Your #1 Source for Jatco CVT Pulley Bearings

Bearing noises can be difficult to track down even in familiar transmissions which we work on daily. The advantage of the familiar is that we know how to take these units apart and have a general idea of power flow and overall operation. Plus, we typically have plenty of extra pieces on the shelf should we need them. Bearing noises in the CVT transmission are much harder to deal with, because it’s not as familiar as the units rolling in the door on a daily basis and spare CVT pieces are pretty much non-existent. This has created some minor paranoia when it comes to taking on a CVT repair. Hopefully this article will dispel a bit of the apprehension regarding these units and prove that - with the right tools and a little know-how - CVTs can be repaired and become decent money makers for a shop.

For this article we'll reference the JF011E, but all Jatco models are similar when it comes to bearings. The most common abnormal bearing noise concern with these units is related to a rotational whining noise in Forward or Reverse. The noise gets worse as vehicle speed increases — sometimes it may even sound like a differential noise. A pan examination will reveal a magnet with a good amount of steel hair on it, which means there is something “making metal.” This happens when the pulley bearing races become pitted, causing metal flaking. To address the problem, the bearings must be replaced, and that requires unit removal.

Once the transmission is out of the vehicle, remove the valve body so that the ratio control motor and arm can be disconnected from the ratio control motor follower.  Next, detach the rear cover and pulley assembly from the case. Once the rear cover is removed, take out the bearing retaining bolts (Figure 1) so the pulley assemblies and belt can be removed from the cover. Wrap two nylon zip-ties around the belt (Figure 2) BEFORE removal to prevent it from falling apart (not a good situation!).

Figure 1	Figure 2

Figure 3 shows a close-up of something to be aware of: the arrow on the belt that shows the correct rotation direction. You’ll need this for reference when the belt is reinstalled into the pulley assemblies, because putting the belt on backwards will damage it and the assemblies. 

Figure 3

The next step is to open up the secondary pulley so it can be removed…but first you need to have the right tools on hand. The secondary pulley has a large spring inside that must be compressed before the pulley can be opened. The toolkit for accomplishing this and related parts to complete the process are well worth it and available in the aftermarket. They work as follows:

1. A split-ring is bolted around the bell-shaped area of the secondary pulley, and two arms are connected to the split-ring retaining bolts. 

2. The upper puller assembly and threaded bolt are attached to the top of the arms with two bolts and nuts (Figure 4).

Figure 4

3. Once the split-ring and upper part of the puller is set in place, tightening the center bolt will relieve spring tension and allow opening of the secondary pulley (Figure 5).

Figure 5

4. Lift the puller assembly and the secondary pulley out of the cover, then place it inside the primary pulley opening (you may want to put a rag over the primary pulley face to prevent scratching). 

Figure 6	Figure 7

5. Now,  lift the belt over the primary pulley and remove from the cover (Figures 6 and 7). Some units have shims between the rear cover and bearing (Figure 8) which need to be saved for the use during reassembly. 

Figure 8

Figures 9 and 10 show the location of the bearings on both the secondary and primary pulley assemblies. There is a primary pulley bearing for the torque converter side and one for the cover side, along with a cover-side secondary pulley bearing. These bearings can be removed with a two-jaw bearing puller or a bearing splitter and puller assembly and pressed back into place with ease. Replacement bearings are readily available in the aftermarket for most CVT units.. 

Figure 9	Figure 10

Jim Dial is a Sonnax technical specialist.

Since Sonnax product support is often asked this question, I'd like to share a few tips on installing PTFE seals on Sonnax 2nd Gear super hold servo kit 22301B-01K for Chrysler 46RH, 46RE, 47RH, 47RE, 48RE, A727 transmissions.

Non-scarf cut PTFE seals can be very intimidating to install for the first time, quite different from installing your average rubber O-ring. The main tool you are going to need with these is patience. Slow and easy will get you where you need to be.

Take the seal between your thumb and pointer finger, while pulling, work seal around to stretch evenly (Figure 1). Fit one edge of seal in the servo groove and install it all the way around. If it is still too snug to fit, you may have to repeat the previous stretching process until you can slide the seal the rest of the way over the end of the servo. 

Figure 1 – Stretching Seal

Once the seal is in the groove, you can roll the part in your hands to help shrink the seal deeper into the groove. You will then take the sleeve, making sure it is square, and gently work it over the seal (Figure 2).

Figure 2 – Fitting Seal

If you are still having difficulty, another option is to tightly wrap the seal with electrical tape and let it sit for several minutes (Figure 3). This will size the solid PTFE seal down. This method can be used on any other seals of this type when a dedicated sizing tool is not available. These seals are very strong and can stretch quite a bit before you break them.

Figure 3 – Still Having Difficulty? Size Seal with Electrical Tape