My shop installed my SGP trans on Friday and filled it with fluid per the manual on Saturday morning. Shortly thereafter I took it out for the first time and encountered an issue:

When giving it about 10% throttle, the trans would buck back and forth and not go anywhere. <10% throttle and it would drive fine. Reverse works perfectly fine. This happened both in AT mode and MM mode. I tried this a couple times and the car went into limp mode with a code for the crank angle sensor. I'm assuming this is due to the trans as this is the same code I've gotten in the past with my blown trans. The crank angle sensor was also replaced just incase not too long ago. The car also ran fine with the trans I was using while this one was being built, so everything is pointing to the trans.

Here's the weird part. After driving it around in low throttle for a while, the car seemed to get better and better and we were actually able to get it into boost. The more it was driven, the better it got, but still happened every now and then. I'm going to take it out again on Monday and see if I can reproduce the problem.

My question is, could this be related to the trans fluid not getting everywhere it needs to be? I do have a cooler and we used Matic J fluid per Nissan's instructions. The trans came bone dry because it took about 10 quarts before the dipstick read full so I'm assuming this is the issue, but was wondering if anyone else with the SGP trans had this initial problem.

I left a message at SGP on Saturday, but I wanted to ask if anyone else has experienced this issue. I'm hoping that it's just an issue of the fluid not being everywhere it needs to be because I've had this problem with both of the trannies I blew after it was leaking and burning fluid. The symptons seem to point to lack of fluid, but I'm not sure.

Sorry for the repetitiveness (is that even a word? lol) Thanks!

 

Member "rcdash" has an upgraded trans but his is from GTM....I would think they're pretty similiar..

 

thanks for the reply, but I decided to just come out and state the prolem, lol. I should just wait for Thomas to call me back, but this is really bugging me

 

What torque converter? If it was a new one did you put fluid in it befoer you installed it? You are supposed to add 2-3qt to a new dry torque converter.

 

I purchased a TQ converter along with the trans as part of the package, which came separately. The shop did the install so I'm not sure. I'm going to assume that they did, but will confirm tomorrow when I go up there.

Hypothetically speaking, if the TQ converter was not filled, will the fluid in the trans get into the tq converter?

 

I just sent you a PM and I was thinking the same thing as Mardi Gras

 

Got your PM...thanks guys!

 

TQ Converter will be damaged if they didnt fill it up first. This may also trash the trans if debris was to circulate. Good luck!!!

 

Hrm...okay. So the tq converter needs to be filled separately from the trans? Filling the trans wont fill the tq converter? What type of fluid does it take?

This would lead me to ask...why did it get better and better after some easy driving and eventually almost go away completely?

Andy (please pardon my ignorance)

 

The trans and the TQ share the same fluid system. The trans fluid pump will eventually get fluid into the tq conv, but not quick enough. The fluid systems are connected and maybe if the TQ conv was not filled it took to long to get fluid to the TQ and its friction material became glazed, I put three quarts in my dry TQ conv, i bet it holds 4-5 quarts total, it would take a while to pump that in to it for sure. Maybe the lack of fluid in the TQ conv caused the whole trans fluid system to not pressurize quick enough and the trans clutch packs were glazed as they spun around through each other dry. Driving it around may have deglazed the friction parts some, but if this happend it would diminish the life and ultimate holding power of the trans.

I'd advise you at a minimum to drain the fluid into a fresh clean pan, pour the used fluid through a fine strainer, like a kitchen strainer, into another container, and look for debris in the strainer and the bottom of the first fresh clean pan. Next drop the trans pan and inspect the magnets and pan for debris. Most trans shops will put a small temporary in line trans filter in with a rebuilt trans to catch any debris that may be present.

 

Make certain that the shop filled up the trq converter before installing the trans. The trans is sensitive to oil level, and must be checked when its completely 100% warm and at operating temp. It can take some time for the oil to completely saturate the clutch packs, and these types of transmissions definately begin to shift better after they have some drive cycles on them.
You also have a higher stall to contend with, so the trans isnt going to feel like stock.

 

Interesting....thanks for the lesson and tips. I will double check with the shop tomorrow.

Does the fluid in the tq converter count as the 10 or so quarts Nissan says the trans holds? If so, we filled it as per the manual.

The only thing I don't know is whether or not the tq converter was filled prior to installation.

Thanks again!

 

What is the stall at? Also does it buck in each gear when under 10% throttle?
Like Mardi said the pump should eventually get the fluid to the TC if it wasn't filled but it could do some damage.

 

Thanks Sharif. Hypothetically speaking again, if the tq converter wasn't filled with fluid first, and obviously is now getting fluid since the problem seemed to go away, what are my options (I know MGM touched on this)? Should I drain and look for debris? Continue driving? Thanks for the input.

 

I'm not sure what the stall is actually. I don't remember. I talked to Thomas about it, but this was a while ago. I'm pretty sure it's a little higher than stock, but not by much.

It bucked while trying to accelerate in 1st gear at about 10% throttle. Once the problem began to go away and the car actually drove so to speak, there were no issues while changing gears. I believe the issue was only during the first couple gears, which would point to the tq converter I suppose.

 

The cooler also raises your capacity I'd throw @ least 1 more quart in there. 2 if they didn't fill the converter before install.

 

Correct, I am aware of that Thanks. After driving it around a bit on Sat and some gentle boosting after the problem went away we let it cool off and sit. We'll check the level again first thing in the morning after warming up the car and see where we're at.

I'm somewhat releaved that my original suspicions may be correct, but at the same time I hope nothing was damaged

 

Thanks again for all the replies guys!

 

617G,

I'm no expert, but through my experience with a built 5AT, I have been told that:

1. the valve body changes are pretty dramatic and as you are experiencing, there is a break-in period for all the components from VB to clutch packs. Take it easy the first few hundred miles - no dyno till the trans is running smoothly.

2. As per Sharif's note, keep an eye on the fluid level - become an expert at reading the stick. The fluid is pretty clear so it makes it hard to read. Follow the FSM and allow the car to warm up, then in place go through the gears, then back to P, then check the fluid level.

3. Also as Sharif mentioned, the high performance clutch packs soak up fluid during break in! I don't know how much, but I know fluid level for my trans dropped and there were no leaks on the ground.

4. Be aware of slipping as it could indicate a fluid level problem. If the clutch packs slip with no fluid for more than a few seconds, I've been told they're done for. This is easier said than done, because you also have a high stall converter now, which changes the driving characteristics.

5. If the 5AT goes more than a quart low, it could very well damage it if run under load. Bottom line, take it easy the first few days, keep checking fluid. Low fluid or overheated fluid are the only things that will kill the clutch packs. If it's a persistent VB issue, that's a relatively easy swap out.

Is the AT light on? Even if its not, I would highly suggest getting a reading from a Consult II tool to make sure you aren't missing something the computer is telling you. Cipher can't read the TCM unfortunately.

I hope it's just the new solenoids in the VB doing their thing... Good luck.

 

When you say bucking at 10% load - was it bucking during a gear shift or while in gear and cruising (in MM mode)? It really sounds like a VB issue - I think it's just the solenoids operating for the first time - but the bucking should've been during a gear shift.