Rotoflex Installation Instructions

[jcocking]

The discussion of the installation of Rotoflex Donuts was a topic of interest on the mail list recently. What do we need to change on the instructions to make it easier. Give your feed back.

The overall installation of the Rotoflex Donuts are:

• Install the donuts to the half-shafts </li>
• Mount to the inboard side/differential </li>
• Mount outboard side</li>

Wait! While rotoflexes are out, take the opportunity to check condition of differential output bearings and hub bearings. Rotate by hand and listen for dry rubbing sound or roughness. If in doubt, replace the bearings.

Installation tips:

• Keep the half-shafts in a parallel position. </li>
• Use hose clamps to expand and contract the diameter as necessary (I find it's actually easier than with the fixed diameter band.) Initially tighten the hose clamp as tight as can be done by hand. Check for size by fitting the shafts to the donuts with the correct fastener. ( two inch hose and four inch hose clamps strung together work fine. 18 inches total are needed) </li>
• Use at least AN spec bolts or better. </li>
• The use of a pilot bolt, to protect the threads on the long term bolts, is recommended. </li>
• Placing items in the trunk to assist loading down the car will help.(Comments of 200kg of fertilizer) </li>
• Remember to be safe. You will be under a vehicle with the suspension system in a load condition. This is potentially dangerous. </li>
• The metal bosses are offset in the rubber, three each way, and it is the HIGH bosses on each face that contact the drive shaft flanges. </li>
• When fitting bolts, their heads must be contact with the LOW bosses in the couplings. The exception to this is the bolts which secure the brake disc and coupling to both the outboard and intermediate drive shafts, when all bolt heads are towards the wheel. </li>
• The three bolts through the brake disc are 3.25inches by 7/16 UNF, and are longer than the other bolts.</li>

Instructions:

1. Mount the donuts on the halfshafts and tighten. Some have suggest that it was easier to assemble the donut to the outer drive shaft/brake first, then to connect the half shaft to the outer donut last. You can do the outer donut/brake while the stuff is still on the bench, much easier than while laying on your back.

2. Install the half-shaft/donut to the differential/inboard.

3. Now the fun part, the outboard side with the brake disc and hub fork. With the car up on four jack stands lift the rear wheel until the frame just leaves the surface of the jack stand (maybe 2 tp 4 mm), this puts the wheel at almost exactly the right height for the final assembly. As you raise the axle you need to "rotate" the drive shafts and the wheel to get the half shaft into a mating position (interleaved between the other bolts). Hang brake disc over stub axle fingers, don't bolt up yet (but now is good time to check rotor runout with temporary short bolts).

4. Some levering with a big screwdriver or pry bar may be required. Be sure you get rotoflexes and bolts in correct orientation (see manual).

5. Install a bolt such that it passes thru the "lowest" hole in the Rotoflex and the "highest" hole on the outboard stub axle. Now it gets harder...Rotate the shaft and axle so that next two holes line up and install another bolt. You will notice that the Rotoflex doesn't really want to "flex" - this makes it difficult to install the bolt - you just have to work at it. Then repeat for the last bolt. The hose clamp comes in handy during the last stages, since you can use the clamp to "adjust" the diameter of the Rotoflex. It takes a lot of effort, but it will just fall into place...By allowing the wheel to have movement, it will be easier to rotate the outboard mounting locations.

[1964 S1]

GREETINGS, I HAVE FOUND THAT CLAMPING VISE GRIPS JUST BELOW THE BOLT HEAD, IN A STRAIGHT LINE WITH THE BOLT, AND USING THE VISE GRIP AS THE HANDLE LETS ME STEER THE BOLT INTO THE OUTER ROTOFLEX AND PUSH IT THROUGH WITH RELATIVE EASE. I'VE ONLY DONE THIS ON A PLUS 2 AND IT WAS ALMOST EASY. I NEVER TIGHTEN ANY OF THE BOLTS/NUTS UNTIL I HAVE THEM ALL STARTED. GOOD LUCK...