o2k

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?

mrvedit

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.

o2k

What happens if your servo play is off? And isn't there a downside to adding an extender? Like if the extender broke..

mrvedit

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.

o2k

ok, thanks for the info!

PBA

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.

mrvedit

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.