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Model # 8808CB

Internet # 100431683

Store SKU # 294733

8 ft. Belt-Drive Extension Kit

This item has been discontinued.
The Home Depot no longer carries this specific product.

$47.99 /each


Model # 8808CB

Internet # 100431683

Store SKU # 294733

The Chamberlain 8 ft. Belt-Drive Extension Kit is compatible with Chamberlain's Whisper Drive and Whisper Drive Plus belt-drive garage door openers. It comes with a rail extension and replacement belt and can be used with garage doors up to 8 ft. high.

  • For use with garage doors up to 8 ft. high
  • Compatible with chamberlain whisper drive and whisper drive plus belt-drive models
  • Kit includes rail extension and replacement belt
  • Comes ready to install with complete instructions

Info & Guides

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Maximum garage door height (ft.) 
Product Depth (in.) 
Product Height (in.) 
Product Width (in.) 
Rail extension length (in.) 
Brand/model/year compatibility 
Drive System 
Garage Door Part/Accessory Type 
Extension Kits 
Product Weight (lb.) 
4.8 lb 
Warranty / Certifications
Manufacturer Warranty 
1 year 


Rated 4.4 out of 5 by 21 reviewers.
Rated 4.0 out of 5.0 by Easy to install, works great. Works great for a 8' door. easy to install. well made product. July 29, 2015
Rated 1.0 out of 5.0 by Did NOT Fit Spent all morning prepping the garage and laying out the pieces. Turns out, I bought a newer version of the garage door opener, unfortunately, the extension kit is not compatible and is from an older version. Turns out, home depot does not sell the new version. Its a shame that Home Depot does not confirm these sort of things. This wasn't an isolated incident as I went to another home depot, bought a another extension kit, and the issue is the same. The pieces will not fit. It took me a while to explain this to chamberlain...they confirmed the incompatibility...and now I get to way 2-3 weeks for a new part to come in. What a waste of a day! Buyer Beware. December 18, 2014
Rated 5.0 out of 5.0 by Exceeded Expectations Replaced 9 yr old Chamberlain chain drive with new belt drive. Unit shipped early, I installed it by myself using the old Chamberlain mounts, took 1.5 hrs. New unit very easy to program and extremely quiet operation! Extremely pleased with the whole experience. One small complaint - Chamberlain should offer separate 7 ft and 8 ft units. The standard garage door is now 8 ft and forcing customers to purchase the 8 ft extension kit is a total waste of resources (the included 7 ft bar and belt goes into the garbage) Just charge more and offer a standard 8 ft unit. May 12, 2015
Rated 5.0 out of 5.0 by Works perfect for my 8' door The 8' extension kit worked perfectly for my opener, but is definitely overpriced at $49.99. It should be much closer to half that price!! May 26, 2015
Rated 5.0 out of 5.0 by Must Purchase for 8' Tall Door Yes, you MUST purchase this kit if you have a garage door that is 8' tall. Be sure to use the tensioner spring enclosed in this kit because the belt is longer and needs increased tension to keep it from sagging on open and close cycles. The instructions are ample and especially easy to follow since most are installing a new opener at the same time. It would be nice if there was an option to purchase an opener specifically for 8' doors so you don't end up with an extra belt an track parts but until then this is the only option. March 25, 2015
Rated 5.0 out of 5.0 by Excellent & back saving install This product was very easy to assemble And has become a back saving friend. My family moved into the rental only to find the door was installed and nothing else. With my family having various medical issues, I felt I needed to step in and install it to prevent any further medical issues. Since then it has been a very helpful equipment. Highly recommend this very quiet operation and the ease to monitor the door owning and closing on the smart phones too March 24, 2015
Rated 4.0 out of 5.0 by This is a solid machine I am very happy with the final result, however, I had to replace a control board and put grease on the sprockets on two of the three openers I installed. There appears to be a quality control issue with these openers. Customer service was very knowledgeable and helpful. They sent out the new control board and a repeater quickly at no cost. The control board was difficult to install though. The repeater was needed since I have one older car. March 25, 2015
Rated 4.0 out of 5.0 by Good value if you already have the opener -- otherwise don't. I believe my situation is rare/unique. I had replaced the garage door (7ft height) and opener (Craftsman) on my old home. I then purchased a new home 2 months later. It was too late to return the opener, but I didn't want to just leave it -- it had fancy features such as battery backup and iPhone integration. So I swapped openers between the homes. However, I discovered that the new home had an 8ft door, and I needed an extension kit. I couldn't find a Craftsman extension kit in stock, so I bought the Chamberlin extension and installed it, and everything works okay. There is a bit of flex in the middle of the rail assembly when opening the door. I would say the extension is a valuable way to save an existing door opener. However, if you are buying a new opener, don't bother with the extension kit. You can get an opener with 8'ft long one-piece rails from any reputable garage door installer/vendor. If I didn't already have the opener I would have rather purchased a one-piece unit. They are much stronger. So I would say the value of this product depends heavily on whether you're replacing the opener (don't do the extension) or if you already have an opener you want to save (extension works okay). May 27, 2014
  • 2015-09-02T11:42:10.280-05:00
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