TH400 transmission downshift electrical connector

[wallew]

OK, my tranny in my older M1009 is starting to make sounds. So I crawled up underneath to take a look see.

Looks like she has leaked tranny fluid at some time in the past. A LOT of blow back that could be oil or tranny fluid (mixed with dirt). But one of the things that jumped out at me is that 'transmission downshift electrical connector' wire was broken and just hanging there.

So, I've gotten into the -20 TM and it tells you to 'disconnect the electrical connector from the downshift electrical connector'... section 5-24 & 5-25 on pages 385/386...

OK, HOW?

The connector doesn't seem to want to either pull or twist off. Given the wire has broken, I'm trying to figure out how to replace it anyway...

So, anyone got any TH400 info they could share I would really appreciate it.

 

[Warthog]

The connector is a regular spade connector.

No twisting but wiggle side to side to unseat the rubber groove on the plug cover.

 

[1986Blazerk5]

The connector is a regular spade connector.

No twisting but wiggle side to side to unseat the rubber groove on the plug cover.

What exactly does this connector do?

 

[jj]

It is connected to a switch at the throttle linkage under the dash. It will cause a transmission downshift when you stomp on the pedal. My transmission rebuilder says it is very important on the 400 that it work properly.

 

[Warthog]

That's correct. It completes the circuit to tell the transmission that it needs to downshift when the throttle is nearing wide open position.

 

[rnd-motorsports]

WoW The first answer in a few threds that are simple and leave no room for ? Perfect

 

[wallew]

OK, I can NOT get this sucker loose. Does it have some kind of lip or something else that must be lifted up?

I've been under my truck twice now and even with a large pair of channel lock pliers I cannot get it off the connector itself.

So, any suggestions?

I'm about to take a razor to it, at least it will be off. And I'd bet I can get one of those covers at any tranny shop.

 

[rnd-motorsports]

Do you have a way to take a pic. and post it sounds like something is not right should not be that hard to pull off its just a spade terminal with a rubber boot on it to keep the elaments off the conection. and a plastic peice on the trans with the male side of a spade sticking out of it. The worst the spade terminal is rusted but as stated it's just a spade terminal

 

[wallew]

Well, with a little persuasion from a pair of vice grips and a flat bladed screwdriver, the cover finally came off.

The reason I was attempting to get this off was my tranny was making strange noises that started about three weeks ago. I have not driven it much since them, trying to figure out what the issue was. While underneath, I saw one wire just hanging there.

Apparently at some point I snagged that wire on something and it pulled loose. So I had no electricity to the connector.

So after getting the cover off, I've put a new spade connector on it and the tranny SEEMS to be working properly again. I'm getting to go run a few errands and when I get back I'll tell you folks how it is running.

Then I'll go out and buy a new connector with a pigtail so I can reconnect the CORRECT spade end on it and it will once again be sealed against the weather.

 

[wallew]

Well, I just ran a couple of hours of errands for my wife. Several normal starts and stops.

My tranny is still making a LITTLE noise, but most of the strange sounds went away after I reconnected the electricity to the connector.

Now all I've got to do is go get a new connector and put it in place of the weatherized spade connector I crimped in place for a temporary test.

Seems to resolve all my issues. We will see.

 

[RedHeadTarn]

Ok, so I am having the exact opposite problem.

My drive to work is a long gentle downhill slope and the speed limit is 35 which is right at my shift point between 2nd and 3rd. The engine has more than enough power to plug along in 3rd for the entire trip but i am having a hard time keeping iit from downshifting into 2nd which burns more fuel then I want to considering the drive.

Is there a way to adjust the downsift points? I would love it if it would wait untill dropping below 28 or so before kicking down.

 

[Warthog]

First question is If you are having the exact opposite problem, why would you post it in this thread? Why not start a new one or find one like the problem you are having?

With that said:

Have you checked the vacuum module of the Injector Pump? It controls the shift points along with the vacuum modulator on the transmission. It can be adjusted.

The electrical connector only controlls the downshift at wide open thottle.

The tech manual covers how to test and set the vacuum module. I even posted a thread about it in the http://www.steelsoldiers.com/cucv/20600-faq-thread-cucvs.html