Universal Joint Replacement Guide for the 1987-1995 Chevrolet Blazer
Address driveline vibrations and clunks by choosing the right U-joint for your S-10 Blazer.
- Prioritize premium, non-greasable U-joints from brands like Dana Spicer for the best longevity, as they were the likely original equipment supplier.
- Be prepared to use a torch to melt the injected nylon retainers on the original factory U-joints.
- Always replace the U-joint straps and bolts when installing a new joint to ensure a secure fit.
- If one U-joint has failed, it's wise to inspect and likely replace the others on the same driveshaft as they have experienced the same amount of wear.
Is Your Blazer's U-Joint Failing?
A failing U-joint is not just noisy; it's a warning that a critical part of your drivetrain is wearing out. Ignoring the signs can lead to more significant damage or a complete driveshaft failure, which could leave you stranded. Listen and feel for these common symptoms when you drive.
🎬 Watch this guide on diagnosing and replacing worn S-10 U-joints.Common Failure Symptoms
- Clunking Noise: A distinct "clunk" or "bang" when you shift into drive or reverse is a classic sign of a worn U-joint with excessive play.
- Squeaking or Chirping: A rhythmic squeaking that changes with your speed, often heard at lower speeds, points to a dry, unlubricated U-joint.
- Vibration: A vibration felt through the floor or seat that gets worse at highway speeds can be caused by a failing U-joint throwing the driveshaft out of balance. This might be confused with a tire issue, but if balancing your wheels doesn't fix it, the U-joint is a likely suspect.
- Visible Rust or Leaks: Look under your truck at the driveshaft. If you see rust-colored dust or grease splattered around the U-joint caps, it means the seals have failed and the internal bearings are wearing out.
A Note on Factory U-Joints
The original U-joints on many 1987-1995 Blazers were installed using a nylon injection method instead of traditional clips. To remove them, the nylon must be melted out with a torch. 🎬 See how to replace a Blazer U-joint step-by-step. Aftermarket replacements use standard C-clips, making future replacements much easier.
Choosing the Right Aftermarket U-Joint
When replacing your U-joints, you have a choice between several reputable aftermarket brands. The original equipment supplier for GM was often Dana Spicer. Aftermarket options range from budget-friendly to heavy-duty, and the right choice depends on your budget and how you use your Blazer.
| Tier | Brands | Best For |
|---|---|---|
| Premium / Heavy-Duty | Dana Spicer, Yukon Gear | Off-roading, towing, and maximum durability. Spicer is widely considered the highest quality and was often the original part manufacturer. |
| Quality Standard Replacement | Moog, SKF, ACDelco (Professional Grade) | Daily driving and reliability. These brands offer a good balance of quality and cost. Note that some users report a decline in Moog's quality in recent years, so check the country of origin. |
| Economy | GMB | Budget-conscious repairs for light-duty use. While functional, they may not have the same longevity as premium brands. |
Greasable vs. Non-Greasable U-Joints
You'll find both greasable (with a zerk fitting) and non-greasable (sealed) U-joints. Non-greasable joints are generally considered stronger because the cross isn't drilled for a grease channel. They also often have better seals from the factory. For most owners, a high-quality, non-greasable U-joint from a brand like Spicer is a fit-and-forget solution that will last for many years. If you frequently drive through water or mud, greasable joints allow you to flush out contaminants.
Frequently Asked Questions
How many U-joints does my 1987-1995 Blazer have?
A 4WD S-10 Blazer typically has three U-joints: two on the rear driveshaft and one on the front driveshaft. Some configurations may vary, so it's always best to inspect your specific vehicle.
Should I replace all the U-joints at once?
If one U-joint has failed due to age and mileage, the others are likely not far behind. It is good practice to replace all U-joints on a driveshaft at the same time to ensure a balanced, smooth-running system and prevent another repair job in the near future.
Can I replace a U-joint myself?
Yes, this is a feasible DIY job for someone with moderate mechanical skill and the right tools. You will need a good socket set, a hammer, and either a sturdy bench vise or a ball joint press. 🎬 Learn how to replace U-joints using only a hammer. Remember that factory joints require a torch to melt the plastic retainers.
Do I need to replace the driveshaft straps?
Yes, it is highly recommended to replace the small metal straps and bolts that hold the U-joint to the axle yoke. They are inexpensive and ensure the new joint is held securely. Re-using old straps can lead to a repeat failure.
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Technical Specifications
The 1987-1995 S-10 Blazer typically uses a 1310-series U-joint, but it is critical to measure your existing U-joint caps and width or verify the part number for your specific application before ordering, as variations exist.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
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