M998 Rim Offset Bolt Pattern

[Agelai]

I'm looking to possible get some aftermarket wheels and tires, but I need to know what size or offset is for the M998.

Help....

Or does a specific truck have the same setup that I could use as a reference?

 

[TOBASH]

Just remove a rim, use a flatedge to measure from the inner rim to the 8 bolt holes... that is your offset.

HMMWV/M998 rims are 16.5 inch rims that require a beadlock component for safest use, especially if you plan to air-down for offroading.

H1 sold 16.5 and 17 inch CEPEK one piece rims that will fit. CEPEK rims are available new from CEPEK and used all over FleaBay.

H1 sold 17 inch 2 piece alloy Hutchinson rims. They are more pricey. Much more pricey. They are available used all over FleaBay.

ModMafia sells brand new Hutchinson rims for like $8000 a set, but MM are known for their prices.

You can also look up offset in the Search function along with the many threads about just this question to see what others have done. There are literally dozens of posts.

You can also look up size and spacing in the free for all user TM's/Technical Manuals.

 

[Agelai]

I must be bad at searching, because I didn't find much.

I am wanting to switch to an 18 inch, but couldn't find much on what bolt pattern I needed to go with.

 

[springer1981]

Here's a post I did a few years ago but all the info is still good. The attached pdf gives a bunch of measurements and sizes. https://www.steelsoldiers.com/threads/my-new-1992-m998-avenger.184818/post-2210080

 

[Action]

Same as Hummer H1.

 

[Mogman]

Same as Hummer H1.

Yes same offset, yes the search engine on this site sucks, you can usually find threads on this site with a GOOGLE search much easier.

 

[Maxjeep1]

I believe it’s 8 on 6.5 with 7” backspacing.

 

[gringeltaube]

.......... I need to know what size or offset is for the M998

See this post...

 

[Mogman]

See this post...

Great, it shows the difference between backspace and offset!! easy for all to understand

 

[Agelai]

Same as Hummer H1.

Really? So if I do a search on say Tire Rack using the H1, it would match up?
Is there a specific year or model I should use?

 

[Action]

Really? So if I do a search on say Tire Rack using the H1, it would match up?
Is there a specific year or model I should use?

Yup. OEM or Cepek are the only ones I can think of right now.

 

[Agelai]

Yup. OEM or Cepek are the only ones I can think of right now.

Cepek and OEM are the only rims that fit?

 

[Agelai]

We saying these will fit my M998?

Fitment | BLACK RHINO Wheels

 

[Mogman]

Yes the BR will fit, many have them, personally I don't like the fake bolts, I think the 24 bolt OEMs are SEXY!

 

[springer1981]

Cepek and OEM are the only rims that fit?

In the link I posted above there is a PDF file attached. In the PDF file there is a list of Common Rim Sizes available in 8x6.5" bolt pattern. There is also a list of Brands and Model of wheel that match the rim sizes. In the lists it gives the offset in mm and the back spacing in inches. There is a column I created called "extended width". The extended width is how much beyond the stock wheel that rim will stick out. For example if the extended width is 1.00" then the wheel and tire will stick out 1" further than stock on each side.

There is also a list of tires choices in 37" (stock size) for 17", 18" and 20" wheels.

That list was created in 2019 so some of the wheels or tire may be discontinued or others may be available now but it should help understand what sizes will fit etc.

Note 8x6.5" and 8x165.1 are the same size. The 165.1 is the mm equivalent of 6.5"
Also note the hub bore of any rim will need to be 117mm minimum to fit.

 

[TOBASH]

Most aftermarket rims stick out. That places stresses on the spindles and they can break or pull out. We don’t have true solid axles, so wider offsets stress the hub spindles adding to risk of failure.

You need BlueHummers. They prevent the spindle from pulling out of the hub. They are $600 from ModMafia. Most important upgrade you can make.

EDIT - Pictures below from a Civilian Hummer H1 hub failure. They use the same exact hubs. Notice the aftermarket rims.

 

[Action]

lots of other rims will fit the bolt pattern bur are not correct specs.

 

[Agelai]

Most aftermarket rims stick out. That places stresses on the spindles and they can break or pull out. We don’t have true solid axles, so wider offsets stress the hub spindles adding to risk of failure.

You need BlueHummers. They prevent the spindle from pulling out of the hub. They are $600 from ModMafia. Most important upgrade you can make.

EDIT - Pictures below from a Civilian Hummer H1 hub failure. They use the same exact hubs. Notice the aftermarket rims.

Are these them? https://modmafia.com/product/bluehummer-locking-differential-mounting-bolt-kit/

 

[TOBASH]

Are these them? https://modmafia.com/product/bluehummer-locking-differential-mounting-bolt-kit/

No buddy. Look at these:

Geared Hub Parts Archives

modmafia.com