200R4 shifting problems

cboyd

New Member
Hey gentlemen and ladies (if there are any on here)
I am new to this forum, popped over from the corvette forum simply because everyone told me that this is hands down the best place to get info on these transmissions. I have a 200R4 transmission in a 79 corvette, with 355 gears behind my 383 stroker with a 2500 stall lock-up converter, with maunal fourth gear lock-up switch. Before we installed the tranny, about 6 years ago, we replaced the clutched, put a big servo with a 2" red eagle 2nd gear band and 10 vein pump in there. I also installed a transgo shift kit, now I don't know exactly what one it was but it required plugging and drilling the plate that separated the servo body from the transmission. I do have pics of the changes made to this plate if anyone thinks that would help. Under normal driving condition the transmission shifts crisp and appears normal but is a little low in the RPM range, 1500 rpm but this I can live with. So that's the background, now for the problem. (1) If you are in second and stomp it, it shifts back in first and shifts in second with a crisp chirp at about 4200 rpm and shifts to 3rd at about 3000 rpm. I would expect these shifts to be a lot higher in the RPM range at WOT. (2) If you are at cruise speed, 4th gear with converter locked and you stomp it, it will shift back in 3rd for a couple of seconds, until the motor reaches about 3000 rpm and then shift back up to 4th. I would think that those WOT shifts would be around 5300 or higher. (3rd) Most of the time when i stop at a light the tranny does not shift back in 1st, usually always starts off in second.
I know tranny problems are hard to diagnosis even when you are there yourself, but any suggestion would be great. I do believe I read somewhere that the WOT shifts are controlled by the governor, if so which one would I need. My valve body has what appears to be pink paint on it if that helps.
The TV cable set to snug at WOT. The bracket I used for the throttle / TV cable for the holly is the recommended on and when I checked the geometry, it appears correct.
As i stated earlier, normal driving conditions it fine except the not shifting back to 1st at stop lights.
Any help would be greatly appreciated.
Regards
Clyde
 

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cboyd

New Member
Jim
No I am sorry i don't. I am away at work now, I do have some pics from when we had it apart. Would "N189" mean anything. Where would I find the code for the valve body. There is some numbers on the posted pic # 2924. What type of number would I be looking for. Last chance i will pull the pan off the transmission once I get home. When I put the transmission in I installed a drain plug, so it shouldn't be too bad. I love the tranny, especially the overdrive on the highway, but the lack of a good downshift at cruise speed sucks when you would like some quick pick up.
Thanks for the response.
Clyde
 

cboyd

New Member
Hey Jim
Went through some picks, the best that I can find is what appears to be an AB or possibly AL. If this is not helpful, we'll have to wait until I get back in town and see if I can better identify the valve body / transmission.
Thanks for you time.
C
 

77 cruiser

Well-Known Member
Something has to be mismatched with shift points like that. If you want to pull the gov. out & post a pic that would help. The 1-2 shift being 1200 rpm higher than the other 2 is weird. Makes me think something is causing the 1-2 to be high.
 

cboyd

New Member
Something has to be mismatched with shift points like that. If you want to pull the gov. out & post a pic that would help. The 1-2 shift being 1200 rpm higher than the other 2 is weird. Makes me think something is causing the 1-2 to be high.
OK, 77 cruiser, i do apologize, that 4200 was a type error, should have been 3200 and that is an approximation, not wanting to keep my eyes on the tach while accelerating. As stated earlier, I am away at work until early next week, once i get home I will get my son with me and I'll try and get some more accurate information. When we rebuilt the transmission, I installed a drain plug in the pan, so doing some check will not be a big problem. I really would like to get the WOT shift RPMs raised, it would add so much more to the performance of the car. The shift back to 1st at a light or stop, guess that could be something as simple as a sticky servo. I am pretty sure the kick down issue is TV cable related.
I will update you with more info when I get home, pulling the governor and getting a pic and count the teeth on the gear. I have changed the speedo gear to match the requirement for my gearing.
Thanks for all your help.
 

