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Why me??? 5.29 gears broken

exactly why i said what i said. it all works as a whole unit and i have experianced quite a few failures where the pinon walked into the ring gear and caused damage. the pinon was loose. whether it streched or the housing flexed i cant say.

ive also seen a new install kit come from randys with pinon bearings way oversized and just slid on the shaft with no press. causing a loose sloppy bearing. when this was discovered and replaced the new stuff was the same out of tolerance.

the only other failures i seen repeated a lot are failure of ring gear bolts...

all in all i believe the consensus of this is size. 8 " too small for the forces being generated.
 
You have a very 1 dimensional mind. crush sleeve crushes more during use, allowing pinion to move side to side, more so than in and out.

Under normal use--they should not crush anymore. Hard hits to the flange is what causes them to be "crushed" more.
 
Under normal use--they should not crush anymore. Hard hits to the flange is what causes them to be "crushed" more.

How so? If so it damages the small pinion bearing.

The flange pushes on the inner small pinion race, then through the bearing into the outer race then into the housing.

Its extremely important to make sure the outer races are seated very well, if it can "settle" in it will change the distance between the bearings.

If a pinion can get moved into the carrier it has to have play somewhere.

How can a person honestly tell if a pinion bearing failed or a ring/pinion failed if they pull it apart and claim the pinion is loose? The pinion could be damaged from ring gear failure, or the ring could be bad cuz of bearing failure.

If the bearing is still tight and its broke, then look at the pattern.

Breakin is extremly important on toyota and other cheap gears. A nice pollished pattern is important for full contact.

The origanal poster complained about chipped teeth and it was still running till he inspected it. He should look at the pattern.

Post up a pic of the pattern on the gears in question.
 
Under normal use




Normal as in pavement pounding yes.. Wheeling is a difference story though. I finally dumped my old truck after I put # 11 and 12 diffs into it. All but 2 of them had loose pinions and huge marks on the carrier from the pinion hitting it. Whats funny is the 2 that were tight were old first gen 3rds with factory solid spacers.


Just for reference the truck had everything from 35-39.5 tires and a retarded 355 under the hood so I was overpowering the poor little 8" diffs constantly. :redneck:
 
Normal as in pavement pounding yes.. Wheeling is a difference story though. I finally dumped my old truck after I put # 11 and 12 diffs into it. All but 2 of them had loose pinions and huge marks on the carrier from the pinion hitting it. Whats funny is the 2 that were tight were old first gen 3rds with factory solid spacers.


Just for reference the truck had everything from 35-39.5 tires and a retarded 355 under the hood so I was overpowering the poor little 8" diffs constantly. :redneck:

That was my point--normal use..
 
Geez this thread took off fast...


Heres more details:
1. For what it matters yes im using a solid spacer.

2. I have had chipped teeth before and totally broken ones, this time its just chipped. Yeah ill put some pics up.

3. Pinion is still tight with good backlash. I wheel pretty hard and very often but i dont nessesarly abuse it to bad.

I would like to upgrade to something better 1 tons or something but not on my current rig. i just wonder if its something im doing or not doing. Ive had youkons and genuine gear sets and broke them both. Other ppl dont have problems good example is Odie, 42s on his red toy with 5.29 genuine gears and hes on 7years on them.
 
I think its actually the area of the carrier that flex's. Look at what, the taco diffs with the cross supporting on the carrier bearing assy--those seem to hold up alot better than the mini truck stuff. The whole works really is a tuna can.

Bottom line--if your exploding parts on a regular basis--any setup in the world isn't going to make up for small parts...

I also have been using the same 3rd everytime, maybe something is wrong with that?? Ill use a different one this time around.

I would like to use bigger parts but doesnt seem like 38s, duals and a tired 22r would be reason for the breakage.

And i do have some axle wrap but not to excessive.
 
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put 4.7"s in the back case and run a ring and pinion in the 3's. V6 thirds as well. 5.29 are :rb:
 
i would say its just cause its small parts. i had toyota axle and couldnt keep gears together in mine either also broke a couple lock rights and aussie locker. this is why i sold my toyota crap and am working on getting all new stronger parts.
 
I also have been using the same 3rd everytime, maybe something is wrong with that?? Ill use a different one this time around.

I would like to use bigger parts but doesnt seem like 38s, duals and a tired 22r would be reason for the breakage.

And i do have some axle wrap but not to excessive.

I am willing to bet the housing on the third is ok esp. if you are getting good patterns with your setups.
 
hey your brother told me once that you run bobbys u joints , bobby told me they are so strong that your ring and pinion become the weak link .just came to mind.when i got my axles i told bobby i wanted everything he had so it wont break .im not broke yet but i am on small tires still .
 
This thread is hilarious. Anyone using a crush sleeve is just lazy. That is why they were invented. To save time in setup. Everyone knows that a diff that sees anything but a mall parking lot with a crush sleeve will fail prematurely.

As for the original question? Toyota differential parts are small. It's time for 60's.
 
doesn't the ring gear tend to move away from the pinion under load? I know it's only a very small amount but when you couple that with pinion gear deflection and a ratio that toyota never really intended for that design your gonna have some problems when you add bigger tires and agressive use.


swap some lower case gears in and go 4.10 in the diffs or drop the coin on some 60's
 
4.10's still break, just a cheap fix especially if you run welded diffs.

Downside is your front toyota tcase output is the next weak link if your running Bobby's rear output.
 
are u running a maual trans? i assume you are.
the manual puts alot of shock on the drivetrain. add that with the wheel hop, the size of the tires, aswell as the components themselves...and u get busted parts.

i think an auto would let them live just a bit longer tho.....
 
are u running a maual trans? i assume you are.
the manual puts alot of shock on the drivetrain. add that with the wheel hop, the size of the tires, aswell as the components themselves...and u get busted parts.

i think an auto would let them live just a bit longer tho.....
next issue.. auto tranny problems.

i just don't like em
 
I wheel pretty hard and very often but i dont nessesarly abuse it to bad.

Theres your problem. As long as its setup decent you only have yourself to blame. Bottom line - toyota **** is small and will break when used hard.

This is the answer that i have been trying to ignore and avoid. But it is very true and probably the one and only reason:booo::booo:
 
I have a guy that will redu ur gears. he has like a computer in his brain. he has done many and is very smart.
 
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