weird problem maybe transmission? 2-3 shift back and forth?

[benoit454]

Well I think our truck is trying to die on us now.

Today going uphill and agin on the highway uphill it acted weird.

it's an 84 with a 305 and th350c I think. it's a 350 trans. for sure but has a plugin under the cooler lines, so i guess it's electronic lock up TC.

Well going up a steep long hill, it was running out 2nd, and when it was time to go to thrid it acted like you left off the gas and got back on several times, then dropped into 3rd.

Came to a stop, got on the four lane(short stretch) same thing was slightly uphill, went to go into third and done the same thing.

We stopped at the bank and looked under, I seen 2 puddles, but checked it 2 times after that on stop at others places and there was no puddles. So maybe it was somebody else's.? Anyways....

When I did check it smelt like burnt trans fluid on the pipes or burnt oil from underneath when I leaned down to look under.

Then it smelt like brunt plastic or clutch a little later.

Well on the way back we shifted from 2nd to drive manually, went just fine with no problems, and then drove home in drive, stop and go several times, no problems then either. Howevr there were no hills, and we checkd the fluid it was fine, checked oil, it was fine. Never ran hot or lost pressure or anything.


Any ideas? I kinda wonder if the lock up Tc burnt up or maybe if it's a lockup clutch inside it burnt up?

[benoit454]

Anyone?

[Srubydo1986]

beats me un hook the tc see what happens. might disingauge the tc to just make it a 350.

[kevinr1970]

On my 1981 GMC Jimmy 4x4 I had a T350; not sure about exactly which one.
Going down the freeway it would just drop into 2nd gear every so often. I could either floor it and then let off the gas and it would shift into drive (3rd), or I could shift it into nuetral then back into drive.
Took it to a tranny shop and they said they suspected the vaccum modulator was stripped. After taking it apart they said it was something on the inside that would require removing to get to and at that point I might as well rebuild it.
I drove it around like that for a while longer until out playing in the snow it just stopped leaving 1st.
And that was it.

[benoit454]

LOL I'm thinking of undoing the tc too and see what happens.

Someone else brought up a point that the kickdown cable might be screwing with it, trying to go from 3rd to 2nd because it might be tight or something.

I already have a brand new th350 non lock up convertor and a th350 with shift kit, brand new rebuild, made to replace a 700r4 in a 4x4. If it keeps acting up I'll have it converted to long tail 2wd and use it.