[Bill-E-BoB]

I have a shot TH350 transmission in my '69 Camaro. But I don't think its shot now...since I have no clue what I"m talking about for all intents & purposes, I was hoping some of you could give me your opinions since you're way more informed than I am.

Brief background...in early 2000 I had the transmission professionally rebuilt & installed it back in the car. Went for a test drive, it was great but I blew the rear main seal in my motor & had to park it. Years later, got it out of storage, had a shop fix the motor, and they test drove it without checking the fluid in the tranny which had apparently seeped out of a leaky dipstick seal over the past 8 or 9 years. They informed me my transmission was "worn out & must be dead" only for me to tow it home & discover it took 5 quarts to bring it back up to the proper level. Slipping like crazy, it seemed clear to me at the time they had fried my transmission & I was back in the year 2000 all of a sudden with no transmission. I was able to pull it into the garage, where it sat in storage again until now.

That's as brief as I can get. Sorry, long winded.

So anyway, today I was taking the car out of storage trying to get it ready to put on the market & decided to take a look at how the transmission behaves. It engages in drive and reverse, so I went to the autoparts store & picked up some Lucas Transmission fix. After putting the whole bottle in & topping off with about 1/2 quart of fluid, it pulls nicely in 1st gear (forgot how quick this car was), but won't ever shift to 2nd. So I'm reading online, and everything I find says if this mechanic really fried my transmission, the fluid would be burnt & brown & smell bad. Since I've added 6 quarts & the Lucas oil, the fluid looks brand new, so that part of the test is wasted...but I can't smell any nastiness at all, even with my nose right on the dipstick tube. this combined with how well it runs in 1st & reverse leads me to believe I might not have major internal damage after all. I'm I being too optimistic?

So, could this be a repairable problem? What do I try first?

[Fergusonic]

Yes,,,,you are dreaming. just kiddin'. It may depend on how long the shop "test" drove the car. Why one would have to test drive it to insure that an engine rear seal is not leaking is beyond my backyard mechanic imagination other than a "Joy" ride to see how fast it is. If they didn't even check the tranny fluid ; then a joy ride sounds even more likely. Did they hookup the Kickdown cable? I would pull the tranny pan and evaluate the contents in the bottom of it.

[sqzbox]

Check the vacuum hose to the tranny modulator. It might have dried out and cracked causing a vacuum leak. Also, check the modulator by pulling the vacuum hose off an see if any trans fluid comes out. If it does, replace the modulator with new vacuum hose. Do all the free trouble shooting first, looking at the bottom of the pan will cost a new gasket and fluid.

[eloc431962]

Originally Posted by sqzbox

Check the vacuum hose to the tranny modulator. It might have dried out and cracked causing a vacuum leak. Also, check the modulator by pulling the vacuum hose off an see if any trans fluid comes out. If it does, replace the modulator with new vacuum hose. Do all the free trouble shooting first, looking at the bottom of the pan will cost a new gasket and fluid.

X2 The hose may have even simply came off the modulator.


Cole

[cobalt327]

The governor gear could have been worn away- this will cause a no-shift condition.

I think if it were the modulator line, it would still shift, just later. The kick down adjustment could also cause bad shift points, etc. but it would shift.

I believe if the governor isn't the problem, bigger problems are at hand.

[blyne3]

as long as it has sit the valves may be sticking also.

[Bill-E-BoB]

Oh good, sounds like there are lots more things I can check before throwing in the towel & putting a new transmission in. I'm headed downstairs to play & I'll be back with my findings soon.

A couple things I can say so far:

-The kickdown is not attached to the carb...didn't have the right bracket & I was told I could just leave it sitting there & it wouldn't have any negative effect other than not hitting a passing gear on the highway. (OOOH! I wonder if its stuck in the open position so it never thinks it should shift up. I'll check that 1st!)
-the linkage connecting the shifter to the transmission isn't right, its a couple pieces of band iron welded together. This makes it so that the P position on the shifter is Reverse, and sequentially down from there. Aside from not being able to get to Park, it seems to work fine though. I found the correct shift linkage, so I'm about to put that on while I'm under there & see if it makes any difference.
-I'm 99.9% sure the shop was joy riding, not test driving, so they could've very well done all sorts of unholy things to it. But since I have no proof, there's no point in speculating I guess.
-The governor gear...where is it located? It's not the speedometer gear is it? Because that broke during removal back in 2000 when I was in highschool & my autoshop teacher said I can just do without it until I start driving again, so its missing. If that's a governor gear & not just a speedometer gear...its probably my problem.

I'm headed downstairs to check out the module & kickdown. be back soon!

[cobalt327]

Originally Posted by Bill-E-BoB

If that's a governor gear & not just a speedometer gear...its probably my problem.

The gov is located under a domed cover w/a wire bail over it.

