yes, I'm well aware that driving it hard could ruin it. My thought was it was already ruined so why not..

The TC is stock. Fluid is good, changed it again recently to amsoil and problem still exists. I've always kept up with fluid since I have tracked the car a few times. I have a trans temp gauge installed and the trans temp is always around 20f lower than the oil temp. usually around 190f or so. I don't have a trans cooler installed since I never saw temps going high enough to warrant it. Since I started noticing the trans issues I haven't driven the car very much, probably only 20 times this year.

just moved in to a new house so been busy with that. just trying to make some time for my car because I really miss driving it.

 

Wait a sec..... Your using amsoil tranny fluid? I have always used Nissan J / S matic tranny fluids because of all the talk that if you use anything else you could seriously hurt the tranny... ?? ... Has that been debunked?

For the heck of it empty all that out and put in J / S matic and see if that does anything at all, at this point it probably couldn't hurt...

 

Problem was happening before, I changed fluids hoping it would help

 

I did a bit of research on trans fluids because I couldn't believe that whole "only use Nissan" BS. AFAIK Nissan doesn't own any oil processing companies, so they get their fluid from someone else. so I knew something else out there had to have something similar. After seeing they switched from J-matic to S, I wanted to know why... How can you be told "only use J-matic or trans will die" then they switch up the formula and say the same thing (apparently they had some problems with their sacred J-matic.) Doesn't make much sense to me. I read up on transmissions and the most important thing with fluid, is viscosity and how that changes under temperature and load. As long as the fluid in your transmission matches the required specs it will be fine. There are issues with people putting in fluids with certain chemicals in it because it can break down seals and solenoids will start having issues. The way it was described to me is some fluids will "eat" certain trans because of the harshness.

anyways long story short, I looked at the specs of the amsoil and it looked perfectly fine for the trans. I also emailed the company and they confirmed it was fine. I also talked to multiple other sources who have run it for awhile and said it well outperformed the stock fluid.

actually after changing it out, my trans did feel like it shifted a little better. I was really hoping it would fix the issue, but it didn't

 

my current guess is between a few things.

1. TC is having issues.. don't really know enough about these to say it for sure but I watched some video on how they work and apparently on the top gear (5th in my case) the TC is supposed to clutch together and be a direct drive. I'm thinking I could have burnt this up?

2. I talked to level 10 a bit and they said 5th is always the weak link in these trans.. possible issues from the clutch packs wearing or something else associated with 5th, again not sure.

3. something wrong in the valve body causing it to shift into the wrong gear.


I'm really close to just pulling the trans and taking it apart to look for some sign of broken ****. although I think the first thing I want to try is replacing the TQ converter.

when I did the drain and fill of trans fluid I filtered the fluid some with a paint strainer and didn't see any indication of metal in it. I felt the fluid and it was still very viscous. I remember one trans that I did a shift kit on recently had brown fluid and it felt like water. That thing still worked so I'm having a hard time believing it has ANYTHING to do with my fluid.

 

I honestly would not worry about 5th gear. I believe the TC unlocking under high input loaf may be by design. The car still accelerates, correct? In 4th gear redline you should be near 140 mph anyway...

 

Yep goes to 140 fine in 4th. Just when I shift to 5th it's useless

 

Drop the fluid and look at it, if its not dark cherry red and clear its new clutch pack time. Like someone previously posted try tripling the line pressure on the uprev torque management in the higher rpms.

 

If you need a new auto tranny... lmk! Got a low mileage one, unmolested, sitting in my garage...

 

well, went to a dyno day to see if power was less (due to trans slipping more) and it wasn't.. I added a larger intercooler and some fans (because my bumper is blocking most of it) and I gained 12hp and I now have silencers (restricting) in my exhaust.

I thought the intercooler was a good idea because with the smaller pulley I was boosting 10.5 lbs and I noticed the IATs were at 65c. I wish I would have logged my runs yesterday to see what the temps dropped to but it was good to see more power out of my setup. Soo still no 5th.. but trans seems to hold power in 3rd gear on a dyno

also it was 100 degrees yesterday, so to be able to make more power with the texas heat is awesome.

 

Still no 5th gear? That sucks. I have a fully built AT with TransGo valve body, alto clutch packs, and ProTorque converter with ZERO miles or dyno time after rebuild. I'm willing to sell it for a fair price. PM me if interested.

 

that would be nice, unfortunately, I just moved in to a new house so money is a bit of an issue. I wish I could get a build trans now, but ill have to figure out something else.

 

I don't know a lot about these AT's but in the process of research for returning my car to health I met and talked with a local trans shop owner.

It is a highly respected shop but only does oem stuff. He stated that draining / flushing an AT was one of the worst things that one could do. I think part of it is that only about half the fluid comes out.

Just throwing this out there.