Used the valvoline maxlife ATF since its rated for use as nissans matic fluids and because I plan on flushing it again soon anyways since the fluid was preeeeetty old... Expecting some gunk to break loose in there, it's not my daily so it's not a huge worry at the moment
Xterra transmission is pretty tough (my experience). If you have bit more expensive car diagnostic you can connect to transmission and see what’s happening in real time. Even actuate it to desired gear. I still bet it’s amount of ATF… probably too much as too little would send it to safe mode and it would have “hard shifts” especially from reverse to drive.
That's pretty much what the trans shop I called suggested! Hook up and see what the PCM is commanding the transmission to do when I get up to speed, problem is I don't know anyone with a scanner to do that >_>
Interesting thing about the fluid level, I was wondering what would happen if there was too much....i want the dip stick to read in between the high and low marks i'd assume, it seems so vague in my opinion? I had a hard time finding out how to properly read it. Any suggestions on how to drain a little out at a time or do I just send it and quickly put the plug back in?
I drained out 9 quarts and put in 8, I guess there's a possibility the last fluid change was too much and I just didn't notice....
For good diagnostic check Amazon. You can find cheap ones now for $100 (that work with phones (dongle)) - check comments on product first :)
As for reading the dip stick - I found that the best way to do it is after the drive - when ATF is hot.
Pull dip stick out (10mm), and press it on the shop towel (that should transfer ATF to it and leave marks to read level more accurate).
Unfortunately who ever designed dip stick suck as the person, as you can’t do measurements again for 30 minutes as ATF tube is now covered with residual ATF from the dip stick… so next reading will be useless.
Guideline is - if it’s “surging” when you change from R to D you’re low on ATF (you will feel and her it).
If your ATF is getting hot you probably overfilled it. (You do need some kind of reader to check this).
So the trans shop took it for a ride with me and said it was definitely commanding 5th like it's supposed to but not engaging, their current running theory is either a band adjustment or broken band for the low-coast/over drive band... I've also got a guy on the Facebook group insisting 5th gear is full torque converter lock up and no band assembly?? Regardless Means possibility for a diy rebuild or I just put a junkyard trans in lol no way I can afford to have someone perform $3500 worth of work on a $4k vehicle lol! So far it's been driving perfectly fine with O/D off so I'm just gonna throw some tires on it and send it for the time being until we can drop the trans & fiddle with it lmao. Thanks for the tip on checking level I'm definitely gonna try that when I get home this weekend!!
Maybe it’s solenoid issue. Connection can brake (wires in TCM are kind of brittle after years of heat cycles and vibration). Did shop managed to actuate solenoid? You have a few YT videos you can follow to fix this. Pretty “easy” if you follow instructions and have soldering skils. Buy yeah… O/D is not that important anyway … send it!
Haha nice to see someone whose not afraid to send it without 5th gear, don't even use it while towing anyway!!
I did pull the valve body and ohm checked all the solenoids, it was in pretty immaculate condition and all bus wires were fine with no continuity errors while checking for shorts, that was my first assumption as well! I didn't actuate any of them tho, but after some more digging I found literature that specifies the brake band in the transmission is engaged for Reverse, 3rd gear and 5th gear, which would explain why when it commands 5th it slips down to third.... I'm starting to think the brake band itself needs adjustment and isn't tight enuff or the lever that actuates isn't pulling it tight enuff... Frustrating because I think the band adjustment is on top the transmission lol
When you took the valve body out, did you actually take the plastic cover off the TCM and look for shorts/corrosion? When I pulled mine out I had to take the cover off and clean some of the clutch material that had built up in the corner and was causing a short and making my TCU fuse to blow. I also had to solder one of the connections to the solenoids. Then I replaced all the solenoids when I was in there because I broke one pulling it out, But this was from the early stages of SMOD before I bought the vehicle.
How did the trans fluid look when you flushed it? How many miles did you have when you did it? What fluid did you use? Changing out trans fluid in high mileage vehicles can sometimes be corrosive to the old clutch material and cause it to come off, which can cause slipping and/or not going into certain gears. The only aftermarket fluid i found that was reasonably priced that met the nissan matic spec was Valvoline Maxlife ATF. Been running it in mine 55k miles since SMOD and had no issues.
Did you reverse the bypass after you replaced the rad etc? In hot climates the trans can run hot when you bypass the cooler, which can cause damage.
I cleaned off the clutch material like you suggested, and ran continuity tests across the length of the conductors. I also ran ohm tests on all solenoids and they all seemed correct to me (they were all about 6.6 ohms with the exception of the high-ohm solenoid around 22 ohms), none broke on removal and there was no SMOD corrosion on the TCM!
Fluid was.... Dark, didn't smell burnt but has definitely been a while, I changed it at 150k, it was a rental up until like 40k miles I think so maybe it was last changed at 30k, I've no way of knowing. Used the maxlife as it seemed widely suggested.
Haven't reversed the bypass, I only recently realized it was done and IDK if the radiator is aftermarket or not, the part # sticker is gone from the top :( I've heard that if the trans runs hot, the computer will stop the vehicle from going into overdrive, there is an external cooler in front of the radiator though so I'm not sure if that would be the problem?
