New trans won't downshift to 1st

[squeeze87]

Well, It's done! Trans is in the car and it actually shifts and goes down the road! One problem, the car wont downshift to first when at a stop when trans is in D. It always takes off in 2nd unless I manually pull it down to 1, then return it to D then the car shifts fine! Shifts are nice and crisp and if someone could help me chase this out i would appreciate it. Is this a TV issue or a gov thing? I have seen this topic posted before but havent seen a definitive answer for what could be causing this. Thanks for helping

 

[77 cruiser]

The only prob. I`ve had like that was press. related I was getting full line press. all the time. Check your press. and see what you have. I`m sure there could be other things too but that`s my .02 cents. Good luck.

Jim

 

[squeeze87]

More info

thanks for the info, 77cruiser, I have about 100 lbs no TV 190 lbs max TV in D. Manual 2 and low are 150, 220 respectivly. I guess I need to add that the trans wont kick down to 1st even if you mat it after it takes off in 2nd. I was hoping Bruce or MeanBuicks could explain how the the trans works to control 1-2-3 shifting when the shifter is in "D". Then, maybe I could figure out why I'm staying in 2 at a stop. Something must be holding the band on, or preventing it from being pushed off, for it to start in 2nd gear! I'm by no means an expert, just a guy trying to figure this out.
Thanks.

 

[MeanBuicks]

Hmmm.

Sounds like excess governor pressure is keeping the shift valve in the second gear position. The fact that you can achieve first gear by pulling the shifter into manual low tells me that the shift valve is not physically stuck.

I'd say that either the governor is being flooded or that the governor is not sealing. The governor is fed through a passage in the valve body gasket and a small orifice in the spacer plate. If the orifice in the plate is oversized or the gasket is not right, that could cause problems.

You may also want to reinspect your governor to be sure that the check balls are sealing off on the governor shaft.

 

[WE4]

yep

Hi line pressure will cause this too. Also if pressures were just increased ( like shift kit installed or PR valve and/or spering changed) and the govenor still has the primary weight spring, it will do just that. Take out PRIMARY spring weight or take a shade more weight of Primary weight and I bet it comes back.

Bruce
WE4
www.PTSnctb.com

 

[WE4]

footnote

I have seen this with the band too tight too but usually will bind a little when put into low or reverse.


Bruce
WE4
www.PTSnctb.com

 

[Lee Thompson]

no 1/st

I had this very same problem, I don/t have the manual here now, but, there is a spool in the 1-2 shift valve bore ( not the one with the spring on it ) that I had put in backwards. I turned the spool around to where it should be and that was the problem.
Hope it is something simple.

 

[squeeze87]

Thanks!

Thanks everyone! I'll check this stuff out this weekend and let you know how it works. I appreciate the advice.

 

[squeeze87]

Governor seems OK

I examined the governor I was running and it only has 1 blue spring on it. Both check balls are present and appear to be sealing against the gov shaft. So you say excess line pressure can cause this? I cant really change that.The seperator plate was not modified to my knowledge so at this point I dont really know what else to check. Is this something I may just have to live with? Will the strain of taking off in 2 prematurly wear the band? I also should note that the first time I drive out of the garage the car is in 1 (I guess because r activates low/reverse) its only after it shifts up that it wont go back to 1 unless manually selected. Thanks

 

[MeanBuicks]

If you've still got the pan off, take another look at the valves in the valve body. Pay close attention to the 1-2 shift valve line up.

Before you remove the valves, stroke them with a scrribe and make sure that they are not physically sticking. If they are, you may have some foreign debris in there.

Pull the valves out and make sure they are properly oriented. The Low/Detent valve and sleeve (no spring) could be backwards as Lee mentioned.

Good Luck!

 

[squeeze87]

not valve body

Thanks for repying Greg. I called Bruce today and he suggested putting my original valvebody back on and driving the car, but it does the exact same thing! However, if you pop it into N then back to D, its in 1st! Bruce said to post the results under a new thread so let's see if we can figure this thing out!!

 

[WE4]

Getting interesting now......

Hrmmm. This is getting interesting now. Did you change plate and gaskets too?If you did , we are probobly looking at something mechincal , but what? Band too tight would be one. unless when you first put in gear servo on high gear side might have drained back allowing it to take off once this way. in other words crossleak to servo port somewhere. I dont get this one. Did you change the gaskets and plate too, thats the big one. I meant to say that on phone but forgot. Rule that VB out.

