Weird 2-3 shifting

[keystoneGerm]

Ok, I searched for a when and can't find a good answer. I don't know what keywords to search for. I am looking for a little help.

I just rebuilt my TH350c with a transtec level 2 kit. All bushings were replaced. I had no shifting problems prior. I also installed the superior shift technologies shift improver kit. I followed all the instruction to a t. This is the kit instructions.



So when I am driving and at a light load the transmission shifts between 2-3, and kinda searches or floats between them. If I give it more gas it is fine, or I am going a little faster it is fine. I am ASE master certified, but truly don't remember alot of the automatic transmission components function.

If I were to check line pressure, I am worried that it would t be accurate because the kit had me block off the intermediate accumulator like in step 12. What do you guys think?

[andyh1956]

I would check & reset the tp cable in it's holder up at the carb 1st.
It has been my experience that you may have to change the gov weights after installing SOME shift kits. I'm unfamiliar with the kit you used, I usually use a Transgo. Anyway B&M makes a simple weight kit for the gov w/ new weights & springs.

[keystoneGerm]

Kick down cable is good. I installed new governor springs supplied in the kit. If I change the springs to something else that was suppied, would you go heavier or lighter? I do t have any weights to select from. Thanks for the fast reply.

Edit*

I just reread the instructions. In step 8, it says to use 1 white and 1 purple spring. If I want a later shift, use 2 purple. What will that do to my 1-2 shift if it is perfect right now? Will it make it hang a lot longer?

[f.monroe]

I have had weird shifts with the th350 in the past that sound like yours . I found my problem with the wrong vacuum or no vacuum to the accumulator . You might give that a good look. I rebuilt my first th350 in my front yard when I was in high school . I was a poor kid and couldn't afford to pay someone so I learned from necessity . I built several for friends after that with only one giving me problems so I think they are fairly simple. Good luck with it.

[keystoneGerm]

Originally Posted by f.monroe

I have had weird shifts with the th350 in the past that sound like yours . I found my problem with the wrong vacuum or no vacuum to the accumulator . You might give that a good look. I rebuilt my first th350 in my front yard when I was in high school . I was a poor kid and couldn't afford to pay someone so I learned from necessity . I built several for friends after that with only one giving me problems so I think they are fairly simple. Good luck with it.

I assume you meant the modulator in the back of the transmission?

[andyh1956]

You can also use an ADJUSTABLE modulator. I think the Turbo 400 modulators were adjustable from the factory.

[kwmech]

After install of the governor springs, did you make sure the valve inside the governor was still free? It can been seen when you have the part in your hand and flip the weights in and out. You'll see the valve move up and down freely

[keystoneGerm]

Originally Posted by kwmech

After install of the governor springs, did you make sure the valve inside the governor was still free? It can been seen when you have the part in your hand and flip the weights in and out. You'll see the valve move up and down freely

I did check operation of valve prior to disassembly, but not after. Could the springs cause it to not move when checking out of the trans? I checked it by flipping it upside down and make sure the Piston drops.

[kwmech]

No, no not unless there was, by chance, a small piece of crap that made its way in while handling. You know dirty hands and stuff. Just hold it by the gear and flap the weights and see if the valve moves up and down if it does you're good

[f.monroe]

Originally Posted by keystoneGerm

I assume you meant the modulator in the back of the transmission?

Yes that is correct. My mind is letting me down more and more with every year that goes by. Actually I think it's just that theres too much going on up there to keep it all straight.