Transgo TF2 in A904

[Mario Keller]

Hello Transmission experts.
I have a probably late 1968 A904. I bought a Transgo TF2 and began to install it. Valve body is ready. Now i should change the spring in the rear band servo.
I cannot change the spring without removing the tailshaft.
Installation manual says if the diameter of the spring doesn´t fit the servo or the retainer --> use original one.
Now i thought about leaving the original spring in it and not to remove the tailshaft.
What would be the consequence? Is it working fine with the original spring? What would be different?
Does anyone know?

 

[Curiousyellow71]

The rear servo should be accessed with the pan off. It is what adjusts the rear band. No reason to take tail shaft off.

 

[493 Mike]

The rear servo should be accessed with the pan off. It is what adjusts the rear band. No reason to take tail shaft off.

How will the OP change his servo return spring with the servo apply lever pinned in the case?
Mike

 

[Curiousyellow71]

How will the OP change his servo return spring with the servo apply lever pinned in the case?
Mike

I didn't take the pin out when I just did one, but.. it was gutted...But, I have also dropped the band strut out and put it back in with a screw driver. With it out, their should be room to drop the servo.
Isn't the spring change to help alleve some of the harshness when applying the low band when you first put it in gear from the increased transmision pressure? When you up the pressure more yet for racing such as Cope and A&A w low band apply they recommend a billet servo to help take the abuse, it can crack.

 

[Curiousyellow71]

 

[Dave6T4]

Loosen the 11/16" nut and back the rear servo adjustment screw all the way off. Now, reach down to the rear band anchor where the strut seats with a medium screw driver. Give the band a pop with the screw driver and the strut will fall out on the band. Fish it out with a magnet, and the apply lever can be flipped out of the way to access the servo piston. When you go to reinstall the rectangular apply strut, the long end seats into the band anchor. Then it is a matter of working the other end back into the apply lever with your screwdriver. It is a lot more work to pull the tailshaft housing and the band anchor pin. You almost need a third hand to get the levers in place and put the pin back in place. If you have that pin out, make sure to put a new seal ring on it.
I don't like working on a 904 as much as a 727. I find the oil pump so much harder to remove and reinstall.

 

[Geoff 2]

The Transgo kits are designed to be installed with the trans in the car. The rear servo spring can be replaced after the strut is removed, all in the instructions.

 

[Mario Keller]

The Transgo kits are designed to be installed with the trans in the car. The rear servo spring can be replaced after the strut is removed, all in the instructions.

Removing the band strut is not listet in the description. I'll give it a try.

 

[Mario Keller]

My tyranny is a late 68 A904. There is no band strut on the reverse band/lever.
Any further suggestions?

There are not many Torqueflite experts over here in Germany.

 

[Curiousyellow71]

My tyranny is a late 68 A904. There is no band strut on the reverse band/lever.
Any further suggestions?

There are not many Torqueflite experts over here in Germany.

Post 6 was a great description. If you watch the video in post 5 you will see what it looks like. Probably a better thing to ask is does a 68 need the spring?... I believe it is a year that transgo supplies a spring for in the kit, but I am not entirely sure. The last one I did was a 72 904..and it had the rear servo spring upgrade in the tf2 kit.

 

[493 Mike]

I didn't take the pin out when I just did one, but.. it was gutted...But, I have also dropped the band strut out and put it back in with a screw driver. With it out, their should be room to drop the servo.

I never tried to change the spring out in a assembled trans, so I stand corrected.

Isn't the spring change to help alleve some of the harshness when applying the low band when you first put it in gear from the increased transmision pressure? When you up the pressure more yet for racing such as Cope and A&A w low band apply they recommend a billet servo to help take the abuse, it can crack.

I did install both servo pistons in my 65 build with Copes billet pistons. I wanted all the insurance I could get with over 750 ft lbs of torque running through the trans!
Mike

 

[Dave6T4]

I have never tried to disassemble the rear servo while the transmission is still in the car. I have rebuilt a lot of Torqueflights over the years, but always on my bench. I can imagine getting the servo all back together, with the snap ring in place, would be difficult. Spring pressure and gravity working against you all the time.

