Ok, I have a 02 ws6 w 40k miles that I recently installed a 3-3200 circle d stall. I don't this in prep for a cam install in the future. Got it in and it wouldn't shift, 3-4 gear it would just go to neutral. Everyone said it was cooked, well took it to my tuner and it has been shifting fine. Well recently after maybe 500 mi since the install, now it feels like the car never downshifts to 1st, leaves like it's in second but immediately it'll go to first and take off, happens really fast. Then it shifts fine thru all gears. I'll be in lockup in 4th and punch it, it downshifts to I'm guessing to 3rd? It slips, doesn't really accelerate hard, it's def slipping. Then the lockup will hit and it goes (stops slipping). Is this something that needs more attention in the tune or is the trans toast. I'm guessing the 3-4 clutches are fried? Trans was fine before the converter, I installed it correctly also. It was an Arizona car so maybe some of the seals are dried up from sitting most of it's life ?? Any suggestions on the smartest move would be great, I don't want to make the wrong decisions and cost me more money! Tia!!

 

I would say a rebuild is needed and yes sounds like seals may have dried and hardened also that or a badly worn AFL bore/

 

Man, it blows my mind how fast the new converter brought the problem out. The car shifted great before, not problems at all, till I added the converter. I haven't even driven it very far either. Guess I was hoping for a simple fix like shift solenoids or something. Oh well, just money right?!?!?

 

If you have to rebuild it and you're going to be adding more (and more) power you should think about swapping to a 4L80E. I had my 60 rebuild and it's fine but now, for the price, I wish I had just swapped it.

 

If the no gear/stuck in neutral/no shift issues started literally immediately after you installed the converter, like right when you got the car off the lift (or jack stands, or whatever), then it sounds like an install error or perhaps a (machining/assembly) fault with the new converter out of the box. Hard to imagine that the trans could go from perfect/no warning signs at all to failure during the same period of time that the converter was being installed. I've read a post or two over the years of brand new converters not seating properly even when other converters will seat no problem in the same trans. So even if you think it was installed correctly, there might be an issue here. It's unlikely but not impossible, and I say this ONLY because you indicated that the issue came out of nowhere immediately after the install, and it's something to check carefully when you install this converter on another trans (or rebuild this one). The fact that it did eventually work leads me to think that install depth is probably correct unless, again, there is some really odd issue with the new converter.

Other install errors that could lead to issues would be related to fluid level. Was it allowed to run low (i.e. was the engine allowed to run after the install with perhaps not enough fluid in the trans)? It may have overheated very quickly if fluid level was too low.

Interesting that some tuning changes got it to function somewhat normally for about ~500 miles. Sounds like some damage was done during or post-install, and then maybe (tuning) changes to line pressure somehow got some extra life out of it. It's unlikely that a trans would be so close to the cusp of failure that it would go from completely perfect behavior to significantly broken right off the lift just because a different converter was installed, unless perhaps you were immediately hammering on it.

I wouldn't expect an age-related failure at just 40k miles unless the trans saw severe duty or abuse at some point over its life. If that 40k miles was put on in the first two years and then the car wasn't moved for the remaining 21 years then maybe I could see an issue, otherwise it's seen plenty of usage to keep things lubricated over that mileage. FWIW, mine is 4 years older and has half the mileage, and is just fine.

 

Are you sure that you're not confusing the looseness of the higher stall converter to a sipping transmission. If the trans is slipping in 3rd gear and the TC locks, (which I don't think it would if the trans was slipping) the trans would still slip even if the TC locked up. What you are describing to me just sounds like a loose converter and the driver isn't used to driving car with a higher stall.

If the 3-4 clutches are brunt the trans fluid should be dark and smell burnt. Have you verified that the trans is filled to the full mark. These 4 gen f-bodies are hard to get a correct fluid level reading on the dipstick right after adding fluid. There is a part of the dipstick tube that is almost horizonal and fluid will take a little while to drain out of that section and will give you false full reading. You have to add fluid and then wait 15 minutes or so before rechecking.

 

Everything you've said I've thought the same thing. One thing though, I bought the car and test drove it, brought it home and started working on it, so I didn't drive it much before the install. It may have had issues before but I just didn't drive it enough to find it. I have a feeling the 2nd owner(guy I bought it from) bought the car and put his foot in it alot. He was an older guy in his late 60's, he only put 4k of those miles on it though, the rest was from the original lady who bought it new, it was a Arizona car. I've already had to do the oil pan gasket, simply from age it was dried out. Maybe the trans is having the same age related rubber deteriorating issues. I've built several hotrods thru the years but this is the first fuel injected cat I've ever modded. I checked and triple checked everything, never ran low on fluid, added a external cooler, checked converter spacing, etc. Idk, I also think it's off that tuning it made it shift good for awhile? Talked to my trans guy and he says when I added the converter it just exsaborated the issue because the 3-4 bands get the oil last? Oil isn't burnt either!

 

I've had cars before with even larger converters, which hell I may be wrong but it sure wasn't going forward under acceleration, just made a lot of noise. Soon as the lockup re engaged it started pulling, very noticable. Even my wife knew something wasn't right when it was slipping she said "well that didn't feel right", lol. Car shifts fine everywhere else, it just does that little hesitation when leaving from a stop, like it's in 2nd, then kicks down to first and takes off, that happens really fast too, definitely doesn't feel right. Idk, I'm sure NOT wanting to pull this trans again, especially if not needed. My trans guy says it's definitely cooked? Sure he's gonna say that, he wants the job.

 

If the car wasn't so low miles I probably would, I'm wanting to keep it original as much as possible. I do agree though, and I've researched the 4l80 swap, looks like it'd be a pita.

 

I wouldn't recommend a 4L80E swap for just a cam/converter car. It's a soild option if you plan on a max effort, huge power build and don't mind the hassles of the swap, but I wouldn't even consider this for anything under 500hp. It's not the '90s any more, guys like Frank and other top builders can build a really good 4L60E these days.

Well that changes things a bit, I was under the impression that you'd owned the car long enough to know that the trans was definitely solid before the install. If you didn't really do more than test drive it, maybe the issues were already present but the trans just wasn't hot enough to expose a problem during the test drive and ride home.

I just don't think it's strictly "age related". The TH350 in my '74 is still original, 51 years old but only has 45k miles on it. Still shifting great in a 4,000lb car. Age will get to things eventually, but 23 years old w/40k miles on a stock car is a baby IMO. You could be right that the previous owner hammered on it hard for the time he owned it, then sold it when he started feeling something wrong with the trans, and you just hadn't driven it enough nor gotten it hot enough to notice - that's certainly possible. And again, the tuning changes might have been enough to get a little more life out of it via line pressure manipulation, etc.

 

So, what would y'all do next? Do I need to take it to a trans shop, or just someone with a scanner? I want to be 100% sure the trans is the problem before I go to taking it all out.

 

Better yet, which would you guys do? Take the car to a transmission shop? Or I've found a shop in East Texas that builds and tunes hotrods, Protree Auto in royce city. The trans shop has a cheaper quote, the Custom shop said he'd look at it first and make sure the issue, then rebuild if necessary. He has a good reputation from what I can tell. BUT the trans shop builds transmissions every day. Idk

 

I would take it to someone that you trust and have it checked out before rebuilding. If it needs to be rebuilt, I would contact Frank at @FranksCustomTrans. Frank specializes in 4L60e, which is the trans that is in your car. I would not trust a trans shop that just rebuilds stock transmissions. These transmissions are old, and Frank has devolved his custom ways of sealing up worn valve bodies and cases. You have nothing to lose by seeing what he has to offer.