How easy to change trans servo's in truck?

[rrmccabe]

During the yank install, I will probably install servos.

I am thinking about trying both the Corvette servo and the Sonnax. This means the tranny shop will do one while the Yank is going in and the other one I will do later.

Obviously, the one when the tranny is out is easy. But how easy is it to do servo's (if even possible) when the tranny is installed?

Not to mention there is the issue of dealing with the pin travel??

Thanks,

Rich

[Lunchbox RR]

Rich,
I just finished installing my fourth gear servo in the transmission, it is much easier with the Y-Pipe out. I removed the exhaust manifold, Y-Pipe and heatshield due to the fact that I am installing the headers tomorrow. Lots of room !! I used a pry bar to push the servo in and at the sametime used a small screw driver to pop out retaining ring, after that is done, pull on O-Ring and pry servo cover off with pliers, working it back and forth. Install supplied washer and lube up new servo with trans fluid before you install. Re install retaining ring and check pin travel movement, should be around 1/8 or .125.

[rrmccabe]

Thanks Lunchbox,

Well the Y-pipe is an issue on this truck.

I tried to remove it last week and never did get it out. I had the Y-Pipe loose, the o2 sensors out, the front driveshaft loose on the front and the transmission crossmember out ! I could not pry that sucker out period ! haha.

I was installing a bung for wideband sensor and was able to get it low enough to weld but never got it out. I think if I was to do it again, I might cut the Y and flange it in the middle or something.

Thanks for the tips on the servos. I was conserned about there being room to slide it out as an assembly.

Not sure I understand the whole pin travel movement thing. I have seen that before but don't understand why. The pin doesn't change right?

[Lunchbox RR]

No, it doesn't change, instructions says to grind pin down, however, when I put it all together, I used the pry bar to push in the servo and the travel was about right.

[TuneTimePerformance]

You can install the servos by removing the shield on the trans . you don't have to drop the Y pipe . BTW unless you guys are hitting 4th wot then I wouldn't waste my money on the outer servo .Also stay with the vette or sonnax servo the billet isn't needed un less you have a built trans .

[westbayou]

As for the 4th gear servo, isn't it more of an issue of punching it in 4th and having it downshift than it is hitting 4th under full throttle?

Also, why not do the 2nd gear billet? The vette servo can't be any cheaper is it?

[TuneTimePerformance]

As for the 4th gear servo, isn't it more of an issue of punching it in 4th and having it downshift than it is hitting 4th under full throttle?

Also, why not do the 2nd gear billet? The vette servo can't be any cheaper is it? It's not a matter of cost it's needs why put more then you have to ? This is not that kind of situation where more is better . The down shift will not be any quicker [ at least that you can tell ] from 4th with the billet OD servo, It will help the trans shift to OD under heavy throttle . I'm only telling you guys because we have tested this and have teamed up with a well known trans builder to offer the best in parts to extend the life of our 4l70e under our abuse.

[westbayou]

Oh, I wasn't doubting you, I just wanted some clarification as to why. Thanks for the good info because obviously you have the experience in this situation. 5K miles on a turbo setup and no tranny issues, you did something right. So do you think a billet 2nd gear servo is just overkill or is the vette servo going to do a better job?

[rrmccabe]

A/T's are all greek to me :) What I know about performance modifications you could put in your eye and it would not hurt.

Here is what I was told by the transmission specialist.

With the mods you have mentioned you could upgrade to the corvette servo which will give you a little more 2nd gear holding power than you have now.. If you want to go more aggressive yet then you can opt for the Sonnax super hold 2nd servo that's on our web page. You can do the same for 4th gear as well with the Sonnax super hold 4th servo

He offered to send me both the Corvette servo and Sonnax servo as a R&D test. Thats the reason I was wondering how hard they are to swap. The first change will be done at the tranny shop when they do the Yank. The second one will be in my garage. And I guess you could say I have to open it up a third time to put the first one back if I prefer that.

I dont think cost is an issue with servo's. I really dont care if its $20 or $80. Its the hassle of changing it out.