Transmission failure to upshift at highway speeds?

PYROSLINGER

MEMBER
1995 TOYOTA 4RUNNER
3.0L
V6
4WD
AUTOMATIC
27,500 MILES

Recently my fully serviced, fluid full and working very well, 3.0 3vze 3.0 A 340F Automatic Transmission began failure to upshift at highway speeds. The RPMs are at about 4,000, at 60 MPH. The Throttle Kickdown Cable outer cover is somewhat worn, but the inner cable moves freely. Also the Electric Over Drive Button suddenly has no effect during these episodes. Sometimes I can stop the engine, re-start it and it operates properly temporarily. I am perplexed? I ordered and plan on installing or having a dealership install a new Kickdown Cable to start with. Is there any other components that may cause this? Where to begin troubleshooting? At this point, I have so much money in this old vehicle, I can only keep adding new parts until this final and sudden issue arose. Any help from a mechanic, very experienced and familiar with the Second Gen 4Runner Automatic Transmission would be more than greatly appreciated. Thanks.

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
42,913 POSTS

It does sound like the kickdown cable needs an adjustment or replacement, here are the instructions on how to do so:

1. Disconnect cable housing from bracket on cylinder head cover, then the cable from throttle linkage.
2. Remove valve body as previously described.
3. Remove throttle cable mounting bolt from transmission case, then pull out cable.
4. Reverse procedure to install. Tighten throttle cable mount bolt to specifications and adjust cable as previously described.

If this doesn't work, we should run the codes this guide can help:

https://www.2carpros.com/articles/ford-lincoln-mercury-obd1-1995-and-earlier-diagnostic-trouble-code-definition-and-retrieval

Can I ask if the speedometer is working when the problem is present? Check out the images (below). Please let us know what happens.

Image (Click to make bigger)