Dodge Caravan The Dodge Caravan is the best selling mini van from Dodge. How many Dodge Caravan owners here at DodgeForum.com would agree? Discuss it now!

A670 (31TH) Transmission Help

Thread Tools
 
Search this Thread
 
Old Jan 8, 2012 | 12:59 AM
  #11  
Iwagner's Avatar
Iwagner
Thread Starter
|
Registered User
Joined: Nov 2011
Posts: 17
Likes: 0
Default

Thanks master tech. I'm ordering the parts Monday and I'll give you an update. Have a good weekend.
 
Reply
Old Jan 15, 2012 | 01:10 AM
  #12  
Iwagner's Avatar
Iwagner
Thread Starter
|
Registered User
Joined: Nov 2011
Posts: 17
Likes: 0
Default

Just wanted to give an update. Pulled governor today and the weight and valve were stuck. Replaced, cleaned and van is running like a champ. Thanks for the help, this ended up being a $65 dollar fix and 4 hours of my time - much nicer on the pocketbook than a transmission shop!
 
Reply
Old Jan 24, 2012 | 02:39 PM
  #13  
dmccrea's Avatar
dmccrea
Registered User
Joined: Jan 2012
Posts: 15
Likes: 0
Default Have similiar problem with my 1998 A670 in Caravan

I have a 1998 Dodge Caravan with 3 speed A670 transmission. And I have something similar to what is being stipulated in this thread:

1) Engine/transmission surges and wants to shift gears (usually up) when at normal cruising speed (no problem when starting out at stop light, etc.).

2) Speedometer goes haywire (way up to 100 mph) even if traveling at 40, 50 or 60 mph.

3) Transmission is brand new Chrysler OEM that has about 20,000 miles on it since last Spring. But the sensors were not replaced at the time.

I thought the answer was to replace both the input and output speed sensors after doing some research last night.

But then read schematics posted here on this thread and realize that this transmission only has one speed sensor.

Any suggestions for me?
 

Last edited by dmccrea; Jan 24, 2012 at 02:52 PM.
Reply
Old Jan 24, 2012 | 06:29 PM
  #14  
dmccrea's Avatar
dmccrea
Registered User
Joined: Jan 2012
Posts: 15
Likes: 0
Default Update on my van diagnosis

After further Google search I found a fellow with same 98 Caravan with 3.0 engine and same A670 transmission and experiencing same problems, i.e. speedometer moving erratically and transmission shifting erratically as well.

He solved problem by replacing Transmission speed sensor. But he also found that the plastic gears on end of sensor needed to be replaced. I have asked him where he found plastic gears but no response yet.

Does anyone here know where to get the plastic gear for the speed sensor that goes on this A670 transmission? By the way the sensor uses 3 wires.

Thanks for all your help.

dennis
 
Reply
Old Jan 25, 2012 | 09:37 PM
  #15  
tomcat48nov's Avatar
tomcat48nov
Registered User
Joined: Jan 2012
Posts: 4
Likes: 0
Default Tomcat

I just ordered the gear today, it cost $22.00 including shipping.
Will check paperwork and input info ASAP.
 
Reply
Old Jan 25, 2012 | 09:44 PM
  #16  
tomcat48nov's Avatar
tomcat48nov
Registered User
Joined: Jan 2012
Posts: 4
Likes: 0
Default Tomcat

http://www.transmissioncenter.org/sp...e_and_jeep.htm
Scroll to end of page, hope I was allowed to print the link.
They have all the gears.
 

Last edited by tomcat48nov; Jan 25, 2012 at 09:54 PM.
Reply
Old Jan 25, 2012 | 09:48 PM
  #17  
tomcat48nov's Avatar
tomcat48nov
Registered User
Joined: Jan 2012
Posts: 4
Likes: 0
Default Tomcat

The 3.0 engine tranny is not the same as the 31TH 3 speed tranny.
 
Reply
Old Jan 25, 2012 | 09:53 PM
  #18  
tomcat48nov's Avatar
tomcat48nov
Registered User
Joined: Jan 2012
Posts: 4
Likes: 0
Default

If plastic gear is bad there may not be anything wrong with the sensor, just the gear.
 
Reply
Old Sep 9, 2012 | 02:24 PM
  #19  
bonesbmx's Avatar
bonesbmx
Amateur
Joined: Oct 2008
Posts: 34
Likes: 0
From: ont canada
Default

does anyone have a part number for the speed sensor? i think i need this as well.
 
Reply
Old Sep 10, 2012 | 12:02 AM
  #20  
master tech's Avatar
master tech
Site Moderator & Tech
15 Year Member
Joined: Apr 2007
Posts: 11,642
Likes: 108
From: Near Sacramento,ca
Default

This is a mopar number. 4707839AA
 
Reply



All times are GMT -4. The time now is 06:24 AM.