Changing The Cv Axle on a GMC Syclone
The CV (constant velocity) axle is made to transfer power from your drivetrain (transmission and differential) to your wheels by using shaft with a variable angle joint to allow articulation to the hub of the wheel. This articulation of the joints allows the wheels to go over bumps and take turns without breaking. The Syclone & Typhoon's AWD system uses 2 CV axles for the front wheels.
- CV Axle
- Various Sized Cotter Pins
A bad CV axle has a few tell tale symptoms of needing replacement. The first and most obvious symptom would be a broken rubber boot that surrounds the joints. If the boot rips, it releases the necessary grease that keeps the joint lubricated and introduces dirt and grime, causing failure. Another symptom would be hearing a metallic clicking noise when turning. This clicking or clunk can also be present during acceleration and deceleration.
While this isn't a hard job, I will assume that you have some sort of mechanical experience and have turned a wrench going into this fix. While the CV axle is not a hard fix, it does require some specialty/oversized tools that you might not have in your collection. There are probably a few different methods on removing the CV shaft on what to take off or loosen first that can be suggested. This article will go about how I change the axle with minimal effort and as quick as possible. Your methods may vary. Make sure to pay attention to my repeated PRO TIP!
CV Axle Removal
With your truck secured on jackstands or a lift, remove the wheel.
With the wheel off, you will want to loosen the castle nut that holds the CV axle in the wheel hub. First remove the cotter pin from the castle nut using a pair of needle nose pliers. Using a 1 5/16" socket, loosen and remove the castle nut and the washer located behind it. Pro Tip - Pay close attention here. This tip will be mentioned more than once in this writeup! More than likely when you go to put torque to remove the nut, the axle/hub is going to spin on you. There's a few methods to help: A. Get a friend to hold the brakes down. The clamping pressure should allow you to put enough torque to break the castle nut loose. B. If you're by yourself, slide a large screwdriver (or similar item that won't bend or break) through the rotor and spin until it stops on the brake caliper. You can now apply torque to break the castle nut loose. There are a few other unorthodox methods I could mention (and have used successfully), but I feel they aren't as safe to try. PB blaster or WD-40 might be your friend here if the castle nut on your truck hasn't been removed since G.H.W Bush was president.
Now, remove the shock. There are two (2) 18mm bolts that hold the shock in at the top and at the bottom. Pro Tip - I like to use my jack and place it under the lower A-arm just so it barely starts to lift up on the suspension. This will help relieve tension on the bolts that hold in the shock so that they don't bind when trying to slide them out of the mounting points. I prefer to start with the bottom bolt first then remove the top. Once you have the shock out, you can lower and move the jack out of the way. NOTE - The picture shows aftermarket shocks. The stock shocks mount exactly the same.
Focusing on the tie rod end, remove the cotter pin and remove the castle nut using a Xxmm socket. With the castle nut removed, take a tie rod end puller and remove the tierod from the spindle. If you do not have a tie rod end puller, a pickle fork can be used but with caution not to tear the rubber boot. For this step, I am using the pickle fork method. Place the pickle fork UNDER the boot (in order not to rip the boot) and give the end of the pickle fork a few light blows with a hammer. You should see the tie rod move upward out of the spindle.
With the tie rod free of the spindle, you want to move it out of the way by bending it upward. Pro tip - turning the wheel can increase your working space to remove the CV axle. Turn the ignition key to the ON position (DO NOT start engine) and turn the wheel so the tie rod end moves inward. In this case I am working on the DRIVER SIDE axle, so I want to turn the wheel to the RIGHT. Once you have turned the wheel, turn the ignition key back off. Trust me on this one, you'll save yourself from screaming and yelling on how there is no room to get the axle out when you get it unbolted.
Without the tie rod attached, the wheel hub will now turn freely. Again, because we are working on the driver side, turn the wheel hub as if you were making a LEFT turn. This will give you easier access for the next step.
The inner joint of the CV axle is connected to a flange that goes into the differential. There are six (6) 15mm bolts that hold the CV axle onto the flange that you must remove. Using an extension, I use an air ratchet to loosen and remove all 6 bolts. You can also use a standard socket, I just recommend having a breaker bar handy. If you find the CV axle wanting to spin, again get a friend to step on the brakes or use the screwdriver/rotor method mentioned earlier in Step 2. You may have to purposely rotate the CV axle in order to reach all the bolts.