Bruce
We4
ww.PTSnctb.com

 

[squeeze87]

seperator plate

I did not change the seperator plate or gaskets. I don't have any other gaskets to try right now and for some reason the local trans places around here dont like to sell parts. I guess its because they dont like people working on thier own stuff! I dont know if this matters but on the 1-2 servo I am running a spring that has a LOT of compression. I mean you have to put some weight on it to start the bolts. As far as the band goes the pin was checked in the case before it was sent to me and I can move the band around with my finger with the pan off. Sounds like I need to do that sep plate change. Man am I going through the trans fluid! Sure am glad I put a drain plug in the pan! Thanks.

could this be a check ball problem? Of the 8 in the case, I'm using 5. If the trans tailshaft is facing you with accum to the left they are as follows: ball by accum-no, ball near center across from accum-yes, balls on right side of case, next three straight up-using all three. next ball straight up-no. ball in oval on left side, across from c-support bolt,-yes. far upper leftcorner-no. Of the three in valve body i have the center one out. I did all this as instructed over the phone so did I leave one out I shouldnt have?
Hope you can decipher all this!

 

[MeanBuicks]

Originally posted by squeeze87
Man am I gong through the trans fluid!

If you use a really clean drain pan, don't hesistate to pour the fluid right back in the dipstick tube. When you're pulling the pan off as often as you are now, the fluid is still fresh and clean.

 

[WFO]

Re: footnote

Originally posted by WE4
I have seen this with the band too tight too but usually will bind a little when put into low or reverse.


Bruce
WE4
www.PTSnctb.com

fwiw,this is how my new tranny was acting right before it sh!t it's guts out all over the track in vegas.

it wouldn't shift into 1st(just like yours)and it felt like it was binding in reverse.

it turned out that one of the teflon seals on the drum got sliced when the trans was being assembled and a piece got free and lodged in one of the ports.the seal was actually still partially in it's groove.it just got far enough out that it was mostly clogging the port right next to it.

thank god for mastercard and len in l.v.! being broke down 1000+miles from home(i drove down from oregon)is not a nice feeling.

later,sean

 

[squeeze87]

Bummer

Man, I really hope its not something like that!! I dont have any binding in rev whatsoever. Can you re-use valvebody gaskets? the ones off my original trans are still stuck to the sep plate and arent ripped up.Bruce, could I slap this on or is it a bad idea? thanks

 

[WE4]

hrmmm

I would replace with new and gently and evenly torque all VB bolts to 100-125 inch pounds. Thats where I would start at this point.

Bruce
WE4
www.PTSnctb.com

 

[squeeze87]

Separater plate differences

Hi its me again, I removed the sep plate and have found (5) differences, this is a pic of the plate I was using .I hope you can make it out as it is the best quality pic I could post. Here are the differences:
1. This hole was manually filled and a small .020 hole drilled as a modification
2. this hole is about .08-.10 dia as opposed to .010-.020 in my stock plate.
3. this hole is not in my stock plate at all
4. this hole has been manually filled in as a modification
5. this hole is much smaller in my stock BRF sep plate.

Bruce, I dont know if any of these could be causing the problem but as it stands, Im planning on getting some new gaskets this week and installing my stock plate with all the stock checkballs. Let me know if anything looks obviously wrong on that plate
Thanks again

 

[WE4]

Holes 1-2....

They should never be screwed with. Why not let me send you a new plate and gaskets, install and see if that fixes. If so you will have maybe 25-30 dollars in and the nightmare ended.Plate is new X and 18.99 I think. I will send out on Monday if you like.
See if that cures and go from there. Let me know...

Bruce
WE4
www.PTSnctb.com

 

[EightSecV6]

Sounds like too high of a line pressure, the governor cannot exhaust enough pres. to downshift. I would check the relief spring in the pump to make sure it is not too stiff or binding. Someone may have put a different boost valve in as well.
Pressure at minimum TV in park or neut at 1000 rpm should be 56-64 pst at max TV 173-198
in rev at 1000 should be 105-118 and 322-369
in d4 and d3 at 1000 should be 56-64 and 173-198
in d2 and d1 at 1000 should be 123-138 and 123-138

I bet if you got the line pres. back down to the higher end of no TV scale in d3 you would correct this problem.
Bill