- EXCEL GM85456, Differential Ring & Pinion, For GM 8.5"/8.625", Gear Ratio: 4.56, 10-Bolt, 30 Spline, 9 Pinion & 41 Ring Tooth –Fits Chevrolet, GMC, Cadillac & More, Replaces USA Standard ZG GM8.5-456

Bought this ring and pinion gear set to re-gear my 10 bolt gm 8.5. Purchased it due to the price and the three 5 star reviews it had. Just picked it up from the shop, the mechanic said it had a good pattern but sounded a little rough. He told me there was nothing wrong with it, it just didn't have a quality finish like the other high dollar brands out there which leads to a noisier gear but it could quit down after break in period. After driving it 30 miles home, it did fine. I could feel slight vibration and a more moderate vibration when turning. Everything was put in right with the correct additive for my carrier. I hope once the gear set is broke in that the vibration subsides. Other than that, the gear set they sent did not match the beautiful picture listed as the product. The gear set I got was a darker metal with tons of oil and some small other plastic like adhesive stuck to a few gear teeth. This is why I gave this product just 2 stars. Shipping was fast and simple. I will update this review once break-in process is completed.Update1-Ihave drove 150miles so far and the ring and pinion has quited down a bunch, its non noticeable. I give them 4 stars now and not 5 due to the gear set I received did not look like the picture listed. I ordered the 4.10 for gm 8.5. Hope this honest review has helped.Update2-6k miles, no sound, no vibrations. So far so good!

This product was just right. I had not one problem with it. This was everything that I had hoped for and it fit perfectly.

Installed Summer before last and it still works perfectly. Just make sure you know how to install these gears.

Had the kit installed professionally and am very pleased with the results. Great product.

great product, fast shipping, very happy....thank you!

Great product

Brand name part. Motive Gear, Exel by Richmond, and Richmond Gear. Same company, maybe different tier of quality. OEM grade so no high hp with this ring.