th350 won't shift up.... help?

[Sam_Fear]

Drove the Olds to get gas today and did a little trouble shooting on my trans. It won't shift in drive, but I can shift it up manually.

Fluid is up, although it was leaking and near empty when I got it. Good vacuum off the manifold, new line to the modulator.

Next I'm going to check the governor, I guess.

I'm just going through what I've searched. Anything else I should check or do?

Where is the governor?

 

[Sniper]

Kick down cable set properly?

 

[sgtpontiac]

350 issues...

If it shifts out of 1st when does it shift...normal....high rpm or does it shift out of 1st? Only things that dictate upshifts on the 350 are vacuum, valve body pressure and governor pressure..... I've seen shift valves stick after sitting.... I need to know if it shifts out of first and if so when/what speed.... like at full throttle type rpms...easy check...take the governor cover off and pull out the governor.... check plastic gear...is it striped... if not hold it upside down...so the weights expand out.... move the weights in and out...look for the vavle inside to move up and down... if that checks good then start looking at pulling the pan and valve body down.... your detent cable only operates for the kickdown into second gear..it's not like a 200R4 or 700R4.. which if out of adjustment can cause high or low pump pressure and sloppy or hard shifts.... it's simply a valve that forces it to downshift to second gear or first if the governor pressure is lower... or not at all if the governor pressure is already maxed out....

 

[Sam_Fear]

Thanks Sarge.

I don't feel it shifting in D or 2 on it's own at all. I maybe had it up to around 3,000RPM at most. No tach or speedo. Kickdown cable is not attached - I should check that for binding I suppose. I can manually shift from 1st to 2nd to 3rd and it will engage - I'm shifting it probably around 1,800-2,000RPM, guessing from engine sound.

I'll have to drive it again to double check that info, but I'm certain it is not shifting on its own.

So where is the governor located - drivers side? I've always ran stick, so I'm in new territory...

 

[williej]

shift modulator, simple fix.

 

[King Herald]

I'd bet the plastic gear teeth are stripped on the governor thing at the rear left side. Pop the rounded cover off, slip a new one in, away you go.

You don't need to use a kickdown cable with this tranny, but it sure make sit more fun to drive if you do have one installed and adjusted correctly. Without the cable it will upshift at about 3500 rpm max, when floored, but with the cable fitted and the throttle slammed it'll hold each gear to 5000rpm, which makes it far 'livelier'.

 

[jfg455]

modulator or govenor. if the modulator diaphram rips then it will only upshift @ wide open throttle. or if the govenor is stripped it will do all kinds of weird stuff.

 

[sgtpontiac]

Thanks Sarge.

I don't feel it shifting in D or 2 on it's own at all. I maybe had it up to around 3,000RPM at most. No tach or speedo. Kickdown cable is not attached - I should check that for binding I suppose. I can manually shift from 1st to 2nd to 3rd and it will engage - I'm shifting it probably around 1,800-2,000RPM, guessing from engine sound.

I'll have to drive it again to double check that info, but I'm certain it is not shifting on its own.

So where is the governor located - drivers side? I've always ran stick, so I'm in new territory...

I'd guess the governor by what you are describing.... drivers side..round cover sometimes has a spring clip helping to hold it on.... has a rubber square cut sealing ring on the cover.... remove the cover and simply slide the governor out..... you'll see right away if the gear is apple cored or not.... it's got a roll pin... tap it out and get yourself a new gear and replace it or replace the governor if you have a spare.... if memory serves me, it might also freewheel if you take your foot off the gas if the governor is bad..then drop back into gear when you hit the throttle again... but if you can upshift manually, I'd guess the governor is bad or the gear is stripped.....

 

[Sam_Fear]

Got under and check the governor - looks fine. Pulled the modulator - looks almost new except it's bent and I'm going to assume I shouldn't be able to suck air through it. Gonna go get a new one. Be right back....

 

[sgtpontiac]

sounds like a plan.....

Got under and check the governor - looks fine. Pulled the modulator - looks almost new except it's bent and I'm going to assume I shouldn't be able to suck air through it. Gonna go get a new one. Be right back....

Nope.... shouldn't be able to pull air through it.... easy fix... surprised it didn't pull fluid into the intake if the diaphram was torn....

 

[Sam_Fear]

It was sucking fluid, but hadn't reach the manifold yet. I still couldn't drive it to check if it's fixed - my fuel line blew.

 

[sgtpontiac]

Man..... what else can go wrong???

Hope you get the BUGS sorted out......

 

[rainman]

It could be the modulator, but most of the time when having upshift problems it's the governor!!!! Let us know!!!

 

[rainman]

One other thing if the modulator valve was blown, and you hadn't pulled fluid into the intake yet, it sounds like you wouldn't have had enough vacuum on it!!!
If it was pulling fluid it would act like a vacuum leak and would pull fluid into the intake rapidly!!

Just something to think about!!

 

[Sam_Fear]

It shifted fine, but ran like crud. Took several days to track down a leaky secondary float valve, a badly seated spark plug wire in the distributor, and badly adjusted valves. And changed the choke to a manual cable.

 

[King Herald]

Sounds like a whole bunch of headache going on at once.

 

[rainman]

Sound like you got it sorted out, good deal!!!