Front Servo Question

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mopowers

mopowers

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I just got done reading Carl Munroe's 727TF Transmission Handbook and have a few questions It mentions modifications to the front servo depending on whether you have an early servo or later servo. What year is the cutoff for "early/later"???

Also do you folks recommend plugging the bleed hole in a later model control load servo? When I installed the TF2 kit a year ago, it didn't mention plugging that hole, but the Carl Munroe books recommends it. What do you guys think? I'm far from a transmission guy.

Thanks!
 
.............the new controlled load servo started for the 1971 model year 727s...u could block the hole in it....or use a spacer tube like the MP kit does or take it apart and use a spacer to block it........this servo only users 1 big outer spring.......also the center rod that works the 2nd gear band lever is probably 1/2 inch or bigger around....old style servo rod is probably 1/4 inch in diameter..........kim.....
 
Thanks for the input. That makes sense considering mine is a 72 model, so it has the later front servo with controlled load. I wonder why transgo advises not to modify the front servo for later 727s but the Carl Munroe book recommends plugging the bleed hole.
 
..........I have always had a good supply of the old style servo so I just replaced them , but I have modded the new style..............kim........
 
oldkimmer said:
..........I have always had a good supply of the old style servo so I just replaced them , but I have modded the new style..............kim........
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When you replace it with the earlier one, what spring(s) do you use? I happen to have a 69 727 core laying around. I'm wondering if I should pilfer the front servo from it.
 
bOb shingler said:
pilfer it along with the springs
Click to expand...

I vaguely remember the Munroe book or maybe it was the TF2 instructions saying to keep the soft inner spring and toss the stiff one. I'll have to look them up.

What does not having that bleed hole do anyway? I'm assuming it makes it act more 'solid'? But how does that make the transmission act in the real world?

Edit- I should add that I've only got the 2.9 band lever. I'd change it, but I really don't want to drop the transmission. I need to get this thing back on the road.
 
A little softer 2nd apply. Hardly noticeable though. If running old style servo & higher line psi use both small & large dia. return springs. With just inner small spring it will cause 2-3 slight bind up because the 2nd band cannot release fast enough before front clutch applys. Even the later load control servos ive used a 904 low reverse spring along with stock one. Works great with higher line psi! No more 2-3 over lap nice quick 2-3 upshifts! I use the sonnax super servo with stock outter return spring & a 904 lower reverse return spring inside it my 47rh has crisp 1-2 & quick no overlap 2-3.
 
mopowers said:
I should add that I've only got the 2.9 band lever. I'd change it, but I really don't want to drop the transmission. I need to get this thing back on the road.
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You don't need to drop the trans to change the lever. Take the converter access cover off and use a 1/4" long wobble extension and you can get the pipe plug out that holds the lever retainer pin. After you remove the plug slide the pin back till the lever drops out then assemble in reverse order using pipe dope on the pipe plug that holds it all in

BTW: don't use a 5.0 lever. Every one I used a 5.0 on overlapped going into 3rd. I find that a 3.8 or 4.2 does a fine job
 
fishy68 said:
You don't need to drop the trans to change the lever. Take the converter access cover off and use a 1/4" long wobble extension and you can get the pipe plug out that holds the lever retainer pin. After you remove the plug slide the pin back till the lever drops out then assemble in reverse order using pipe dope on the pipe plug that holds it all in

BTW: don't use a 5.0 lever. Every one I used a 5.0 on overlapped going into 3rd. I find that a 3.8 or 4.2 does a fine job
Click to expand...

Is it hard to guide the pipe plug back in once it's out without cross-threading it. I'd think the converter would get in the way. Every time I look at it, it seems like quite the impossible task.
 
..............Absolutely use both front servo springs from the 69 tranny..........the TF-2 will most certainly have bind up/overlap if u don't......I mostly use a 3.8 lever.......kim.........
 
Thanks guys! Well, I opened up the bigblock 727 core I have and low and behold, it had a 3.8 kickdown lever. I pilfered it and will attempt to replace the 2.9 lever in the 68 that I'm working on with it. Hopefully I can get it in without dropping the trans. Wish me luck... Has anyone else been able to replace the front band lever in the car with converter in place??? Any tips??
 
oldkimmer said:
..............Absolutely use both front servo springs from the 69 tranny..........the TF-2 will most certainly have bind up/overlap if u don't......I mostly use a 3.8 lever.......kim.........
Click to expand...

Whats the difference in the way the trans "acts" between the early and late front servos? Thanks!

Also, should I go ahead and replace the sealing rings while I'm at it? Where would I even get those?
 
mopowers said:
Whats the difference in the way the trans "acts" between the early and late front servos? Thanks!

Also, should I go ahead and replace the sealing rings while I'm at it? Where would I even get those?
Click to expand...

I would replace them. Check with NAPA. I haven't tried to buy them individually for several yrs. but they used to sell individual parts.
 
Honestly, as long as it's not the 5.0, I'd leave it alone. 2.9 to 3.8 isn't much of a change given the work to change it.
 
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