MUSCLE PERFORMANCE ’69 CAMARO
March 27, 2024
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THE AUTO BUILDER
Featured
Product Spotlight – Gentleman Joe Schubeck: A Living Legend Tells His Story in Hot Rods, Trains, & Planes
Don “Big Daddy” Garlits, in his “Foreword” says, “People of all ages, especially young people just starting out, should read this book for inspiration”
FASTER PASTOR
Keith Shuley is a genuine hot rodder and a bona fide car nut. In that respect, he’s no different from any of you reading this article, but what makes him a little different is how he spends his days. Shuley is a Catholic priest and a Lieutenant Commander in the U.S. Navy, serving as the Command Chaplain aboard the amphibious assault carrier U.S.S. Peleliu, the LHA-5. He spends his days filling the spiritual needs of those sailors, aviators and Marines who help keep our country free. But during his personal time, he fills his own need for speed. What a concept!
The Test Car
If you’ve attended a Goodguys event in the past couple of years, chances are you’ve seen this blue ’69 Camaro, owned by Stacy Tucker of Detroit Speed & Engineering. The car rarely sits still at a rod run, especially if there’s an autocross event on the grounds—then it’s time to race.
Spotlighter
Smooth Trails Ahead: Installing Skyjacker’s Slip Yoke Eliminator Kit for Your Jeep Wrangler TJ
Getting Bad Vibes from Your Jeep? Skyjacker has the solution for this and more!
Author
Brenda Summers
Photography by Arnold Hemedinger
Upgrading your Jeep for better off-road adventures sounds awesome, but sometimes it can cause unexpected problems. For example, when you install a Skyjacker Rock Ready-Double Flex Suspension Kit, you might notice your Jeep vibrating more than usual. That’s because the lift can mess with how the transfer case and rear axle line up. Luckily, Skyjacker has a solution called the Slip Yoke Eliminator (SYE) kit. It not only stops the vibrations but also makes your Jeep’s drive shaft stronger. In this guide, we’ll walk you through installing the NP 231 Short Shaft “Fixed Yoke” Kit. We’ll cover everything from the tools you need to important things to think about before you start. So, if you’re eager to boost your Jeep’s performance, keep reading to learn how Skyjacker can help.To improve your vehicle’s performance on trails and raise its clearance, we added a 6-inch Skyjacker Rock Ready-Double Flex Suspension Kit to the TJ’s suspension. However, this adjustment has a drawback: lifting the vehicle by just 2 inches causes the rear part of the transfer case to move up and away from the rear axle. This change increases the angle, causing a binding effect on the U-joints and creating vibrations throughout the vehicle’s driveline. This happens because the factory transfer case extends too far out and uses a drive shaft that’s too short. The vibration worsens as the suspension flexes away from the transfer case.
Solution
To fix this issue, replace the stock slip yoke with a slip yoke eliminator kit (SYE) that features a constant velocity (C/V) joint bolted to the back of the transfer case. Though dismantling the transfer case might seem daunting, don’t be discouraged from doing it yourself.
Benefits
Skyjacker’s Slip Yoke Eliminator (SYE) provides a 32-spline shaft instead of the stock 27 splines, boosting the torque capacity by 54%. This upgrade lengthens the output shaft and extends the drive shaft by 4.5 inches. These kits also feature an oil seal to prevent fluid leaks, and if the rear driveshaft fails, you can continue driving using front-wheel drive.
Kit Description
- NP 231 Short Shaft “Fixed Yoke” Kit
- Slip Yoke Eliminator Kit
- Project: 1998 TJ Jeep Wrangler
- Skill Level: Intermediate to Advanced
Kit Components
- Tailhousing, Diecast
- Main Output Shaft
- Rear Yoke Seal Washer
- Rear C/V Yoke
- Rear Yoke Nut
- Front Yoke Seal Washer
- Speed-O-Ring Gear
- Snap Ring, 207 Bearing
- 207 Open Ball Bearing (No Snap Ring)
- Snap Ring, 207 Bearing
- Mode Retainer Ring
- Tailhousing Seal
Special Note
Installing this kit involves nearly dismantling the entire transfer case. If your transfer case has endured significant wear and tear, consider rebuilding it at this time. Before disassembling the transfer case, secure your transmission with a jack. You’ll also need to purchase a C/V type driveshaft to complete the installation. Skyjacker offers a pre-measured C/V Drive Shaft ready to install, or you can follow their instructions to have one custom made. Plan for a day to complete the installation.
Things to consider before you start
- Before disassembling the transfer case, label small containers into groups for easier clarification later.
- This kit is shipped with a rear 1310 series C.V. type yoke. You will need a C.V. equipped driveshaft.
- Have enough OEM fluids for installation.
- Follow your States’ guidelines for proper disposal of fluids.
- If you should get into trouble, call Skyjackers Tech-Support line for assistance.
- Wear safety glasses.
- Make sure to read the manufacturers instructions before attempting the install.
