350turbo question

[rkbowles]

I am hoping someone can help me with this. I just dropped a 350 in my 79 camaro, and now the 350 turbo transmission is acting crazy. It acts like it is not completely in gear. I can barely feel it changing gears, and with the 305 it was noticeable. It acts like it is slipping in each gear, and I have to let off the gas for it to shift from 2nd to drive. If i am running slow up hill, the engine is revving up alot to just get up the hill. It just seems ironic that the tranny would go out as soon as I replaced the engine. I feel like I did something wrong. I have good vacuum to the modulator. Any ideas?

Thanks
Rk Bowles

[Tony]

what about the detent cable? it could be out of adjustment. Also, the 350 is pushing more power than the 305 and the trans may actually be slipping. I know that the 700r4 did the same thing to me when I took out a tired 305 and put in a hopped up 350.

[rkbowles]

Detent cable seems to be working properly. Had a guy drive it from a garage and he said to check the modulator valve and the vacuum line going to it. The line seems to have good vacuum. The modulator valve is cheap, so will try that before looking at rebuilding the tranny.

[Paulster2]

I don't remember ... does the TH350 have a lock-up TC? I had a 200r4 (I think) which did this same type of thing. I don't think the TH350 has one, but thought I'd bring it up. I replaced the TC and everything was grand once more. I have to say what Tony said seems spot on, though.

[Tony]

No, they do not have a lock up TC. That is what makes them so fun

What TC do you have in it?

[DTP-101]

Just putten this out there but , when I went to move my 79 It was doing the same thing acting crazy like that , It was combination of a few things , The tranny fluid was low and I needed to change the tranny filter....Might help Not to sure . Hope u figure it out soon!

[mullettman]

i agree with above start with tranny flush and filter

[rkbowles]

well, took it to another mechanic. he has been building trannies for about 20 years. he said that the toque converter was the problem. says it feels like it was meant for a 283 not a 350 engine, that is why I felt minor slippage with the 305. Does this sound logical?

[Tony]

The only thing that I could think that would do is up your stall a little. One small mod that you can do to the LT1 autos is to put a Vortec V6 TC in the trans to get the stall up to about 2500. I think this one did the same thing. Won't hurt to replace it to try it out though. Just make sure that they old one didn't put metal into your trans.

[rkbowles]

ok, still fighting with this tranny. Everybody around here keeps saying it's not in the tranny because you can shift it manually, but cant tell me what it is. We adjusted the kickdown cable yesterday and it ran perfect. 10 miles down the road it started bogging down. Now it feels worse than before. It is intermittent. I am pretty sure it is not pulling out in 1st at times. also now it feels like it is between gears, which makes the engine rev up. I have 12 lbs port vacuum, and a new modulator valve. I have even adjusted on it. just cant seem to find the problem. May be my imagination, but seems like the engine runs a little rough when this happens.any ideas??? I'm about to lose my mind.
Thanks

[Tony]

If the trans is jumping into N then going into the next gear, then that's not good. You are looking at a rebuild. I will bet that your clutches are worn out, and some of the clutch material has gotten into the VB. But, as stated above, when was the last time you had the fluid changed along with the filter? What did the bottom of the pan look like? Was there copper or aluminum shavings in there? What about the magnet, did it have a lot of crap on it? If so, how fine was the material?

[rkbowles]

rpelaced the filter and fluid about 3 weeks ago. pan didn't look bad. a little bit of metallic. small enough to look like sludge. Dont know if this helps, but when i pull out and it acts like it is pulling out in second, i let off and accelerate again and it pulls out good.

[mullettman]

that sounds like kickdown not working

[rkbowles]

if that is the case, and the cable is adjusted properly, what is the fix? does it require tearing into the transmission?

[Tony]

Yup, the detent cable is connected to an "S" hook inside the trans, and if it's not working right, there could be something wrong inside. But, there is only one way to find that out.