First time ever replacing pads and rotors. Did not go well...

[Lunentucker]

21 and 23 both take the same size bolt (different part numbers?), so I don't know why they would have jacked the torque specs up +18 lbs. That seems like a lot. Perhaps they changed the grade of the bolt?

2023 - Rear caliper adapter bolt M12X1.5X30
2021 - Rear caliper adapter bolt M12X1.5X30

Sponsored

 

[ShadowsPapa]

21 and 23 both take the same size bolt (different part numbers?), so I don't know why they would have jacked the torque specs up +18 lbs. That seems like a lot. Perhaps they changed the grade of the bolt?

2023 - Rear caliper adapter bolt M12X1.5X30
2021 - Rear caliper adapter bolt M12X1.5X30

Weird - read the descriptions -

Now look at this one -

Both say caliper adapter, but then also rear tow hook, etc.

And was is 2021 that had the caliper bracket bolts coming loose and/or missing?
There's a TSB about that.

 

[XraytecH]

That's a fair bit over 74 - wonder if they changed bolt sizes?

Got a new set of bolts for the front and rear going with these torque specs.

 

[Lunentucker]

Weird - read the descriptions -

Now look at this one -

Both say caliper adapter, but then also rear tow hook, etc.

And was is 2021 that had the caliper bracket bolts coming loose and/or missing?
There's a TSB about that.

I do recall some reports for the caliper bolts being loose.
I never saw the TSB on it though. Would love to. If the torque specs need to be changed in the tables I can do that, but I want to see the documentation.

 

[Lunentucker]

Never mind.
I found it.
They added 3 mm to the bolt and upped the torque to 92. (PN 06513551AA still comes up as 30mm though)

https://static.nhtsa.gov/odi/tsbs/2021/MC-10204371-9999.pdf

 

[XraytecH]

Never mind.
I found it.
They added 3 mm to the bolt and upped the torque to 92. (PN 06513551AA still comes up as 30mm though)

https://static.nhtsa.gov/odi/tsbs/2021/MC-10204371-9999.pdf

Okay ?

 

[Lunentucker]

Okay ?

I wish I could tell you more.
I think 80 ft pounds with blue loctite would be my move.

 

[ShadowsPapa]

Never mind.
I found it.
They added 3 mm to the bolt and upped the torque to 92. (PN 06513551AA still comes up as 30mm though)

https://static.nhtsa.gov/odi/tsbs/2021/MC-10204371-9999.pdf

I'd like to see one of each side-by-side (bolt that is, not Jeeps)
Apparently since this applies to 2020-21 it makes me wonder if they decided the torque wasn't enough, and the added length if they actually are physically longer is either to engage more threads, or, to keep the bolt in the hole 3mm longer if it comes loose.

Is it the same class bolt, or a higher class?
Did they go from a class 10.9 (roughly equal to Grade 8) to a 12.9 or is the class the same? (12.9 not having an ASTM hex bolt equivalent)

 

[XraytecH]

I'd like to see one of each side-by-side (bolt that is, not Jeeps)
Apparently since this applies to 2020-21 it makes me wonder if they decided the torque wasn't enough, and the added length if they actually are physically longer is either to engage more threads, or, to keep the bolt in the hole 3mm longer if it comes loose.

Is it the same class bolt, or a higher class?
Did they go from a class 10.9 (roughly equal to Grade 8) to a 12.9 or is the class the same? (12.9 not having an ASTM hex bolt equivalent)

When I get go home I’ll post a pic of both the factory and the replacement.

 

[XraytecH]

I'd like to see one of each side-by-side (bolt that is, not Jeeps)
Apparently since this applies to 2020-21 it makes me wonder if they decided the torque wasn't enough, and the added length if they actually are physically longer is either to engage more threads, or, to keep the bolt in the hole 3mm longer if it comes loose.

Is it the same class bolt, or a higher class?
Did they go from a class 10.9 (roughly equal to Grade 8) to a 12.9 or is the class the same? (12.9 not having an ASTM hex bolt equivalent)

From left to right

New MOPAR bolt M12x1.5x30
Factory Bolt M12x1.5x30
Stretched Factory Bolt M12x1.5x30

All three are class 10.9

 

[ShadowsPapa]

From left to right

New MOPAR bolt M12x1.5x30
Factory Bolt M12x1.5x30
Stretched Factory Bolt M12x1.5x30

All three are class 10.9

So the new bolt and factory original are identical.
I'd double-check the torque wrench. I'd also use some Loctite knowing the history with these.

BTW - the one on the right is no longer class 10.9 - it looks more like no class.

 

[Gatorized]

From left to right

New MOPAR bolt M12x1.5x30
Factory Bolt M12x1.5x30
Stretched Factory Bolt M12x1.5x30

All three are class 10.9

Is that the new TSB bolt p/n 06513551AA, or just a new replacement bolt?

 

[XraytecH]

Is that the new TSB bolt p/n 06513551AA, or just a new replacement bolt?

Same as the factory bolt
Someone mention that the TSB bolt is 3mm longer

 

[ShadowsPapa]

What I'd find ironic is that Jeep is still selling the original and yet there's a TSB replacing that bolt with a new bolt. Normally you can then no longer get the original, it's superseded.

 

[FitfulGoat]

So the new bolt and factory original are identical.
I'd double-check the torque wrench. I'd also use some Loctite knowing the history with these.

BTW - the one on the right is no longer class 10.9 - it looks more like no class.

I’m not sure I’ve seen a better representation of single use hardware! I have owned a few cars that require new head bolts when replacing due to high compression and stretch. Amazing the forces these components undergo.

I’m getting close to the 60k mile mark and brakes are likely in the near future for me.

Sponsored