Tools Needed
- Safety Glasses
- Jack Stand
- Basic Mechanics Wrenches/Sockets
- Cut-off Saw or Hacksaw
- Pick
- Hammer
- 3/8″ and 5/16″ Allen Wrenches
- RTV Sealant or OEM Sealant
- Flat Chisel
- Snap-ring Pliers (C-clip and E-clip Type)
- Torque Wrench
- Gear Lube (OEM Recommended Fluid)
- Measuring Device (Ruler)
- Impact Wrench (if available)
- Clean Workbench
- 9/16 Wrench
- Diagonal Cutters
- Brake Cleaner or Suitable Solvent
1. Tools required.
2. Remove the front yoke with a 1-1/8” socket using an impact wrench-slide off the yoke.
3. Remove the speed-o-drive.
4. Remove the inner spline seal by using a pick.
5. Make sure to move lever into 4-lo, then remove range selector using a 9/16”inch or 14 mm wrench.
6. Cut the factory clamp to remove shaft boot
7. You can use a punch, chisel, or puller to remove the shaft boot slinger.
8. To remove the retaining c-clip, use a c-clip removal tool.
9. A chisel or screwdriver will work to remove the output shaft seal.
10. To extract the bearing retaining clip, use an e-clip removal tool.
11. Remove the tailhousing bolts, then set them aside for later.
12. Important! When removing the tailhousing, before removing the oil pump, pay close attention to how the oil pump pick-up tube is positioned. Inspect the “o-ring” in the pump and replace if needed. The same goes for the front shaft seal. DO NOT, DISASSEMBLE THE PUMP: IT IS NOT A SERVICEABLE ITEM.
13. Remove the pump from the main output shaft.
14. Remove the bolts from the rear case half.
15. Remove the rear case from the front case by inserting pry bars at the cast-in locations ONLY! Pry apart evenly to break the sealer bead along the case mating surfaces. Remove, clean and inspect the inner case for damage. (Inspect oil feed tube in opening)
16. Exposed chain drive assembly, take notice of the position of both shafts home position for future use.
17. Front output shaft removal: Follow steps (a-c) (a) Pull the front output shaft out of the front bearing. (b) Slide drive chain off the rear output shaft and remove both shaft and chain for cleaning and inspection. (c) Rear output shaft removal: grasp the main shaft and remove the shaft, drive sprocket and mode hub assembly.
18. Inspect gears and chain for excessive wear, replace as needed, you be the judge.
19. Seeing them side by side, it’s clear why the 32-spline would increase the strength of the transfer case as opposed to the 27-spline shaft.
20. Output shaft disassembly: Remove the mode hub retaining ring with heavy duty snap ring pliers.
21. Now slide remaining components, mode hub and drive sprocket off shaft.
22. Install the new supplied c-clip.
23. Lubricate chain and shaft with ATF then insert main shaft assembly into the housed planetary assembly.
24. Install the drive chain onto the front output shaft.
25. Pre-lube the front output shaft bearing located in the rear case.
26. Apply a thin film of sealant to the front case. Use a good RTV, like the OEM sealant, available from your local Jeep dealer.
27. For assembly of case halves: Slide the pump & case into position. If you have difficulty, check for possible problems. DO NOT FORCE! MODE FORK RAIL EXTENDS THROUGH THE REAR CASE!
28. Make sure to install all fasteners to their original positions. (Black bolts at dowel locations!) Torque evenly to 27-34N.m or (20-25ft/lbs)
29. Inspect and condition the oil feed tube o-ring, replace if necessary. Carefully insert oil tube into pump while installing assembly.
30. Install the supplied oil pump retaining c. clip.
31. Now slide on speed-o-ring gear into position and install retaining ring behind ring gear.
32. Note: On some NP231 transfer cases, the shift rail must be shortened. This shift rail protrudes out of the transfer case and goes into the tailhousing. The new tailhousing has a shaft depth of 1.25”. Shift your transfer case so the shift rod is protruding the furthest out of the transfer case. If this shifter rod protrudes more then 1” out the back side of the transfer case, then the shift rail must be shortened. Transfer cases that will normally require this rail to be shortened measure 1.5”. Using a hack saw or cutoff wheel and safety glasses, trim the shift rail shaft so that it protrudes out only 1”inch.
33. Short tailhousing installation: Pre-lube bearing and seal in new short tailhousing assembly. Apply sealant to tailhousing, mating surface of rear case. (Thin film) While supporting main shaft, slide new tail assembly into position. Use care when indexing pumps outer tabs and aligning tail assembly for installation. Note: Pull back on the output shaft to seat it against the rear bearing.
34. Install the supplied five 10mm bolts that retain the tailhousing and torque evenly to 20-27 N.m (Newton Meters)or (15-20 ft/lbs.)
35. Lube yoke with ATF, this will apply to both front and rear yoke assemblies.
36. Install the 32-spline seal.
37. Inspect the spline seal for correct alignment. Torque to 140 -150ft/lbs. with a 1/1.8” socket. Install the front output yoke in the same manner.
38. Install the shift rail plug with new seal. Be sure to apply thread-lock to the retaining nut.
39. Install your stock speedometer housing into your new tailhousing. A touch of RTV-Blue Silicon around the o-ring will help seal this area. Reconnect all exterior items: 4WD switch/lever, speedometer cable, and driveshaft etc.
40. Install transfer case and fill to recommended level and fluid.
ARTICLE SOURCES
Alpine Auto Werkstatt
2535 Rhea Co. Hwy.
Dayton, TN 37321
423/775-5959
Skyjacker Suspensions
212 Stevenson Street
West Monroe, LA 71292
318/388-0816
