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Sticking in 1st

U

Unclewolverine

NAXJA Forum User
Location
Kansas
For the last week when I first take off in the morning it has been reluctant to shift out of first. Once it shifts it's fine for the rest of the day. Fluid is full and looks good. What might be the issue?
 
Since it's intermittent by temp, either a poor electrical connection or a gummed up valve body.
 
I have the same issue.... definitely temp sensitive. I tested tps and it wasn't healthy so I replaced it... same issue persists... I'm assuming trans shift solenoids are to blame. For a trail rig it'll be fine lol

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I should add that I've had this problem for maybe 3 years.... it drives fine lol

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My odometer didn't work for around 7 years, but I would guess my trans has well over 350k... maybe 400 honestly..

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I too have had first gear shifting late on cold mornings.
Since installing a Magnefine trans filter the problem has
gone away (after about 2K miles). I also run a bottle of
LubeGard Red in the trans.

I think the solenoid sticks when it's cold, especially after
sitting for awhile and possibly having low voltage from
high resistance wiring...???
 
The transmission fluid is thicker when cold causeing higher pressure. Higher pressure cause the transmission to shift later and harder.

I know very little about the aw4 but i do know i would drain all fluid. Replace all consumable parts make any service adjustments that are possible
Reinstall pan fill with chevron thf1000 transmission fluid.
Then run it for a couple hundred miles. Dump fluid again change filter again. Then refresh again with thf1000 fluid then run it for 20k and service it.

Id would also research what pressures these transmissions are susposed to run at and how to read these pressures then get the get set up and drive it to make sure it pushing the appropriate pressure maybe slightly higher since its running on thf1000



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Evan03 said:
The transmission fluid is thicker when cold causeing higher pressure. Higher pressure cause the transmission to shift later and harder.
Click to expand...

The transmission computer controls when to shift Hydraulic pressure as controlled by the throttle-body to trans cable adjusts the pressure and firmness. (way out of adjustment can cause sloppy, delayed, or overly harsh shifting)

Evan03 said:
I know very little about the aw4 but i do know i would drain all fluid. Replace all consumable parts make any service adjustments that are possible
Reinstall pan fill with chevron thf1000 transmission fluid.
Then run it for a couple hundred miles. Dump fluid again change filter again. Then refresh again with thf1000 fluid then run it for 20k and service it.
Click to expand...

I would recommend using the CORRECT fluid Dex/Mec, not a universal hydraulic oil meant for tractors. There are no service adjustments on the AW4. A couple of partial fluid changes by draining the pan is a good idea though.


Evan03 said:
Id would also research what pressures these transmissions are susposed to run at and how to read these pressures then get the get set up and drive it to make sure it pushing the appropriate pressure maybe slightly higher since its running on thf1000
Click to expand...

The AW4 is electronically controlled, not like an old-school trans that uses a kickdown cable. As you noted the THF1000 is thicker and may cause mre problems.
 
I already knew all this, just didn't want to take the time to explain it. Never use anything other than dex 3 in an aw4. Tv cable is great. Shifts perfectly the rest of the day, just that 1st one out of first in the morning hangs up. Fluid looks and smells great. Probably a cruddy connection, just haven't had time to check it. Also using a 01 trans in a 95 so had to do some wiring changes so may be a poorly sealed heart shrink.
 
Swapped the rotor and tail housing. Super easy. I have another 01 tranny in storage for when this one goes out, ill do the same thing then too, but I should have another 50 to 100k in this one, hard to tell though; postal miles are hard miles. I would of rather had the proper year but I happened to get really good deals on these two 01s right after another.
 
Unclewolverine said:
Swapped the rotor and tail housing. Super easy. I have another 01 tranny in storage for when this one goes out, ill do the same thing then too, but I should have another 50 to 100k in this one, hard to tell though; postal miles are hard miles. I would of rather had the proper year but I happened to get really good deals on these two 01s right after another.
Click to expand...

Yeah, I think I might remember a thread on you doing that. Reason I mentioned it is that no signal from the rear sensor would cause not upshifting out of 1st.
 
Any fluid will work better than water.

Most will run whats specced and be perfectly happy as long as good service intervals are followed.

In my world everything is tunable and can work better and last longer than the factory intended or designed.
A simple temp gauge can tell alot about different fluids

Researching transmission/hydraulic fluid will bring more questions than answers. You guys should try it.


I do not like long service intervals with synthetic fluids.



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To tell a bad story on myself...
Years ago i listened to autozone on trans fluid... did a back to back drain and fill with I'm wanting to say atf+4... after that when I would stop at a stop sign the engine would die... actually looked at the fluid requirement myself learned it was dextron and did 3 drain and fills.... everything went back to normal.... super strange.

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That is strange. Specially since theyre virtually the same just +4 is synthetic
My pickup transmission runs warmer on it compared to dex, tractor fluid and ford f.

Ive got about 250k worth of fluid testing in the transmission.

I will never run any fluid with a label that matches the parts store name. Am also leary of wamart fluids

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There's been a lot of reports over the years on these boards of AW4s not taking well to the ATF+4 or other synthetics. Some have had success, others (like SlowXJ) the opposite.

Best to stick with what seems to work for vehicle.
 
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