700R4 Late Shifts When Cold
#1
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Engine: LO5
Transmission: 4L60
700R4 Late Shifts When Cold
TBI car with the 4L60(700R4). When the trans isn't up to temp, all the shifts come in late at light throttle. For example, 1-2 won't happen till almost 30mph, 2-3 at almost 50, etc. .
Once the car is up to temp, everything is fine. 1-2 is back at 19 etc...
All the gears are there, the car shifts fine, the shifts are just late.
I've reset the TV cable using the factory procedure, no change. I was gonna drop the pan and check the TV valve and plunger for freedom of movement, anything else I should check while I'm in there?
Besides that, I'm stumped. I swapped the governor out of curiosity to no change (I've read the gov only deals with WOT shifts)
Any ideas?
Thanks in advance.
-Pat
Once the car is up to temp, everything is fine. 1-2 is back at 19 etc...
All the gears are there, the car shifts fine, the shifts are just late.
I've reset the TV cable using the factory procedure, no change. I was gonna drop the pan and check the TV valve and plunger for freedom of movement, anything else I should check while I'm in there?
Besides that, I'm stumped. I swapped the governor out of curiosity to no change (I've read the gov only deals with WOT shifts)
Any ideas?
Thanks in advance.
-Pat
#3
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Car: 89' T/A, 00' Firehawk
Engine: 406 Roller
Transmission: TH700R4 w/2800 stall
Axle/Gears: 3.23 Posi
Re: 700R4 Late Shifts When Cold
I just logged on to make almost the exact same post.
Mine is a 89 T/A 700R4 all stock.
When the outside temps get below 40 degrees. First drive in the car won't shift till 3 grand, and when it does it shifts HARD. It does it in all gears.
I can drive it a mile or so. Let the car sit for a few minutes like going into a gas station and then it's fine.
Fluid has been changed regularly and I even flushed it with the BG machine at work.
I have dropped the pan and verified the TV cable is adjusted properly.
It seems that something is sticking when the valve body is cold.
Mine is a 89 T/A 700R4 all stock.
When the outside temps get below 40 degrees. First drive in the car won't shift till 3 grand, and when it does it shifts HARD. It does it in all gears.
I can drive it a mile or so. Let the car sit for a few minutes like going into a gas station and then it's fine.
Fluid has been changed regularly and I even flushed it with the BG machine at work.
I have dropped the pan and verified the TV cable is adjusted properly.
It seems that something is sticking when the valve body is cold.
#4
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Engine: LO5
Transmission: 4L60
Re: 700R4 Late Shifts When Cold
Fluid level was the first thing I checked, spot on. Ambient temp doesn't seem to make a difference in my case, simply cold vs. up to operating temp
Haven't found much in the way of similar issues on the googles. I plan on dropping the pan this week when its nice, I'll report back on any findings.
Still open to suggestions until then!
Haven't found much in the way of similar issues on the googles. I plan on dropping the pan this week when its nice, I'll report back on any findings.
Still open to suggestions until then!
#5
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Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
Re: 700R4 Late Shifts When Cold
Fluid level was the first thing I checked, spot on. Ambient temp doesn't seem to make a difference in my case, simply cold vs. up to operating temp
Haven't found much in the way of similar issues on the googles. I plan on dropping the pan this week when its nice, I'll report back on any findings.
Still open to suggestions until then!
Haven't found much in the way of similar issues on the googles. I plan on dropping the pan this week when its nice, I'll report back on any findings.
Still open to suggestions until then!
#6
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Engine: LO5
Transmission: 4L60
Re: 700R4 Late Shifts When Cold
I am going to suggest that it is likely a normal operating condition. The fluid is thicker when it is cold. Being that it is mechanically/hydraulically shifted it has no way to compensate for the thicker fluid (higher pressures) acting on the, pressure regulator, shift valves, TV plunger sleeve, boost valve and governor. My 700r4 in my old G20 van always had a higher rpm and firmer shift when it was cold.
I meant to drop the pan today and inspect, but spent most of the day doing research. I've convinced myself its a TV issue (sticky, worn, whatever) and ordered a TransGo "Jr." correction kit for it. Should be here in a couple days, I'll report back when I get it installed.
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#8
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Re: 700R4 Late Shifts When Cold
When was the last time the fluid and filter was changed? That's what they do when cold. That's why you should let them warm up in cooler temps. People seem to think you can get in a 25+ year old car and just start it and take off. I let mine warm up some even in the summer. It's better on the engine and the transmission.