cboyd

New Member
Solid. Well, with the early shifts I would have to put my guess out there that it isn't a brf or other performance VB. With the 2nd gear shifts I would Hazzard my guess that the tv isn't returning when activated or the line pressure is just too high at idle. Have you measured the pressure in the trans?
Depending on your desire for trans fluid baths vs spending the coin on another VB/gov combo, you can go either way. Several of the vendors(extreme automatics in Ohio comes to mind) offer a VB that replicates the brf characteristics but without the correct brf governor setup you will still have problems as the VB and gov are a set. Others might not agree and there are known combos that can produce higher rpm shifts by swapping parts it isn't advisable unless you are liking those trans fluid baths fooling with it to get her to shift like you want.
Moring Tex
OK. So far what I got is the governor controls WOT shifts. I do believe some of these valves bodies are set to shift at 3000 RPM. The only way to change this is by changing the governor. The governors and valve body are calibrated to each other. The only way to get a correct higher RPM governor id to know the type of valve body I have. Correct?.
I have disconnected the TV cable from the throttle linkage and when pulled out and released it does return.
I have the TV cable set taught at WOT.
I do have a pressure gauge connected to the transmission, I have between 60 and 70 psi at idle.
I am really not enthused about spending $600.00 or so dollars on a performance valve body at this point.
I have installed a drain plug in the tranny pan, so I can remove the pan and do some testing / experimenting without too much mess.
I guess it still comes down to identifying the valve body.
Tell ya what Tex, I am going to copy this conservation over to my other thread "200R4 shifting problems" , just to make it easier to follow. I will be home early next week and will be able to do some checks for you. I have a procedure to check the transmission pressures, which I will complete and post the results.
BTW in the cast of the bell housing on the transmission it has "408" and underneath thet it has "XX G". I have no idea what that means.
Thanks for all your help.
 

77 cruiser

Well-Known Member
When you check your pressure bring the rpm up to about 1500. It should be more than 60-70 more like 90, more important is the full TV pressure.
 

cboyd

New Member
When you check your pressure bring the rpm up to about 1500. It should be more than 60-70 more like 90, more important is the full TV pressure.
This is a pic of the governor I found from when we dis-assembled the transmission, don't know if it is clear enough to determine anything or not. I do believe I have a green one in there now to match the speedo with my gear ratio.
DSCF5632.JPG

C
 

TexasT

Texas, Where are you from
That doesn't look like a brf governor. The weight that I can see looks too big. If you do pull it and can get the weights off and weighed that would help with identifying. That servo looks to be the 653. too small in diameter to be a 694

You can see that tv valve there on that vb. see how it isn't connected except that it is pushed by the lever that attaches to the tv cable. If you do pull it apart again you can make sure that the tv valve is able to return easily to the 'at rest" position.
 

cboyd

New Member
That doesn't look like a brf governor. The weight that I can see looks too big. If you do pull it and can get the weights off and weighed that would help with identifying. That servo looks to be the 653. too small in diameter to be a 694

You can see that tv valve there on that vb. see how it isn't connected except that it is pushed by the lever that attaches to the tv cable. If you do pull it apart again you can make sure that the tv valve is able to return easily to the 'at rest" position.
Hey Tex
Thanks for the reply. I have been doing a lot of online research and I will be pulling the pan when I get home for sure.
That is the original servo. I installed a billet one during the rebuild.
I will try and find the painted number on the VB.
Take some pics of the governor weights, weigh them if possible.
Confirm the TV cable fully closes at WOT, and returns all the way when accelerator is released.
I will be performing a pressure test I took from the Bowtie Installation guide as well as the after install function test they recommend. I will upload both of those procedures and if there is anything else i can check or you or anyone else on here would like me to check, please let me know.
As far as the function test goes, I know the transmission performs most of these functions, i just don't know at what RPM it does it at, this is information that I will also get. One function I pretty much know for sure it does not do. That is from cruise speed, in OD, when I stomp it down, it does not go back in 2nd, just to third and then just for a brief couple of seconds. I will attach the task that I will be performing, that way if if there is something else you would like to be checked, just let me know. Once again, thanks for sticking with me in this.
Clyde
 

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TexasT

Texas, Where are you from
Jump to the 7:10 mark. This is a different trans but your tv valve should move like this one does. Should return out like this does, or like he sez, it wont shift back to low. If you search up this guys channel, they have some 2004r content. They do some things I don't think are necessary but he is the professional and I'm not worried about a come back.

Does your servo have the 694 cast into the cover?
 

TexasT

Texas, Where are you from
In that vid above about 12:25 he drops some knowledge about the accumulator. Mr Husek told me to have the piston stacked up in the 2004r to where the spring hangs about 1/4" above the housing surface. Just have to know that you need to push the housing down to where it is seated and don't try to draw it up with the bolts as it can strip the threads out of the case.



I used a nut under the piston to space it up.
 
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