Ok getting tired of all the conflicting answers by running searches and picking up some info here and there when i post in other threads, so I will start my own thread!

Car has a 3.4L engine…
700r4 auto tranny. TransGo Shift Kit and 2800 Stall convertor.
3.73 gears.
No Tach!! So no clue on RPMs at occurrence!

I'm hitting the rev limiter at 75mph or so @ WOT. Speedo is not calibrated for the 3.73s so speed approximate.

Because of my 3.42 rear the condition never happened before. I went to the 3.73 rear and then took the car and raced it. On the 1/4 mile, I kept hitting the rev limiter about 3/4 of the way down the track, approx 75mph. I thought the condition was gone till I was out tuning the car the other night and it did it again!

What I understand about 700r4s...Well at WOT 700r4s WILL NOT upshift into OD period! Even with the Trans Go Shift Kit. OD is not a power gear. The average person never experiences a major problem with this because their gearing makes it so that 3rd (D) will not top out till around 90 to 100…well past the ¼ for most 6s. But because of my 3.73 rearend gearing, I'm getting the car into the higher RPMs sooner. So soon in fact, that before the end of the track I'm hitting the rev limiter.

Now the question is with 3.73s, what gear am I running out of at 75mph? 2nd, 3rd? Do I need to get the tranny modded so that the tranny will upshift to OD before it hits the rev limiter. Allowing me to stay on WOT thru the ¼ w/o danger of running out of gear! Or is something amiss in my tranny and its hanging on the 2-3 shift?

See there are LT1s that experience a rev limiter problem when they go to higher geared rearends. They need the 3-4 (OD) upshift finish the ¼.

For the WOT 3-4 upshift, I know about the GM 8673948 (no directions) that fixes this, I also know about the Identical B&M 70249 kit, comes with instructions, but costs a lot more. I also know B&M 70237 is not the right kit to fix this!

 

B&M has a 4-3 kickdown kit that TomP installed, it's supposed to make it so it won't do that anymore.

 

I actually already know about the kits. Listed part numbers above. Just trying to find out if that is indeed the prob! Is that what you think, that it is indeed the 3-4 shift?

 

isn't the stock rev limiter around 7200??? You should be able to tell if your that high. sure its not something else???

My motorcycle acted like it had a rev limiter once. at or above 5000 rpm the kick stand safety switch would vibrate and kick the motor on and off.

 

Well on the dyno Its been to about 6300 Darn i need a tach...Should just get a cheapy to hook up just to see whats going on!

 

Are you hitting your govener?

 

I would guess the 2-3 shift is hanging up on you. When I had the auto still in my car, I could NEVER get it to do a WOT 2-3 shift so it was hitting the rev limiter at the end of the 1/4 mile. And that was with 3.73 gears and a 700R4 that I had rebuilt. It was doing around 85-90 mph in second gear. 700R4s are very touchy and difficulty to get to run right after mods have been done. Just another reason why I converted it to a manual.

 

a tach would be a good idea. Even a cheap one.

Though what I hate is all the tachs you see have the red line set for a V8 engine. They color the marks to soon. There is a digital one you can get cheap, it not made anymore but still out there. Its the only one I have found that matches the V6 3rd gen tach right on the money. as fas as the red lines go.

I know its no big deal but I like it to look right.

 

redraif, i have a 700r4 and 3.73s in my car. my tires are 26" tall and i can almost guarantee you that you're not stuck in 2nd gear. i can only get mine to about 60 mph in 2nd and that's somewhere between 6500 and 7000 rpms. i would venture to say that your problem is somewhere else. i run 88 mph in the 1/4 and that's at about 6000 in 3rd. also, my speedo is still calibrated for the 3.23 stock gears so it is showing roughly 100 mph in the 1/4.

 

And so I guess I am full of crap since I already said that my 3.4 with the 700R4 would max out in 2nd gear at 85-90 mph. Like I already said, the loss of the 2-3 shift at WOT when modifications are made to the 700R4 are very common. This would be so much easier if someone would just count the shifts when the car launches.

 

um, would you like me to go do it, again, right now? or would the other 10 times i do it about every day count? i know how to count shifts if you're referring to me. i am running a shift kit in my 700r4 and it still upshifts from 2-3.

