Hard shift from 4-3 manually and some noise

[Infinitiguy19]

Due to my laziness/incompetence my transmission possibly has little life left in it. I am deciding between throwing in a manual transmission or going with a G35 transfer case and staying with the OEM 4 speed auto(Thanks Rabs for the tip).

But before I spend $100+ smackeroo's on a senior Infiniti techs diagnosis I was hoping you guys could help me. When going 40 MPH or more and I downshift from D(4) overdrive into 3'rd gear there is not much shock (Normal) but if I do the same thing with the throttle slightly depressed the whole front end of the car takes a nose dive. Obviously that can't be good for the transmission or the rest of the car.

There is a noise coming from the transmission that varies with engine speed but it barely audible.

Sometime when I take off from a stop the whole car shudders back and forth and this also happens in Overdrive when driving and excessive load is placed on the engine.

The TPS is set at .44 Volts and was set correctly. The IACV/AAC screw is turned all the way in (Idle issue I have yet to fix). The fuel pressure was tested with the car in Park and the numbers match the service manual.

[rabsusa]

save your $$.... that transm had it... i wish you were closer to me, I d give you wat was left of my driveway hulk!

[Infinitiguy19]

Thanks!

But know one knows what could be causing this? I mean if its the valve body or a sensor I would be happy or even the Torque Converter because I have a spare.

[rabsusa]

Thanks!

But know one knows what could be causing this? I mean if its the valve body or a sensor I would be happy or even the Torque Converter because I have a spare.

- hard to say without actually driving your car and "feeling it" for myself,,,,but usually the Torq when its nackered will cause bump or rough gear changes across the board, whilst mechanical noises coming from inside the transmission means death. When i was younger I "fixed" some peoples issues with a new TC and transmission honey LOL - dont ask!
I ve never taken transmission apart coz i dont have the time patience nor the tools, I usually send away for Xchange reman if its a difficult one to find OR just source low miler. I seriously doubt any of the minor fixes you mentioned above will remedy the issue,

JMHO,

Rabs

[goody90q45]

.....Sometime when I take off from a stop the whole car shudders back and forth and this also happens in Overdrive when driving and excessive load is placed on the engine......

I had the "shuddering" problem on my black 90Q mostly going uphill and from a dead stop. There was no shuddering and the transmission shifted smoothly as long as I was driving on level roads it wasn't under a load. I attributed it to a bad torque converter.

[Infinitiguy19]

Your right Goody I think its the Torque Converter and the High clutch causing the problems.