Th350 not shifting at wot

[Justin79maro]

So I’m not sure if this should go here or in trouble shooting but, here is my problem. First this transmission was rebuild 5-6 years ago, I’ve put it through its paces, but it was rebuilt by a guy who knows his stuff and it’s got the harden sprag, shift kit and all that stuff, but now since I put in a motor making over 100hp more then the last one, at wot it will not shift into the next gear, it just goes to rev limiter and will not shift, 1 st gear it won’t shift into 2nd and if I drop it into 2nd and floor it it will not shift to 3rd (it has 1 time about 500rpm after I shifted manually) so I thought okay could be governor, so I pulled it out it looked fine and everything moved like it should so just to be safe bought a new one and a new vacuum modulator and it is still doing the same thing. So tonight I drove it over to the garage raised it up on the lift and the trans cooling lines going to the rad (the lower line) was leaking badly I tightened it up along with the upper line. Dropped the pan and the filter was setting in the pan because it had came off. Now I’m not a trans expert or anywhere near it, but would that cause it not to shift at wot? It shifts completely normal just driving around, I have the kickdown cable hooked up and adjusted correctly too. I even pulled the plunger out that it behind the vacuum modulator and it seems fine. I have googled and searched so much to see if anyone else had this problem but to no luck. So before I call the transmission shop I wanna know what you guys think it could be. Anyway, thanks for any help and thanks for reading this novel I wrote lol

 

[Twisted_Metal]

Between the leak (low fluid level) and the filter dropping out of place... It was probably sucking air instead of fluid.

Have you tried replacing the filter and refilling it to the proper level?

 

[Justin79maro]

Between the leak (low fluid level) and the filter dropping out of place... It was probably sucking air instead of fluid.

Have you tried replacing the filter and refilling it to the proper level?

I dropped the pan this evening and didn’t get a new filter yet but I will tomorrow after work. I do know for a fact tho it started spraying fluid out the cooling lines today when I drove it, because yesterday I was messing with some stuff under the hood and there wasn’t any fluid on anything I could see or on the ground so it must have been sucking in air I guess

 

[Fbird]

fix your leak, fix the filter, fill it up.....test. THEN.....if it still has no WOT upshift i would disconnect the kickdown and retest. NOW it will not downshift when you floor it so....once in 2nd gear keep rolling on the throttle to the floor....if it shifts at XXXXX rpm...then your kickdown cable is causing your lack of shift..."adjust setting as needed" if still NO up shift...next would be remove the governor to see if you lost a weight/pin/spring

 

[Justin79maro]

fix your leak, fix the filter, fill it up.....test. THEN.....if it still has no WOT upshift i would disconnect the kickdown and retest. NOW it will not downshift when you floor it so....once in 2nd gear keep rolling on the throttle to the floor....if it shifts at XXXXX rpm...then your kickdown cable is causing your lack of shift..."adjust setting as needed" if still NO up shift...next would be remove the governor to see if you lost a weight/pin/spring

So basically test and see if the kickdown cable is broke inside of the plastic tubing where I can’t see it, and can the governor gear inside the trans be worn and not show up on the gear that’s on the governor?

 

[Justin79maro]

Will the kickdown not let it up shift even if I’m manually shifting it too?

 

[Fbird]

no.....if the kickdown is adjusted too tight...it will affect how high you rev before shift....so by removing the kickdown cable you are making the tranny ONLY use gov pressure for shift up at high rpm

 

[Fbird]

IIRC...the kickdown is adjusted per a "click" button on the housing mount....to loosen you push carb to wot...then if you need it to be a little "looser"...you simply push down on the cable ..between housing and carb...(while holding carb at wot) push down on cable so housing will go 1 more "click"

 

[Justin79maro]

IIRC...the kickdown is adjusted per a "click" button on the housing mount....to loosen you push carb to wot...then if you need it to be a little "looser"...you simply push down on the cable ..between housing and carb...(while holding carb at wot) push down on cable so housing will go 1 more "click"

I’ve adjusted it before, it’s the original one so it could be broke, I do have the stock weights and springs in my governor so it should shift on its own about 4500rpm I think

 

[Justin79maro]

So I just tried to see if it would adjust right and it’s hooked toght on the throttle on the carb no with zero slack in it which always before it had some in it