G2 Axle & Gear Hammer GM 10 Bolt 8.5" Differential Cover (Gloss Black) - 40-2021ALB

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  • G2 Axle and Gear | Part Number: G/240-2021ALB
  • Popular Axle Manufacture:GM
  • Axle Location:Rear
  • Fitment:Universal Fit
  • Finish Type:Powder Coated
  • Type Of Material:Aluminum
  • Axle Type:GM 10 Bolt 8.6 Inches|GM 10 Bolt 8.5 Inches
  • Oil Capacity:Extra Capacity


G2 aluminum differential covers are designed to not only protect your ring & pinion, they are designed to help cool your gear oil for prolonged bearing life. Made from high strength heat treated aluminum to withstand direct hits, these covers help protect your investment while adding a distinct look to your vehicle.

Customer Reviews

3.8 3.8
6 Customer ratings

Customer Images

5.0 Easy access for maintenance

Looks great and easy access to drain and fill for my next differential fluid change, just don’t over tighten the drain or fill plug

from Texas |
4.0 Very easy install

Very easy to install. It came with both full set of bolts SAE & metric, just in case! Just a little Dremel grind to brake bracket and it too fit like a glove. Very happy to have this now on my truck....keeping it cool!

from Boerne, Texas |
5.0 G2 Diff cover

Super sick product . Fit perfect on 2005 Chevy avalanche . Looks sweet

from California |
3.0 G2 Differential cover

The product is well made however, the gm 10 bolt cover is advertised as extra capacity. It is in fact stock capacity as confirmed by G2. It also shows that there is a dipstick to check fluid levels, when in fact there isn’t one just simply a fill plug. If looking for extra capacity and cooling for towing go with the brute option.

from Ontario |


Question & Answers

16 Answered questions

Q: Will it fit 1977 Chevy 4x4 Blazer? Answer this question

A: I’m sorry I’m not sure if this will fit on your trail blazer. I installed it on my 2006 z71 suburban 1500 4x4. It fit perfectly. The only thing I wish were different was the magnet that it has on it.  It’s way to small to collect any metal shavings. 

Answered by Joycejeff38 from Orange County, California on 04/23/2021

A: There were multiple rear axle options. This cover fits the GM 10 bolt one. Please call our sales line toll free at 1-877-474-4821 if you need further assistance

Answered by Brent from 4WP HQ on 04/23/2021

Q: Will this fit on the front axle of my 87 Silverado ?  It is a gm 10 bolt I’m more concerned about clearance for the tie rod.  Thanks for any help  Answer this question

A: No, it will not fit. It is a different shape.

Answered by Kelly from 4WP Corporate Headquarters on 05/11/2021

Q: Will this fit 94 impala Answer this question

A: Hello Bart, We apologize for the delay in response. That diff cover should fit the Impala, its a 10 bolt. Feel free to call into the sales line to place an order. If you live near a store you can set it up for in store pick up. Sales & Support Toll Free: 1-877-474-4821 Phone Sales (PT) Monday - Friday: 5 a.m. - 7 p.m. Saturday: 7 a.m. - 3 p.m. Sunday: 8 a.m. - 2 p.m. Customer Service (PT) Monday - Friday: 6 a.m. - 5 p.m. Saturday: Closed Sunday: Closed Thanks!

Answered by Kelly from Ohio on 09/29/2020

Q: Will this fit my 2010 Chevy Silverado 1500 Z71 5.3L? Answer this question

A: Thanks for the inquiry The Real Deal, the G2 Axle and Gear GM 8.5in./8.6in. 10 Bolt Aluminum Cover Black part # G/240-2021ALB will fit a 2010 Chevy 1500.

Answered by RK on 03/27/2015

Q: not sure which size rear diff i have.will this unit fit my 2005 H2? Thanks, Alex Answer this question

A: Sir, unfortunately we don't have a diff. cover that will fit the H2 due to the Track bar being so close to the diff. cover.

Answered by RK on 03/26/2015


G2 Axle & Gear uses the strongest and latest generation materials to manufacture products capable of handling heavy loads. When it comes to axle assemblies, core lockers, driveshafts and sway bars, G2 is the first name in durability and reliability. Off-roading can heap punishment on a Jeep and G2's laser-cut components offer superior handling on challenging terrain and on-road drives. Parts are easy to install and easy to service and above all, they remain operational in adverse environments. Shop G2 Axle and Gear Now


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