4th to 5th gear is a bear

[03swap]

New to this forum. I recently swapped my 03 with a nv5600 after burning up 2 48re’s. I drove it around town for about 200 miles before taking it on my hour journey to work so my wife could drive my gas getter. I got about 20 miles down the road and for the life of me could not shift into 5th from 4th. If I go from 4-6 I can down shift to fifth no problems and forgot feels great. Any one have any advice or insights on why this might be?

 

[RVTRKN]

Do you have the history on the NV5600, syncro could be the issue? However my NV5600 was always a bear from 4th to 5th. Try different RPM's when going into 5th.

 

[03swap]

Do you have the history on the NV5600, syncro could be the issue? However my NV5600 was always a bear from 4th to 5th. Try different RPM's when going into 5th.

I tried several different rpms just couldn’t get it to go. I’ve been researching into it and I’ve heard lots of guys say they are a bear when it’s cold out. It was 45 this morning vs 70-80 all the other times I’ve drove it. It cane out of a truck with 90,000 miles. I scanned the truck when I got home cause the CEL was on and it gave me a accelerator position sensor code. I don’t know if maybe that could be contributing? It wouldn’t let me get above 2200 rpm or so towards the end of my drive. This is the first 5600 I’ve drove so I don’t really have anything to go off

 

[RVTRKN]

Is the truck a 4X4?

 

[03swap]

Is the truck a 4X4?

Yes I have a 241dhd behind it now

 

[RVTRKN]

Warm it up with the transfer case in neutral and trans in gear, I always put it in 4th gear. It is what I did, because it was a stiff trans cold.

 

[03swap]

Warm it up with the transfer case in neutral and trans in gear, I always put it in 4th gear. It is what I did, because it was a stiff trans cold.

I’ll have to try that thanks! Would you happen to know what the accelerator position sensor would control?

 

[AH64ID]

Did you put new fluid in it? If so, what fluid?

My NV5600 never had any shifting issues, even in sub-zero temps. I only ever would warm up the trans when it was well below 0°F. My only issue was the occasional difficulty getting into gear when stopped and a warm trans (never an issue cold or hot)... but that was more clutch related I think.


The accelerator position will likely be the issue getting above 2200 rpms. It shouldn't have any effect on your shifting thou.

 

[03swap]

Did you put new fluid in it? If so, what fluid?

My NV5600 never had any shifting issues, even in sub-zero temps. I only ever would warm up the trans when it was well below 0°F. My only issue was the occasional difficulty getting into gear when stopped and a warm trans (never an issue cold or hot)... but that was more clutch related I think.


The accelerator position will likely be the issue getting above 2200 rpms. It shouldn't have any effect on your shifting thou.

I used 6 quarts of penzoil synchromesh

 

[RVTRKN]

That is the correct oil, I don't remember the quantity, but the trick is to fill to proper level then add one quart. I would pull up onto a curb causing the truck to lean, with the filler hole high, then pump in 1 quart.

 

[AH64ID]

I used 6 quarts of penzoil synchromesh

Should be good, and shouldn't need to warm up in those temps.

Does it shift fine now that it's cooled off?

 

[AH64ID]

That is the correct oil, I don't remember the quantity, but the trick is to fill to proper level then add one quart. I would pull up onto a curb causing the truck to lean, with the filler hole high, then pump in 1 quart.

IIRC 4.75qts was the OE spec, so 6 QTS is good.

 

[03swap]

Should be good, and shouldn't need to warm up in those temps.

Does it shift fine now that it's cooled off?

I don’t know I took it back home and got my car before I got to far down the highway. Driving back home I managed to shift from 4-5 but I had to take 4th all the way too 55mph

 

[RVTRKN]

To further explain my NV5600, when new I would mistaken 3rd for 5th because I thought I passed the gate for 5th. Man, I did that only a few times until I learned the trans.

 

[NIsaacs]

To further explain my NV5600, when new I would mistaken 3rd for 5th because I thought I passed the gate for 5th. Man, I did that only a few times until I learned the trans.

OP, since you came from an auto to the 6speed, is it possible you are manhandling the stick too much and going to reverse?

 

[petersonj]

I tried several different rpms just couldn’t get it to

Depending on your technique, your test may not be valid. If you match engine rpm's to the road speed for 5thgear, then the transmission should easily slip into gear. BUT, you must match the rprm's while the transmission is passing through neutral AND the clutch pedal is NOT pushed in.

for the life of me could not shift into 5th from 4th

Try this. Without the engine running shift through all of the gears. Starting from neutral, the shifter should default to be in alignment with 3rd and 4th. Move the shifter to the right against a light spring and the shifter should be in alignment with 5th and 6th. Move the shifter further to the right against a heavier spring and the shifter should be in alignment with reverse. Not being familiar with this transmission, you may be pushing the shifter too far to the right when shifting from 4th to 5th (it can be difficult to learn the feel of the end of travel against the lighter spring, thus the shifter ends up between 5th and reverse gate).

- John

 

[03swap]

OP, since you came from an auto to the 6speed, is it possible you are manhandling the stick too much and going to reverse?

I did a couple times this morning. I need to drive it again after work, I thinking I may have missed 5th then kept screwing my self up from getting stressed out.

 

[03swap]

Depending on your technique, your test may not be valid. If you match engine rpm's to the road speed for 5thgear, then the transmission should easily slip into gear. BUT, you must match the rprm's while the transmission is passing through neutral AND the clutch pedal is NOT pushed in.



Try this. Without the engine running shift through all of the gears. Starting from neutral, the shifter should default to be in alignment with 3rd and 4th. Move the shifter to the right against a light spring and the shifter should be in alignment with 5th and 6th. Move the shifter further to the right against a heavier spring and the shifter should be in alignment with reverse. Not being familiar with this transmission, you may be pushing the shifter too far to the right when shifting from 4th to 5th (it can be difficult to learn the feel of the end of travel against the lighter spring, thus the shifter ends up between 5th and reverse gate).

- John

Thanks for the write up I’ll have to look into my technique. My biggest problem I think is I’m driving it like manuals I’m used to and shifting fast.

 

[GCroyle]

Shift it slower, out of 4 slight pause in N then go for 5th. It's like 3 moves.

That's a big trans, disc etc IMHO it doesn't like speed shifting or even quick shifting some times.

 

[Prairie Dog]

At 120K, mine shifts better than ever and seems to have finally "broken in".
I've never had any issues with 5th gear though. A little sticky going down to 3rd but no problem anywhere else.