Editing TH700R4 through 4L70E tips and tricks

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==Summary==

This section will contain some rebuild tips and tricks on the 700r4 - 4L70E transmissions.

*These transmissions are all METRIC bolts, nuts and threads.

==Rebuild manual==
There are several manuals, DVD and videos found online to aid the DIY person with the rebuild process for these transmissions.  [http://www.atsgmiami.com/ '''ATSG''' manuals] are suggested as a reference material for a proper rebuild. They contain specs, photos, and a few upgrades for a basic non-high performance rebuild.

==Performance section==

*Kits for performance modifications.

'''TransGo''' seems to lead the market in quality kits.  '''Superior Transmission''' brand products offer quality too.

*3-4 clutch pack.

The 3-4 clutch pack in these transmissions have been a problem area since production release in 1981.

Various 3-4 clutch pack kits are offered.  '''Z-Pak''' from '''Raybestos''' is a high energy material single sided friction plates , '''ALTO''' offers a kit with single sided red friction material friction plates.

Clearance on the 3-4 clutch pack frictions should be in the area of .050 to .070 . This can be adjusted via thin or thicker friction plates or steel plates

*Boost valves;

In a 700r4 - 4L60 non electronic trans, you will want a .470 to .500 main boost valve.  The low-reverse boost valve a .282 or .296 works well. On the low-reverse boost valve measure the long valve land for size.

In a pre-1987 700r4 - 4L60 trans a larger low-reverse boost valve will hold off the auto upshift to 2nd gear while the shifter is in manual 1st gear 

== Pump modifications ==

*Drain back hole behind front seal


Drain back holes from behind the converter hub seal at the bushing  should be enlarged in some pumps. This is year dependent since GM did enlarge this hole in the late 1980's.

[[image:Drillhole2.jpg]]



The matching hole on the pump cover stator support (shown in yellow circle) should be enlarged too.


[[image:Drain_back_hole.jpg]]

===3-4 clutch oil passage===

Early 700r4-4L60 pump covers (stator support) have an extra bleed hole in the 3-4 clutch circuit that can be plugged off. 

Modification for better 3-4 clutch pack apply on early pumps. The circled hole can be tapped and plugged with a 5/16 inch set screw.  GM deleted this hole in later pumps

[[Image:3-4_hole.jpg]]


===Stake the pump bushing in place===

Drill bit location to stake bushing. Pump bushing is removed for this operation. 1/4 inch drill bit works well here

[[Image:Stakebush3.jpg]]

This photo shows the small spot make with drill bit to stake the pump bushing in place.  Does not need to be very deep.

[[Image:Stakebush4.jpg]]

== Reference and reading material ==

A great place to read up on articles that have been written already and multiply this information in your recent re-build.

=== Links ===
*[http://purplesagetradingpost.com/sumner/techinfo/700R4p1.html 700R4 Info]
*[http://www.hotrodders.com/articles/TH-700R4_basics.html TH-700R4 Basic Information]


[[Category:Transmission]]
[[Category:Good articles]]