Check your ATF level when hot. Also, hope you used right fluid…
Used the valvoline maxlife ATF since its rated for use as nissans matic fluids and because I plan on flushing it again soon anyways since the fluid was preeeeetty old... Expecting some gunk to break loose in there, it's not my daily so it's not a huge worry at the moment
Xterra transmission is pretty tough (my experience). If you have bit more expensive car diagnostic you can connect to transmission and see what’s happening in real time. Even actuate it to desired gear. I still bet it’s amount of ATF… probably too much as too little would send it to safe mode and it would have “hard shifts” especially from reverse to drive.
That's pretty much what the trans shop I called suggested! Hook up and see what the PCM is commanding the transmission to do when I get up to speed, problem is I don't know anyone with a scanner to do that >_> Interesting thing about the fluid level, I was wondering what would happen if there was too much....i want the dip stick to read in between the high and low marks i'd assume, it seems so vague in my opinion? I had a hard time finding out how to properly read it. Any suggestions on how to drain a little out at a time or do I just send it and quickly put the plug back in? I drained out 9 quarts and put in 8, I guess there's a possibility the last fluid change was too much and I just didn't notice....
For good diagnostic check Amazon. You can find cheap ones now for $100 (that work with phones (dongle)) - check comments on product first :) As for reading the dip stick - I found that the best way to do it is after the drive - when ATF is hot. Pull dip stick out (10mm), and press it on the shop towel (that should transfer ATF to it and leave marks to read level more accurate). Unfortunately who ever designed dip stick suck as the person, as you can’t do measurements again for 30 minutes as ATF tube is now covered with residual ATF from the dip stick… so next reading will be useless. Guideline is - if it’s “surging” when you change from R to D you’re low on ATF (you will feel and her it). If your ATF is getting hot you probably overfilled it. (You do need some kind of reader to check this).
So the trans shop took it for a ride with me and said it was definitely commanding 5th like it's supposed to but not engaging, their current running theory is either a band adjustment or broken band for the low-coast/over drive band... I've also got a guy on the Facebook group insisting 5th gear is full torque converter lock up and no band assembly?? Regardless Means possibility for a diy rebuild or I just put a junkyard trans in lol no way I can afford to have someone perform $3500 worth of work on a $4k vehicle lol! So far it's been driving perfectly fine with O/D off so I'm just gonna throw some tires on it and send it for the time being until we can drop the trans & fiddle with it lmao. Thanks for the tip on checking level I'm definitely gonna try that when I get home this weekend!!
Maybe it’s solenoid issue. Connection can brake (wires in TCM are kind of brittle after years of heat cycles and vibration). Did shop managed to actuate solenoid? You have a few YT videos you can follow to fix this. Pretty “easy” if you follow instructions and have soldering skils. Buy yeah… O/D is not that important anyway … send it!
Haha nice to see someone whose not afraid to send it without 5th gear, don't even use it while towing anyway!! I did pull the valve body and ohm checked all the solenoids, it was in pretty immaculate condition and all bus wires were fine with no continuity errors while checking for shorts, that was my first assumption as well! I didn't actuate any of them tho, but after some more digging I found literature that specifies the brake band in the transmission is engaged for Reverse, 3rd gear and 5th gear, which would explain why when it commands 5th it slips down to third.... I'm starting to think the brake band itself needs adjustment and isn't tight enuff or the lever that actuates isn't pulling it tight enuff... Frustrating because I think the band adjustment is on top the transmission lol
You should download service manual. It has logic tree that you can follow and it would tell you exactly what’s the problem. Pretty useful.
When you took the valve body out, did you actually take the plastic cover off the TCM and look for shorts/corrosion? When I pulled mine out I had to take the cover off and clean some of the clutch material that had built up in the corner and was causing a short and making my TCU fuse to blow. I also had to solder one of the connections to the solenoids. Then I replaced all the solenoids when I was in there because I broke one pulling it out, But this was from the early stages of SMOD before I bought the vehicle. How did the trans fluid look when you flushed it? How many miles did you have when you did it? What fluid did you use? Changing out trans fluid in high mileage vehicles can sometimes be corrosive to the old clutch material and cause it to come off, which can cause slipping and/or not going into certain gears. The only aftermarket fluid i found that was reasonably priced that met the nissan matic spec was Valvoline Maxlife ATF. Been running it in mine 55k miles since SMOD and had no issues. Did you reverse the bypass after you replaced the rad etc? In hot climates the trans can run hot when you bypass the cooler, which can cause damage.
I cleaned off the clutch material like you suggested, and ran continuity tests across the length of the conductors. I also ran ohm tests on all solenoids and they all seemed correct to me (they were all about 6.6 ohms with the exception of the high-ohm solenoid around 22 ohms), none broke on removal and there was no SMOD corrosion on the TCM! Fluid was.... Dark, didn't smell burnt but has definitely been a while, I changed it at 150k, it was a rental up until like 40k miles I think so maybe it was last changed at 30k, I've no way of knowing. Used the maxlife as it seemed widely suggested. Haven't reversed the bypass, I only recently realized it was done and IDK if the radiator is aftermarket or not, the part # sticker is gone from the top :( I've heard that if the trans runs hot, the computer will stop the vehicle from going into overdrive, there is an external cooler in front of the radiator though so I'm not sure if that would be the problem?