A Guide to Universal Joints for the 1983-1991 GMC S15 Jimmy
That clunking or vibration from your truck could be a bad U-joint about to cause a major problem.
- You MUST measure your old U-joints (cap diameter and width) before ordering; multiple sizes were used on the S15 Jimmy.
- Dana/Spicer is the most recommended brand for durability, with non-greasable versions often preferred for their strength.
- A vibration, clunk, or squeak from your driveline should be inspected immediately to avoid a complete failure.
- Replacing U-joints is a manageable DIY job if you have a strong vise or a press, but improper installation can damage the driveshaft.
Is Your S15 Jimmy's U-Joint Failing?
Universal joints on the 1983-1991 GMC S15 Jimmy live a hard life and are a common wear item. Because they are constantly moving and under a lot of stress, they eventually wear out. Ignoring the signs of a bad U-joint can be dangerous. If a U-joint breaks completely while you are driving, the driveshaft can fall off the vehicle, causing you to lose power and potentially leading to a major accident and expensive damage to the underside of your truck.
Symptoms of a Bad U-Joint:
- Vibration: A common symptom is a vibration that you can feel throughout the truck, which gets worse at highway speeds. This is often confused with an unbalanced tire.
- Clunking Noise: You might hear a loud "clunk" or "ping" when you shift from Park into Drive or Reverse. It can also happen when you accelerate or let off the gas.
- Squeaking or Chirping: A rhythmic squeaking sound that changes with your speed is a classic sign of a dry, failing U-joint. This is often most noticeable at lower speeds. 🎬 Watch: 7 common signs of a failing universal joint
Important: Verify Your U-Joint Size!
The 1983-1991 GMC S15 Jimmy was built with several different U-joint sizes depending on the year, engine, drivetrain (2WD or 4WD), and even the specific driveshaft installed at the factory. There is no single part that fits all models. Before ordering, you must measure the bearing cap diameter and the overall width of your existing U-joints to guarantee you get the correct replacement. Relying on a parts catalog alone can lead to buying the wrong part.
Choosing the Right Aftermarket U-Joint
For a vehicle of this age, original OEM parts are likely discontinued or very hard to find. The aftermarket offers a wide range of quality and price. Here’s how the available brands generally stack up based on owner experiences.
| Brand Tier | Brands | Typical Price (Each) | Quality & Notes |
|---|---|---|---|
| Premium / Heavy-Duty | Dana Spicer Chassis, Yukon Gear | $40 - $108 | Dana/Spicer is widely considered the gold standard, often used as the original equipment manufacturer. They are known for durability. Many experienced mechanics prefer their non-greasable joints as they are solid and stronger. Yukon Gear is a strong choice for off-road or heavy-use applications. |
| Standard Aftermarket | Moog, SKF | $25 - $60 | These are popular and widely available brands. SKF is generally seen as a reliable choice. Moog's quality has received mixed reviews in recent years, with some users reporting premature failures, while others have had no issues. |
| Economy | GMB, Store Brands | $18 - $35 | These are the most affordable options. While they will work, forum discussions often warn that their lifespan can be significantly shorter than premium brands. They may be a choice for a vehicle that is not driven daily. |
Pro Tip: Greasable vs. Non-Greasable
You will see two types of U-joints: greasable (with a zerk fitting) and non-greasable (sealed). Original factory joints were non-greasable. Many experts prefer non-greasable replacements because the solid cross design is stronger. Greasable joints can last a long time if maintained, but they are structurally weaker and will fail quickly if you forget to grease them regularly.
Frequently Asked Questions (FAQ)
How many U-joints does my 1983-1991 S15 Jimmy have?
It depends on your drivetrain. A 2WD model typically has two U-joints on the rear driveshaft. A 4WD model will have those two, plus two or more on the front driveshaft connecting the transfer case to the front axle. Some long-wheelbase models may have a two-piece rear driveshaft with a third U-joint and a center support bearing.
Were there any recalls for the S15 Jimmy U-joints?
No. Searches of the National Highway Traffic Safety Administration (NHTSA) database show no recalls or major investigations specifically for universal joints or driveshaft failure on the 1983-1991 GMC S15 Jimmy.
Can I replace a U-joint myself?
Yes, this is a DIY-feasible job for someone with moderate mechanical skill, but it requires the right tools. You will need to remove the driveshaft from the truck. The hardest part is pressing the old joint out and the new one in without damaging the yokes (the "ears" on the driveshaft). 🎬 See how to replace S-series plastic ring U-joints Using a sturdy bench vise and sockets is a common method, but a ball joint press or hydraulic shop press is the best tool for the job.
🎬 Watch: Two ways to replace U-joints with or without a pressWhat happens if I install the wrong size U-joint?
It simply won't fit. The bearing caps will either be too large to fit into the holes on the driveshaft yoke, or too small and loose. This is why it is critical to measure your old parts before ordering. There are also "conversion" U-joints designed to connect a driveshaft of one series size to a yoke of another, so be sure you are buying a standard replacement.
Helpful Videos
Technical Specifications
The S15 Jimmy commonly uses U-joints from the 1310 or 1330 series, but variations exist. Key measurements are the bearing cap diameter (commonly 1.062" or 1.125") and the overall width of the joint. Retention is typically done with external snap rings. Verification by measurement of the original part is required.
We Have This Part in Stock
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.
- GMC S15 Jimmy: