changing 2-4 servos

is there enough room to change the 2-4 servos without dropping the trans down a bit? Or should I just lower the crossmember and gain some more clearance right off the bat?

Much easier if you drop the crossmember. It's only 4 bolts.

Frank
CPT

is there enough room to change the 2-4 servos without dropping the trans down a bit? Or should I just lower the crossmember and gain some more clearance right off the bat?

If you don't mind me asking, whats the advantage to swapping them out? I take it you mean with something aftermarket, correct?

Replacing corvette style servos with a superior/sonnax combo. Specifically a superior-fairbanks 2nd apply servo and a sonnax overdrive servo. Don't quote me on the numbers but the 4th has 40% more holding power and the second :
SUPER POSITIVE 1-2 SHIFT
IMPROVED 2-3 SHIFT
QUICKER SERVO RELEASE ON 4-3 DOWNSHIFT
POSITIVE 3-2 KICKDOWN
ADJUSTABLE PIN TIP INCLUDED TO SET PERFECT BAND CLEARANCE
35% MORE APPLY SURFACE AREA THAN CORVETTE SERVO.

I am sure one of the experts on here can tell you more about them.

Hmmm...That combination sounds a little familiar...LOL. Just so you know, when we use that combination, we always use a 2-4 band with a reinforced anchor. This combo will rip a stock type anchor off the band.

Just wondering why someone built you a "level 3" transmission without the good stuff. This combo is standard on our "Race" and "Pro Race" transmissions. I think it has a little to do with the fact that some "lesser" shops use the Vette servo over again to save the $150 this combination costs.

Frank
CPT

The **explitive deleted** shop that built my transmission offer up to a "level 25" build. I guess I should have known that before I bought it. They took many cheap shortcuts. I have since educated myself on these transmissions and intend on building one myself soon. They reused the input drum and used a stock width kevlar band. It does have reinforced lugs though so hopefully it won't tear out. Part of me kinda hopes it does because then it will force me to pull this thing out and either build my own or at least patch this one up. They appear to have used all alto red clutchs and a z-pak 3-4 clutch. They just screwed up the pump and the valve body with there own "custom" shift kit. I need to install a sonnax high RPM pump slide spring. I also need to stake the PWM valve and remove the input shaft check ball to make my converter lock up properly. You have any opinions on those last two mods Frank?

Oh and by the way, stay very very far away from Goodfellas transmission in Tarpon springs, FL. If you want one of there level 3 4l60e's I will sell you mine real cheap!

The pump slide spring is really a neccessity at anything above 5000 RPM's.

The input ball is optional. I prefer they be left in, so it doesn't make lock-up too abusive. This is hard on the input drum.

I use the extremely heavy springs that my kits give me for the TCC reg. valve. This is an alternative for blocking the valve, instead of staking it.

Even most "rookies" stopped using Kevlar 2-4 bands a long time ago.

Frank
CPT

Well my parts are finally here and I just thought of this....Do you have to drain the tranny to remove the 2-4 servos or is it above the fluid level? I guess I will find out soon enough.

There may be a small amount of fluid in there but wont be alot. You dont need to drain the trans for that. Be extra carefull that you get the snap ring fully seated it will if not break the case when it comes out.

Good to know, thanks. Haven't been able to break loose here at the shop long enough to do this, maybe tommorrow.

Well, I got em in tonight. I made a few spirited romps on the way home. 1-2 seems better but not as harsh as I expected it to be. Other than that I really didn't notice much. Should I have?

The 1-2 shift should be much more positive with a billet servo. It should've also helped the 2-3.
it could just be that Kevlar band on it's way out. They usually go in a short period of time.

Frank
CPT

Well, I got em in tonight. I made a few spirited romps on the way home. 1-2 seems better but not as harsh as I expected it to be. Other than that I really didn't notice much. Should I have?

Going from the corvette or stock servo to the FAIRBANKS billet servo you should have notice a very subtantial difference in as "Frank" Mentioned in both the 1-2 and 2-3 shift. I have see that servo install in a stock trans with no other mods and go from semi sloppy stock shift to chirping the tires at WOT on the 1-2.
Its possible there are allready band issues or you may have presure issues.
As for the kevlar band the only thing I have ever seen those seem to do ok in is heavy trucks used for towing but have never used them myself. The take very long breakin "wear in times" and the tend to damage the drum itself over time. While they can take alotta heat and even survive slipping the problem is they have poor friction properties and tend to slip alot more to start with.
I like the redline and/or the carbon bands best.

I also need to stake the PWM valve

What does this accomplish? :p

Blocking the PWM control regulator valve will help cut down on the 1870 codes, and esssentially make your lock-up an on/off deal, instead of pulsing the clutch. Pulsing it is hard on small diameter race converters.

Frank
CPT

I like the redline and/or the carbon bands best.

Definitely the 2 best band materials.

Frank
CPT

Blocking the PWM control regulator valve will help cut down on the 1870 codes, and esssentially make your lock-up an on/off deal, instead of pulsing the clutch. Pulsing it is hard on small diameter race converters.

Frank
CPT

Which Position should it be staked in? Do you have a small write up? Whats the best way to stake it?

Which Position should it be staked in? Do you have a small write up? Whats the best way to stake it?

Some stake them. We actually install a heavier spring which essentially blocks it.

Frank
CPT

Some stake them. We actually install a heavier spring which essentially blocks it.

Frank
CPT


I think i found the appropriate tables in tunercat, gonna mess with this when i get home.

How much work am at looking at just to change the band? I eventually want to build a whole new transmission. I just want to try to patch this one up a bit until then so I can take my time building the new one. I don't expect my build to compare to anything you guys put out but I am a professional aircraft mechanic and I have the time and I have a core so I figured I'd give it a try. When I take this one out to do the band I will probably go through the pump as well seeing as it will be laying there anyways. Anybody have a "recommended" build sheet for my first build?