I've currently got a 05' Z with an AT that has been sitting in a garage the last 5 months since I've been overseas but was having some issues before I took it home. Prior to driving it home to Ohio from California it was starting to slip, and it was having issues going into reverse after it was warm. Before driving it home, the dealership looked it over while I had my oil changed along with everything else and suggest that I just get a new transmission through them costing nearly $5,000. Obviously it made it back to Ohio, and it still continued to slip from time to time. One night it wouldn't go past 3k before I had to manually shift, and then the next day it was running fine again. Anyone have any suggestions before I have to go and spend a few months pay on having it replaced? I plan on flushing it when I get home, as well as installing a TransGo Valve Body Upgrade along with a Z1 Rear Diff Upgrade, and see if things will go smoother.

 

Nissan dealers seem to be very lazy about actually diagnosing problems. Since this model of transmission was used in most all of the Nissan trucks and SUVs as well as a lot of Infinity cars, independent transmission specialists are familiar with its quirks and can give you a much better analysis of the problem. In years past a member here had a similar issue, the Nissan dealer didn’t identify the cause and just suggested a complete replacement at a sky-high cost. A trans specialist preformed a simple pressure test and was able to identify the problem and give a detailed estimate of repair cost.

 

I sure would get the trans fluid chaged.Could be that from the car sitting up all those months it got things clogged and added moisture.THere are additives that work
to clear some of this up.I had a Alfa that was prone to not shift in super hot
weather.A Lambo tech recommended a additive that reduced the heat of the fluid.
It ran fine.I think the cold weather is a factor.I sure would not do a TransGo until
it runs perfectly.Have you had a tune?I've got a AT.One mod I had done when it was tuned is to increase the line pressure.This resulted in crisper shifts.Z1 did the tune.

 

There's no condensation in your transmission, let me clear that up right now.

Do not add a shift kit, and do not flush it either. You can do a fluid exchange using a fluid exchange machine, but no flush. It shouldn't slip now, so adding a shift kit would be foolish.

What do you mean wouldn't go past 3k rpm? The engine wouldn't rev past 3k?
I think you may have an electrical issue, but you should start by having the transmission codes read, if they exist. Then make sure the fluid level is up and do a complete ecu reset. You can also unhook the battery for 24 hours to guarantee a good reset of everything. Then drive normal for 30 miles so the trans can learn your habits.

 

Not true. Many codes will not reset simply by disconnecting the battery. The car needs to be hooked into an appropriate scan tool that can check and clear transmission DTCs.

I do agree that all codes be scanned prior to doing anything else. This will require a better tool than your typical $39 Actron.

As far as Nissan is concerned about wanting $5K for a new transmission without even trying to diagnose the problem... yeah, how typical.

 

Not true huh? Whatever. You do know that some codes will re-appear instantly right? 24 hours is more than enough to erase codes.

 

Self-edited because I'm not a douchebag.

 

Typical dealership, not properly diagnosing the issue and suggesting a major repair.

They make a ton of money on people that believe this crap. They tried to tell me a new clutch and flywheel would cost me $1,500 plus tax. No thanks.

It sounds there could be some pending or ready codes. Could need the nissan consult II machine to properly look at the issues. If it wouldn't go past 3k rpm while driving sounds like it can't find the right gear or something.

Flushing an auto trans is never a good idea