With the 6 bolts removed from the inner joint of the CV shaft, you can now remove the CV axle. Give the CV axle nose a light tap with a hammer in order to free it from the splines if it does not want to move freely. Now, working with the back of the CV shaft that was bolted into the flange, pull towards you to help compress the joint and bend the rear joint between the tie rod and lower control arm (towards the front of the truck) until it passes and falls clear. Once the CV axle is clear on the backside, you should now be able to slide the front splines out of the wheel hub and out of the truck. NOTE - If you simply cannot get the rear of the axle free, you will be forced to remove the upper ball joint. Move to the next step if this is the case. If you succeeded in getting the shaft out, move to Step 9.
IF YOU CAN'T GET THE AXLE FREE - then you will be forced to remove the upper ball joint. Remove the cotter pin and castle nut from the ball joint. Use the tie rod / ball joint removal tool to free the balljoint from the spindle. If you don't have a remover, a pickle fork and hammer can be used being careful not to tear the ball joint boot (same method as the tie rod end in Step 4). Once the balljoint is free of the spindle, you should be able to tilt the spindle forward giving more room to free the CV axle.
At this point, you are ready to reinstall the new CV axle.
Installing the CV Axle
Typically, new (or remanufactured) CV axles will come with a new castle nut. If your axle doesn't come pre-lubricated, apply a liberal amount of lithium grease to the front splines of the shaft. It doesn't hurt to also apply some on the inner wheel hub on the teeth where the axle splines mesh.
To reinstall your new CV axle, you will take the reverse steps of how you removed it. Insert the front of the CV axle so the splines line up with the wheel hub and slide in without binding. If you would like to loosely place the washer and new castle nut back on, by all means....you don't need to tighten it at this point.
Now compress and bend the rear joint and carefully push it back between the tie rod and control arm. Yes, this might take some effort. If you had to remove your upper ball joint, then this step should no problem. If by chance you just simply can't get the axle back in with the upper balljoint in place, then go ahead and look back a few steps on how to remove it.
With the CV axle now in place, you may have to spin it to align it with the inner flange bolt holes. Once you have it aligned, put all six (6) 15mm bolts back in and tighten them down. PRO TIP - Use the friend/brakes or screwdriver/rotor trick if you find the axle spinning on you (Step 2 of axle removal). You may have to spin the axle around to gain access to all the bolts.
If you DID NOT remove your balljoint, skip to Step 6. If had to remove your upper balljoint, you now will reinstall it. Simply bring the spindle back up and push the balljoint end back into the top of the spindle. Reinstall the castle nut making sure it is fully tighten and the cotter pin hole is not obstructed. Reinstall a new cotter pin.
Retighten the castle nut on the end of the CV axle nose. Be sure the washer is installed BEHIND the castle nut. Once fully tightened, make sure the cotter pin hole is not obstructed and reinstall a new cotter pin. PRO TIP - Use the friend/brakes or screwdriver/rotor trick if you find the axle spinning on you (Step 2 of axle removal).
With the CV axle now fully tightened you need to reinstall the tie rod end. REMEMBER - You had turned the wheel to the RIGHT to make clearance to remove the CV axle. The wheel hub is still free to move left/right at this point. My method is to simply turn the wheel hub to the right and align the tie rod end back up into the spindle. Loosely retighten the castle nut and with the ignition key on (DO NOT START), turn the wheels back to center. Once you are back center, retighten the castle nut making sure it is fully tighten and the cotter pin hole is not obstructed. Reinstall a new cotter pin. PRO TIP - If by chance the tie rod end is spinning while trying to tighten the castle nut, give the tie rod end a forceful (not superman force where you break and bend stuff) hit to help seat the tie rod into the spindle. DONT hit it on the grease joint end. A few inches back on the actual rod will suffice.
Reinstall the shock. Again, I use a jack to support the lower control arm and start with the top bolt and then the lower bolt. If the lower mount doesn't align (typical scenario), use the jack to push the control arm up to align it. Once both bolts are tightened, you can remove the jack.
Because you remove the tie rod, you'll want to add grease again to it. You will also want to do this to the upper ball joint if you had to remove it as well. Most all tie rods/balljoints will have a grease fitting on top. You will use a standard grease gun to refill. Also, while doing this step, take the opportunity to grease any other joints (lower ball joint, idler arm, sway bar - if it has fittings, etc.)
Double checking all bolts have been properly tightened, you can now reinstall your wheel and remove it from jackstands. Job completed!