Engine & Transmission Post your Engine and Transmission related problems here.

1993 K Blazer, hard 1-2 shifts, non-PWM L460E

Thread Tools
 
Search this Thread
 
Old Jun 30, 2018 | 11:10 PM
  #1  
hamlet's Avatar
Thread Starter
|
Beginning Member
Joined: Feb 2018
Posts: 10
From: PacNW
hamlet is on a distinguished road
Default 1993 K Blazer, hard 1-2 shifts, non-PWM L460E

Like night & day. Go to work, fine, coming home, hard shift between 1st & second.
Does this every day now, every 1-2 shift. All other shifts fine, overdrive seems okay,
(hard to tell, always thought it was too steep) and all gears work when manually selected.

TPS maybe? 1-2 shift solenoid? I'm leaning towards electrical, 'cause it happened
all at once, and not slowly over time like a tcc regulator wearing out.

My '93 is all stock, except for replaced exhaust piping. 195k miles.

 
Old Jul 1, 2018 | 02:44 PM
  #2  
Transman304's Avatar
Senior Member
Joined: Aug 2016
Posts: 505
From: West Virginia
Transman304 is on a distinguished road
Default

Does this happen after an extended drive at highway speeds? Sounds a lot like high line pressure is being commanded after sensing a slip in the TCC circuit. Is the CEL light on?
 
Old Jul 1, 2018 | 09:01 PM
  #3  
hamlet's Avatar
Thread Starter
|
Beginning Member
Joined: Feb 2018
Posts: 10
From: PacNW
hamlet is on a distinguished road
Default

Originally Posted by Transman304
Does this happen after an extended drive at highway speeds? Sounds a lot like high line pressure is being commanded after sensing a slip in the TCC circuit. Is the CEL light on?
Yes. This isn't neck-snapping, but it isn't subtle either. It punches harder 1-2 than it ever did before, warm/cold, easy or lead footed.
 
Old Jul 2, 2018 | 12:08 AM
  #4  
papajim's Avatar
Starting Member
Joined: Nov 2011
Posts: 120
From: S,E Ga
papajim is on a distinguished road
Default

Go to Amazon and order you a valve body and install, prob solved
 
Old Jul 2, 2018 | 02:51 AM
  #5  
hamlet's Avatar
Thread Starter
|
Beginning Member
Joined: Feb 2018
Posts: 10
From: PacNW
hamlet is on a distinguished road
Default

[QUOTE=Is the CEL light on?[/QUOTE]


I have a single OBD1 code, 32. It's for the EGR, which I disconnected.

Originally Posted by Transman304
Does this happen after an extended drive at highway speeds? Sounds a lot like high line pressure is being commanded after sensing a slip in the TCC circuit. Is the CEL light on?
I took it out today for many errands, mild or no hard shifting cold, harder shifts as the day went on. Mixed freeway and city driving.
 
Old Jul 3, 2018 | 11:00 AM
  #6  
WolfsK5's Avatar
Beginning Member
Joined: Jun 2018
Posts: 16
WolfsK5 is on a distinguished road
Default

what tranny is it? 700r4? If it is the 700, I would think perhaps the TV cable slipped or needs adjusted. The tension on the line controls the strength of the shift.
 
Old Jul 3, 2018 | 12:38 PM
  #7  
hamlet's Avatar
Thread Starter
|
Beginning Member
Joined: Feb 2018
Posts: 10
From: PacNW
hamlet is on a distinguished road
Default

4L60E. My '93 Blazer is almost stock, Never off road, and little or no towing. Stock wheels/tires. I'm leaving now to see a buddy, 6 miles away, freeway, uphill. I'll note the performance again.
 
Old Jul 3, 2018 | 12:54 PM
  #8  
Transman304's Avatar
Senior Member
Joined: Aug 2016
Posts: 505
From: West Virginia
Transman304 is on a distinguished road
Default

Would you have a tach in the instrument cluster? That being a really early 4L60E it will be hard to pin point over a keyboard. What’s fluid condition? Have you recently done a fluid change? My feeling is the PCM is sensing a transmission component slipping and setting up line pressure to try and preserve itself. Can you feel lockup apply at highway speeds? If so as you feel it engage, stay at a steady speed and just touch your brake pedal and see if engine rpms will raise and let off the pedal to see if rpms go back down.
 
Old Jul 3, 2018 | 04:08 PM
  #9  
hamlet's Avatar
Thread Starter
|
Beginning Member
Joined: Feb 2018
Posts: 10
From: PacNW
hamlet is on a distinguished road
Default

Yes, I have a tachometer. I just took a short little trip, and found that the hard 1-2 shift is intermittent after all. Does it cold and hot, but stronger when hot, & with most, but not every upshift. (accumulator piston?)

I do notice the lockup depending on how light my foot is on the accelerator, about 200rpm difference.. Next time out I will try deliberately dragging the brakes & watching RPM.
 
Old Jul 4, 2018 | 05:49 AM
  #10  
Transman304's Avatar
Senior Member
Joined: Aug 2016
Posts: 505
From: West Virginia
Transman304 is on a distinguished road
Default

Very well could be the 1-2 accumulator. That year will have the aluminum piston but springs were known to break.
 



All times are GMT -5. The time now is 01:57 PM.