C5 Corvette M/T Differential Strut Installation Instructions

Transcription

1 1 P a g e 6930B Derek Dr. Fort Wayne, IN Phone: Fax: C5 Corvette M/T Differential Strut Installation Instructions Application: C5 Corvette with M/T using a 2 or 3 rib case with any gear ratio and 2.5 or 3 exhaust. Thank you for purchasing the HPE Differential Strut for the C5 Corvette! This product was successfully engineered by HPE to solve the problem of differential case fracture and/or transmission output shaft housing breakage caused by inherent driveline stresses present during high performance street driving, road racing, or drag racing. This kit increases the strength of that vulnerable attachment point of the transmission-to-differential to reduce the likelihood of fracture in that area causing complete trans/diff failure. The entire kit only weighs approx. 21 lbs. (about 3.5 gallons of gas) and is engineered to spread the stress loading during hard acceleration over a greater area of the driveline architecture. Kit Design Features: This design counteracts the natural upward "wrap-up" action of the IRS driveline during hard acceleration by tying the transmission and differential together via adjustable strut rods. These steel strut rods provide a pre-load against this destructive wrap-up action that causes differential case fracture at the trans/diff mounting flange. I n some severe cases, this fracture can also destroy the transmission output shaft. The installation of this product provides added rigidity to the entire Corvette drivetrain as a whole, while the steel perimeter brackets mounted to the transmission and differential cases act as case "girdles that provide additional strength in those areas. These steel "girdle" brackets spread the driveline shock loads over a greater surface area; therefore decreasing differential mounting flange cracks, decreasing case distortion, and increasing driveline durability. The differential bracket cross-strut rod counteracts any possible deflection between them by tying them together side-to-side. Each one of the four strut rods are secured to the trans/diff brackets via heavy duty heim joints at both ends, where each rod is independently adjustable to set a pre-load of the entire assembly at all 4 corners. Kit Packing List 3-piece differential girdle bracket set 2-piece Trans bell housing bracket set 4-piece main strut rod set 4-piece right hand thread heim joint set with lock nuts 4-piece left hand thread heim joint set with lock nuts 1-piece cross-strut rod Trans bracket mounting bolts/&washers Differential bracket mounting bolts/washers Cross strut rod bolts/washers 2 aluminum heim joint spacers Detailed installation instructions

