Follow up ??'s to Transgo TF-2 installation Sticky

jauringer

jauringer

Member
The installation sticky for this shift kit is very helpful! I notice the spring replacement and modification to the l/r servo piston was not covered or mentioned in the installation thread. Is this an optional modification for this kit? I've seen where this step was not performed on some installations. Would you recommended that it be done?

I'm looking at my tf-2 kit right now and have slowly become to understand and feel comfortable with the vb modifications. I am not yet comfortable with the low/reverse piston mod and spring replacement. I have not had issue with piston cocking or binding. Will this kit increase pressure to the piston requiring this modification?

Thanks,
jason

72 Scout II 304ci/727/d20
4'' rc lift, pertronix
 
Last edited:
jauringer said:
the installation sticky for this shift kit is very helpful! I notice the spring replacement and modification to the l/r servo piston was not covered or mentioned in the installation thread. Is this an optional modification for this kit? I've seen where this step was not performed on some installations. Would you recommended that it be done?

I'm looking at my tf-2 kit right now and have slowly become to understand and feel comfortable with the vb modifications. I am not yet comfortable with the low/reverse piston mod and spring replacement. I have not had issue with piston cocking or binding. Will this kit increase pressure to the piston requiring this modification?

Thanks,
jason

72 Scout II 304ci/727/d20
4'' rc lift, pertronix
Click to expand...

The modification to the low/reverse piston is not really part of the transgo system. That is a common modification done on any 727 whether the shift kit is installed or not. It's been done on these units long before transgo was formed.

I personally do the piston mod on any transmission I overhaul. This does not increase any pressure, but simply allows the piston to react in it's bore in a more effective manner. There are also numerous aftermarket versions of the piston itself, some in steel, some in aluminum.

Both the transgo and the B&M systems do call out installation of a shim to the low/reverse piston assembly and installation of a different spring. And I neglected to include that step in the online instructions I posted,...my mistake.

Hopefully in the next few days I'll have the transmission pulled out of our t-all and will show what happens when the rear band breaks and the low/reverse piston attempts to escape it's bore.
 
Thanks for the info michael.

I wouldn't mind going ahead and doing it if it means less heartache later but I'm not certain how to use the c-clamp to remove/reinstall the piston. The service manual calls for some type of adapter between the clamp and piston which I don't have. I'm also not sure how to get the "arm" out of the way to make room for the c-clamp.

I'll probably go ahead and tackle the tf2 kit and put aside there servo mod until I see your article. It doesn't look like it requires removing the vb again, so all I'll have to do is drop the pan.

*edit* one more question. I'm a l/r pivot pin o-ring away from having this tranny completely dry. Is there another way to replace that o-ring without removing the tail housing while I'm in here? Can it be pulled out instead of pushed out through the tranny case?

Thanks again,

jason
 
Last edited:
In order to perform the entire low/reverse piston mod, the valve body must be removed. Then the short strut is removed from the actuator arm position in order to allow full travel of the arm for piston removal.

In order for the arm pivot pin to be removed, the output housing must come off. There is a projection on that housing that is holding the pin in place, no way it can come out from the opposite direction.

This pic shows the pivot pin partially removed from the rear. Some rods have two "o" ring grooves but use only a single "o" ring. I buy the "o" rings in bulk and always use two if the rod has two grooves.
 

Attachments

  • L_R band link rod.jpg
    L_R band link rod.jpg
    46.1 KB · Views: 1,243
What a big project for such a little o-ring! I guess I'll let it be until I can pull the tc for a rebuild. I might as well go ahead and perform the servo mod while I'm in there I guess. I May be posting to this thread if I get stuck!

I really appreciate the very helpful information.
 
Mr. Mayben,

I've got some more questions. I apologize if I'm buggin the shiz out of you. I decided to go ahead and replace my o'ring while I'm in the tranny. I'm justifying all the extra work for an o-ring in my mind by rebuilding the tc and cleaning and inspecting the precious bearing in the rear housing.

Everything is pulled and I've got a couple questions.

First, I pulled the pivot pin o-ring and nothing is wrong with it! I expected it to be brittle and cracking. Is there something I can do while I'm in here to assist this new o-ring in keeping this area sealed. (ie:right stuff, jb weld around the crevice after it's reinstalled....something.)

when cleaning out the tc and extension housing I'll be using the standard autozone brake cleaner. I noticed from a previous thread that I'll need to spray some lubricant on the governor assembly. Will penetrating oil work? Also, do I need to coat the bearings and or the inside of the ext housing with this oil as well? I want to spray down the output shaft and seal surface as well on the back of the transmission but I will definitely be spraying it in the tranny also. (of course the pan and vb are out for the shift kit.) this is ok right?

