So, im driving to work like usual and everything feels fine. I didn't abuse the car or anything on the way. I stop at the red light before i turn right. I start to go and the car begins to chug. It doesn't sound like the cars gonna die, it just chugs (go, slow, go, slow). I get the rpm's over 2500ish and the car takes off like normal. It shifts to 2nd and then into 3rd and the car goes crazy. While in 3rd, the car revs like its in neutral, then i feel it shift into overdrive and it continues to rev up like its in neutral. I pull over and turn the car off. Since im really close to work, i turn the car on again and i hear a whurlling sound like a supercharger coming from beneath my car. It would have been an awsome sound if i knew i installed a blower. The whurling sound goes according to the rpm's. Reverse works, kinda, and so does 1st and 2nd, kinda.

I put on about 30,000 miles since the rebuild. The car has seen about 3 track nights since the trans was rebuilt.

After the rebuild, i noticed that when i was on the freeway going about 60, if i pushed the gas a little more, the rpm's would drop to about 1500. If i let off the gas, the rpm's would go back to about 2000. The guy who rebuilt my trans said that's normal, but I havent experianced that on any other car. What do you guys think? Thanks!

 

What year car do you have? It sounds to me like a 3-4 Clutch failure. Requires a rebuild. You might need to increase clutch capacity or install the newest z-pak clutches from Raybestos in the 3-4 area. You should also increase the Pressure Regulator valve size to maximize clutch clamping force. A shift improver kit might also help, if it has not already been done. Superior Products makes a very good 2 or 3 stage kit for 4L60's and 4L60E'S. Street/ Strip is a very firm but not obnoxious shift.

Tranzman

 

I have the same problem. 3 4 clutch pack is gone. This was a performance rebuild with a Trans Go shift kit. It had 26K on it when it went out.
I refuse to spend 2grand or more to rebuild it AGAIN and then not be sure it will hold up.
I am going with a TH350 or TH400 conversion, professionaly built tranny that I can be reasonably sure will last a good long time.
Good luck, my advice is to look into a Rossler built 60E or Frank from CPT seems to have good luck but I am not taking the chance again.

 

Thanks for the response. Mods are in the sig, its a 93 z28 with a 4l60 and a transgo shift kit. I thought that the 4l60 was a th700. Isnt the 700 supposed to be really good? I had 30,000 miles on the rebuild before it kicked the bucket. I want to rebuild it in a way that it will last another 90k miles or more before i need to tend to it again. It does see very seldom track time, and i don't really race on the streets. What do i need to get, or tell the trans shop to do in order to get a reliable trans. My budget is limited. I think i spent $2,500 on the last rebuild. The trans guy said that he built a stock trans with a race shift kit installed. What do you guys think?

 

Do what tranzman said, do a search on this site , get some of the performance parts....boost valve ,good clutches ect..

 

The 3-4 clutch pack is a weak point on these units, and that is what is gone on yours at the least. Have you thought of building the transmission yourself and save money in the process? I carry all of the parts needed to do this right and the build books to go with them. If not, I would recommend the Street/Strip transmission. By the way, what torque converter are you using now? And are you wanting to reuse it? Making these units very durable is what I specialize in. Give me a call, 909 7951876, and I will answer all of your questions on this.

 

Clutch packs took a ****, call Frank at CPT! DO IT, DO IT, DO IT!

 

Sounds like your 3-4 clutches.

As Kevin (Hodges) said. We're the only one's who can build these things for high HP and have them last.

$2500??? We only charge $1400 ($1300 for Christmas special) For out top of the line "Pro Race" rebuild. These transmissions are 9 second proven AND last. You won't find a better transmission anywhere...at any price. We even see transmissions on here from other suppliers costing near $1900....For a transmission not built nearly as well as ours, and using extremely inferior parts to what we use.
*EDIT* Now that I've checked again, those $1900 "top of the line" rebuilds don't use as good of build quality or parts as our $800 Performance Rebuild. I guess the old saying is true..."a chain is only as strong as it's weakest link". If you can't get past repeated 3-4 clutch failures, you may never have to worry about breaking an internal reaction hub, or an output shaft.

