eTorque Bearing Replacement, Fixed Grinding Noise

[skid_valve]

The front bearing is definitely 6305-RS. The rear is the mistery. I don’t think you can tell from outside other then if someone can find out when those MGUs started coming out with smaller rear bearings 6003-RS. My truck was manufactured in September 2018 as a 2019 year model. My MGU has 6203-RS in the back. If you want I can mail you the 6003-RS I bought by mistake. No charge just pay for shipping.

I appreciate the info I went ahead and ordered all 3 for sub $50 from skf whatever I don’t use if anyone wants it I’ll send it too them.

 

[RHO]

I just read online where a late model ram owner with no mgu trouble yet, bought a new mgu for $900. He said he likes access to spare parts, especially ones that can ground your truck for 4 months. Plus you can always resell it later. Some on ebay asking $2000.

how did he find one for 900.00 ?

 

[pensfan]

how did he find one for 900.00 ?

allmorparparts sell them at 30% off for about 940. That doesn't mean you will get one right away if you order it.

 

[Ramathorn19]

Hello,

I recently completed the bearing replacement on the MGU and for a bit the truck ran fine. A day later the truck threw code U0594 "Invalid Data Received From Hybrid Powertrain control module." Has anyone else run into this issue? When going through the MGU nothing looked damaged, everything was torqued to spec when installing back on the truck. I am wondering if there is a software update need on it or if something else is going as well.

Truck is a 2019 with the 5.7 hemi etorque

 

[skid_valve]

Just got my bearings in, Boy I didn’t realize just how big the front case bearing is. I plan on doing a in depth video on how to do it, I’ll share it once I’ve posted it. But for anyone curious the big bearing to the left is front case bearing, the two to the right are the two different sizes the rear bearing can be. Make sure they are c3 because that’s high speed rating.

 

[Trooper4]

Hello,

I recently completed the bearing replacement on the MGU and for a bit the truck ran fine. A day later the truck threw code U0594 "Invalid Data Received From Hybrid Powertrain control module." Has anyone else run into this issue? When going through the MGU nothing looked damaged, everything was torqued to spec when installing back on the truck. I am wondering if there is a software update need on it or if something else is going as well.

Truck is a 2019 with the 5.7 hemi etorque

Might have a contact/plug not seated all the way.

 

[Tsr2nd]

In my unit the bad bearing was an SKF 6003 double sealed bearing. I was not able to read the bearing part number due to corrosion but I measured the shaft at 17mm, bearing OD at 35mm, and thickness at 10mm. This is a 6003 size bearing and it is double sealed. I have no idea what precision level bearing was installed from the factory. I went with a 6003-2RS double sealed bearing in ABEC 3 precision level. The bearing was in stock at McMaster Carr and I had it next day. McMaster Carr part number 6661K86. Cost about $40 without shipping.

Re-assembly is pretty much the reverse of the above steps.

1. Press new bearing onto shaft.
2. Install reluctor wheel back onto shaft and secure with nut. Install the resolver sensor if you removed it.
3. Very carefully start putting the case halves back together. Take care to line up the marks you made earlier.
4. I started the long torx bolts back into their threads once I was happy with alignment. Keeping an eye on the gap around the halves, start snugging up the long torx bolts in a star pattern. Take your time to bring the halves back together evenly. Once everything seemed tight, I tightened up the torx bolts. I have no idea what torque is needed, I just went until it felt correct.
5. Re-install the electronic module onto the motor generator using the reverse of the above steps. Keep everything loose until you get all 4 stand offs back in place and the bolts through them. This was a bit tricky, but not too bad.
6. Snug up and then tighten the 4 bolts holding the module on before fully tightening the electrical connections.
7. Plug in the small round electrical connector.
8. Re-install the black plastic cover. Mine had debris in it from the resolver damage so I cleaned it before putting it back on. Go easy on those little screws. I did not crack the cover but it seemed like it would be easy to do.

At this point the motor generator should be reassembled and ready to put back in the truck. Give it a spin. It should spin nice and smooth. There are no brushes or commutator so it should not have anything dragging or grinding. Just normal friction from bearing grease and seals dragging.

I’ve got one apart right now out of a 2020 etorque hemi and the back bearing was the one that was causing trouble but I’m gonna replace the front bearing to and it measures 25mm ID 62mm OD 17mm thick McMaster carr part number is 6661K126 $43.61 took me a couple hours to get the unit out and apart. Rear bearing is coming today and front bearing is coming tomorrow.

 

[lecmopar]

Install back in the truck is reverse of removal. Again, I do not know what torque requirements are for the bolts. I went by feel. 4 bolts on the front of the MGU and one on the drivers side. Then connect the 48V connection, take caution as it is LIVE, followed by connecting the harness on the passenger side.

Reinstall the belt and unpin the rotary belt tensioner to release it back onto the belt. Check belt routing and alignment and you should be good. Probably make sure you have no extra parts or bolts laying around.

When I fired my truck up after rebuilding the MGU it was as if I never removed it. No lights and no more grinding noises. Everything functions as normal, but I have been disabling the auto start/stop out of caution. System is showing normal voltage and charging fine. As I mentioned above, there was damage in my MGU from the failed bearing so I do intend to have it replaced under warranty when/if parts ever arrive.

I hope this info is helpful to those of you in the same boat. If you have questions let me know and I will do my best to answer. Thanks.

Thank you for the great write-up. just performed the bearing replacements on my 21. We are experiencing some issues. We did both front and rear bearings since we don't know when we will ever see the new MGU. When we re-installed the unit, we are getting the start/stop system failure message. We also had that message before we took the MGU out to replace the bearings. Replaced 12V battery with a new one. We are getting the same voltage reading at the battery whether the engine is running or not. Voltage is slowly decreasing so I believe we are not getting juice from the MGU.

The only thing I can think of is that I installed the reluctor wheel on backwards, but I'm not sure that's possible.
Was your truck displaying a fault message before you pulled your MGU?

Install back in the truck is reverse of removal. Again, I do not know what torque requirements are for the bolts. I went by feel. 4 bolts on the front of the MGU and one on the drivers side. Then connect the 48V connection, take caution as it is LIVE, followed by connecting the harness on the passenger side.

Reinstall the belt and unpin the rotary belt tensioner to release it back onto the belt. Check belt routing and alignment and you should be good. Probably make sure you have no extra parts or bolts laying around.

When I fired my truck up after rebuilding the MGU it was as if I never removed it. No lights and no more grinding noises. Everything functions as normal, but I have been disabling the auto start/stop out of caution. System is showing normal voltage and charging fine. As I mentioned above, there was damage in my MGU from the failed bearing so I do intend to have it replaced under warranty when/if parts ever arrive.

I hope this info is helpful to those of you in the same boat. If you have questions let me know and I will do my best to answer. Thanks.

 

[The_Dude]

Thank you for the great write-up. just performed the bearing replacements on my 21. We are experiencing some issues. We did both front and rear bearings since we don't know when we will ever see the new MGU. When we re-installed the unit, we are getting the start/stop system failure message. We also had that message before we took the MGU out to replace the bearings. Replaced 12V battery with a new one. We are getting the same voltage reading at the battery whether the engine is running or not. Voltage is slowly decreasing so I believe we are not getting juice from the MGU.

The only thing I can think of is that I installed the reluctor wheel on backwards, but I'm not sure that's possible.
Was your truck displaying a fault message before you pulled your MGU?

The rear reluctor/encoder has ultra fine wires on it and if any of them are broken then obviously that is a problem. I'd also check to see if your contact surfaces on the copper flex jumpers are clean and free of corrosion.