What do you suggest? Thanks a bunch
 
Last edited:
The pivot pin "o" ring does not "brittle and crack". They simply leak. Replace it with a new"o" ring of the proper dimension and it will be fine. If the shaft has two grooves, then put two "o" rings on the shaft.

The only thing to do to the "o" rings is to lube with trans fluid. Never use anything else and most especially don't even think about applying jbweld anywhere!!!!! There is no need to do stuff like that, these units have been in service more than 50 years with no problems at all!

Brake cleaner of any brand is fine for parts cleanup. Don't use penetrating oil on anything, use a proper lubricant. Penetrating oil is not a proper lubricant. Transmission oil is what I use for many items including the bearing, it's for initial lubrication only after repair. Once the trans starts internal rotation, lubrication issues are handled.
 
Well, I need a little help. I had a feeling the transgo installation went a little too easy.

Here's the deal. Just filled her up and took her for spin to check out the success level of my latest project. Tf2, rebuilt d20, and resealed extension housing.

She hold gear wayyyyy too long. Starts out in first perfect and gets up too about 4k rpm and then I let off because I don't want to take any higher. As soon as I let off the gas she shifts into 2nd. Then I hit the gas in second and take it up to 4k rpm and let off the gas and she stays in second. I haven't felt third yet!

Is pressure too high in there? Any help would be appreciated.
 
First off, the "pressure" will be correct as long as you set the adjustments exactly as specified in the transgo instructions, using either the supplied gauge or making the measurements with a steel rule. The measurements used should be the set for street-driven vehicles, none of the mods for "race only" should be used at all.

Next, you must verify/set the kickdown control adjustment at the carburetor and manifold-mounted control as spec'd in the vehicle service manual. There is no reason to change this setting because of the installation of the transgo kit.

Installation of this system does not change the transmission shift points at all from the oem function. It does make the actual shift much more firm (that is depending upon the throttle plate setting when the unit shifts) and operation of the transmission in the manual shift mode is instant when the shift control is moved.

Any other issues are dependent upon the actual correct reassembly of the entire valve body.

Did you actually remove the governor assembly? If so, are you sure it was reassembled and correctly lubricated? The governor operation is a major part of the entire "upshift" and "downshift" scenario.
 
Thanks for the response Mike. I'll double check the throttle pressure linkage. I've adjust this to spec a few times with carb changes and never had anything like this occur.

The pressure was not set with a gauge. It was set to be flush with the spring seat and no more than 4 turns counter clockwise for full race mode.(this setting is quit different from the service manual) I adjusted this a few times as it was difficult to tell when it was "just" flush with the spring seat.

After reading the directions over and over, this would be the only step I might be off on. Spring May be cocked in bore according to manual. I don't know if the symptoms are the same but at least I have somewhere to go with this problem.

As far as the gov. Is concerned, I did not remove it but I did spray it down with carb cleaner as I was cleaning that area before installation of the extension housing. While the housing was off the output shaft and gov were bagged and tapped to keep them covered.
I also sprayed it down with a light oil afterwards.

I've gone over and over this in my head and manual. I was so careful and clean I just don't get it. It's got to be something simple.

Don't know if this makes a difference but I did a complete drain and refill, tc and all.
 
Last edited:
The "gauge" is the actual small cardboard item supplied in the kit.

One other possibility...the "kickdown sleeve" is installed on the throttle valve/kickdown valve backwards. This will cause a very late upshift. This step is found on the right hand side of page 4 of the instructions

the currently-supplied instructions from transgo were shortened and changed considerably a few years ago. Much information was eliminated that explained why certain changes were done and what the outcomes would be. Because this kit is designed to be installed by a transmission professional (not a handy dan), their efforts at simplifying the install actually created more potential issues in my opinion.

The older instruction set is far superior, but is much more complicated to deal with, even for me!
 
Got the vb out.

1. The tv valve, new yellow spring, plunger, and sleeve are all in the correct order. There is a variable here however and it May be a problem. The shift kit mentions nothing about this but the manual requires me to use a special tool to adjust the throttle lever stop screw. Before I removed it the first time for the kit I measured the distance distance from the back of the lock nut to the edge of the stop screw. It 1.095 and that's exactly where I put it when it all went back together. Now that I'm looking at it along with the manual it doesn't look right. There's a pretty good gap between the stop screw and the throttle cam tang. .3" gap to be exact and the manual seems to show no gap between them?? Is this where this gauge comes in? Btw: I can assure you that it is not in my kit. I keep everything that I put in this truck. I've got the box as well as the I instructions, gasket, parts I removed, parts I did't use....everything and there's no gauge or mention of one in my I instructions?? Is the a way to set this some other way?


