Automatic Transmission 2-Speed thru 10-Speed GM Autos | Converters | Shift Kits
Sponsored by:
Sponsored by:

servo pin extender

Thread Tools
 
Search this Thread
 
Old Oct 16, 2014 | 04:10 PM
  #1  
o2k's Avatar
o2k
Thread Starter
Staging Lane
 
Joined: Feb 2014
Posts: 87
Likes: 0
From: Jacksonville, FL
Default servo pin extender

Just purchased a billet servo for my 700r4

http://www.ebay.com/itm/700R-4-4L60E-True-Performance-Billet-2nd-4th-Apply-Servo-Kit-K010-K034-/261608015742?pt=Motors_Car_Truck_Parts_Accessories&hash=item3ce90d877e&vxp=mtr
I noticed that there is a pin extender in there. What exactly is the purpose of a pin extender?
Reply
Old Oct 16, 2014 | 04:47 PM
  #2  
mrvedit's Avatar
Moderator
15 Year Member
Photogenic
Photoriffic
Community Favorite
 
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
Default

I am not familiar with this brand billet servo, but I suspect the directions tell you that the servo end play should be close to .075. If it is much more with your existing pin, you will need to add the extender and then grind down the extender to reach the correct end play.

In contrast the Sonnax billet 2nd gear servo comes with a longer pin and you grind down the pin for the correct end play.
Reply
Old Oct 16, 2014 | 05:30 PM
  #3  
o2k's Avatar
o2k
Thread Starter
Staging Lane
 
Joined: Feb 2014
Posts: 87
Likes: 0
From: Jacksonville, FL
Default

What happens if your servo play is off? And isn't there a downside to adding an extender? Like if the extender broke..
Reply
Old Oct 16, 2014 | 07:13 PM
  #4  
mrvedit's Avatar
Moderator
15 Year Member
Photogenic
Photoriffic
Community Favorite
 
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
Default

Originally Posted by o2k
What happens if your servo play is off? And isn't there a downside to adding an extender? Like if the extender broke..
The servo end play determine the tightness of the band. Too tight and it will drag and wear prematurely. Too loose and you will loose 2nd and 4th gears.
The guideline is about .075 of end play when new.
Yes, there is a downside of an extender - it can break or fall off. A longer servo pin is preferred. Some trans builder just weld a blob at the end and then grind it down to a good shape and proper end play.
Reply
Old Oct 16, 2014 | 08:59 PM
  #5  
o2k's Avatar
o2k
Thread Starter
Staging Lane
 
Joined: Feb 2014
Posts: 87
Likes: 0
From: Jacksonville, FL
Default

ok, thanks for the info!
Reply
Old Oct 26, 2014 | 08:26 PM
  #6  
PBA's Avatar
PBA
TECH Resident
20 Year Member
 
Joined: May 2006
Posts: 969
Likes: 119
Default

I have never seen one so loose that you lose 2nd & 4th gears, but I suppose it could happen. But with too much pin to band clearance you can get a 2-3 shift flare, or you will not have a very good 2-3 shift. That is why you want to keep the pin clearance to a minimum. On the 2-3 shift (with the shift selector in OD) the apply oil is doing "two things", pushing off the 2-4 band, and applying the 3-4 clutches. On the 2-3 shift (with the shift selector in D) the apply oil is doing "three things", pushing off the 2-4 band, applying the 3-4 clutches, and applying the over run clutches. 700R4's do not have this problem. So with a "stock valve body" you will want to use the shift selector in OD to keep the 3-4 clutches living longer in "high throttle conditions". If you want to use the shift selector in (D) when in "high throttle conditions", you will need to add the Sonnax Heavy Duty 2-3 shift valve to keep from robbing 2-3 shift apply oil from bringing on over run clutches on the 2-3 shift. This valve will keep the over run clutches on when the shifter is in 1, 2 or 3 (D). If you grind on the tip of the pin (you will notice that the tip of the pin is somewhat round), make sure you keep the tip just like it was. If you "do not" maintain the round original shape, the band clearance can change drastically in a short period of time, effecting the 2-3 shift negatively. The band clearance has little to do with the 2nd & 4th shifts, but it can have a major effect the 2-3 shift.
Reply
Old Oct 26, 2014 | 08:56 PM
  #7  
mrvedit's Avatar
Moderator
15 Year Member
Photogenic
Photoriffic
Community Favorite
 
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
Default

Originally Posted by PBA
I have never seen one so loose that you lose 2nd & 4th gears, but I suppose it could happen....
We just has another thread where 2nd gear was slipping badly, I suggested a longer servo pin (or lengthening it) and it worked:

https://ls1tech.com/forums/automatic...cond-only.html

Obviously this is a bandaid, but this has helped a few others, and IIRC, one OP reported getting another 10,000 (easy) miles out of the trans.
Reply




All times are GMT -5. The time now is 08:49 AM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE