Transmission rubbing sound

[Mad dog Slim]

I've had my 2002 manual TJ for 4 years now. It has always had this rubbing whirring sound coming from the transmission or gear box area. It occurs when I let off the gas. The noise slightly decreases when I engage the clutch. I've had all gear oils and transmission oils replaced. My clutch works fine. Do you think it is throw out bearing? I've read one post that say to put in heavier oils. Other posts seem to say this is normal. I believe the previous owner towed the jeep behind an RV as it has the tow bar attachments on the bumber and my jeep had only 80k miles on it when purchased. Help on this matter will be greatly appreciated! Thanks

 

[Jamison C]

Is it rubbing or rumbling? Like it’s full of marbles? The NV3550 is a noisy transmission to begin with. The one on my 2002 wasn’t too bad but the one on my current 2000 is ridiculously loud. Sound goes away when I push in the clutch.

 

[Mobusaki]

I have the NV3550 as well and it is noisy at idle (the full of marbles description is pretty good) until I disengage the clutch (ie, push the clutch pedal) or put it in gear and go. It may still be noisy in gear but at that point other sounds start to take over.

As long as it is shifting fine and your fluid level is fine I wouldn't be worried.

 

[Jerry Bransford]

The transmission's input shaft and bearings are constantly being spun by the engine until you step down on the clutch to disconnect it. The spinning/whirring sound that is very audible when the transmission is in Neutral with the clutch pedal released is normal.

 

[Mad dog Slim]

Hi there. It's a rubbing sound. Metallic sounding. I never paid it much mind because in the army in the 80s the old jeeps made that sound. My friend is the one that pointed it out to me.

 

[Mad dog Slim]

Hi there. It's a rubbing sound. Metallic sounding. I never paid it much mind because in the army in the 80s the old jeeps made that sound. My friend is the one that pointed it out to me.

 

[Mad dog Slim]

Is it rubbing or rumbling? Like it’s full of marbles? The NV3550 is a noisy transmission to begin with. The one on my 2002 wasn’t too bad but the one on my current 2000 is ridiculously loud. Sound goes away when I push in the clutch.

I would say it's a metallic rubbing sound.

 

[Mad dog Slim]

Is it rubbing or rumbling? Like it’s full of marbles? The NV3550 is a noisy transmission to begin with. The one on my 2002 wasn’t too bad but the one on my current 2000 is ridiculously loud. Sound goes away when I push in the clutch.

I think it's more rubbing but maybe I guess you could say sounds like marbles. So it's kind of normal huh. I got concerned and got a quote to change the clutch and all but maybe I can hold off on that since my clutch works fine. Any reason why it's so noisy? It just dosnt seem right. Thank you for your responses!

 

[Mad dog Slim]

I have the NV3550 as well and it is noisy at idle (the full of marbles description is pretty good) until I disengage the clutch (ie, push the clutch pedal) or put it in gear and go. It may still be noisy in gear but at that point other sounds start to take over.

As long as it is shifting fine and your fluid level is fine I wouldn't be worried.

Thank you so much for the info. Do you think a heavier oil will help with the noise?

 

[Mad dog Slim]

The transmission's input shaft and bearings are constantly being spun by the engine until you step down on the clutch to disconnect it. The spinning/whirring sound that is very audible when the transmission is in Neutral with the clutch pedal released is normal.

Thank you for your reply. I feel better about it now.

 

[Jamison C]

I think it's more rubbing but maybe I guess you could say sounds like marbles. So it's kind of normal huh. I got concerned and got a quote to change the clutch and all but maybe I can hold off on that since my clutch works fine. Any reason why it's so noisy? It just dosnt seem right. Thank you for your responses!

Hey sorry I’ve been moving and fixing the parking brake on my Jeep today. If it’s shifting fine I wouldn’t worry about it. I’ll take a video just so you can see how loud mine is and see if you can compare it to yours.

Redline MTL is the forum recommendation for fluid. It quieted my last one down and I plan to do the same with my current one.

 

[Mad dog Slim]

Thank you. You are very kind. I'm up here in Page enjoying all the desert canyons here.

 

[Flivver250]

I found avery low mileage NV3550 to replace my original one which was a sloppy box of rocks. New clutch assembly, Red Line MTL and now it runs, shifts and sounds new. Still a noisy box of marbles at idle, just a lot less so. It is the nature of the best.

 

[Mobusaki]

You can post a video of the sound if you want us to listen. Would give you more piece of mind I'm sure. As for the fluid, when I was trying to find a fluid to improve shifting on cold mornings I ended up using Royal Purple Synchromesh because I could not find the Redline in a store. It seemed like a big improvement.

 

[Mad dog Slim]

Thank you so much for the info. I'll try the red line mtl. To everyone that responded I give a heartfelt thank you!! Happy Jeeping!!

 

[Mad dog Slim]

Oh

You can post a video of the sound if you want us to listen. Would give you more piece of mind I'm sure. As for the fluid, when I was trying to find a fluid to improve shifting on cold mornings I ended up using Royal Purple Synchromesh because I could not find the Redline in a store. It seemed like a big improvement.

Thanks for the tip on the oil if I can't find red line.