 

I wasn't talking to you, I was talking to the original poster of this thread. They made the comment that they weren't sure if it was in 2nd or 3rd. There is no way a V6 with a 700R4 with 3.73 gears would hit the rev limiter in 3rd gear before the end of a quarter mile run.

 

ok, sorry, i thought since you quoted mine that you were talking to me.

 

No, sorry about that. I understand that the shift points can be all over the board. The author can make it alot easier if they can tell us what gear they are in.

You will have to forgive my attitude. Someone on the other firebird site is threatening to kick my butt, online.

 

Redraif,

You would have to be stuck in 2nd gear for that to happen. 75mph in second gear is about 5900 rpms with 3.73's.

Alan, yours is shifting at 5000 if you are shifting 2-3 at 63mph.

That OD valve in not what you want for drag racing. It only prevents the tranny from DOWNshifting from overdrive into drive unless you are full throttle, otherwise it will do it now (stock) at about 60% throttle. Even with that valve installed, you would still have to lift off the gas in order for the tranny to shift from drive to OD. Better to gear the car to run the trap in the first three gears rather than having to lift and wait for a shift.

 

If it had not been so long ago I could tell you for sure what gear I was in on the track! Honestly, I figured it was a fluke and left it at that. Last night, we did not count. Will have to count and get back. Was more busy watching out for cops then counting gears. Was running it in a 45 zone up to 80!

Now the kits are what has me confused. The B&M 70249 directly states its for WOT 3-4 UPshifts, per Summit's site. I have gotten conflicting info though from here. I put a call into my tranny guy to see what he has to say, but had to leave a message. Called 3 times, n/a.

Definately don't want to have to lift off at the track to get a shift!

Now would my cam be putting the car into a higher RPM at lower MPH then your car? This is getting out of anything I have had experience with, so my knowledge is breaking down. So sorry if I ask a stupid question.

But will try and count shifts tomorrow on way to work, see what is going on. Let you know when I get there!

 

Cam isn't going to affect it. I'm definately with dean and Jerriko on this one, you aren't hitting 3rd if you're bouncing off the limiter. Adjust that detent cable a bit, see if you can bring the shifts lower in the band, sometimes they hang up.

 

Yeah tried to check my shifts in traffic today...

tell me if this sounds right...WOT...1-2 shift @ 35-40...2-3 shift 75-80 if let off gas otherwise hit rev limitor...

Guess it always thru me that the 1-2 shift was so close to 40mph when it shifted. Figured it happened at lower speeds even at WOT.

 

hmmm, mine normally shifted 1-2 at 35-40 mph also....after the rebuild (and back when i had a speedo, lol) it read 45-55 once second gear would catch....vette servo, valve, and shift kit really give some neck snappers...boy, if she only had torque.

 

Transmission is on its way out sister, that's what it sounds like. Have you had it rebuilt since the 3.4 went in? It's common for the 3.4 to kill those trannies I hear. I know mine took a crap maybe a month after I installed the bigger motor. Have it rebuilt NOW, while it's cheap. WHen mine went, it cost me a front pump assy. and a torque converter

 

Called and left message for teh tranny guy...hoping he will call me back soon!

 

Red, I would not worry about that OD valve for drag racing. You are never going to get close to OD running the 1/4. If you had 4.56 rear gears you would still be running the quarter in drive (3rd) at 5500 rpms and 92mph. I don't see you ever going shorter than a 4.11, that will even make the car hard to freeway drive even in OD- you'll be tacking 3K when trying to cruise. If you drive the car streets at all I would really stay a 3.73 or lower- and lets face it, a V6 isn't a fulltime drag car. 3.73 would let you trap at 112mph @ 5500rpms if you could get the V6 to ever pull that speed in the 1/4.

 

i watched my speedo last night when i got on it. 1-2 shift was at 25mph and 2-3 shift was at 50. both shifts were over 6000 rpm...probably atleast 6500.

 

Either your tach, or your speedo (or maybe both) are off.

13"radius tires (26"tall)
3.73 R&P
3.06 1st/1.63 2nd

3687rpms @ 25mph in 1st
3928rpms @ 50mph in 2nd

6000rpms in 1st would be 40mph
6000rpms in 2nd would be 76mph

 

Guess you were right...now can you predict I will millions if I play the lotto! If you are right turbo kits all around! Sucks cause i was calling the guy to get it in BEFORE it was too late just as you suggested. Just my luck, it was too late anyway!

