2 years into my 2004 TJ. Newer clutch. Grinds in 2nd gear at any RPM, every time. New fluid. No grindings. Every other gear in sync. I'm not ready for a new clutch...or at least I hope I'm not, yet. SMH.
2nd gear / 2nd year grind
- Thread starter melloyello
- Start date
It’s likely a bad synchronizer in the transmission. The usual fix is to install a remanufactured transmission. My 6 speed also grinds almost solely in 2nd gear, but I’ve developed a workaround method of shifting that I can live with for now.
Before replacing the transmission, try changing the gear oil. Redline MTL is more expensive than most, but has provided a lot of good results for a few forum members. Definitely cheaper than a new transmission, so give it a shot.
There may be some workarounds you can use in the meantime. Before I went to 35” tires, I had 31” tires and 4.10 gears, so I almost exclusively started from 2nd gear. (Now I start from first in most situations.) I’ve learned I can mostly avoid the grind by pausing a specific amount of time while shifting right where the synchronizer ring would be. Occasionally it’s unavoidable, and I’ll have to rev the engine and slam it back into first and shift at 5000 RPM straight to third.
I’ve also found my grind is very rare at higher RPMs. If I shift from 1st to 2nd at 3000+ (ideally 3500-5000 RPM) it almost never grinds.
Bad synchronizers can be caused by a number of issues, most often just ordinary wear and tear. But it can also be caused by other mechanical failures or by abuse. If the clutch doesn’t fully disengage, the synchros will wear significantly faster and the damage will still be there after the clutch is replaced or fixed. Another common cause is slam-shifting. It’s not a sports car, but some people treat it like one and try to slam the shifter into gear or use a lot of force to get it in gear quicker. This will quickly trash a synchronizer. Clutchless shifting will also cause premature wear if not executed perfectly.
Before replacing the transmission, try changing the gear oil. Redline MTL is more expensive than most, but has provided a lot of good results for a few forum members. Definitely cheaper than a new transmission, so give it a shot.
There may be some workarounds you can use in the meantime. Before I went to 35” tires, I had 31” tires and 4.10 gears, so I almost exclusively started from 2nd gear. (Now I start from first in most situations.) I’ve learned I can mostly avoid the grind by pausing a specific amount of time while shifting right where the synchronizer ring would be. Occasionally it’s unavoidable, and I’ll have to rev the engine and slam it back into first and shift at 5000 RPM straight to third.
I’ve also found my grind is very rare at higher RPMs. If I shift from 1st to 2nd at 3000+ (ideally 3500-5000 RPM) it almost never grinds.
Bad synchronizers can be caused by a number of issues, most often just ordinary wear and tear. But it can also be caused by other mechanical failures or by abuse. If the clutch doesn’t fully disengage, the synchros will wear significantly faster and the damage will still be there after the clutch is replaced or fixed. Another common cause is slam-shifting. It’s not a sports car, but some people treat it like one and try to slam the shifter into gear or use a lot of force to get it in gear quicker. This will quickly trash a synchronizer. Clutchless shifting will also cause premature wear if not executed perfectly.
Airjunky
TJ Enthusiast
Same here. New clutch, Redline MTL added, still grinds going into 2nd.
Slow down on your shifts like tworley suggests.
It's a tractor, not a sports car, not really meant to slam gears or speed shift.
Slow down on your shifts like tworley suggests.
It's a tractor, not a sports car, not really meant to slam gears or speed shift.
Thank you so much for the response. All of this makes total sense and will try the fluid first. I'm on mostly flat lands so it starts in 1st gear regularly. It's just that damn move to 2nd. Going to do some RPM testing too.
Yep. This is truly a 'truck' and I shift it as such. Thanks again!
Yep. Did that for a little. Worked for a little. Now I'm waiting 3 - 5 seconds and it's still grinding. Going to look into changing out the fluid first. Thanks for the response. Only joined the forum and hour ago. This is awesome!
Absolutely. It's a big motor. I do take it slow. I'll check back in after adding the new juice.
The NV3550 in my 2000 doesn't so much grind as "buzz" into 2nd if I shift it quickly when cold. Usually I shift halfway, wait to feel the synchro engage, then complete the shift. When the transmission has warmed up a bit, I can make the shift straight without a buzz, but I typically wait a split second first. Redline MTL helped the situation, but not entirely. I figure it will go a long, long way like this, and when the synchro gives out entirely, I'll swap in a new AX-15.
If you end up needing to replace the transmission, consider replacing your NV3550 with an AX-15 transmission. The NV3550 is no longer in production, and you will only find used or remanufactured units at a premium.
The AX-15 was the 5-speed that preceded the NV3550, and is considered to be just as strong. After the NV3550 went out of production, several aftermarket companies were able to source brand new AX-15 transmissions. The AX-15 is a direct bolt in swap for the NV3550 and can be found brand new for $1,500.
These websites will have more details on both transmissions:
https://www.novak-adapt.comhttps://advanceadapters.com
Edit:
Looks like you beat me to it
Note that the later 6-speed NSG370 is not a bolt in swap.
The AX-15 was the 5-speed that preceded the NV3550, and is considered to be just as strong. After the NV3550 went out of production, several aftermarket companies were able to source brand new AX-15 transmissions. The AX-15 is a direct bolt in swap for the NV3550 and can be found brand new for $1,500.
These websites will have more details on both transmissions:
https://www.novak-adapt.comhttps://advanceadapters.com
Edit:
Looks like you beat me to it
Note that the later 6-speed NSG370 is not a bolt in swap.
Worst case you can double clutch the trans. Clutch pedal in, shift out of 1st to neutral. Clutch pedal out. Clutch pedal in, shift into 2nd.
This is (was) how most tractors are shifted. They had no syncros at all in them. I have heard that's how the big rigs are shifted also, tho I think they are predominantly auto now.
This is (was) how most tractors are shifted. They had no syncros at all in them. I have heard that's how the big rigs are shifted also, tho I think they are predominantly auto now.
Clutchless shifting is quite popular for larger rigs. Much more difficult on small cars though
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