Plug and bolt size for stock 11.5 diff cover replacement

[Oliver Closehauf]

Anyone know what the stock plug and bolt size is for a stock replacement differential cover for a 11.5" rear differential?
I'd like to try and source some new replacements. All of the combo kits seem kinda pricey.

 

[HemiLonestar]

2005 Dodge Ram 2500-3500 Parts Manual

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[Oliver Closehauf]

Thank you sir. I used it to look up the part numbers. I wish the Mopar sites would just say what size the bolts are. 1/4 20 x 1/2 inch or whatever they are. Would rather not pull one to find out.

Apparently the cover bolts are made of moon metal. Over 5 bucks a piece from Mopar. If I have to pay that I'm going with stainless allen heads. Found the plug for 7 bucks.

 

[Oliver Closehauf]

Think this is it.
m8x1.25mm cover bolt for gm 7.25 7.6 8.0 8.6 9.25 9.5 14t & 11.5

 

[GTyankee]

Depending on the year of the differential
The hardware may be SAE & not Metric thread

For instance, the last year for the 9.25 AAM rear differential was 2010, they still used SAE hardware

In 2011, Chrysler began using ZF 235 MM, ( 9.25 ) rear differentials,
The hardware was all Metric

I have not looked up the 11.5 rear differentials

 

[HemiLonestar]

Thank you sir. I used it to look up the part numbers. I wish the Mopar sites would just say what size the bolts are. 1/4 20 x 1/2 inch or whatever they are. Would rather not pull one to find out.

Apparently the cover bolts are made of moon metal. Over 5 bucks a piece from Mopar. If I have to pay that I'm going with stainless allen heads. Found the plug for 7 bucks.

Just buy one and then match them up.

 

[Oliver Closehauf]

I found them. M8x1.25x20. Buck a piece. Bolts on Amazon

 

[Mister Luck]

Depending on the year of the differential
The hardware may be SAE & not Metric thread

For instance, the last year for the 9.25 AAM rear differential was 2010, they still used SAE hardware

In 2011, Chrysler began using ZF 235 MM, ( 9.25 ) rear differentials,
The hardware was all Metric

I have not looked up the 11.5 rear differentials

On my 2016 ZF 9.25 limited slip the cover uses BPT

I ordered a set of 12 Differential Cover Bolts (60337000) from MOPAR PARTS GIANT
Brought out my thread pitch gauges and thought this will be basically 1.25 metric 8mm
But No


The Flange Bolts are width 5/16” X 18G X Length 1/2”


What is 18G I asked myself
I learned it is a standard G “general grade” is a British “Whitworth 55 degree “ pipe thread which is almost 1.5 pitch metric but has more taper even though it’s referred to as a “Parallel” pipe thread because it only holds a slight taper.

There are many different diffs out there and depending upon parts availability at the time of production its a good idea to positively ID the suitable replacement fasteners.

I wouldn’t know know the difference myself if it wasn’t for family members with engineering degrees and the access to the proper inspection tools.

 

[Oliver Closehauf]

They were the metric bolts.

 

[Oliver Closehauf]

So, I went from this




To this




And I live in the city where the truck sits 8-10 feet above the street so it does get seen. The old one was a LOT worse. I knocked most of the rust off and hit it with rust converter last year. It didn't sound healthy.