Remove the bail then pry the cover off. The valve just pulls out. Don't lose anything! lol

The gear is nylon/plastic and will be very evident if it's chewed up.

[sqzbox]

If your careful, you can re-use the rubber o-ring when you pry off the gov. cap.
Good idea to have a new one on hand. Fluid will come out (about 1/2 qt.) when you pull the cap. It pry's off like a front wheel bearing dust cover.
The gov. cover is on the drivers side just ahead of the tailshaft housing.
If the gear looks ok and the weights are free, check the shaft for any wear. Just a few K wear will affect the pressure.

[Bill-E-BoB]

Good news/bad news...Good news is I got under there & found the vacuum hose was not connected to the module. Bad news, after connecting it, nothing changed.

Kickdown cable, I tried pulling it & pushing it & whatnot, and it has just about no motion at all. Shouldn't it be able to move back & forth? When its pulled out the kickdown should be engaged & lock it in a lower gear right?

I'm pleased to say I got the correct shift linkage on there...though the cable is still not quite long enough for it to reach all the way into Park. Grrr...

I'll inspect the governor tomorrow & see what we come up with there.

[jeffvega]

check to make sure you are getting vacume to the modulator (stick you finger over it while unpluged and engine running) if you have no vacume at the modulator thats most likely your problem. if not then the modulator itself is not moving internaly. but I think it would suck fluid past the diaphram in that case. either way I would look to the modulator for the problem..

[Bill-E-BoB]

ok...so work gave me a major case of the mondays and after getting home at 8:00pm I just really didn't feel up to lifting a car back up in the air to go under it & check the vacuum line on the modulator, so I'm being lazy, and I think it paid off.

In the attached image, there's a vacuum line in my hand that goes down behind the engine following the firewally down into the dark depths of under the car land. Without jacking it up in the air again (lazy, hungry, sorry...) can I assume this is the line to the vacuum modulator? The vacuum advance is connected to the front of the carb, and the brake booster is connected as it should be, I can't think of any other vacuum lines that should be anywhere. So, should I just grab some spare hose & connect this line to the port coming off the manifold right next to it? Why on earth would someone have blocked this line & left the tranny with no vacuum? What purpose would that serve?

Oh, and I also futzed around with the kickdown cable & was right, it was in the wide open position, but now its back in the closed position...still not connected, but at least its not wide open anymore.

Now if only I had tail lights or neighborhood street lights or a car thats not quite so black so I could test drive it right now instead of waiting for daylight!!

[cobalt327]

The modulator won't prevent the tranny from shifting- it will, however, cause the shift to occur much higher than it should be.

If the OP were to take the car out and run it in first to where the governor would cause the shift (a kind of "default" shift where the tranny will shift into a higher gear, regardless of the shifter being in a lower position, for instance).

But if the governor is bad, it won't shift to a higher gear, regardless.

Good news/bad news...Good news is I got under there & found the vacuum hose was not connected to the module. Bad news, after connecting it, nothing changed.

This still doesn't mean there's no problem w/the modulator (see above).

If you've not determined that there is NO shift- even when running it up to 5000 RPM in first (where a shift would be forced, unless a shift kit has been installed or mods made to prevent the "default" shift from occurring), then the modulator might be the culprit. I neglected to mention this earlier, thinking that you knew these ins and outs, which you may not have known.

You can remove the modulator valve and use the engine as a vacuum source- a piece of vacuum tubing temporarily connected to a manifold vacuum port w/the engine running will do- and then connect the tubing to the modulator valve and see if the valve retracts.

You can also do this by mouth or a hand vacuum pump. The modulator valve must be able to hold a vacuum, as well. If it retracts, plug the tubing or bend it over like a garden hose to see if the valve stays retracted.

If the modulator doesn't retract, replace w/a new one. If it does retract, and it holds a vacuum- replace it back into the tranny and mark it off your "possibilities" list.

[jeffvega]

since the modulator isn't hooked to any vacuum source I would fix this first and go from there. It should be hooked to a full vacuum sorce just like the brake booster and most of the time the vac advance on the distributor. I just looked at your pic and yes hook it to there and I bet your problem is gone.

[Bill-E-BoB]

Ok, seriously, you guys are my HEROES!!!! Jeff & Sqzbox nailed it on the head!

I grabbed an old tach out of a drawer, hooked it up so I could rule out the modulator like you said, Cobalt, without worrying about redlining the motor.

Then once the tach was on there & working I decided to go ahead & hook up that vacuum line & see what happens. So I got the brake lights working so I'd show up to other cars, & took a test drive around the neighborhood. And...I have a working transmission!!!!! Shifts smooth as butter at about 2200 for 1st to 2nd & at who knows when for 3rd, I was too excited to stare at the tach.

Seriously, thank you guys so much!! I can't believe I can actually drive this thing now!

I'm curious though...the vacuum port was very intentionally blocked off. Why would someone do this? Poor mans shift kit?