350 transmission

[Randy Terry]

I have a 1985 Chevy short bed pickup 350 engine with 350 transmission when I start off slow it shift from first to second fine, but when it goes into second gear a few seconds later it shift to 3rd and lugs like it's in Overdrive, the kickdown cable is adjusted fine and I just put a new transmission module on it but it still shift the same? Any info would be greatly appreciated thanks

 

[animal]

Moved to a more appropriate sub forum for better visibility.

@HotRodPC

 

[Randy Terry]

I am new to this forum, where was it moved to?

 

[animal]

Hi Terry. I moved it into the transmission section. HotRod is one of our transmission guru's and I tagged him. He's looking now and may have some ideas for you.

 

[Randy Terry]

Thanks for the help, yes I found it in the transmission forum I should have posted it there thanks for the help.

 

[HotRodPC]

I am new to this forum, where was it moved to?

It was moved to Automatic Transmission Category. Welcome Aboard !!!

So I read your post. I'll get @74 Shortbed in here to concur or add his .02 cents, but it sounds to me you've lost 2nd gear which is consistant with the #1 failure of the Th350, broken intermediate roller clutch outter race and it usually takes the roller clutch with it.

I'd imagine you have to get the rpms up real good to before it'll shift and when it does it goes to 3rd.

 

[animal]

Thanks for the help, yes I found it in the transmission forum I should have posted it there thanks for the help.

That's what we're here for.

 

[HotRodPC]

It was moved to Automatic Transmission Category. Welcome Aboard !!!

So I read your post. I'll get @74 Shortbed in here to concur or add his .02 cents, but it sounds to me you've lost 2nd gear which is consistant with the #1 failure of the Th350, broken intermediate roller clutch outter race and it usually takes the roller clutch with it.

I'd imagine you have to get the rpms up real good to before it'll shift and when it does it goes to 3rd.

OK scratch all that. I see you have 2nd gear now. But you mention Overdrive, so you don't have a Th350. You've got a 700r4. Now I'll go reread it again and give thought for a minute.

 

[Randy Terry]

No actually it'll do all this in about 75 to a hundred feet when driving slow, if I take off real fast it shift just fine all three gears and it down shifts fine, it has no RPM elevation or it doesn't rev High when it changes.

 

[animal]

OK scratch all that. I see you have 2nd gear now. But you mention Overdrive, so you don't have a Th350. You've got a 700r4. Now I'll go reread it again and give thought for a minute.

Could it be a TH350C??

 

[Randy Terry]

No it's just a regular 3-speed it's not the C lock up it just went shift from 2nd to 3rd it feels like an Overdrive

 

[HotRodPC]

OK first off, let's get you on the right terminology so if you're calling around shops and such, you're not talking like an unaware dude and they bend you over a barrel and twist it off in your ass if you know what I mean. If you know nothing, the tend to take advantage of you. So, Ford have kickdown rods and such. Th350 has a detent cable, a 700r4 which is what you have has a TV Cable aka Throttle Valve Cable. It does sound as if it could be adjust a little loose and causing an early shift from 2-3. Now what is this Transmission Module you're speaking of? Do you mean Vacuum Modulator? If so, then you do have a Th350, but Th350 DOES NOT have Overdrive. Is it possible when you feel converter lock-up you're thinking it's OD? Converter lock up just gives you an actual 1:1 final drive ratio like a manual transmission had in it's top gear just before OD.

 

[HotRodPC]

Could it be a TH350C??

Exactly what I'm thinking, and he's thinking the lock up he feels is a **** to OD. We'll get him nailed down here and helped out for sure, we just gotta know exactly what he has first and go from there, because diagnostics is totally different between a Th350, Th350C and 700r4. Thought the Th350 and Th350C are very similar in diagnostics, it just depends on what the problem is.

 

[Randy Terry]

Sorry if I was being confusing. It's the 350 Transmission it has the vacuum module on the side of the transmission it was leaking transmission fluid so I had it replaced when I pull the vacuum hose off of the modules it leak transmission fluid that's why I replaced it

 

[HotRodPC]

No it's just a regular 3-speed it's not the C lock up it just went shift from 2nd to 3rd it feels like an Overdrive

hmmm, so how do you mean if feels like an OD? Are your rpms dropping, or going higher? Is it bogging the motor down, is that what you mean? That would be an uncommon problem on a Th350, but If I had to take a guess, you may be getting a bleed in the valve body to where when it's going from 2 to 3 there is a valve that's not moving 100% to where it's supposed to.

Did this just start all of sudden all at once, or have you been able to it's gradually gotten worse and worse?