Technical TRANSMISSION PROBLEM

Yesterday on my way home from the monthly club meeting I noticed the 350 automatic transmission in my old beater never went into third, I started off and felt the familiar first to second shift but I never felt the transmission go into third.

I checked the transmission fluid when I got home and it was fine, I checked it agin this morning when it was cold and the transmission dip stick showed the fluid wasn't low.

This is something that hasn't happened in the past 34 years, could it be the modulator valve gone bad? HRP

 

I'd try the modulator area and first check that the the rubber hose hasn't slipped or split. If that checks out okay, then modulator. I've also had the fitting in the intake crack and leak, another easier area to inspect for trouble.

 

This happened to me in my 31 Ford years ago about 80 miles from home. No third gear all of a sudden. I stopped at a AutoZone on the way home and swapped out the modulator and nothing. Made it home in second gear no problem just went slow. Monday when I talk to my trans guy he said the second to third something or other had broke so when I pulled the trans and took it to him sure enough that's what it was. Could be your problem or maybe not hope it's a better outcome for you. If the modulator didn't work it wouldn't go into second

 

Faulty governor...?

 

I'd place my bet on the governor.
Going back to milwscruffy's post (post #2) it wouldn't hurt to check the hose to the modulator and if you have a Mighty vac or similar little vacuum pump test it real quick. I had one that the hose jumped off the modulator a couple of tiimes before I replaced the hose. It will take you longer to get the car up in the air than to check it.

 

The first thing to check is to see if it will go into reverse and not slip. If it doesn't want to go or it slips, the front clutch friction discs and/or piston seals have failed.

If the 1-2 shift is correct in that it occurs at the normal time and isn't harsh, it probably isn't the vacuum modulator. THM 350's use a dual seal setup on the front clutch (high and reverse gear). There are two outer seals and one inner. In high gear just a portion of the clutch piston is used so fluid is trapped between the inner seal and one outer seal. If the inner seal wears too much, you will lose high gear. In this case reverse will work fine (as long as both outer seals are okay), you just won't have high gear. If that's the case, the trans has to come out and be gone through.

 

Reverse works like a charm. HRP

 

What he said. Not uncommon for the plastic gear on the governor to fail. And a fairly simple job to inspect and repair.

Do you feel lucky?

 

I don't even have a hose hooked up, and my TH350 shifts fine without it. Been in the car 12 yrs. and never an issue. I do have a Transgo Competition shift kit in it, so maybe that could be why it doesn't need the vacuum hose?

 

Wondering how it gets into 2nd gear then?

 

So does it stay in 2nd ? Freewheel or slip in 3rd? Does manual 2nd feel the same as D, or does it gear down and decelerate in 2nd?
If it doesn't slip in R, not much left except maybe the 2-3 shift valve gummed up and sticking.

 

I vote for the governor. Transmission shops used to have them on the shelf and could swap one in a few minutes. I got stuck in lower NJ in 1986, slowly lost all gears until it stopped moving.

 

I had a Ford C-6 do that on me when I was in the Navy in Norfolk, Va. One of the old heads around here told me to dump two cans of brake fluid in it. Something about it swelling the seals so it would build more pressure. I did and managed to limp it home. It was a temporary fix, I still had to get it rebuilt , but I knew I could get it done here a lot cheaper here than up there. Those people thrived on taking advantage of sailors far away from home and no local friends. Good Luck.

 

Bob , The governor has to spin to open and allow pressure to move the 1-2 shift valve, which it does, just fine, according to HRP.

 

HRP made it home without the brake fluid . ;-)
Decades ago, a kid comes in the gas station with a 55 Buick, peeing fluid out of the front seal, which was common.
I give him 20 bucks for the car, and pour in a pint of brake fluid. I then drive it 20 miles down the highway and back, and the leak had stopped!
I used the car all summer to flat tow my racecar. So far, so good
I then sell the car to another kid. The trans promptly quits on him and has to be completely rebuilt, which is what will happen if you put brake fluid in them.
Recently I did a C4 that had bf in it. I had to blow the pistons out of the drums with 150 psi air to get them apart

 

My experience was with an OT Monte Carlo with a metric Turbo of some sort. We lost 3rd gear, then 2nd and finally 1st within a mile or so and had to be towed to a Lee Myles shop.

 

Check the kickdown cable to make sure it's not stuck fully extended. Good Luck

 

200 /200 C/ 2004 R all have governors but also a TV cable that regulates the part throttle upshift .Different dynamic, but still ..No governor rotation..No 1-2 upshift.

 

I thought of that the other night. If the kickdown cable is worn, frayed, it could possibly be doubled over and not returning. That would cause a big problem for a 2-3 upshift.
I guess we're waiting for teardown results here

 

“Interested readers want to know”

 

Follow up?

 

I have been laid up with covid and haven't even been in the shop. HRP

 

Hope it’s a mild case.

 

Well that blows the big green weenie. I had it, the whole family has had it, it sucks. I even know a few people that have had it twice. Hope you feel better soon, Danny.!

 

Everybody but Brenda, I even had all the shots and still got it. HRP

 

Hope ya get better soon HRP

 

God bless all in need

 

I'm not vaxxed at all, everyone around me was and had it just before Xmas...

 

But you didn't die...

 

Exactly the reason to get the shots.
Now back to our regularly scheduled programming.