Th350 shifts odd

[Obwonkonobe]

I've dailyd my th350 for 6 months or so now pretty well, but have noticed something odd this week. Under slight acceleration, when it shifts into 2nd it feels like theres a drag somewhere in the driveline. Ive never had gears go out on me before so this feeling is foreign to me, if anyone knows a basic way to see what the problem is Id appreciate it.

I can manually shift it and it feels healthy, so that kinda leads me to believe that its the vaccum solanoid thingy on the side that gets manifold vacuum, maybe that went out and now the trans is out of sync with the motor? Just my first thought, I figured I'd ask around before I go buying parts, thanks

 

[HotRodPC]

It's so hard to diagnose transmission problems over the internet because you never know what someone means by their description. If you mean dragging like feeling like a brake is on, it's not the vac modulator. Vac modulator determines shift points. Has nothing do with friction parts at all.

 

[Obwonkonobe]

It's so hard to diagnose transmission problems over the internet because you never know what someone means by their description. If you mean dragging like feeling like a brake is on, it's not the vac modulator. Vac modulator determines shift points. Has nothing do with friction parts at all.

Yea I thought it may be a bit of a stretch ha, I'm just not sure what else to check, besides rebuilding the trans, but it'll get overdrive if it quits

 

[1987 GMC Jimmy]

Have you serviced the transmission recently? It might be a good idea to see if there are any shavings or particles.

 

[Obwonkonobe]

Have you serviced the transmission recently? It might be a good idea to see if there are any shavings or particles.

Haha well funny you should ask, 2 weeks later and my guess is the forward drive went out. She quit on me..
It still has reverse but I plucked it today and am starting a 700r4 install, il have another post up with questions and updates on the install

 

[HotRodPC]

Haha well funny you should ask, 2 weeks later and my guess is the forward drive went out. She quit on me..
It still has reverse but I plucked it today and am starting a 700r4 install, il have another post up with questions and updates on the install

Just don't take it for much of a test drive until you're sure that TV cable it set probably. You can burn it up in less than 100 miles if you're hard enough on it and that cable isn't set right. Usually takes in the 400-500 mile range to cook one without that cable set up properly.

 

[Obwonkonobe]

Just don't take it for much of a test drive until you're sure that TV cable it set probably. You can burn it up in less than 100 miles if you're hard enough on it and that cable isn't set right. Usually takes in the 400-500 mile range to cook one without that cable set up properly.

Is it something I should have a shop double check? Or as long as I do my homework should I be ok

 

[HotRodPC]

Is it something I should have a shop double check? Or as long as I do my homework should I be ok

As long as you do your homework you should be OK. Just wanted to express and make sure you're aware it's not like a normal Detent or Kickdown cable to where you can put off hooking it up later on. It'll need to be hooked up fairly quickly. If you do have to drive it without it being hooked up, make slow gradual take offs and such. The deal is, that cable also regulates the fluid pressure. If it doesn't detect you're getting on the throttle, it won't bring up the pressure to hold the clutches tighter and they'll just slip and spin in the drum until they're cooked.