2 2 P a g e BEFORE YOU BEGIN- Please follow these Instructions closely when installing this product and if you have any questions at all during the install, please call HPE to speak with someone who can answer the question for you. Also, be sure to support the vehicle evenly and safely with heavy-duty jack stands or a commercial vehicle lift before attempting this modification. If you do not feel you are mechanically inclined enough to perform, this Installation, please consult your local GM Service Technician or a trusted independent technician that's qualified to do the job. Finally, make sure the vehicle s battery is completely disconnected before attempting to install this product. Installation time is 4-5 hours on average. Vehicle Disassembly/Preparation: 1. Locate the rear transverse mounted mono-leaf spring that's located in the rear sub-frame area. (Fig. 1) 2. Locate the rear ride height adjustment nuts on each end of each spring and count how many threads are showing at its current adjustment. Write this information down, as you will need it for re-installation later. (Fig.2) 3. Release the spring tension slowly by using a support jack under one side of the spring at a time, loosening and removing the adjustment nut until the thru bolt can be completely removed. Gently and slowly lower the jack until all of the tension has been completely removed from the spring end until it's relaxed. Do the same procedure for both sides. (Fig. 3) 4. Remove the two upper and two lower anti-sway bar mounting strap fasteners on each side of the sub-frame and lower the anti-sway bar out of your way for now by swinging it down. (Fig. 4) 5. Remove the bolts that secure the over-axle pipes to the main center section of the exhaust system. (Fig. 5) 6. Remove the muffler assy. from each side of the vehicle completely to allow for maximum clearance when installing the differential strut. (Fig. 6) 7. Locate the four rear sub-frame mounting nuts that secure the sub-frame to the vehicle chassis and loosen all four of them until 1 thread is showing on the end of the stud. This step will drop the rear sub-frame down approx. one inch to allow for maximum clearance when installing the differential strut. (Fig. 7 & 8) *The vehicle ready for the differential strut installation. Transmission Bracket Installation on Transmission/Torque Tube Flange: *These installation procedures were completed on a sample transmission/differential assembly located outside of vehicle to better illustrate fitment procedures and to provide concise photos. 1. Locate passenger side of transmission mounting flange where it attaches to the torque tube and remove the four O.E. bolts. You will discard these O.E. fasteners. (Fig. 9) 2. Remove the main wiring harness retaining clip from the stud on the upper mounting bolt and drill the original mounting hole out to 3/8" for re-installation with new differential strut bracket bolt. (Fig. 10) 3. Locate 24 large washers that are supplied in the kit and separate them into 8 stacks of 3 each. These will be used as spacers between the differential strut transmission bracket and the O.E. transmission flange. (Fig. 11) 4. Using an adhesive of your choice, secure the 3-washer pack together as shown: (Fig. 12 & 13) 5. Set them aside to dry for installation later. (Fig. 14) 6. Place 1 washer on the transmission bracket mounting bolt, pass it though the bracket, then through the washer pack and finally install the pre-assembled bracket onto the transmission mounting flange. The final order of assembly for the transmission brackets should be: Supplied mounting bolt-washer-bracket-washer packtransmission mounting flange. Tighten these bolts to 35 ft. lbs. (Fig. 15 & 16) 7. Perform steps 1-6 for the driver side of the transmission. (Fig. 17) *The differential strut bracket installation for the transmission flange and it should look like this: (Fig. 18 & 19) Differential Strut Bracket Installation on Differential Housing: 1. Locate the NVH suppression counterweight on the driver side of the differential and remove it temporally. (Fig. 20 & 21) 2. Starting with the passenger side, remove all the O.E. differential cover bolts except for the lower two at the 6 'oclock position near the lower "ear" tab on the cover. Discard the O.E. bolts you ve removed. (Fig. 22) 3. Install the passenger side differential bracket as shown using the supplied bolts in the kit, making sure to use a supplied washer under the head of the bolt. Torque the differential bracket bolts to 20 ft. lbs. (Fig. 23) 4. The Installation of the differential bracket on the passenger side should now look like this: (Fig. 24) 5. Now go to the driver side of the differential and remove the two lower O.E. differential cover bolts located in the 6 and 8 o'clock positions. You will discard these O.E. bolts. (Fig. 25) 6. Install the left lower differential strut bracket onto the driver side differential cover as shown and torque to 20 ft. lbs. (Fig. 26) 7. Remove the remaining differential cover side bolts from the driver side cover and discard. (Fig. 27) 8. Install the left upper differential strut bracket onto the driver side cover as shown using the supplied bolts in the kit making sure to use a supplied washer under the head of the bolt. Torque the differential bracket bolts to 20 ft. lbs. (Fig. 28) 9. The installation of the differential brackets on the driver side should now look like this: (Fig. 29) 10. Re-install the NVH suppression counterweight back onto the left side of the differential cover as shown and torque to 25 ft. lbs. (Fig. 30) a. Install the differential bracket cross-rod (shortest of the five rods) between the two main upper

