TH350 5 neutrals (delayed shifting/won't go into gear)

[IcePatch]

That transmission has had some water in it at one time. That’s what valve body gaskets look like after soaking in a ATF/water bath for a while.

The B&M kit severely restricts accumulator function, and is a little more aggressive with spacer plate drill sizes. I actually prefer the B&M kit IF the car in question has a aftermarket torque converter. The looser converter with higher stall speed really tames the shift feel just cruising around. With a stock converter, it’s not a pleasant daily driver.

The TransGo kit is more “civilized”.

Once I had the valve body off and was scraping old gasket off the transmission, it actually started dripping water on me after a fair amount of ATF had dripped out. Just a couple tablespoons, but enough to know that your verdict is correct.

Couldn't say what kind of converter it has, but based on the shift feel the one time I did drive it it doesn't have a very high stall. Probably stock.

 

[Matt69olds]

Once I had the valve body off and was scraping old gasket off the transmission, it actually started dripping water on me after a fair amount of ATF had dripped out. Just a couple tablespoons, but enough to know that your verdict is correct.

Couldn't say what kind of converter it has, but based on the shift feel the one time I did drive it it doesn't have a very high stall. Probably stock.

Be conservative on the hole size. It’s easy to make it bigger. Can’t make the hole smaller. And if the accumulator piston in the valve body is plastic, replace it with an old school aluminum piston. If it hasn’t broken yet, it will when you compress it to remove the e clip.

The fact that you got water AFTER draining instead of strawberry milk shake is encouraging. That means water hasn’t circulated and contaminated the friction material. Water dissolved the glue that holds the friction material to the backing plate. Sometimes I tear apart a core that’s spent some time underwater and the perfect looking friction material just falls off the backing plate.

 

[MikeB]

How would you use the Gear Command feature on a street truck? Have to say I've always been able to keep a TH350 in second as long as I needed to, but must admit the speeds were probably under 60 mph.

 

[IcePatch]

Gear command is a compromise between the full manual valve body I want in it, and user friendliness for my aging parents who can use it as a farm truck once I get it on the road. It's entirely possible that I don't need it, it just seemed like the thing to do when I bought it

The truck's also got a 6" cowl on it (Mom calls the truck "Jimmy Durante" in protest to the "schnoz" on the hood) from a previous owner and I'd like to run it down a drag strip eventually to see that dream realized.

 

[Matt69olds]

Gear command is TransGo speak for manual/auto valve body.

Put the shifter in drive, it will shift normally. Put the shifter in 1st, is going into first regardless of vehicle speed. Start out in first, thr trans will stay on first until you move the shifter, or you drive over the crankshaft.

Same thing for 2nd gear. Put the shifter in 2nd, the trans will make a 1-2 shift and go no further. If your going 100 mph and pull the shifter down into 2nd, it will go to second.

Some transmissions (like the TH400) have a built in safety feature, if you have the shifter in 1st, the trans will upshift. I’m guessing GM designed that to limit warranty concerns. The gear command feature delete that.

 

[IcePatch]

Shift kit showed up yesterday, just got the springs and clip installed into the valvebody on my lunchbreak at work. I'll head out to the farm on saturday, get everything put back together, and post an update.

 

[IcePatch]

Unsuccessful Update: On friday I went out to the farm and spent the afternoon getting everything put back together. Had to look up a couple diagrams to figure out how the servo goes back in the bottom of the trans, and getting everything in place to put the valvebody back took some fiddling, but overall it was pretty painless. The aftermarket dipstick has the "low" mark about even with the pan-rail on the transmission so I used that as my target for filling.
I put 4 quarts in the pan, checked the level, added another half a quart and fired it up. It went into reverse and drive right off the bat, but then the gears went away. I wanted to fiddle with it more but I discovered that the engine isn't getting oil to the top end. (pressure gauge reads 0 and no oil seems to be coming out of the push-rods when I pulled the oil cap to look at the rockers).

When it's not 100+ degrees outside I'll be going back to diagnose the oil pressure issue, (either low fluid or sludge from sitting too long) and when I resolve that I've got a pretty good idea that I straight up didn't put enough fluid in the trans. I wasn't able to check the level with the engine running because oil pressure, so there's still a chance the trans is good.

I put a note in my car budget spreadsheet that when I first bought the truck all the gauges except the speedo worked, so it had oil pressure when I parked it. If it's not one thing it's another.

 

[IcePatch]

Successful update: put the rest of the second gallon of atf in it, it, WE HAVE SHIFTAGE! I just didn't put enough fluid in it, it goes through all the gears just fine now, upshifts, downshift and engine brakes with no slippage.

I put some marvel mystery oil in the motor, ran it for a couple minutes. The top end isn't clacking around so it seems as tho the top end is getting oil. I pulled the plug at the fron of the block just below the intake and pushed 100 psi of air pressure through it. (The plug had marvel mystery oil on it when pulled so it is circulating) pushed all kinds of fluid through the pushrods and heard it bubbling in the pan. Still no pressure on the gauge but that's probably just either a plugged fitting on the engine or a bad gauge. It seems fine.

Now to take the carb Off and rebuild it. It stumbles bad with anything more than 1/4 throttle. Gonna siphon the varnish out of the tank that it still miraculously runs on and get some premium in her. Good progress, thanks all for the input!