TH700R4 through 4L70E tips and tricks
From Crankshaft Coalition Wiki
(→Stake the pump bushing) |
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*These transmissions use METRIC fasteners exclusively. | *These transmissions use METRIC fasteners exclusively. | ||
| + | *4L65E/4L70E will have 5 pinion planetary housings and 13 vane oil pump rotor - internal parts will retrofit into the non-electronic 4L60 and early 700R4. | ||
==Rebuild manual== | ==Rebuild manual== | ||
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===External cooler=== | ===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 ATF 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. | + | 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 ATF 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. If you don't use an external cooler, consider using a transmission temp gauge. It's just as important to let the transmission warm up before it takes abuse as it is to keep it from overheating. And, if you don't have an external cooler you'll have a great idea of when to take it easy on the trans. |
===2nd gear Servo=== | ===2nd gear Servo=== | ||
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[[file:700r4_servos.jpg]] | [[file:700r4_servos.jpg]] | ||
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| + | Not pictured is the 4L70E servo - which looks similar to the Corvette servo but with a slightly smaller diameter. | ||
== Pump modifications == | == Pump modifications == | ||
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| − | ===Stake the pump bushing (for pre-1987 model year 700R4)=== | + | ===Stake the pump bushing (for pre-1987 model year 700R4 )=== |
Photo shows drill bit location to stake bushing. Pump bushing is removed for this operation. 1/4 inch drill bit works well here. | Photo shows 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:Stakebush.jpg]] | [[Image:Stakebush.jpg]] | ||
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| + | ;{{Note1}} The #732 pump (manfactured since October 1986 which includes some early 4L60Es without the 2 piece bellhousing) has a cast in step to help retain the bushing. The early pump had an issue with the pump bushing walking out, requiring staking and/or Loctiting it in place. Also, the #732 pump has an additional oil drain hole which is a connection for the oil transfer tube used with the auxillary valve body. The early and late pumps do not interchange (same with the pre- and post-October 1986 transmission cases (the late 1988-1993 cases have a "St. Louis Gateway" arch casting and the absence of 3 oil pressure fittings). Also pump assembly from 4L60E (PWM (pulse with modulator) or non-PWM) does not interchange with nonelectronic 4L60 and early 700R4; oil pump gear (esp. the 13 vane pump from the later 4L65E/4L70E) and later design Teflon bushing will fit 700R4 pump. | ||
===Pump rotor clearance check=== | ===Pump rotor clearance check=== | ||
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[[file:700r4_rotor_clearance01.jpg]] | [[file:700r4_rotor_clearance01.jpg]] | ||
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| + | ==Tailshaft/tailshaft housing== | ||
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| + | ===Speedometer/speed sensor=== | ||
| + | Some GM vehicles (GMT400 trucks, S10s and Astro/Safari vans after 1989, 1990/'91 R/V series trucks (square body SUVs and crew cabs) came with a 40 tooth reluctor wheel (used with a speed sensor and a Digital Ratio Adapter Control (DRAC) module which is matched to the rear differential gear ratio) where the speedometer drive gear is usually located. For older cable driven speedometers, the reluctor wheel can be swapped out. Cable driven speedometers were used to 1990 (B-body) and 1992 (F-bodies) which had a hybrid speedometer gear and VSS housing. This also includes the early 4L60E (1993-97) with the driver side VSS (some 1995 applications with the early design one piece case with the pulse width modulator solenoid (PWM) will have the VSS mounted on the passenger side similar to the 1996+ 2 piece case with bolt on bellhousing). | ||
==Pressures== | ==Pressures== | ||
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*[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] | ||
| + | *[http://www.700r4transmissionhq.com/gm-automatic-transmissions/4l60e-identification/ 4L60E Basic Information] | ||
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