salspmp

iTrader: (8)

I purchased a yank 4000 Stall converter for my stock 4L60E about two years ago (model number 4000ss I believe). I have a 2000 Pontiac Trans Am. I probably on have a MAX of 2000 miles on the converter and the transmission went out on me. I then purchased a Dr Evil 4L60E transmission. It is used and said to have 8k miles. I installed the converter into this trans and the trans into my car. The previous owner of the trans said that he used Royal Purple ATF fluid. So the trans had a little left in it. I add more royal purple without knowing about Yank not recommending synthetic. The trans or converter (I believe the converter) will not hold when I give it a lot of throttle. Under normal driving the trans shifts firmly and the converter seems to operate just fine.

Is the slip do to the synthetic fluid?

Please note that my stock trans had dexron fluid and the verter seems to act fine. I would estimate I am around 500 Crank HP and about 400 at the wheels.


Let me know if you need more information. Again, everything shifted fine until the stock trans failed...

NHRAFORMULA00

iTrader: (2)

Drain it all out,and flush out the verter.

salspmp

iTrader: (8)

So, you are saying it is the fluid?! Or is this the guess and check method? I don't mean to make it seem like I don't trust you. Its just that I spent so much in synthetic in the past few days!!!

z99ls1

iTrader: (12)

I really don't think it's the fluid. Explain better what the car is doing. It kinda sounds like you got a sheet transmission. I haven't heard of Dr Evil transmissions though.

salspmp

iTrader: (8)

To me it is acting like it is low on fluid. If I hit the gas pedal pretty hard it will just bang the rev limiter and I won't go an anywhere. It is not low on fluid though.

I had also wondered about the tranny being bad. But it shifts very well. I can accelerate in overdrive pretty well.

I did fail to mention that this tranny was made with a vacuum hook up. I have it plugged into where one of the EGR vacuum lines normally go. (EGR removed) It has the standard large connector but has a vacuum line near it.

z99ls1

iTrader: (12)

I don't see why it would have a vacuum? Is it like to tell it when to shift? 4l60e's usually have a little tube that comes off the top, but idk what vacuum your talking about

LS_Canuck

He's probably talking about a vacuum modulator to control line pressure. Fluid level and condition, as well as line pressure tests are always good places to start when diagnosing A/T faults.

salspmp

iTrader: (8)

It is not fluid level or condition....
Fluid leve is a touch high according to the dipstick. The fluid is brand new royal purple synthetic.

The vacuum on this is to control line presures. It has the breather tube on top as well.

72blownvert

That is not the best spot for the vacuum line.It should be tied into the line that goes to your brake booster you may not be getting enough vacum.

BrianC98Z28

iTrader: (11)

it needs to be tied into the brake booster for proper vacuum and drain the synthetic and use proper DEXIII fluid. There is a reason they dont want you using synthetic fluid. Couldve saved yourself a lot of headache and money by just reading first.

salspmp

iTrader: (8)

I don't disagree with the headache. I had no idea about the synthetic. The previous owner was running it, so I was trying not to mix. Should have done some more homework. I will try the vacuum first. I am curious as to which will cure it or the majority of it.

jimbob

iTrader: (4)

The synthetic fluid issue is only related to lock up clutch material. It's too slippery for good and strong lockup. It can also cause your stall rpm to increase slightly. It will not cause an issue with the rest of the tranny not working well. Sorry, you have problems elsewhere. Also, if you loose vacuum to the modulator the shifts will just be 100% line pressure so, that also will not cause a slipping issue. A bad verter that contaminated will take out a new tranny pronto. Or you just got a bad tranny...

Vince B

iTrader: (1)

Slspmp what type of failure did you have with your last transmission before installing the Dr Evil unit? BTW I built for them for about 5 years before working for my last employer.

salspmp

iTrader: (8)

I think it was caused at the track. Throttle got stuck wide open. Full throttle shift into overdrive before I shut it down. After that I lost gears one and two. Third gear worked, but as I was testing to try to figure what the problem was, I lost third. Don't know if that helps. I did swap the converter from that trans over to the new trans. Hope that the converter isn't to blame

Vince B

iTrader: (1)

Depending on the actual internal failure of the old unit I guess anything is possible. It might be a good idea to pull the pan off the old unit to see if it was full of metal. If it is extremely full of fine silver (aluminum) then I would say the converter is probably hurt.

salspmp

iTrader: (8)

Are we all in agreement that the fluid is not the cause of it? It also sounds as though the vacuum spot needs to be changed, it is ultimately not the cause of my problems either?

salspmp

iTrader: (8)

I changed around the vacuum line that I used. That had no affect on the condition. I then drained all of the synthetic fluid out of the transmission. That also had NO AFFECT!!!!!!!!!!!

I have noticed this issue is more prevalent the lower the gear I am it. It "holds" better in third gear that it does in first or second.

With changing to a partially vacuum controlled trans, do I need to change anything in the tuning?

Please HELP

lt1-xjs

Dexron VI is the replacement for Dexron III. It is also a synthetic blend. Yank approves the use of Dexron 6. I installed my Yank over 6 years ago with Mobil 1 and never had an issue. Even with the tons of WOT lockups its been through. Although my car doesn't have a ton of power either. I agree it's not the fluid.

hookngo

Where did get the dr evil trans

salspmp

iTrader: (8)

I got the trans from a local private party. I am about ready to show up at his door with a baseball bat. We his car for a ride with the trans in the car. But we never really pushed it.

I do have HP tuners. Is there anything I could watch while driving the car that may lead me to my issue?