room for movement in each direction or things will break because they are too tight or too loose...
In the case of the installation and problem with this TJM installation I'm guessing the carrier bearing pre-load was not correct and the side to side movement was off resulting in the carrier moving side to side away from the pinion and breaking. Just a guess... I don't know much...
Backlash is the amount of depth the pinion sits on the ring gear. In this case the installer probably didn't have to manipulate anything involving the pinion depth or pinion bearing pre-load. The old Toyota carrier was in for years and ran fine - so backlash in theory should've been correct. Swapping the old ring gear over the the new same size carrier should've resulted in the pinion sitting in the same place on the ring gear (as far as depth is concerned).
There is also a carrier bearing pre-load which determines how tightly the carrier sits in the axle housing basically. I guess you could think of the two bearing pre-loads (pinion and carrier) as front and back and side to side tolerances for play or movement. You need just enough room for movement in each direction or things will break because they are too tight or too loose...
In the case of the installation and problem with this TJM installation I'm guessing the carrier bearing pre-load was not correct and the side to side movement was off resulting in the carrier moving side to side away from the pinion and breaking. Just a guess... I don't know much...
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- Thread starter
- #34
I appreciate you both being humble on the topic - I am learning quite a bit from what you are posting and trying to understand how this could have happened.
Is there anyway to pin cause down (as I don't necessarily have expertise to do it)? I have to decide in the next week before I get the gears back whether I get them reinstalled by the same installer. Given his background, he's not the type to say he made mistake and likely feels like crap if in fact his installation was wrong. I would expect he get it right second time considering the first error if in case it was his fault; I know he is willing and wanting to get it right.. hard thing for me to guess is if he actually can do it right second time around.
I'm in the sticks a bit and have limited option elsewhere (read, don't know of any reputable places that can install gears, and especially on the 100 since they are non existent here). I would assume the 100 isn't any different than any other truck, but just throwing that out there.
Thanks for all the opinions and feedback. I always learn something from the forum here.
Is there anyway to pin cause down (as I don't necessarily have expertise to do it)? I have to decide in the next week before I get the gears back whether I get them reinstalled by the same installer. Given his background, he's not the type to say he made mistake and likely feels like crap if in fact his installation was wrong. I would expect he get it right second time considering the first error if in case it was his fault; I know he is willing and wanting to get it right.. hard thing for me to guess is if he actually can do it right second time around.
I'm in the sticks a bit and have limited option elsewhere (read, don't know of any reputable places that can install gears, and especially on the 100 since they are non existent here). I would assume the 100 isn't any different than any other truck, but just throwing that out there.
Thanks for all the opinions and feedback. I always learn something from the forum here.
my gear/locker installer said the 100 series was probably the most challenging set up he has done to get perfect, but he took his time to make sure all was set up right..... that being said, if you are questioning his abilities i would get the guys at JT's to send you a whole front case already set up with your locker and the new gears. Yes it will be a pain to send them your front gear housing, but they will get it perfect.