Nissan 4speed auto to auto swap question

Dream about your 240's turbo power in this forum.
Post Reply
niceguy
240sx Wannabe
Posts: 144
Joined: Mon Apr 17, 2006 6:01 pm

Nissan 4speed auto to auto swap question

Post by niceguy »

Hey guys, I have a '93 Altima but am looking for as much experience as possible on this.
Recently, I had a 2001 Altima automatic tranny installed in my '93 while I was out of town by a friend (mechanic). The benefit is the '01 has a 4.08FD and shorter 1-3 gears vs the '93 3.61FD and taller gears.

He had to swap over the '93 linkage, neutral safety switch and speed sensor to get it to work and just drained and filled it with Nissan Matic D fluid that I supplied but we left the '93 TCU to control things.

Now the tranny works pretty well but I have 2 issues:
1. When you take off in first gear, if you go WOT, the car will actually hit the rev limiter and bog the car.
2. Also, after cranking and driving the car cold, it shifts fine (OD works) but after a few miles of steady driving, the rpm will suddenly jump about 200rpm and stay there. The other day, after about 2 miles of driving (from a cold start), the rpm jumped 200rpm, then dropped 200rpm, then back up where it stayed the rest of the time.
Now for the first thing, it's funny that I hit the rev limiter even with the shorter FD since the 2001 tranny came from Altimas with a lower 6250 redline vs my 6500 redline. I don't see how this can be happening unless I need the newer TCU.

Second, the TC is locking up properly because OD works but I know this is related to the new tranny setup. I can live with it, but I'm just curious if it's the TC solenoid switch or something else, maybe TCU related?

I figure most here won't care since this is an automatic tranny but I figured I'd post here since alot of you guys have more hands on DIY experience with the KA platform than the average person.


Any input you have is appreciated!

Jeremy
niceguy
240sx Wannabe
Posts: 144
Joined: Mon Apr 17, 2006 6:01 pm

Post by niceguy »

Well after some thinking on things, I believe the reason for me hitting the rev limiter in first is due to using the old '93 TCU which was controlling much taller gearing with the old tranny. I'm going to check out the '01 TCU and try to find an FSM to compare the pinouts between the 2 TCUs.

The other issue with the rpm jumping up 200rpm after a few miles, no idea what's causing that yet, oh well....
Post Reply