Ring gear bolts sheared off

[paul blair]

Originally Posted by AussieinNC

It looks like the bolts bottomed out in the gear without clamping fully against the carrier surface...make sure the bolts are not too long...
also...

not sure original bolts were correct grade...its not that easy to drill a true grade 8 bolt...these looks like grade 5 hardware store quality...

Thanks for your input--this is one of the bolts

[AussieinNC]

That bolt has been bottomed out and the carrier has been working back and forth against the threads...

see the mid area of the threaded section....

Did I see you were going to use 1 1/4" bolts ?

I believe these bolts should be:

Head Style: Hex
Thread Size: 3/8-24 in. RH
Underhead Length (in): 0.875 in. or 3/4"...

not 1 1/4"

I would be double checking the depth of the holes then add the thickness of the carrier section...

I believe 1 1/4" will be too long...

[paul blair]

Originally Posted by AussieinNC

That bolt has been bottomed out and the carrier has been working back and forth against the threads...

see the mid area of the threaded section....

Did I see you were going to use 1 1/4" bolts ?

I believe these bolts should be:

Head Style: Hex
Thread Size: 3/8-24 in. RH
Underhead Length (in): 0.875 in. or 3/4"...

not 1 1/4"

I would be double checking the depth of the holes then add the thickness of the carrier section...

I believe 1 1/4" will be too long...

There is a spacer for the thin 488 gear so the bolts are longer, seem to have enough depth in ring gear!

[AussieinNC]

Ok...a 1/2" spacer is really thick...

Is there any way you can replace the gear set with a "thick 4.88 gear"...

Adding a 1/2" spacer increases the leverage point against the bolt shanks...you can see the wear on the original bolt where the spacer allows the movement that will eventually break yet another set of bolts...

Are the holes in the spacer plate elongated due to the earlier failure?

[paul blair]

Originally Posted by AussieinNC

Ok...a 1/2" spacer is really thick...

Is there any way you can replace the gear set with a "thick 4.88 gear"...

Adding a 1/2" spacer increases the leverage point against the bolt shanks...you can see the wear on the original bolt where the spacer allows the movement that will eventually break yet another set of bolts...

Are the holes in the spacer plate elongated due to the earlier failure?

I have to reassemble with a new spacer and bolts so it can be driven to a shop for a new pinion and thick gear! The owner wants to up grade to all new some time. We live on a small island so no qualified shops here, maybe change every thing inside this winter. IS THE BOLT PICTURED GRADE 8 ?

[AussieinNC]

Originally Posted by paul blair

I have to reassemble with a new spacer and bolts so it can be driven to a shop for a new pinion and thick gear! The owner wants to up grade to all new some time. We live on a small island so no qualified shops here, maybe change every thing inside this winter. IS THE BOLT PICTURED GRADE 8 ?

The bolt head is stamped with six dashes which is the usual standard marking for Grade 8...

see : http://www.globalspec.com/learnmore/...asteners/bolts


I have seen foreign knockoffs stamped the same that were below grade 5...

The fact the threads on the shank are rounded off from the spacer plate tell me to suspect the actual grade...

Have you considered changing the carrier out to a series 4? style over the current series 3 you have in there?

[paul blair]

Aussie, So a series 4 carrier would eliminate the spacer even with a thin gear? I will check the thread depth to make sure bolts don't bottom out. The bolts I drilled out seemed soft and didn't have that sound of hard steel. Since the pinion and ring gear are ok, going to use ARP bolts for now. I am surprised this set up has lasted for 20+ years of tire burning and beach riding. Might change to all new correct parts this winter. THANK YOU for YOUR TIME AND INFORMATION! HAPPY TRAILS P.B.

[AussieinNC]

Check out this website especially Tip # 12...

https://www.markwilliams.com/bulletproof.aspx

You could use the original ring gear without the spacer if you moved to a series 4 carrier...assuming it is usable long term...

Stay safe mate !

[mike16]

I sell spacer deletes. 124.99 plus shipping. pm me. special hardware 34.99

ha ha ha ha ah. I think I wet my self

[snipescastle2]

Just curious, this may have been mentioned already, but is this a true 12 bolt "Truck" carrier? They are different and that may have placed the ring gear bolts too close to the bearing cap/differential case causing them to shear off....just a suggestion.....

Ben


P.s. If the passenger carrier was used, what happens is the ring gear bolts crash into the pinion gear, was there any scrapes/ gouges in the pinion gear at all?

[paul blair]

Originally Posted by mike16

I sell spacer deletes. 124.99 plus shipping. pm me. special hardware 34.99

ha ha ha ha ah. I think I wet my self

Hi Mike, Sorry if my dumb question made you wet yourself, I should have edited that part of the question ( it was stupid and funny at the same time )Well at least you got a good laugh out of it.

[paul blair]

Originally Posted by snipescastle2

Just curious, this may have been mentioned already, but is this a true 12 bolt "Truck" carrier? They are different and that may have placed the ring gear bolts too close to the bearing cap/differential case causing them to shear off....just a suggestion.....

Ben


P.s. If the passenger carrier was used, what happens is the ring gear bolts crash into the pinion gear, was there any scrapes/ gouges in the pinion gear at all?

Series 3 carrier with a spacer and a thin 488 gear some one installed. It lasted more than 20 years with heavy beach use and some tire burning. Only a couple small dings on the carrier and housing from the broken bolts and no gear damage. No Loctite on bolts! Not a good set up!

[mike16]

Originally Posted by paul blair

Hi Mike, Sorry if my dumb question made you wet yourself, I should have edited that part of the question ( it was stupid and funny at the same time )Well at least you got a good laugh out of it.

It was funny. Same sort of jokes went around in the corvette community about a guy with an origonal spare tire, unused, We thought it would be funny to sell the air from it in 1 lb plastic bags. It was even suggested there might be a part number for origonal air from the spare tire. It was not dumb or stoopit. just funny .

I saw the same thing happen to some contruction equipment. The bolts were not tightened properly and backed out. Its easy to tell what caused it. if you have the actual failed parts in front of you and a factual history of the rear.

Its hard to tell what happend unless you can inspect each part carefully. I have had a rear end specialist do 3 rears for me, he always insisted that he would never install a spacer, better to get the correct parts to begin with.

that belief was further strengthened when I saw the prep that needed to be done to the parts, including a spacer, to another rear that I saw being assembled. the mating surfaces of the carrier, the spacer and the gear all had to be deburred to an almost polished quality, otherwise everything would tourque up according to specification but the burrs and uneven mating surfaces would "crush" a bit and the parts would start loosening up and moving around. any wear on mating surfaces would reveal that. If the bolts simply loosened up and backed out specific and certain damage to the bolt and its head would reveal that. several other possiblilties.

a reliable rear end specialist will be able to diagnose the fault. May be able to avoid it when the rear is rebuilt.

Half off on those spacer delete's if you buy two

[toolboxchev]

All I can say is freakin wow man, that is some serious force to shred that thing!