2. I checked the pr valve for binding at the bottom spring seat, good. I also checked the distance between the adjusting screw and the manual valve in 1-low, good. The top spring seat is just flush with the the retainer as the kit mentions.


Please advise and I really appreciate your help thus far.

I guess I'm going to tear into my box and see if this gauge is hiding somewhere.

*edit: I saw the gauge in monroe's book and mine didn't come with that but I've verified all those settings. I just havn't verified the stop screw setting if mines is off.*
 
Last edited:
Another note Mike. I took the entire vb apart for cleaning so there was more out than just what was required for the kit.
 
If your kit did not include the cardboard template for several functions, then you only adjust the pressure relief valve as spec'd in steps 2 and 3 on page #5. That also means you have a kit manufactured in the last couple of years as some items did change from the last generation kit.

I'd go back over every step in the sequence and verify carefully against the instructions.

The functionality and adjustments contained in the service manual do not correspond directly with the transgo installation. Use only the transgo info and set the adjustables as indicated. Be certain you also adjust the bands using the transgo specs and not the oem specs.

Again, this is why this kit is spec'd to be installed by a pro...someone that knows the sequences and has had valve bodies apart several times.
 
Thanks. I just went back through everything. All valves springs and such are installed correctly. All of the measurements that were on that "gauge" are in spec. The only item that's not is the stop nut and screw for the throttle cam and valve.

I guess the my main question is could this be my problem. I found some info online that would indicate that the stop scew and nut could cause this (similar at least) but I have no way of knowing how to adjust it as the manual explains how to use a certain tool that does not exist anymore.

Can you tell me if this is possibly the culprit and how I can adjust it without that tool?
 
jauringer said:
thanks. I just went back through everything. All valves springs and such are installed correctly. All of the measurements that were on that "gauge" are in spec. The only item that's not is the stop nut and screw for the throttle cam and valve.

I guess the my main question is could this be my problem. I found some info online that would indicate that the stop scew and nut could cause this (similar at least) but I have no way of knowing how to adjust it as the manual explains how to use a certain tool that does not exist anymore.

Can you tell me if this is possibly the culprit and how I can adjust it without that tool?
Click to expand...

The "spacing" for the throttle stop adjusting screw-to-the kickdown cam is 3/16". The earlier version of that kit included a 3/16" drill bit used for that operation and one other drilling operation. This dimension can be easily measured using a steel rule also. The kickdown cam should be just touching the end of the valve and not compressing the valve at all when being set. This provides the correct "freeplay" for this assembly.

The throttle stop adjustment provides a significant amount of space between the throttle pressure control lever and the valve tip for when the throttle is actually closed. If that adjustment is too tight, then the transmission is fooled into thinking the throttle is at wot and won't upshift at all or will only upshift (automatically) at an extremely high engine rpm.
 
Thanks.I got it fixed. It was only the stop screw adjustment. I'm not sure how it was incorrect but it was way too far out. I guess the transmission didn't even know the throttle was engaged and I would have had to slam the accelerator to the floor to engage that valve enough to do something.

Monroe's book gives the measurement of .625 to edge of cam. Stop screw gently touching the tang and tightened down.

Shifts great. Kit is definitely noticeable. Nice, firm shifts.
 
As I posted, the correct measurement is 3/16" or 0.1875".

If you actually used a measurement of 0.625", that is more than half an inch!
 
Mike,

the two measurements are not comparable.

Monroe's measurement is taken from the valve body itself and measures .625 out from the valve body (at the throttle pressure valve bore) to the very edge of the cam. The stop screw buts up gently against the back of the cam at that point. I didn't measure the cam free play but just by eying it before installation it could have easily been 3/16. The points of measurement May be different but they both are coming to the same conclusion.

If you check out his tools section (chapter 5, page 404 I think) he has a sketch to follow if you want to make throttle pressure adjustment tool. I'm not going to be taking a bunch of torqueflite vb's apart but if I was it would be a pretty handy tool.

Also, since I had backed off the throttle pressure rod yoke I completely readjusted to the manual spec. Tc rebuild, extension housing reseal, and now transgo tf2, all working great. A successful "large for me" project completed. Now I need to follow your guide on the the rocker assembly cleaning and replace a couple rockers I have with play between the shaft and bushing and maybe I can take a break for a while.
 
Last edited:
You must log in or register to reply here.
Back
Top