Well to answer my own question I found out today what gear the tranny was hanging in for sure...yall were right...it was the 2-3 shift...

I just blew out 2nd on the way to work. So the car must have been hanging in 2nd at WOT. I was going along just fine taking it easy. Hit a hill and suddenly it had nothing above 30mph. Like I was in Neutral. Limped it home @ 30mph...man are people rude even when you got your flashers on...up in my bumper like they weer pushing me...was even pulling over to let them by!

So I have yet another mess into the tranny shop. Well I guess i will come out of this with a real tranny now. This one was a jasper rebuild and was always suspect for perfromance because of it. Though it held up for over a year with the 3.4 and the Transgo shift kit I installed, so I guess it was pretty good rebuild after all.

Going to tell the tranny guy to build it like he builds the 700r4s for the V-8 cars that race. All the goodies. Make this baby strong. Then when I turbo it I should not have to worry about it not handling the power. So much for saving for Dowards turbo kit anytime soon!

While its there I will have him address all WOT shifting issues. Should come back out with a solid tranny! While its there I will also see what he can do about the speedo gears. Then I can actually say how fast I have gotten my car and I will be able to do it @ WOT!

Said at one point he would build the 82s tranny for $600 if we brought in a coreand theat it would hold over 500 HP and torque at the Rear wheels! So mayeb he can do the same for my tranny for RAIF!

Will let you guys know what he says happened. So far we checked the dip stick...fluid does not seem burnt and was not low. Fluid has always been good and clean in this tranny in the past! No Excess metal on the pans magnet when I was installing the shift kit. Fluid did not look bad either.

We are going to pull it tonight 6pm, so I will check the pan and let you all know what we find. Planning to get it to Keith Neal on MON hopefully it will be done before the holidays...though then I got to figure how I'm gonna pay for it. Need to start up a donation...I need tires too!

Fbodtrek I know you said the pump went...How did it act when you were driving it?

When everyone elses failed after the 3.4 swap what happened internally? How did it behave when it broke?

Since I have to wait the whole weekend before I can get the shop on the phone, I guess I want to have an idea how bad it is!

 

not trying to hijack your thread redraif but now i'm wondering where my problem is! i run about 72-73 mph in the 1/8 mile and my car hits 3rd before it goes through the traps. i run 88 in the 1/4, still in 3rd but turnin lots of rpms. why are my rpms so much higher than they should be for the mphs i'm getting??

 

RedRaifs first: When your front pump comes apart, you KNOW it. It sounds like a bunch of metal in a blender when the car is idleing or worse in gear. I got lucky and blew mine while testing for misfires by powerbraking slightly (wasn't that much of a load, pump was already ready to go, I just didn't know it). A bunch of its guts got blasted into the TC, So i turned the engin off and went to get a car hauler to take it to a different shop (I was bogged down at mine, and ws too pissed off to mess with it that night). Cost me a grand to have it rebuilt with new guts and TC.

Now for AM-91, depending on the gearset you're running, you shouldn't be hitting 3rd in the 1/8. I CAN hit 3rd, but it depends on where my detent cable it set. I'm 3 tenths slower if I go through the traps in 3rd. I'm hitting 5200 rpm in 2nd through the traps, maybe a bit higher- Dean, care to throw out some math? I'm runing a 3.42 open rear as well.

 

https://www.thirdgen.org/newdesign/t...ulations.shtml

3.42/ 2nd gear (1.63)/ 5200rpm/ tire radius 13"= 72mph

 

You the man ! I figured I was pretty close. Even got the trap speed the same (on my timeslip). See kids, math CAN be useful! Thanks Dean.

 

that's about the same mph i'm running in the 1/8 but i'm turnin close to that many rpms in 3rd with the 3.73s. that doesn't make sense. i think i've got a problem somewhere.

 

Sounds like the tranny is slipping to me. My LB9 shifts into third just before the traps in the eight but it is shifting at more like 5000 RPM's. That is with a 3.45 gear.

 

Darn computer has kicked me off 3 time prior to this. Hopefully I will be able to get this responce down this time.

Ok, no cluck bang, or anyhitng weird with the car when 2nd went. It was just gone!

