Transmission downshifts suddenly - YotaTech Forums



86-95 Trucks & 4Runners 2nd/3rd gen pickups, and 1st/2nd gen 4Runners with IFS

Transmission downshifts suddenly

Reply
 
LinkBack Thread Tools Search this Thread
Old 07-16-2009, 09:57 AM   #1
Registered User
Thread Starter
 
95 Yoda 4runner's Avatar
 
Join Date: Jun 2009
Location: San Diego, Ca
Posts: 33
Transmission downshifts suddenly

I could use some help from you guys,

I have a 1995 4runner with 168k, 3.0L 4wd etc. Every once in a while i'll be driving on the freeway at about 60mph and suddenly the tranny will downshift quickly and go right back to normal. This "slip" happens really fast from over drive to 4th gear (shoots up to about 4k rpm) and back into OD in a blink of an eye. When this slip happens the A/T oil temp light AND CEL blinks on and off during the downshift moment. The lights blink on and off as fast as this slip happens. If these lights would stay on then that would help me figure this out but they don't for some reason. this slipping occurance can happen after 10 minutes of regular driving or an hour or sometimes it doesn't happen during a drive at all. I drive normally, i'm not offroading it when this happens and i checked the fluid level and it read normal for my tranny. This occurance can also happen when just driving in a parking lot and accelerating normally but it's rare. Can anyone give me some advice? Thanks for looking.
95 Yoda 4runner is offline   Reply With Quote
Old 07-20-2009, 02:09 PM   #2
Registered User
Thread Starter
 
95 Yoda 4runner's Avatar
 
Join Date: Jun 2009
Location: San Diego, Ca
Posts: 33
Some more info for anyone that can help.

I just jumped Te1 and e1 to read any codes that may be stored and there isn't any. The check engine light continuously blinks with no pauses. That confuses me further, i was hoping for a code since my CEL flashes on real quick when this problem occurs.

Another idea may be my speedo cable? When i drive my speedo waves back and forth as i drive and accelerate. It sways about 5mph. If i'm driving around 55 mph the speedo is swaying from 53-57mph. I heard a bad speedo cable (i think mine is mechanical) can mess up your transmission by something called 'lock up'?
95 Yoda 4runner is offline   Reply With Quote
Old 02-14-2012, 08:39 AM   #3
Registered User
 
Join Date: Feb 2003
Location: Mt. Holly Springs,Pa.
Posts: 22
I have a similar problem with a 95 6cyl auto. Most of the time all is well then suddenly it will downshift. No light s or gauges are affected. My experience has been at speed under 50mph on the level. Is there a sensor involved? Any help appreciated.
Brian Smith is offline   Reply With Quote
Old 08-05-2012, 06:43 PM   #4
Registered User
 
Join Date: Feb 2003
Location: Mt. Holly Springs,Pa.
Posts: 22
random transmission shifts

Might have found a possible solution. I decided to replace the radiator due to pin holes that developed in the tank. In the course of doing so, I found out that there were different sensors that send coolant temperatures to the transmission. Since the radiator replacement, the problem has gone away.
Brian Smith is offline   Reply With Quote
Old 08-05-2012, 07:44 PM   #5
Registered User
 
Join Date: Sep 2007
Location: San Francisco East Bay
Posts: 5,677
While I've never figured out exactly which vehicle has an electronic speedo, I'm pretty sure that a '95 4wd would be electronic. The easy way is to look at the back of the transfer case: is there a fat cable or a supple wire coming out of the sensor?

Unfortunately, a failure of the electronic VSS1 is more commonly "drops to zero for a second or two, then springs back up to the right speed." Your wavering sounds more like a cable type. Under the vehicle for you!

Either way, VSS1 (whether it is the electronic one in the transfer case, or the reed-switch inside the combo meter driven by the speedo cable) is an input to the Transmission (missing VSS1 is the first diagnostic code http://www.ncttora.com/fsm/1990-1995...2/troubles.pdf ) so I would definitely look in that direction.
scope103 is offline   Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
22RE misfire due to electrical issue calderp 86-95 Trucks & 4Runners 17 11-16-2015 03:49 AM
22R idle is surging with AC on Gurr 84-85 Trucks & 4Runners 2 09-12-2015 10:51 PM
91 Toyota speedometer problem toyotafreak98 86-95 Trucks & 4Runners 9 09-10-2015 03:57 PM
I want to swap 3rd gen 4runner transmissions bu need accurate wiring diagrams kelly1450 95.5-2004 Tacomas & 96-2002 4Runners 1 09-02-2015 01:29 PM


Tags
aode, downshift, downshifting, downshifts, driving, hwy, makes, quick, reason, suddenly, tranny, transmission, transmition, trnasmission, truck

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -8. The time now is 10:05 AM.


2017 InternetBrands, Inc. We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: