Technical Th350 reverse gone?

Hey everyone, I'm making this post to hopefully fix my issue I have a rebuilt th350 trans everything seemed to work good, well at first nothing worked do to low fluid.. put more fluid in and was working good backed right out of my driveway through her in drive and took off. Came back home and was going to back it to the side yard but nothing no reverse sadly

 

Still sounds low to me. Did you install the dipstick and pan? Just because there is a stick in it that says full doesn't mean it was****embled correctly. I normally set my dipstick with the pan on and no gasket, stick touching the pan. Then when the gasket is installed the stick will sit 1/8th or so off the pan.

When you filled it did you cycle through the gears?

 

After adding more yes I pulled out and drove around my neighborhood everything seemed to shift work just fine until returning home and putting it back in reverse.. but with the dipstick I had to buy a new one old one was lost and tbh idk how far it sits in etc

 

Did you check the level via a dipstick, or just guess?

 

I should add, my experience with fluid changes on TH 350’s and 400’s, when I didn’t have enough, I always had reverse., forward wasn’t correct. Not a******* guy so can’t tell you why.

 

A 350 takes around 10 quarts of fluid if the******* and torque converter are both empty. How much fluid did you put in it?

 

When my newly rebuilt 400 lost reverse, it also lost 3rd gear. Turned out a snap ring came off the 3rd reverse drum.

 

Do you have engine braking in manual low? On a 350 the low/reverse clutch operates in manual low and reverse. If you do not have any engine braking in manual low, it points to a problem with the low/reverse clutch. The other cause of no reverse would be the direct clutch, but it also is used in 3rd gear. It is possible to have a direct clutch seal problem and still have 3rd gear. The direct clutch piston uses 3 lip seals. The two inner ones seal the area of the piston that is used for 3rd gear. In reverse the outer seal is used. If that seal is leaking you would only lose reverse.

Either problem means pulling the transmission.

 

Well this may be my problem then I've only put 7 quarts in so far but after adding the last bit showed little under full, after driving it went back down so added more but haven't messed with it since cause I wanna get it figured out b4 messing things up. About to run and check again but if it takes 10 quartz to fill I'm definitely 3 quartz short which I've read a th350 under 2 quartz will tend to lose reverse because reverse take more pressure to engage or something? Ima add more tomorrow and try again

 

I checked but before leaving it seemed to be full after returning it was low added more but I stopped messing with it cause I don't wanna ruin anything

 

Sorry I don't really understand this I will look into what your saying and get back with you

 

So a TH transmission is not checked like oil. It’s done by running, forward the reverse a few times. In park, then check fluid level.

 

Can you please rewrite this I don't understand

 

Nvm I think I get what your saying. Will be sure to do that next time

 

Okay. Engine running, preferably with a “warmed up” trans as well.
Take the selector and put it in drive with the brake on, now put it in reverse. Do it a few times. Put the selector in park While the engine is running pull and wipe off the dipstick, inset it again, then pull the stick and check the level.

 

OK yes this it way more understandable but I'll definitely do that it the morning cause like the other guy stated it takes about 10 quartz fully empty and I've only added about 7 but like I said seemed to be almost full drove came back and was like it was empty barely on the stick so added another quart and left it sitting so I can go back to the drawing board lol. But I appreciate you taking the time to rephrase this hopefully this gets her going and sure gave me a better understanding on checking levels

 

All good.

 

I will second or third the idea that it's low on fluid, reverse is the first thing that won't work when low on fluid.

 

This man! The dip stick means nothing if it is not calibrated correctly. If it was me, I would drop the pan, save all that expensive fluid that you can via the drain plug. If you do not have a drain plug, considering adding one while it is apart. Install the dipstick, see where it lands when fully inserted in regard to the pan. You need to make the adjustment to the dip stick, so it reads properly.
Or, you can indicate new "full" levels on the current stick, so the future owner knows what the hell is going on when he can't back out of the garage in the morning.

 

Yep.
Maybe if a factory one from a wrecking yard, from exactly the same application would be okay.

 

When you refill a transmission have the drive tires off the ground. Run it through the forward gears a couple of times and then in reverse a couple of times. Keep doing this and checking fluid until trans is full. With no load on the drive tires you run less of a risk of burning up clutch plates or seals than you would if driving.

 

This my be a bit hard where I'm located cause I've been trying to find the same truck for parts for about 3 months now. I have a chevy c10

 

Well,,,,you already know you are about 3 quarts low .
I would add a quart and see if you have reverse ?
Then add another quart .
Test drive it if possible a short distance,,,,,,drive around the block .
Then check the fluid level .
It should be close,,,,if necessary,,add another quart .
It should probably be okay if the level is correct .
Good luck man !

Tommy

 

Yea I think it's fried ima have to get it rebuilt again added a but more let it fit for a while check did the forward and back thing check good but reverse is still gone drained fluid and all black pretty sure clutches are got do to driving around the neighborhood with low fluid... guess you can say you only learn from your mistakes