Need help with my 4l60e. Shifting
Thread Starter
On The Tree
Joined: Dec 2014
Posts: 103
Likes: 3
Need help with my 4l60e. Shifting I have a 1938 Oldsmobile business coupe it weighs around 3050 lbs with me in it it has a stock lq4 out of a 06 Chevy express with a 4l60e with up grades and I was told by the tourk converter shop with my motor and weight of the coupe the stall would be around 2200 to 2900 but I’m not sure it’s a gm310-Vj tourk converter the stall is 1800-2000 with the v6.
it also has the stock 04 truck harness dbw and psi conversions did my computer deleting vats and extra stuff not needed
and I asked and they turned off the neutral safety switch.
i also have a b&m quick silver shifter in it .
i noticed today if I leave it in drive it will burn off the tires tell it shifts to second and if I put in 1st it won’t stay n first the rpms get to a certain rpm and it shifts into second with out me shifting and doesn’t burn out it seems dogish.
Any ideas why ?
thank you kelly
it also has the stock 04 truck harness dbw and psi conversions did my computer deleting vats and extra stuff not needed
and I asked and they turned off the neutral safety switch.
i also have a b&m quick silver shifter in it .
i noticed today if I leave it in drive it will burn off the tires tell it shifts to second and if I put in 1st it won’t stay n first the rpms get to a certain rpm and it shifts into second with out me shifting and doesn’t burn out it seems dogish.
Any ideas why ?
thank you kelly
Last edited by Gksportster; Jul 14, 2019 at 10:07 PM.
TECH Junkie
Joined: Dec 2012
Posts: 3,617
Likes: 1,328
From: Iowa
It does this because it's supposed to. It's a safety shift function.
The stock tuning will force a shift into 2nd gear even if you are in D1 on the shifter.
The best way to correct this is to use a valve from the transgo HD2 kit. The 1-2 shift valve.
You can also try a tune to correct the issue.
The stock tuning will force a shift into 2nd gear even if you are in D1 on the shifter.
The best way to correct this is to use a valve from the transgo HD2 kit. The 1-2 shift valve.
You can also try a tune to correct the issue.
TECH Junkie
Joined: Dec 2012
Posts: 3,617
Likes: 1,328
From: Iowa
Then you're not used to stock older transmissions.
TH400 and th350 both had the same safety shift function in stock form. Neither would let you downshift to 1st if you were moving to fast...and both would upshift out of first if the wheelspeed/rpm was too great.
TH400 and th350 both had the same safety shift function in stock form. Neither would let you downshift to 1st if you were moving to fast...and both would upshift out of first if the wheelspeed/rpm was too great.
TECH Junkie
Joined: Jun 2008
Posts: 3,202
Likes: 1,390
From: Nitro Alley
Like Maroony said older stock GM automatic transmission usually required valve-body modification... For example the THM400 usually will not hold first gear, it will do the same as you are experiencing and shift up into second gear on its own.
Also like MaroonMonsterLS1 said... This is a safety feature... Think of it as away to try and keep from over revving an engine that does not possess a rev limiter.
"Shift Kits", "Shift Reprograming Kits", and any other "TRADE MARKED" name products that have been around for more than half a century to modify auto-trans. valve-bodies make it possible to hold any gear range to any RPM (Without a Rev Limiter).
The TransGo 1-2 shift valve modifications as already posted is my recommendation.
Otherwise Talk to Dana (PBA on our forum) at ProBuiltAutomatics to set up completely anything you could need for the 4L60E units.
