Area51 Project Foreman - WARN 424 Shifter:

 

Installation and 424 Rebuild

 

The WARN 424 shifter kit replaces the front drive shaft with one that can be engaged and disengaged via a handle will will allow you to run your full time four wheel drive bike in two wheel drive at your own choosing. WARN has since discontinued these units, but a company called Wide Open is producing these exact kits under their own brand. Since they are the same, replacement parts & rebuild kits for the new units fit the old WARN units perfectly.

I originally installed my WARN 424 in somewhere around 2000 or 2001. On one of my rides in the summer of 2012 I started having trouble getting the shifter to lock in 2wd. This unit is a great design, if the cable or handle fails, a spring will keep the unit locked in 4wd, which is much more desirable if it breaks in a hard spot! My unit was over 10 years old and had never caused trouble or required service until now, so I thought it was time for a rebuild. This project will show you how to install a WARN 424, as well as rebuild one.

 

To take out the existing driveshaft (in this case my broken 424) you remove the Left Front wheel, the black lower fender as well as the inner fender. On a stock bike you also remove the black plastic guard covering the driveshaft. On a 424 unit, disassemble the handle and remove the cable routing it down through the frame for removal from the bike.

 

Next take out the 2 bolts that attach the foreword most differential mounting bracket to the frame of the bike. You can leave the bracket attached to the differential, just loosen the bolt so it pivots up out of the way. Remove the other 2 mounting bolts, the rear one is accessed from the front right wheel well, the last one is on top of the differential. With all the bolts out slide the differential, driveshaft and the coupler that attaches the shaft to the engine forward. There is a spring inside the coupler, you will need to compress it to push the coupler forward to disengage the splines from the engine. When loose, remove the coupler then the driveshaft from the bike.

 

To perform the rebuild of the 424 unit, there are instructions with the kit from wide open, but I recommend Google searching for the WARN instructions called "BEARING AND SEAL SERVICE KIT INSTALLATION INSTRUCTIONS."  These are much more clear, have better pictures and include steps that are necessary for proper reassembly.

 

To take apart the 424, you remove the 4 Allen or Torx head bolts. Once removed gently tap the housing to separate the 2 halves. My unit was full of dirty grease, water and silt and I found that my cable was worn through inside the unit. The worn out seals let in water and of course the bearings were completely fried. I ordered a rebuild kit from Wide Open which included a new handle, cable, bearings, seals and grease.

 

With everything cleaned in my parts washer, I was able to disassemble the shafts, remove the defective seals and bearings and press in the new ones with a mallet and my seal/bearing driver kit. Following the instructions I greased the new bearings, filled the void between the seal and bearing, and coated all internal parts liberally with grease. It is important here to follow the instructions from WARN to ensure that the correct shaft is installed in the correct case, and follow the installation directions so that the bearing does not move from its place in the housing as you install the shaft. Once both halves have been reassembled, the space inside was filled (but not completely) with grease before bolting the two halves back together.

 

The kit came with a new paper gasket, I chose to apply a very thin coat of automotive silicone to each side of the gasket. This helps keep the gasket in place during assembly and provides an extra measure of protection against water penetration.

 

With the new unit rebuilt, installing it is exactly the reverse of removal. I always apply grease to the splines on the engine output shaft and on the splines on both ends of the driveshaft. The only real difference between the WARN kit and the Wide open kit can be found in the design of the handle. the Wide Open handle is thicker and seems sturdier then the WARN handle it replaces. Therefore I had to drill out the hole in the handle mounting bracket as the body of the new handle is much thicker. I used a step drill that can bore holes in steel up to 3/4". The rebuild kit is a great product and I am glad to have a properly working, easily shifting 4wd selector on my Foreman.

Cheers, MIKE

 

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