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Technician Chris
Technician Chris, Technician
Category: Car
Satisfied Customers: 425
Experience:  I am a certified ASE Master Technician with L1 Advanced Diagnostic Specialist and over 15 years experience.
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I am trying to replace the rear u-joint on a 1994 GMC 4WD with

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I am trying to replace the rear u-joint on a 1994 GMC 4WD with a 5 speed manual transmission. However, I am not able to remove the driveshaft from the trans tail shaft. What's the trick. What am I not seeing?

what engine is in the truck?

Customer: replied 3 years ago.


1. Mark shaft for assembly reference.
2. Support shaft in a horizontal line with a suitable vice.


3. On models with external snap rings, remove snap rings, Fig. 4 . If ring does not snap out of groove, relieve pressure on ring by tapping lightly on bearing cap.



4. On all models, place joint in tool No. J 9522-3 or equivalent with lower yoke ear supported by 1 1/8 inch socket, Fig. 5 , then press out cap. If cap is not completely removed, insert spacer tool No. J 9522-5 or equivalent and continue to press, Fig. 6 . If using a vice in place of special tool, use 1 1/8 inch socket to receive one cap and 5/8 inch socket to push opposite cap.
5. Rotate joint in tool or vice and press opposite cap out, then remove cross from yoke.
6. Inspect and clean retaining ring grooves.
7. Check cap bores for burrs and imperfections.

1. Use finger to coat needle bearings with thin layer of grease. Do not fill cups completely or use excessive amounts. Over lubrication may damage seals.


2. Put one bearing cap part way into one side of yoke, then insert cross into cap, Fig. 7 .
3. Press cross and cap into yoke until cap is flush with yoke ear.


4. Press opposite cap into yoke, ensuring trunnion alignment, Fig. 8 .
5. Continue to press cap into yoke ear while working cross to ensure free, unbinding movement until retainer groove clears inside of yoke. If binding occurs, stop pressing and check for misaligned bearings.



6. Snap retainers into place, Fig. 9 . Yoke can be sprung slightly with firm hammer blow if retainer is difficult to seat, Fig. 10 .

Before disassembling any universal joint, examine the assembly carefully
and note the position of the grease fitting (if used). Also, be sure to mark the yokes in relation to the propeller shaft for assembly reference. Failure to observe these precautions may produce rough vehicle operation resulting in rapid wear and parts failure, as well as placing an unbalanced load on transmission, engine and rear axle.

When universal joints are disassembled for lubrication or inspection, and
the old parts are to be reinstalled, special care must be exercised to avoid damage to universal joint spider or cross and bearing cups.
Customer: replied 3 years ago.

I understand this part. But I can't get the driveshaft out of the transmission (5-speed).

the driveshaft should just slide right out. You have to twist it just to get it started, but it is not bolted or otherwise locked it. See below for a TSB that applies:



File In Section:XXXXXAxle

Bulletin No.: 46-41-01

Date: September, 1994


Slip Yoke Replacement and U-Joint Servicing

1995 and Prior Light Duty Trucks

U-joints that are pressed out of the propeller shaft or slip yoke must not be re-used. When it is necessary to press out the u-joint to replace a slip yoke, a new u-joint must be installed. A new u-joint is necessary as the bearing cup seals and slingers are easily damaged. If these components are damaged, dirt and water can contaminate the bearing causing early bearing wear-out. Replacement of the rear u-joint is not required if the retaining straps holding the u-joint to the rear axle pinion flange are removed.

Light duty trucks make use of three types of yokes:

1. Vented slip yoke. This yoke can be identified by a small hole in the center of the slip yoke welch plug. This yoke uses grease for internal lubrication. The internal splines of the yoke should be coated with a light covering of grease before installation to the output shaft. A small amount of grease may be forced from the vent hole during operation. No attempts should be made to plug the vent hole.
2. Non-vented slip yoke. This yoke has no vent hole and relies on transmission or transfer case fluid for internal lubrication. Grease should not be used on the yoke internal splines as it may contaminate the transmission or transfer case fluid.
3. Bolted or fixed yoke. This yoke does not slide so it needs no internal lubrication.

The transmission/transfer case output shaft seal should be inspected for damage before installing the yoke. The seal lips should also be greased before yoke installation for longer seal life and better performance.

Customer: replied 3 years ago.

There might be a two-piece driveshaft and a center support bearing. I think I will have to remove the bracket. Does that sound correct? Or do I have to do more to slide it out? Or more to free up the center bearing bracket?


if you do have a center support bearing, the bracket will just unbolt from the bottom of the vehicle
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