 

[Curiousyellow71]

I have never tried to disassemble the rear servo while the transmission is still in the car. I have rebuilt a lot of Torqueflights over the years, but always on my bench. I can imagine getting the servo all back together, with the snap ring in place, would be difficult. Spring pressure and gravity working against you all the time.

Transmission fluid dripping on you doesn't help.
FUN times..

 

[Curiousyellow71]

I never tried to change the spring out in a assembled trans, so I stand corrected.


I did install both servo pistons in my 65 build with Copes billet pistons. I wanted all the insurance I could get with over 750 ft lbs of torque running through the trans!
Mike

I am working on a 65 too..
But the smaller version..65 Dart Gt
440 with every aluminum part you can buy...but street engine around 550-575hp. edy heads and a Trick flow HR cam.
we had a 727 in the car but it didn't fit Worth a darn...so we adapted a 904,with a 5000 ultimate convertor, A&A hd Pump, 5 clutch front drum w reverse wound spring, 4 clutch rear, billet rear servo, hd strut rod, etc.
I had a tranZact of indy brake to use but it sat on the shelf too long and is toast.. So I am going to try a Tf2 and robbing the heavier pressure spring out of the tranzact.
I didn't think we are to the point where we need the expensive billet shafts that the high hp guys run..I guess we are going to find out though.Lol

 

[Mario Keller]

That is how it looks like. It's different from the video above. There is no strut to take out. I contacted Transgo support yesterday. They answered me even on Sunday . Their technician says in my case with the double wrap band, I have to take the tailshaft off.
My question is now, do I really need to change the spring on the rear servo? Its not a race car.
Just a regular 318cui. I just wanted to improve the shifts.
The spring slows down the impact on the rear band, right?

Mario

 

[Curiousyellow71]

When I get a chance today I will take a look for a older 904 with the single wrap band, that I could pull the rear servo and compare for you. I have a new tf2 kit on the shelf so I can try to id a spring.
I do believe a upgraded spring is preventive. I have done several and left the rear servo alone. I would think the lesser pressure settings would be easier as well, vs street/strip. I have ran into a servo once that got messed up and stuck in the bore...which was not good! Although I wouldn't say its common.. It can do damage to the case.

 

[Dave6T4]

Band strut would be at opposite end of band pictured. Adjustment screw has to have something to react against.

 

[Mario Keller]

Band strut would be at opposite end of band pictured. Adjustment screw has to have something to react against.

Please stop with band strut. There is not a band strut on this rear band design.
The adjusting screw is pressing directly on the band. You can see that in the picture.

There is no question, to work on the rear servo the tailshaft has to come off.
That's also what the Transgo tech support told me.

My last question is, can I leave the rear servo alone and go with the original spring?

 

[Dave6T4]

Most of my experience is with 727. Part of the modification to the rear servo is to render the small cushioning piston spring inoperable. This is done by removing it, in early style, or by blocking it with a spacer, in the later style. In my experience with 727, failure to do this when using the TF2 kit, causes a 1 to 2 shift overlap. You can feel the car stall momentarily until the shift is completed.

 

[Curiousyellow71]

Please stop with band strut. There is not a band strut on this rear band design.
The adjusting screw is pressing directly on the band. You can see that in the picture.

There is no question, to work on the rear servo the tailshaft has to come off.
That's also what the Transgo tech support told me.

My last question is, can I leave the rear servo alone and go with the original spring?

I have the same transmission in the shop. You don't need to pull the servo to switch the spring.
Take the snap ring off that holds the spring pushing on the servo.
Slip the stamped steel spring holder over the cast arm so it's out of the way.
Pry the end of the spring up enough to wind it out over the band apply arm.
Install the new one by winding it back in.

The new spring looks similar but is much beafier..I would switch it.
The new spring will certainly take more effort to wind in..but should not be a problem. I posted a picture so you have an idea of what I mean by "winding it out".