on the way to work this morning something terrible happened. when i shifted from third to fourth i could barely engage into fourth. it was extremely tight but it did engauge. from fourth to fith was fine and smooth also 1st to 2nd shifts smooth as well but 3rd to fourth is tight. also the car will not even go into third and fourth if i am stopped. i must be moving to shift into 3rd and fourth or i can not engage in those gears... i can already tell this is gonna put me broke so please break the news to me gentlely... louis

 

That nice "click in" sound and feeling when you engage a gear comes from a part of the transmission called the detent assembly. When you move the shifter from Neutral into any gear you are moving one of three shift rods. There is a separate shift rod for each plane in the shift pattern: one for 1/N/2, one for 3/N/4, and one for 5/N/R. Each shift rod has three deep notches in it. A spring-loaded steel ball settles into one of those notches and produces the "click in" sound and feel. These parts (the notched rod, steel ball, and spring) compose the detent mechanism. The detent helps the driver know the shift has been completed, and it also helps to keep that gear engaged until the driver moves the shifter again.

Your symptoms suggests a problem exists with the 3/N/4 shift rod or detent assembly. These parts are internal to the transmission. Here's where you get lucky... maybe...

Raise the front end of the car and support it on sturdy jackstands. Slide under and look at the part of the transaxle case which faces the front of the car. You will see the lubricant fill port. Below that port, and slightly toward the driver's side of the car, you will see the heads of three bolts. They look like ordinary bolt heads but they are actually the detent plugs. The one nearest the driver's side of the car is the 1/N/2 detent, and the one in the middle is the 3/N/4 detent.

Remove the 3/N/4 detent plug. A small coil spring and a steel ball should come out. If they don't, a small magnet may be used to coax them out. As soon as these parts come out the gear lube will pour out. You may immediately install the plug without the spring or ball to stop the loss of fluid.

Examine the steel ball and spring. If the ball is damaged, replace it. If the spring is broken or crushed, replace it. When the new parts are in hand, remove the detent plug, insert the ball, the spring, and reinstall the plug. You should be able to feel the difference in the shifter immediately, even without starting the engine or taking the car off the jack stands.

 

WOW !!! you really know your stuff i will attempt to fix this tonight i guess this may finally be a good reason to get some mobile one synthetic and my sts in.. so what part should i exactly ask for when i go to the dealer today. thanks for all your help.. i always see people asking for your advice you are definitly a valuable member to this board.. thanks again..louis

 

I suggest you hold off installing that expensive synthetic transmission lubricant until this problem is resolved. There is a possibility that your tranny will require disassembly for inspection and repairs. This will involve draining (and loss of) the lube.

For more information about 5-speed transmission internals ...
Go to http://www.motorvate.ca/
In the left window click on Transmission
In the left window click on 5 speed rebuild
In the left window click on each of the subheadings (The Saga, Failed Bearing, etc.)

This is an excellent site for the Maxima home mechanic.
You may like to browse all of it.

 

See:
http://integra.vtec.net/geeser/megam...fluid_page.gif
http://vbxmaxima.8m.com/mtoil.html

The drain plug is horizontal, low on the transaxle case near the engine, and near the shifter boot. It is fairly small and looks like an ordinary bolt.

The fill plug is on the side of the transaxle housing nearest the front of the car. It is fairly large and has a square recess. The tool to remove it is an ordinary 1/2-inch ratchet wrench, with no socket fitted.

Remove the fill plug first, and then the drain plug. That will eliminate the risk of draining the old lube and then discovering you can't install new lube because the fill plug is too tight. It will also help the gear lube to drain faster.

Observe the color of the old lube as it pours out. It should be brown or black. If it is shiny and silvery, that is cause for concern. That silvery color is thousands of tiny metal particles which have flaked off internal transaxle parts such as bearings.

Install and tighten the drain plug before installing the new lube. (Don't laugh, plenty of people have forgotten to do this and wound up with a large puddle of new lube on the garage floor.) You may find it convenient to install the new lube with a funnel and a short length of plastic tubing fitted to the funnel spout. Position the funnel in the engine compartment, near the battery. Route the plastic tubing into the fill port. Add gear lube until it begins to overflow. Nissan recommends API GL-4 SAE 80W-90 gear lube. The capacity of the 5-speed is 4.5 - 4.8 liters. Do not use API GL-5 gear lube.