So stupid me decided to save some money and bought a done up transmission that was slightly used with a 2800 RPM stall on it. And dropped it in my done up 377 Supper Ram, low and behold 1 2 shift is flawless but the 2-3 shift is horrible at 4000rpm and part trottle,it takes almost 2 seconds to shift into third and has a 500RPM surge just before going in. At slow acceleration it shifts okish and I'd hate to see what it does at WOT. on the down shifts it works flawlessly on all gears from 4 down. and when it third gear it holds well no slipping that I can notice but since the engine is still on the beak in I've yet to try mashing it down to see if it holds. With the movement that I have in the 1 2 shift it does obviously have a shift kit in it

Now the last time I tore a transmission apart I was in trade school about 10 years ago so I'm a little weary breaking it down and attempt to make a stout transmission but with 12 grand soaked into the car already I'm REALLY not wanting to drop 2 1/2 grand for the local tranny shop to do it for me. So any indications on where to look. Oh and before everybody says check the TV cable it is properly adjusted for WOT tightness by GM specs

 

The 2-3 shift timing is critical. What happens is the the 2/4 band needs to release and the 3/4 clutch pack needs to engage. And they need to do this at the proper time to get a good clean upshift. Which in your tranny is not occurring.

I'm not an expert on this, but understand the basics of getting these timed correctly. Check the 2nd apply band servo. At a minimum it should be the 'Corvette' version. Also check the servo pin length. Too short and the band releases too soon.

There are some feed holes in the plate that can also be altered for a quicker 3/4 clutch pack apply.

If none of these are the issue, or fixes the flair. The next step is to check the 3/4 clutch pack clearance. Too much and it takes too long to engage.

The long time to do the actual upshift may be from low line pressure, or from internal leakage. This area I am not sure about.

RBob.

 

Sounds like the "done up" transmission is not so done up. You could go in there and add one of my modified TransGo Shift kits that come with the Corvette servo, larger boost valves, accumulators, etc. This will hold up to whatever you have here as long as the 3-4 clutches are still in good shape. In the meantime drive it easy and "do not" allow it to slip, flare or what have you, or you will be building the transmission possibly sooner than you want. Call me with any questions on this 909 795-1876 anytime in the afternoon or evening.

 

so I've dropped the pan today and this is what I found, I'm thinking I might be needing a new 3 4 clutch pack unless it is normal to have that little bit of blackness at the bottom of the pan, the oil was in good shape but it also was brand new. what do the transmission Gurus here think?