200-4r early shifting

[TurboBuRick]

Thank You!

Heres an idea. How about the builders get in here and ask a few questions and answer a few questions so that others can benefit from the tech. This is a fairly common problem that could have several causes. With that said Otto is asking the right questions. Rick which TC are you using with this trans?

Running a PTC non lock up. It seems to magnify the problem. Stuck in mush zone. I'll pull the pan this weekend and get more info.

 

[bison]

Running a PTC non lock up. It seems to magnify the problem. Stuck in mush zone. I'll pull the pan this weekend and get more info.

An efficient converter will do that

 

[chris718]

Here is how I would go about checking it.Disconnect tv cablr from throttle body.Pull it all the way ou and lock it smartly with a vice grip.Now go for a road test and see what rpm it shifts out of 1st @ WOT.If it is over 5000 check cable,cable adjustment etc.If not,we now now the valve body is commanding a 1/2 shift at lower rpm.Why?First thing to do is check line pressure .If it is low ,the lo psi fed to the tv limit valve could be feeding the plunger less than the pre set 85 to 90 psi needed. This will cause an early shift condition.If line is ok and shifts get firmer with the cable pulled out further the problem is between modified tv upshift oil that leaves the plunger and the 1/2 shift tv valve.I have seen this many times and couldnt fine anything worn in the valve body.Remedy,replace valve body.I have a whole bin of bad ones.The governor is almost never responsible for this.Look into the valve body replacement after testing.

 

[jasjamz]

An efficient converter will do that

So Bison, are you saying this may be normal? I have a trans with the same issue and same converter dealer. I just got back to the OD from a 400 and this not what I was inspecting. Mine is back at Jimmy's Rick. Give him a call and see if he did something simular and what we could do to solve it. Was it like that with other converter?

 

[TurboBuRick]

Here is how I would go about checking it.Disconnect tv cablr from throttle body.Pull it all the way ou and lock it smartly with a vice grip.Now go for a road test and see what rpm it shifts out of 1st @ WOT.If it is over 5000 check cable,cable adjustment etc.If not,we now now the valve body is commanding a 1/2 shift at lower rpm.Why?First thing to do is check line pressure .If it is low ,the lo psi fed to the tv limit valve could be feeding the plunger less than the pre set 85 to 90 psi needed. This will cause an early shift condition.If line is ok and shifts get firmer with the cable pulled out further the problem is between modified tv upshift oil that leaves the plunger and the 1/2 shift tv valve.I have seen this many times and couldnt fine anything worn in the valve body.Remedy,replace valve body.I have a whole bin of bad ones.The governor is almost never responsible for this.Look into the valve body replacement after testing.

Chris, thanks for the procedure. That makes perfect sense. As soon as the weather clears up, I'm on it.

 

[TurboBuRick]

So Bison, are you saying this may be normal? I have a trans with the same issue and same converter dealer. I just got back to the OD from a 400 and this not what I was inspecting. Mine is back at Jimmy's Rick. Give him a call and see if he did something simular and what we could do to solve it. Was it like that with other converter?

I think Bison means that it's normal to be mushy if it shifts too early. These converters don't really go to work till your crankin on them. They work best 5000rpm and up IMO.

Shift point has always been a problem even with other brf trans I had before this one. They just don't hold the gears on there own. Same with other converter too just not as annoying as with this PTC.

Did you hear back from Jimmy? I'll give him a call tomorrow.

 

[bison]

I think Bison means that it's normal to be mushy if it shifts too early. These converters don't really go to work till your crankin on them. They work best 5000rpm and up IMO.

Shift point has always been a problem even with other brf trans I had before this one. They just don't hold the gears on there own. Same with other converter too just not as annoying as with this PTC.

Did you hear back from Jimmy? I'll give him a call tomorrow.

What i really mean is that the driveshaft speed will be higher than it previously was with the looser converter at the same engine speed so it will shift earlier. Going from a loose converter to a PTC that couples well may change the shift rpm by 500 or more. As you crank up the boost it will gain some rpm

 

[jakeshoe]

Here's a thought...

This post is a prime example of some non-transmission builders cramming one vendor down everyone's throat.
I count 3 (not including myself) qualified builders who care enough to answer the technical question on an open forum, free of charge.
That would be Otto, bison, and chris718.
Dave Husek may be an awesome builder, but those who seem to keep pushing his services might step back and let the man offer advice on this forum the same as others do. That would be more beneficial to his business than a few friends, customers, or whatever the relationship may be throwing out his business info everytime someone asks a tech question.

 

[jasjamz]

I think Bison means that it's normal to be mushy if it shifts too early. These converters don't really go to work till your crankin on them. They work best 5000rpm and up IMO.

Shift point has always been a problem even with other brf trans I had before this one. They just don't hold the gears on there own. Same with other converter too just not as annoying as with this PTC.

Did you hear back from Jimmy? I'll give him a call tomorrow.

Not yet. Today I have to try to get that Cobra moving. We are in the final stretch.... I haven't forgot about the other thing, I will get it to you today even I if I have to Paypal it.

 

[BEATAV8]

I've seen similar behavior on my car when I installed a 9.5" PTC, but not nearly as pronounced. My Vigilante was "sloppy", so it shifted @ 57-5800 @ 55mph on the 2-3. The PTC has better coupling, so it reeled her in all the way back to a more stock type shift RPM, 52-5300 RPM @ 55MPH. The solution was to install an olds KC valve body as recommended by Bison and Chris K. Now it shifts 2-3 @ 5900-6000RPM @ 80 MPH. I kept the stock unmodified BR governor too, and the new shift point matches my cam / heads combo.

For yours to be shifting at 4000 though sounds to me like it is way too low to be all converter. Even a stocker shifts a lot higher than that. There's probably something else going on there like Chris suggests.

 

[TurboBuRick]

Chris from CK is setting me up with one of his modded valve body's.

I'll post back the results when I get testing in.

 

[DCVING 6]

subscribing to thread.

 

[TurboBuRick]

subscribing to thread.

New custom valve body from CK on the way. Can't wait to see how it works.

 

[TurboBuRick]

We have a winner!

Well got the valve body from CK installed today.

Rock-N-Roll! The entire shift curve has been moved up and she holds all the way to 5800.

Finally a resolution to a problem that I been dealing with long time.

Thanks Chris, you really know your stuff! :biggrin:

 

[BEATAV8]

Well got the valve body from CK installed today.

Rock-N-Roll! The entire shift curve has been moved up and she holds all the way to 5800.

Finally a resolution to a problem that I been dealing with long time.

Thanks Chris, you really know your stuff! :biggrin:

Take a look at how fast you are going now when it shifts too.... enjoy all that extra 1st and 2nd gear and rock on!

 

[jasjamz]

Did you do it yourself? Only a VB change, or was it more items involved to get it right?

 

[TurboBuRick]

Did you do it yourself? Only a VB change, or was it more items involved to get it right?

Yes sir. Changed the metering plate and the valve body. Pretty cut and dry.

Ended up backing off the tv cable a couple notches. Thats about it. It's a different animal now.

 

[DCVING 6]

Ended up backing off the tv cable a couple notches. Thats about it. It's a different animal now.

I'm guessing ANIMAL is the key word to decribe it.

 

[TurboBuRick]

I'm guessing ANIMAL is the key word to decribe it.

Thats for sure Glen.

 

[jasjamz]

Spoke with CK earlier. This will be the route I go too. I will do testing at the track to see which shift point gives me the best results and shoot for that RPM with him.