3 3 P a g e differential brackets as shown using the supplied Y4 x 20 bolts in the kit, making sure to use the supplied washer under the head of the bolt. (Fig. 31) b. Once you have the differential cross strut rod located and are getting ready to install, make sure you place a washer under the head of the bolt as shown and also place a washer between the inside of the differential bracket and cross strut rod to be used as a spacer. The order should be like this: bolt-then-washer-then-differential bracket-then-washer-then-cross strut rod. 13. Torque each end to 12 ft. lbs. and all of the brackets, including the cross-rod. Now fully installed on the differential it should look like this when finished: (Fig. 32) *You should now have the differential strut mounting brackets securely mounted onto the differential case at this time. Strut Rod Installation: 1. Locate the four main strut rods in your kit. You'll notice that two are of equal length and the other two are not. The two that are equal in length are the right & left, TOP strut rods, the next is shorter in length is for the PASSENGER SIDE and the shortest strut rod is for the DRIVER SIDE. (Fig. 33) 2. Your kit has 4 left hand thread heim joints with matching jam nuts and 4 right handed thread heim joints with matching jam nuts. Install the appropriate jam nut onto the heim joint stud and screw it all the way on until the nut bottoms out on the stud as shown. Do this procedure for all eight heim joints and studs until they look like this: (Fig. 34) 3. Each main strut rod has a right handed and a left handed thread machined into the ends of it for which you'll screw the appropriate heim joint stud into equally on both ends. (fig. 35 & 36) 4. Position all 4 main strut rods on your workbench so the machined rings around the rod are all on one end. These rings dictate which end is to face "rearward" or towards the rear of the car when they are installed. 5. Locate one upper, long, main strut rod and the second to the shortest lower main strut rod for the passenger side and put these next to each other. Locate the other upper, long, main strut rod and the shortest main strut rod for the driver side and put these two together. (Fig. 38 & 39) 6. Be sure each strut rod is installed with the ring towards the rear of the car to insure proper installation. *FAILURE TO FOLLOW THIS STEP ACCURATELY **WILL**LEAD TO DIFFERENTIAL FAILURE!!! 7. Install 6-3/8-24x1 bolts in the threaded holes and 2 3/8-16x1.75 bolts, spacers, and nuts. - The 2 longest bolts are to be used in tandem with the provided aluminum spacers to secure the 2 rear Heim joints of the upper strut rod ends onto the differential bracket mounting holes as shown. Torque to 30 ft. lbs. (fig. 42 & 43) - The 4 intermediate length bolts are to be used to secure the 4 front heim joints of all the strut rod ends onto the two transmission bracket mounting holes as shown. Torque to 30 ft. lbs. (fig. 45 & 46) 8. -The 2 shortest length bolts are to be used to secure the rear lower heim joints of the 2 lower strut rod ends onto each respective side of the differential brackets as shown. Torque to 30 ft. lbs. (fig. 47 & 48) 9. Make sure all 8 heim joints are adjusted evenly out of the out of the 8 strut rod ends as shown. *IF THEY ARE NOT, YOU THEY WILL BIND WHEN PRE-LOADED AND THE DIFFERENTIAL STRUT KIT WILL NOT BE ADJUSTED PROPERLY, LEADING TO DIFFERENTIAL FAILURE. DO **NOT** NOT SKIP THIS CRITICAL STEP!!! (FIG. 49 & 50) 10. *You should now have the entire differential strut kit brackets, strut rods, and mounting hardware securely mounted onto the differential/ transmission cases at this time and it should look like this: (FIG ) Strut Rod Pre-Load Adjustment: Please follow the pre-load adjustment instructions EXACTLY as we describe here to avoid any possible diff/trans damage with this products Installation! 1. Adjust the pre-load on all the main strut rods to a static ZERO-lash by turning each rod clockwise by 2. HAND until just snug then stop, making sure they are PULLING THEMSELVES TOGETHER as you tighten them. 3. The proper adj. sequence is- Driver-upper first, Pass-upper second, driver-lower third, pass-lower last. 4. After ZERO-lash is completed, tighten each respective main strut rod, in sequence, in ¼ turn increments until 1 full turn on each rod is reached and lock down with the jam nut on each heim joint stud. (fig.54) 5. Follow this step for all four main strut rods, in the previously described sequence. 6. DO NOT adjust preload rods tighter than 1 full turn past ZERO-lash or differential damage/gear whine WILL occur. Once ZERO-lash has been completed for each rod, DO NOT try to tighten rods even further past ZERO-lash as you proceed through the tightening sequence, even though the next rod in the preload sequence will "FEEL" loose before your adjustment sequence is complete. These steps are absolutely critical!! *You should now have the HPE Differential Strut completely installed and adjusted properly on your Corvette! Congratulations!!

4 4 P a g e Chassis Reassembly: 1. Follow the reverse pattern of outlined disassembly to re-assemble your vehicle successfully, paying particular attention to installing the adjustment nuts on the rear leaf spring with the same number of threads showing before you started. You should have written this number down to refer back to as outlined in the disassembly procedures.

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