Mercruiser Alpha One Replacement Upper Unit 1.81 w/ Short Yoke

Sterndrive Engineering Mercruiser Alpha One Replacement Upper Unit 1.81 Ratio w/ Short Yoke1.81 ratio also replaces the 1.84 ratioComes with an [old style] 8-1/8″ input yoke.This drive is generally used on older inline 6 and 4 cylinder engines.For Alpha One Gen I Sterndrives 1972-1990.3 Year Manufacturer’s WarrantyApplication:Model: 470Year Range: 1976-1982Serial Range: 4208730-6225576Model: 485Year Range: 1980-1982Serial Range: 4893835 and upOE#: 5523A67Item is subject to a 20% restocking fee (Boat Covers, Bimini Tops, Outdrives, Drop Ship Items and Special Order Parts)!**Year, Serial Number, and Horsepower are required to order. Please contact us with this information after you place your order otherwise processing will be delayed.How to Install Sterndrive Engineering Short YokeFirst, determine the length of your yoke. Newer styles are 9-9/16″ and older styles are 8-1/8″. Remove the clips that hold the u-joint together. You can use a screwdriver to push on it to make removing the slips easier. You may need to use the screwdriver on both sides.After the clips are out, use a hammer to tap the u-joint in one direction until you can remove the cup on the opposite side. Use a suitable socket so you do not hit the yoke with the hammer. If the seal is stuck to the u-joint, use a small pick or screwdriver to remove it.Using a socket of the appropriate size, pound the u-joint in the other direction. The purpose of the socket is so that you don’t hit the u-joint post with a hammer. The socket should fit over the post and contact the body of the u-joint before the post.With the yoke out of the way, you can start reassembly. Install both u-joint clips and the u-joint and check to make sure they rotate smoothly. If everything looks good, take them off. If you’re experiencing rough rotation, your u-joint will most likely need to be replaced.Install the yoke over the posts of the u-joint then insert both u-joint clips while centering the yoke.Tap the u-joint together. You may be able to tap one side in all the way and put the clip in, or you may need to tap each side in a little bit at a time.With both clips in, turn the yoke and see if it turns okay. If it is stiff, try hitting the opposite side.You will need to grease the u-joints using a grease gun and grease that is approved for u-joints.Sterndrive Engineering Model ChartRefer to Sterndrive Engineering’s model chart below to find your proper Mercruiser Sterndrive Replacement. These are typical applications; it is best to confirm your ratio by couting the teeth in the upper. Although great care was taken in the creation of this guide, its accuracy cannot be guaranteed.ModelYear RangeSerial RangeNotes (See Below)Standard RotationCounter Rotation120,1401967-19692062141-27919561,2,3,4,5,61.941.94 CR120,1401970-19822791957-62255762,4,5,61.941.94 CR1601967-19692065190-27634411,2,3,4,5,61.621.62 CR1651970-19772763442 and up2,4,5,61.621.62 CR225-S19743856268-42004994,5,61.471.47 CR2331975-197742005004,5,61.471.47 CR25019774791300-48987294,5,61.471.47 CR2601978-19824898730-62255764,5,61.471.47 CR4701976-19824208730-62255762,4,5,61.811.81 CR4851980-19824893835 and up2,4,5,61.811.81 CR8881971-19773106717 and up4,5,61.471.47 CR898/2281977-19824782330-6225764,5,61.