My 88 300zx shifts late out of 1st gear around 3000 rpm

2wd right?(1995 is GEN1, T100)
auto trans or manual trans no told and both are told.
we can't guess drivelines blind,so tell it.?
2.7L, 3.0L and 3.4L engine options new.
toss coin land on A/T box. (most common )
the TCM decides all this not you,
the Tcm/Pcm/or TCU are all transmission brains , the PCM does engine too, and tells the TCM speed, and engine loads (hills etc)
rpm based on all that and gear ratio, in the transmission, 1:1 or overdrive. too and the axle ratio and tire size (circumference)
are tires stock, or low rider tiny.???????
5 speed manual or 4speed automatic and 4 engine choices not one told and if an automatic the TCM is turned to all things stated above.
a hard fact that. the RPM drips in OD ,overdrive and TCC lockup
the service manual lists 5 transmissions
A340F, A340H, A440, A442F and A343F units
top 2 are A340e & A340f (USA answers me) 2wd/4wd

A340F (30-40LE) 4speeds + tcc

seen too on
2000-2004 Tundra (4x2)
A = Aisin-Warner Automatic.
340 generation 3. 3L v6 used.
E=electronic shifted (TCM brain
F= 4wd same as E shifted.
3 electrically controlled solenoids for shifting and torque converter(TC) lock up(TCU runs the SHOW)

There is s TV cable here too, that causes upshifts late or early.
super hard top find this, Asian boxes. but here goes.
?1st: 2.80
?2nd: 1.53
?3rd: 1.00 (end to end lockup , look ma' NO gears here !)
?4th: 0.75 (23-spline, 0.705 21-spline
4th gear cam be less on smallest engine.(less rpm drop)
now you learn vast version of transmissions exits.
I read the side of box and it tells me the model there fully, every time.


so are you not getting 4th gear OD or the TC lockup failing
scan the PCM see if there are P07xx errors"? tranny errors. ?

in 3rd gear the RPM is the axle ratio and tire diameter (pi X r squared is circum and distance moved is that)

I can tell you the math below see the online calc. at end here.
and some TC slip. (it slips not locked up)
4 gear is RPM ,= is 0.75 x 3rd gear RPM. and tc slip.
TCC lock up is is less RPM but that depend slip and hills.
that is why I call them slush pumps, TC SLIPS and turns HP in to wasted heat and is why TCC was mandated by the EPA, for more MPG, and less waste.
that is how the pump slips as they say.

why not just see if all gears work (count them with easy right foot on flat earth)
and TCC locks up, in 4th
and scan the PCm for errors.
1,2,3,4+TCC is really like 5th speed, if you noodle that.
4-1/2" gear,(5th) locked.
make sure TV cable not rusted and jammed up and for SURE not jammed in the Pulled out position, rusted, there. and is WOT
wot is wide open throttle and that make the tranny shift way late
or never goes past 3 gear... test it.(or worse 2nd)
I see folks put a new transmission $2500 for the want of $20 cable.
wow. that. The TV cable bad is an on car fix.
P0750 to P0770 are all tcc errors to the box. scan it if gears ever shift wrong. and speed sensors failing or clutch packs slipping in the box,will dtc code out too.

so in 3rd gear the axle 3.4L auto T100 4x4 should have 4.30 gears.
so 1:1 x 4.3 is still 4.3 so 3000 rpm the read prop shaft.spins

at 3000 rpm and axles spin 698 RPM( AND TAD LESS TC SLIPS.)
knowing tire circumstance or diameter. nets speed.
manual trans runs 4.10 axles. (and no slip at all)
if not running stock tires the SPEEDO lies to you.
taller large tires spin slower and VSS lies. to cluster.
called ticket getter
235/75R15 (stock'ish)
Diameter : 28.9"

here is 4.3 axles.
3rd gear, 60mph , axle above 28.9" stock tires
is 3000 RPM
so shift to 4th, be on flat ground and light right foot and not hills]
and TV cable not JAMMED (rusted and locked out)
https://purperformance.com/p-29669-rpm-calculator.html

so 4th OD is, what .75 x 3000 is 2250 RPM (my guess never seen)
TCC locked up ,is less RPM, a bit.

so learn to scan any TCM(PCM) when gears fails.
scan it. now.

well is that hummer that a 2 ton or 4 ton vehicle ?

would take a lot of revs for first gear to make it roll from a standing start
think it will be fitted with an 6 speed automatic transmission

guessing only from my heavy vehicle driving experiences
first should change below 3000 rpm

if transmission was slipping in first gear you would know

suggestion
ring up the local hummer service division for the correct answer

• A/T or M/T (auto or stick, gee)
• if A/T is this the 42RE box>? are you in DRIVE? or 1 or 2 gear.
• does rpm rise above 3000 rpm > at your attempt? if not ,its a bad engine (weak)
• is the shift linkage even shifting correctly (movement top and bottom)
• check levels yet. (and for pink ./red AFT not black-metal flake
• change the filter yet? or skip service. at 50k miles. ?????
• check all fuses yet>?
• using a basic OBD2 scan tool are there any tranny DTC errors?>
• does the FSM stall test pass? in 1st.? and reverse?
• if stall fails, slips , then tranny bad. if not its really stuck in 1st gear.

The TCM commads the gear change, there is no valve body brain.
the TCM shifts to second with good inputs to the TCM
if the TCM sees bad inputs it will tell you, SCAN IT.

1st check your fluid level, if its good I would suggest taking it in to your mechanic and have them service the transmission which involves dropping the tranny pan and replacing the filter and reinstall pan with new gasket and top fluid levels. A step further would be also have a tranny flush which will cost more due to labor and all the fluid neccesary to flush the system.

Depending on what gearing setup the car was originally put on, most cars that I have owned that were automatic shifted between 3000 and 4000 RPM. My 97 Ford Escort ZX2 needed to shift around 2000 RPm from 1st into 2nd, but it was a manula which allows you to feel the point of shift alot better. maybe have your onboard computer checked and tranny serviced.

If you have a tachometer, shift around "3" (3000 rpm) on each gear or every 15 miles per hour (1st gear 1-15, 2nd 15-30, 3rd etc-----------------------------------------------------------------------------
VAG Dash K+CAN V5.14

Check the fluid in Neutral not park make sure parking brake is on and/or tires are scotched before doing so, you can also try putting some " Trans-X" in it from the part store.

It winds up in 1st and then shifts right from 1st into 3rd. Then never shifts into 4th. Plus rev is gone. You broke the sun shell. The transmission will need to rebuilt or replaced.

Have you changed the fluid & filter lately? Start there, much cheaper fix than anything else.

the tranny is slipping ,,in other words its starting to go.