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Gritty and rough shifting

Outdoordude

New Member
Joined
Nov 3, 2019
Messages
8
Location
Michigan
I have a 2000 TJ with 91k miles and just with in the last week or so Iv noticed the shifting had gotten pretty rough. First gear is really no issue but second gear feels gritty like it wants to get hung up. Third gear is the same way and forth is too. Nothing feels smooth anymore. Iv only had the Jeep a for a month and the thing drove very smooth until now. I’m not hard on it either. Plenty of pressure on the clutch pedal too.
 

Steel City 06

TJ Addict
Joined
Mar 12, 2019
Messages
1,523
Location
Pittsburgh, PA
I have a 2000 TJ with 91k miles and just with in the last week or so Iv noticed the shifting had gotten pretty rough. First gear is really no issue but second gear feels gritty like it wants to get hung up. Third gear is the same way and forth is too. Nothing feels smooth anymore. Iv only had the Jeep a for a month and the thing drove very smooth until now. I’m not hard on it either. Plenty of pressure on the clutch pedal too.
This could be a couple things. If the clutch is not completely disengaging, it will make shifting into all gears difficult.

Try this:
Shift into first gear and 4 low on flat ground. Take the parking brake off. Hold the clutch pedal all the way down and rev the engine. The jeep should not move. If it does, there's an issue with disengaging the clutch. If not, it's probably the transmission going bad.

Next step is to change the fluid in the transmission. We generally recommend Redline MTL. It may take a few days for it to improve, if it does.

If it still does not improve, you may need a new transmission. With the NV3550, there are no new units left. You can buy a remanufactured unit for around $2000. A better option is an AX-15 retrofit. The AX-15 was offered in Jeeps up through 1999. And it's actually back in production, so you can buy a brand new AX-15 for about $1600. There's a couple parts you have to swap, but for the most part it's almost a perfect swap.

Here's one source:
 
OP
O

Outdoordude

New Member
Joined
Nov 3, 2019
Messages
8
Location
Michigan
This could be a couple things. If the clutch is not completely disengaging, it will make shifting into all gears difficult.

Try this:
Shift into first gear and 4 low on flat ground. Take the parking brake off. Hold the clutch pedal all the way down and rev the engine. The jeep should not move. If it does, there's an issue with disengaging the clutch. If not, it's probably the transmission going bad.

Next step is to change the fluid in the transmission. We generally recommend Redline MTL. It may take a few days for it to improve, if it does.

If it still does not improve, you may need a new transmission. With the NV3550, there are no new units left. You can buy a remanufactured unit for around $2000. A better option is an AX-15 retrofit. The AX-15 was offered in Jeeps up through 1999. And it's actually back in production, so you can buy a brand new AX-15 for about $1600. There's a couple parts you have to swap, but for the most part it's almost a perfect swap.

Here's one source:
Out of curiosity how does a Jeep with 90k miles start to go bad in a month?
 

Steel City 06

TJ Addict
Joined
Mar 12, 2019
Messages
1,523
Location
Pittsburgh, PA
Out of curiosity how does a Jeep with 90k miles start to go bad in a month?
Not quite sure. Most manual transmission problems are gradual. It's possible the previous owner noted it was going bad and decided to sell rather than repair it.

It could also be improper shifting. Slam-shifting or shifting very aggressively is a sure-fire way to destroy the synchronizers. When shifting, I will simply gently hold it against the synchro until the gears line up and let it in. Use of any significant force will accelerate synchro wear. (Even worse is clutchless shifting, unless done perfectly.) Some manual drivers also pick up the bad habit of beginning to let out the clutch before the gear is fully engaged, or not pushing the clutch all of the way to the floor when shifting. It's not a mustang transmission; nor is it an 18-speed.

If there's leakage in the master/slave clutch cylinders, it will cause shifting issues.