When we pulled the tranny Sat night...here is what we saw. The fluid on the dip stick looked and smelled fine. As the fluid was drained form the pans drain hole, is looked ok at first, but got sig darker and more burnt smeeling as it drained. When enough was out we pulled the chrome pan. Replaced it with the stocker, figured did not want the chrome boy getting messed up in transit to the tranny shop. In the bottom of the pan it was black. No chunks of anything, just fine metallic powder in the fluid. About the consistantcy of brake dust. Most came out of the filter when it was pulled off. There were a few sand sized particles, but not many. The pans bottom was black w/ a fine layer of the powder mixed with fluid.

So we pulled the convertor and cooler to take with the tranny to the shop to get flushed out. Do you think they are ruined? Anyone know what we ccan flush the braided lines with?

What happened to the tranny, just wore out 2nd? Not familiar with the inner workings of the tranny outside of installing the shift kit a while ago.

I just what I did is not of much matter. Going to have Keith, if I can get him on the phone, rebuild the darn thing with whatever he would put in a 700r4 for a v-8 seeing 500+ hp & torque... granted I will never put that to the ground, no matter what I do to the 3.4, but not going not going to let this happen again! Car is going to be making more power then it is, then even more when we eventually turbo it. But not sure what the numbers would be.

 

You can use WD40 to flush the lines if in a pinch- best thing to use is an actual tryanny line flush kit.

 

Thanks! Finally got in touch with Keith Neal. Apparently he has been having phone probs. Said he wondered why it had been so quiet. Got his cell number this time!

So tranny got dropped off after work last night. Said it will be done this Wed or Thurs. Said convertor should be ok will flush it. Same for tranny cooler. Asked him what he thought happened. Said car is making too much power for the tranny. Said the v-6 700r4 are pretty weak don't have near the band or clutches. He is going to save me the carnage from the inside!

So I told him build it like it was for a strong V-8. So the plan is to throw ALL the goodies at it. He is going to build it with all the V-8 clutches and bands. Said it will be build as he builds the trannies for the LT1/LS1 type cars that run w/ 400+HP and Torque. Said that he can easily valve it for the WOT 3-4 upshift prob too. Also will fix the gears inside to fix the speedo calibration for the 3.73s. Gonna see what he can do to get some strong shifts for me, but the convertor is going to keep it a bit mushy. Said he will set it up superior to what the Trans Go kit does! Looking at $600-800 in price! Not bad, that is what a standard rebuild usually is!

Also going to look up this convertor he build for me. It was originally set up for the 2.8. With the stonger torque the 3.4 produces however the stall is going to be different with the 3.4 versus the 2.8. So he will let me know for sure what stall he originally build for the 2.8, then calculate what the new stall is when taking into account the torque the 3.4 is producing. This should be interesting!

Oh on the 2-3 shifts some 700r4 experience...he says thats common when the cars start making more power then the tranny can really handle esp with some clutch wear...

 

2 things come to mind. governer wieghts and governer wieght springs. then once you can bring the shift points down to something reasonable with the governer readjust the TV cable to get the ****s were you want them. usually an inscrease in line pressure will cuase delayed upshifts at WOT on a 700r4 becuase people dont remember that adding line pressure also ups the TV line pressure which drive up the governe vs Tv line spool valve. and that is what controls shifts. with the stock springs and wieghts the its easy for the TV pressure to tip the spool valve in the governer to hold the gear change/shift .

 

Not gonna read thru the whole thread cuz I'm tired but-

1. Yeah everyone should have a tach installed; I'm surprised you didn't with all your mods, Red!

2. Dean's 100% right, don't worry about a 3-4 upshift while drag racing. And Also 100% right on the 4-3 kickdown kit, it allows high speeds, but not WOT upshifts.

3. Yep GM went cheap on the v6 insides; in one spot, we've got a thin sprag and a spacer, while V8 trannies got a thick sprag. But the v8 rebuild kit fits inside, in fact, you can't buy a V6-specific tranny rebuild kit.

4. My first (original) trans would never complete a 2-3 WOT upshift. My second trans (1st rebuild) did the 2-3 upshifts all the time. It's not so much "engine making more power on a worn out tranny", it's simply "worn out tranny". It's a very common occurance on third gen's, not just v6's.