a340 not acting right

[Dave C]

My automatic tranny has not been shifting into overdrive when warm and o/d indicator light off. O/D button does make o/d light go on and off. Also will not kickdown when I floor it. I replaced the 3 solenoids, filter and fluid recently with new aftermarket parts. Throttle cable is adjusted. Ideas? Thx, Dave

 

[bioskyline]

sounds like the friction discs inside are worn and not letting it shift. does the tranny slip at all? how did the pan look for fillings when you droped the pan? mine was doing the same thing and then stoped working one day.


might be time for a rebuild, replace, or a manual swap.

 

[Nick M]

If the O/D off light is on, it isn't supposed to go into overdrive. Check DTC's first.

 

[Dave C]

Bioskyline, The pan looked good. And I didn't flush the tranny. There may have been some slippage, but I guess not that bad if I am not sure... I would be interested in good a340, parts or whole.

Nick, I agree. DTC is a new acronym for me tho.

 

[Dave C]

I dropped the fluid level down to halfway between the marks and the o/d works again. It shifts smoother too. Still has the kickdown problem tho. btw, I can manually downshift and it responds fine.

 

[hvyman]

There is hot and cold marks on the dip stick. Auto trans fluid should be checked with the engine running also.

Kick down cable is adjusted properly?

 

[3p141592654]

That's a line pressure modulator cable. Has absolutely nothing to do with kickdown. I'd check for A/T codes like Nick said in post 3!

 

[Devin LeBlanc]

If the OD light is blinking check ECT codes.

 

[Dave C]

I get no codes when running tranny diagnostics since installing new solenoids. But, I saw in the TSRM that there are several things that can go wrong with the tranny and codes won't be thrown because the diagnostics system is not checking those things. I think I will throw another ECT at it to start and see if that helps...prolly can't hurt anyway. Do throttle cables stretch after 24 years? Mine is adjusted as good as I could get it per instructions, but I suppose an 1/8 or 3/16" could make a difference. Thanks all for your input.

 

[Devin LeBlanc]

That wont make a difference with what you are describing is taking place.. Has nothing to do with it.. All it does is adjust valve body line pressure

 

[Nick M]

Unplug the range selector switch. That is where the harness plugs into the transmission. Drive it, then come back.

DTC=Diagnostic trouble code

 

[Dave C]

I did the manual shifting test and there were no problems.

 

[Devin LeBlanc]

Sounds like a problem in the valve body.

 

[Dave C]

Sorry for misplacing the post....Can I get this thread moved to the tranny section?

 

[hvyman]

Moved it for you.

 

[24vtoy]

hi guys

quick hijack on same topic.

if you replace the a340 with a w57 manual box does is the propshaft shorter or longer ? or does it fit perfect ?

 

[Nick M]

W58 is the trans...FYI. It will fit perfect, with the correct driveshaft, flywheel, and pressureplate.

---------- Post added at 01:37 PM ---------- Previous post was at 01:35 PM ----------

I did the manual shifting test and there were no problems.

It has to be the control system. If by manual shifting you mean unplugging the trans and it drives normal.

 

[Dave C]

Yeah it functions as the TSRM says it should with the tranny control unplugged. TSRM says that means it's an electronic issue. I replaced the ECT ECU and have same kickdown and early shift problem, but only some of the time. The tranny acts like it likes the replacement ECU better. I will clean the contacts on the harness and report back.

 

[Nick M]

Knowing you have a control problem, try diagnosing the control system. Have you ever had a computers 101 class? Junk in, junk out.

 

[Dave C]

lol they didn't mention "junk in, junk out" in computer class. I hope the "junk in" wasn't me shorting out the ECT. I am suspecting the TPS and will put a meter on it.