TH700R4 through 4L70E tips and tricks
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==Summary== | ==Summary== | ||
| + | This section will contain some rebuild tips and tricks on the 700R4 through 4L70E transmissions. | ||
| − | + | *These transmissions use METRIC fasteners exclusively. | |
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| − | *These transmissions | + | |
==Rebuild manual== | ==Rebuild manual== | ||
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==Performance section== | ==Performance section== | ||
| − | + | ===Kits for performance modifications=== | |
| − | + | '''TransGo''' seems to lead the market in quality kits. '''Superior Transmission''' brand products offer quality too. | |
| − | '''TransGo''' seems to lead the market in quality kits. | + | |
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| + | ===3-4 clutch pack=== | ||
The 3-4 clutch pack in these transmissions have been a problem area since production release in 1981. | The 3-4 clutch pack in these transmissions have been a problem area since production release in 1981. | ||
| + | Clearance on the 3-4 clutch pack frictions should be in the area of 0.050" to 0.070". This can be adjusted via thin or thicker friction plates or steel plates. | ||
| − | Various 3-4 clutch pack kits are offered | + | Various 3-4 clutch pack kits are offered |
| + | *[http://www.raybestospowertrain.com/raybestos/images/stories/high-performance/broch_zpak.pdf '''Z-Pak'''] from '''Raybestos''' "is the patented, single-sided design clutch system that outperforms OE in torque and heat capacity without coning". | ||
| + | *'''ALTO''' is the original manufacturer of Red Eagle® friction materials and Kolene® steel plates and Red Eagle bands. They offer a kit with single sided red friction material friction plates. Also available are "Commercial Duty" 3-4 clutch packs that allows up to 9 friction clutches and steels for the 3-4 clutch pack. These 3-4 clutch upgrades are considered a heavy duty upgrade and will save the transmission in the event of the governor sticking in 3rd gear. | ||
| − | + | ===Boost valves=== | |
| + | In a 700R4 - 4L60 non electronic trans, you will want a 0.470" to 0.500" main boost valve. For the low-reverse boost valve a 0.282" or 0.296" 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. | |
| − | + | ===External cooler=== | |
| − | + | The key to longevity in any automatic transmission is to keep the fluid cool; therefore installing an external bypass cooler is recommended. The factory transmission coolers are an integral part of the radiator and will only cool the fluid in accordance with the engine temperature. Transmission fluid life decreases as temperatures rise above 160º F. An external transmission cooler will help to prevent trans fluid breakdown and torque converter "ballooning" or expansion which will cause (catastrophic) pump bushing failure. Use the largest external cooler that will fit and not block radiator airflow. | |
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| − | The key to longevity in any automatic transmission is to keep the fluid cool; therefore installing an external bypass cooler is recommended. The | + | |
===2nd gear Servo=== | ===2nd gear Servo=== | ||
| − | + | Photo of typical 700R4 - 4L60 series servos. | |
| − | Photo of typical | + | |
*On left is Corvette size servo. OEM and various aftermarket parts sources for this servo. | *On left is Corvette size servo. OEM and various aftermarket parts sources for this servo. | ||
| − | *In middle is a rare servo size from SSR truck and TrailBlazer SS, not a common size to find. Number on | + | *In middle is a rare servo size from SSR truck and TrailBlazer SS, not a common size to find. Number on inside of the bottom section will end with 159. |
| − | *On the right is common V8 sized servo, also used in 4. | + | *On the right is common V8 sized servo, also used in 4.3L V6 applications. Numbers on inside of the bottom section will end with 553. |
[[file:700r4_servos.jpg]] | [[file:700r4_servos.jpg]] | ||
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== Pump modifications == | == Pump modifications == | ||
===Drain back hole behind front seal=== | ===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. | |
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| − | Drain back holes from behind the converter hub seal at the bushing | + | |
[[image:Drillhole2.jpg]] | [[image:Drillhole2.jpg]] | ||
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The matching hole on the pump cover stator support (shown in yellow circle) should be enlarged too. | The matching hole on the pump cover stator support (shown in yellow circle) should be enlarged too. | ||
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[[image:Drain_back_hole.jpg]] | [[image:Drain_back_hole.jpg]] | ||
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| − | Early | + | ===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 | 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 | ||
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===Stake the pump bushing=== | ===Stake the pump bushing=== | ||
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Drill bit location to stake bushing. Pump bushing is removed for this operation. 1/4 inch drill bit works well here | Drill bit location to stake bushing. Pump bushing is removed for this operation. 1/4 inch drill bit works well here | ||
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[[Image:Stakebush3.jpg]] | [[Image:Stakebush3.jpg]] | ||
| − | This photo shows the small spot make with drill bit to stake the pump bushing in place. | + | This photo shows the small spot make with drill bit to stake the pump bushing in place. Does not need to be very deep. |
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[[Image:Stakebush4.jpg]] | [[Image:Stakebush4.jpg]] | ||
| − | This photo shows the pump bushing edge dimpled into the location created with a drill bit. | + | This photo shows the pump bushing edge dimpled into the location created with a drill bit. Use the side of a screw driver and hit it with a hammer to bend the bushing edge into the recess area |
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[[Image:Stakebush.jpg]] | [[Image:Stakebush.jpg]] | ||
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===Pump rotor clearance check=== | ===Pump rotor clearance check=== | ||
| − | Photo shows the depth micrometer at .0015 showing clearance on the rotor. This is | + | Photo shows the depth micrometer at 0.0015" showing clearance on the rotor. This is an ideal clearance. Set it at 0.001" to 0.002" for good pump performance. |
[[File:700r4_rotor_clearance.jpg]] | [[File:700r4_rotor_clearance.jpg]] | ||
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A wide view photo of the depth micrometer in use. | A wide view photo of the depth micrometer in use. | ||
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[[file:700r4_rotor_clearance01.jpg]] | [[file:700r4_rotor_clearance01.jpg]] | ||
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| − | + | ==Resources== | |
| + | *[http://www.superior-transmission.com/ Superior Transmission] | ||
| + | *[http://www.atsgmiami.com/ ATSG manuals] | ||
| + | *[http://www.transgo.com/ TransGo] | ||
| + | *[http://www.raybestospowertrain.com/ Raybestos] | ||
| + | *[http://www.altousa.com/ Alto] | ||
| − | + | == Links == | |
| + | Articles that have information on transmission modification and/or rebuilding. | ||
*[http://purplesagetradingpost.com/sumner/techinfo/700R4p1.html 700R4 Tech Info] | *[http://purplesagetradingpost.com/sumner/techinfo/700R4p1.html 700R4 Tech Info] | ||
*[http://www.hotrodders.com/articles/TH-700R4_basics.html TH-700R4 Basic Information] | *[http://www.hotrodders.com/articles/TH-700R4_basics.html TH-700R4 Basic Information] | ||
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