Transmission grinding

[HarryG]

Hey y’all. About 2 weeks ago my 04 tj started making a weird grinding/ rattling noise when I put it in reverse. So I got my transmission flushed and since then it has made even worse noises.

I’ve been driving stick for over a year and never heard these noises. Ever time I put the clutch in and go from first to second there is a huge grinding noise. When I let off the clutch the noise begins again until the clutch is fully released. This also happens when I go into third.

I thought it might be my pilot bearing but I just replaced my clutch, flywheel and pilot bearing with stage 2 clutch kit and steel flywheel, about a month and a half ago.

please help with any advice!!!

 

[glowell222]

This is really starting to sound like the synchros are going bad. How many miles and what year is your rig? Also, and I hate to ask, how is the clutch fluid reservoir? Are you low? Either your synchros are going out or you are not getting the full disengagement when you are pushing in the clutch pedal.

 

[HarryG]

This is really starting to sound like the synchros are going bad. How many miles and what year is your rig? Also, and I hate to ask, how is the clutch fluid reservoir? Are you low? Either your synchros are going out or you are not getting the full disengagement when you are pushing in the clutch pedal.

Just over 100,000 miles. Do you know Mitch about synchro mesh fluid?

 

[glowell222]

We are talking about 2 different fluids here. First there is the manual transmission gearbox fluid, which you say you had flushed. This fluid helps to lubricate the synchronizing gears. What year is your Jeep? Different years had different gearbox fluid requirements. If this is the incorrect fluid, your synchronizing gears can get chewed up. Same if the fluid is low.

Did you install the clutch yourself? Did you change the gearbox fluid yourself?

Second, there is the clutch slave cylinder fluid, and this is shared with the brake fluid. You can check this fluid level under the hood-consult your owner's manual. If the fluid level is low, the clutch slave cylinder may not fully engage or disengage the pressure plate and this may be causing your grinding.

 

[Fonz54]

2004 TJs use the NV3550 transmission. While it does sound like there might be some worn syncros, I would try changing the trans fluid and use Redline MTL. It is not cheap but worked miracles for my 04 with NV3550. The NV 3550 uses brass components. If you use the incorrect type oil it may cause premature wear of the brass components.

https://www.amazon.com/review/RE8VPGS70KSCV?tag=wranglerorg-20

 

[Jerry Bransford]

2004 TJs use the NV3550 transmission. While it does sound like there might be some worn syncros, I would try changing the trans fluid and use Redline MTL. It is not cheap but worked miracles for my 04 with NV3550. The NV 3550 uses brass components. If you use the incorrect type oil it may cause premature wear of the brass components.

https://www.amazon.com/review/RE8VPGS70KSCV?tag=wranglerorg-20

If the Synchromesh gear lube used in the transmission was from GM or Pennzoil (which makes it a conventional not a synthetic gear lube), it's not a good lube even though it technically meets the minimum specs for the transmission. Many report degraded shifting qualities after filling with GM or Pennzoil Synchromesh.

X2 to the recommendations for Redline MTL, a synthetic. It's as good of a lube for the NV3550 and NSG 370 as there is.

 

[Goatman]

X3 Redline. When I got my 06 I could hardly find R. 6th was near impossible to go into. Flushed and new fluid almost made it worse. Guys here pushed me to spendy MTL. After about a month of crappy shifting I gave in. Trans started to feel smoother almost imedeatly. After a short time R and 6th are easy to find. I was truly impressed what a different (the right) brand of fluid could do.

 

[Rubicon88]

Hey y’all. About 2 weeks ago my 04 tj started making a weird grinding/ rattling noise when I put it in reverse. So I got my transmission flushed and since then it has made even worse noises.

I’ve been driving stick for over a year and never heard these noises. Ever time I put the clutch in and go from first to second there is a huge grinding noise. When I let off the clutch the noise begins again until the clutch is fully released. This also happens when I go into third.

I thought it might be my pilot bearing but I just replaced my clutch, flywheel and pilot bearing with stage 2 clutch kit and steel flywheel, about a month and a half ago.

please help with any advice!!!

This sounds like your TO is not working properly or bad. I know you said got a new one but new parts at times can be junk right out the box. Sadly.

Your clutch fluid....level and condition?

Lastly...noise in neutral?
Does the noise change? Example...a cold start in neutral (noise) vs. Running after warmed up in neutral (noise)

Does the noise change no matter neutral or gear cold vs operating temp?

 

[01TJ-Blues]

This sounds like your TO is not working properly or bad. I know you said got a new one but new parts at times can be junk right out the box. Sadly.

Your clutch fluid....level and condition?

Lastly...noise in neutral?
Does the noise change? Example...a cold start in neutral (noise) vs. Running after warmed up in neutral (noise)

Does the noise change no matter neutral or gear cold vs operating temp?

X2 here. Try feathering the clutch in neutral and as if you are taking off in first second and third. If it’s the TO is should make the same noise but at a stand still so you can really pin point it.