Thanks,
Frank
CPT
302-250-1202

 

Send that '60E to us and you'll never have another problem. You'll enjoy it more than a 400. BTW, a TH350 isn't any stronger and won't hold up any better/longer than one of out "Pro Race" 4L60E's. We're also way under that $2000.

Thanks,
Frank
CPT
302-250-1202

 

Kevin,
You should really create a SIG. Some of these folks might like to know you have a Supercharged/nitroused '99T/A that runs 9.7 @ 144 MPH with one of our 4L60E's. Yes, we made it work where others had failed 5 other times. The largest key to that was getting the vacuum modulator out of it, and building it correctly.

Frank
CPT

 

I find it funny that you blame the vacmod for killing so many transmissions when I have personally built many with it with no problems. There are some issues that have to be modified from the original setup from transgo but I have made them work. I will not say that the epc units do not work because I build them both ways. Here is a picture with one that has 100+ passes on it this year alone in the 9's with 750rwhp that is vacuum modulated.


Here is another of a very popular 1000rwhp truck running a 4l80e with it as well. This is Parish 8's truck.


Both of these vehicle attended Hot Rod's drag week this year and both did very well. You can read the articles in the January issue of the magazine.

 

Vince,
We get vacuum modulated transmissions in constantly. The complaints are always the same..."It never shifted right, and didn't last". I know they're all much happier with their transmissions after we switch them back to an EPC. Every vacuum modulated transmission we take apart has cooked 3-4 clutches. This applies no matter WHO built it. I won't go into specifics about who's rebuilds we've made right, but I will say that there are a few that were previously built by some others on this board who praise vacuum modulators.
In no way am I trying to make this a me vs. them thread. It's "me vs. building transmissions wrong" post. I'm not just a transmission builder. I build and race 2 Camaros also. I spend time in every section of this message board. My point is, I hate seeing my fellow F-Body enthusiasts spend money on stuff that's not going to last. If a builder want's to keep replacing 3-4 clutches and asking his customers to keep it hush hush, that's not very good buisness practice. I specifically won't use vacuum modulators because I see what they destroy. I've actually spent alot of time researching these transmissions enough to know what they need. I don't just throw a bunch of parts together because someone else tells me how to do it.
Vince, If you guys think vacuum modulators work for you then keep on using them. We know how to take them back out and build them correctly when they get to us.

Frank
CPT

 

while i don't see where the mod would really kill third since if anything it will cause high line most of the time , We don't use them either mostly because the ECM does a much better job in our opinion of controlling the line making the car feel much more drivable and isn't affected by low vacuum etc from cams, turbos and super charger as the vac mod would be .
And we don't see the advantage it gives for the additional cost,
But as I have stated several different times if it work for some people great seems there are several different ways that work to make these transmissions live and yes they can live in some xstreme conditions,
One of the big things I have seen cause 3-4 clutch failure early in these units is excessive clutch clearance and restriction of the 3rd accumm feed disallowing adequate fliuld to get the servo released in time causing overlap.
But thats just and observation I have made. Excessive clutch clearance accompanied by high line and and agressive shift kit set up tends to break the ring out of the drum for the 3-4 clutch ,I call it hammer effect pressure+distance= speed and excessive resulting impact
As I said just a few things i have noticed and opinion on them over the years

 

All I know is I had enough of getting the tranny rebuilt time and time again and I don't even remember how I came across Frank's # but I am glad I did because ever since I took it to him I have yet to have any problems with it at all, so whatever hes doing is right in my book, looks like some of you guys have different approahces on how to build a race tranny, all I'm saying is that I found mine and plan on bringing it back to him now that its out of the car just for a check up for next season!

 

thats cool And we are here to if anyone needs us 24/7 who else can do that ?