Automatic shift problem
Thread Starter
Racer
Joined: Mar 2002
Posts: 309
Likes: 6
From: Troy Al
Automatic shift problem
My 93 coupe has a shift problem with the automatic transmission. When cruising down the hiway at a slow speed of 55-65 I can hear it try to shift from 3rd to 4th. This is easily overcome be either speeding up, or slowing down. Now that it’s summer time I’m giving serious consideration to selling her, 
and I need to fix the problem. Is there an adjustment to correct this?
THANKS!
and I need to fix the problem. Is there an adjustment to correct this?THANKS!
Race Director
Joined: Jun 2001
Posts: 10,956
Likes: 679
From: Marlboro country MA
The 700R4, standard issue for a 93 auto, is a three-speed transmission. The fourth gear you experience is just the torque converter locking up. This lockup is controlled by the computer. IIRC, the standard chip sets the lock-up speed around 52-55 mph. If you're driving at that speed, the TC can lock and unlock depending on throttle setting. An aftermarket chip will usually set this speed to a lower speed, perhaps around 45 mph, depending on the tuner. From what you describe, the behavior is normal.
Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
Originally Posted by MTVette
The 700R4, standard issue for a 93 auto, is a three-speed transmission. The fourth gear you experience is just the torque converter locking up. This lockup is controlled by the computer. IIRC, the standard chip sets the lock-up speed around 52-55 mph. If you're driving at that speed, the TC can lock and unlock depending on throttle setting. An aftermarket chip will usually set this speed to a lower speed, perhaps around 45 mph, depending on the tuner. From what you describe, the behavior is normal.
Race Director
Joined: Feb 2004
Posts: 12,517
Likes: 19
700r4 and 4l60's are known for killing the 3-4 clutch pack first. Not always, but usually. They are also prone to torque converter "chuggle". This is locking and unlocking of the torque converter sometimes caused by a failing torque converter. Both problems involve removal of the trans for repair or overhaul.
Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
Originally Posted by Pete K
700r4 and 4l60's are known for killing the 3-4 clutch pack first. Not always, but usually. They are also prone to torque converter "chuggle". This is locking and unlocking of the torque converter sometimes caused by a failing torque converter. Both problems involve removal of the trans for repair or overhaul.
Race Director
Joined: Feb 2004
Posts: 12,517
Likes: 19
Originally Posted by aminnich
Hi Pete, Which one would have been in a 93 model and why would someone say only a 3 spd auto? Am I missing something?
Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
Originally Posted by Pete K
All 700r4, 4l60 and 4l60e models were 4 speed only models. All were equipt with lock up.
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Burning Brakes
Joined: Feb 2006
Posts: 1,098
Likes: 1
From: Webster Texas
3spd
All automatics from 82 on were 700R4-4L60 variants. All are 4spd auto trans. The 4th gear is a .7 overdrive. In gears 2-4 the torque converter also locks at different speeds and RPM's depending on load, speed,etc.... The TV cable is NOT an adjustment cable for shift points.
Eric
84 Z51 Auto
05 Repsol Rep
00 TLR 1000
Eric
84 Z51 Auto
05 Repsol Rep
00 TLR 1000
Thread Starter
Racer
Joined: Mar 2002
Posts: 309
Likes: 6
From: Troy Al
adjustment
I was told once that there is an adjustment on the left side, over by the computer to control when the shift to 4th (or overdrive) . I don't think this has been normal for the car in the past. Perhaps as a new problem that could indicate future transmission problems?? It's shift-shift-shift-shift at about 55. It seems to do this more then it used to.
Wish I'd gotten a 6 speed manual. Couldn't find that in the polo green. Any suggestions appreciated.
Wish I'd gotten a 6 speed manual. Couldn't find that in the polo green. Any suggestions appreciated.
Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
Originally Posted by choopes
I was told once that there is an adjustment on the left side, over by the computer to control when the shift to 4th (or overdrive) . I don't think this has been normal for the car in the past. Perhaps as a new problem that could indicate future transmission problems?? It's shift-shift-shift-shift at about 55. It seems to do this more then it used to.
Wish I'd gotten a 6 speed manual. Couldn't find that in the polo green. Any suggestions appreciated.
Wish I'd gotten a 6 speed manual. Couldn't find that in the polo green. Any suggestions appreciated.
Melting Slicks
Joined: Nov 2002
Posts: 2,471
Likes: 2
From: 1993 Quasar Blue 'vert Scottsdale AZ
Forget about messing with the TV cable. I had the same exact problem. I had the tranny rebuilt with HD parts, shift kit and hi-stall converter. The problem became even more pronounced. Between 51 and 53 mph, you could feel the car surging and watch the tach going up and down. Now this is weird, and I have no explanation for it, but replacing my worn brake booster cured it. I have no idea why. Doesn't seem like they should be connected in any way. Maybe the vacumn leak was messing with the RPM's, causing it to shift up and down. Maybe it was just coincidence. Maybe it was a miracle. But it worked.
