NV3500 2nd gear grind

[chino1969]

Got a little bit of a grinding noise when I shift to 2nd gear. Doesn't happen all the time and if I feel it I am able to time the shift so it doesn't grind. It is a 2004 TJ Sport I6 5 speed NV3500 trans.. Synchronizer? No problem downshifting. It has a 3.5" RE lift and a 1" body lift with a 1" lower skid plate. I bought it like this. New trans. fluid Synchromesh 5W30. Did it before and after fluid replace.

 

[TJ_2000]

I’m going to tell you the easiest fix.
I had this EXACT same problem with my NV3550.

Step 1: Remove NV3550

Step 2: Order a brand new AX15

Step 3: Install new AX15.


Seriously. Parts are hard to find for the NV3550 because it’s an out of date transmission that’s no longer made. The AX15 is still being made and used today so parts are easy to fine as well as new units. I spent $300 on a NV3550 “rebuild” kit only for it to not have everything I needed and find the parts I did need was impossible. $300 down the drain.

 

[Jerry Bransford]

Got a little bit of a grinding noise when I shift to 2nd gear. Doesn't happen all the time and if I feel it I am able to time the shift so it doesn't grind. It is a 2004 TJ Sport I6 5 speed NV3500 trans.. Synchronizer? No problem downshifting. It has a 3.5" RE lift and a 1" body lift with a 1" lower skid plate. I bought it like this. New trans. fluid Synchromesh 5W30. Did it before and after fluid replace.

Who's Synchromesh? The Synchromesh from GM and Pennzoil does not have a good reputation among everyone. Redline MTL, a full synthetic, fully meets the requirements for your NV3500 and has a great reputation.

 

[Chris]

I’m going to tell you the easiest fix.
I had this EXACT same problem with my NV3550.

Step 1: Remove NV3550

Step 2: Order a brand new AX15

Step 3: Install new AX15.


Seriously. Parts are hard to find for the NV3550 because it’s an out of date transmission that’s no longer made. The AX15 is still being made and used today so parts are easy to fine as well as new units. I spent $300 on a NV3550 “rebuild” kit only for it to not have everything I needed and find the parts I did need was impossible. $300 down the drain.

This is the reason I always recommend the NV3550. It's not that it's a crappy transmission, it's just a lot harder to find parts for, whereas the AX-15 bolts right in and is much easier to find parts for, as well as entire replacements. Hell, AA sells brand new AX-15s for around $1500 or so.

 

[TJ_2000]

This is the reason I always recommend the NV3550. It's not that it's a crappy transmission, it's just a lot harder to find parts for, whereas the AX-15 bolts right in and is much easier to find parts for, as well as entire replacements. Hell, AA sells brand new AX-15s for around $1500 or so.

That’s exactly who I bought my AX15 from. AA.

 

[chino1969]

I’m going to tell you the easiest fix.
I had this EXACT same problem with my NV3550.

Step 1: Remove NV3550

Step 2: Order a brand new AX15

Step 3: Install new AX15.


Seriously. Parts are hard to find for the NV3550 because it’s an out of date transmission that’s no longer made. The AX15 is still being made and used today so parts are easy to fine as well as new units. I spent $300 on a NV3550 “rebuild” kit only for it to not have everything I needed and find the parts I did need was impossible. $300 down the drain.

Thanks for the reply but I'm not there yet. I'm trying to determine exactly what is causing this in order to prioritize a future fix/replacement. I can live with and work around it now that I am aware of it. If I feel it starting to grind before fully shifting I just pause and then shift with no grind.

 

[Chris]

That’s exactly who I bought my AX15 from. AA.

Yep, hard to beat that price for a brand new transmission!

 

[TJ_2000]

Thanks for the reply but I'm not there yet. I'm trying to determine exactly what is causing this in order to prioritize a future fix/replacement. I can live with and work around it now that I am aware of it. If I feel it starting to grind before fully shifting I just pause and then shift with no grind.

I’m telling. There is no fixing it. I drove for a year with second gear grinding. I wasted $300 to $500 on parts to fix it just to reassemble it and 2nd gear still grind. Parts are impossible to find. Your easiest, safest, and possibly cheapest fix is to swap in a AX15. I’ve been down this very road.

 

[chino1969]

Who's Synchromesh? The Synchromesh from GM and Pennzoil does not have a good reputation among everyone. Redline MTL, a full synthetic, fully meets the requirements for your NV3500 and has a great reputation.

Jerry,
Amsoil 5W30 synthetic.

 

[bromel]

I have the same problem with the NV3550 in my 2000. Upshifting to 2nd when cold produces not so much a grind but a "buzz" you can feel in the shifter. It mostly goes away when the transmission is warmed up. Replacing the fluid with Redline MTL does help significantly, but the problem remains as new oil ultimately can't fix a wearing synchro. I've done countless research on this, and the issue is widespread with these transmissions.

The good news is that you can drive a long, long time with this. I find shifting halfway until I can feel the synchro engage, and then shifting the rest of the way, works fine. If the problem ever gets very bad I'll just swap in a new AX-15, but until then, I've learned to shift more carefully into 2nd and it' second nature now.

 

[chino1969]

I’m telling. There is no fixing it. I drove for a year with second gear grinding. I wasted $300 to $500 on parts to fix it just to reassemble it and 2nd gear still grind. Parts are impossible to find. Your easiest, safest, and possibly cheapest fix is to swap in a AX15. I’ve been down this very road.

Is it that simple? Just swap transmissions? If it is that simple I won't waste time or money on the NV3500 trans. when the time comes. Is the AX15 as rugged?

 

[chino1969]

I have the same problem with the NV3550 in my 2000. Upshifting to 2nd when cold produces not so much a grind but a "buzz" you can feel in the shifter. It mostly goes away when the transmission is warmed up. Replacing the fluid with Redline MTL does help significantly, but the problem remains as new oil ultimately can't fix a wearing synchro. I've done countless research on this, and the issue is widespread with these transmissions.

The good news is that you can drive a long, long time with this. I find shifting halfway until I can feel the synchro engage, and then shifting the rest of the way, works fine. If the problem ever gets very bad I'll just swap in a new AX-15, but until then, I've learned to shift more carefully into 2nd and it' second nature now.

That is exactly how I'm dealing with it and will probably go to the AX15 trans. when the time comes.

 

[TJ_2000]

Is it that simple? Just swap transmissions? If it is that simple I won't waste time or money on the NV3500 trans. when the time comes. Is the AX15 as rugged?

100% bolt in. Only thing different is the reverse plug is on the opposite side but there is enough slack in the harness to reach.

I’m even using the NV3550 bell housing on the AX15.

 

[bromel]

100% bolt in. Only thing different is the reverse plug is on the opposite side but there is enough slack in the harness to reach.

I’m even using the NV3550 bell housing on the AX15.

Were you able to use the original transmission mount for the NV3550 or did you have to buy one for the AX-15? I've heard this is the only issue when swapping.

 

[chino1969]

100% bolt in. Only thing different is the reverse plug is on the opposite side but there is enough slack in the harness to reach.

I’m even using the NV3550 bell housing on the AX15.

Thanks for the info; appreciate it.

 

[TJ_2000]

Were you able to use the original transmission mount for the NV3550 or did you have to buy one for the AX-15? I've heard this is the only issue when swapping.

Same NV3550 transmission mount.