The real differences in 700r4/4l60/4l60e transmissions by year

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haroldwca

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How do you identify the the 700R4 from the 4L60 E ?
I know this is a two-year-old-question, but the answer may help someone. The 700R4 will have a throttle-valve (TV) cable on the right side going into the top of the valve body area. The other end of the cable connects to the throttle shaft on the carburetor (or throttle body on TBI engines). The position of the cable gives the transmission an indication of how much effort is being required of the engine, and adjusts the shift points in the RPM scale accordingly. The 4L60e will not have this cable. The shift points are controlled electronically, and managed by internal solenoids that the 700R4 does not have.
 

Dirtball

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This thread doesn't mention the TH400 tranny in my 88 C3500, but I still have a question.

My cooler lines are leaking badly, and I need to replace them.

Do they clip onto the radiator, or do they screw on old school style? Also, I've found lines from a company for the 700r4/4L60, but not for the TH400. I've emailed a question, but does anyone have a source for the lines for the 7.4/TH400 combo?
 

WayCar6162

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I know that this is an old post but was there any major differences between a 94 and 97? Output/ Input shafts spline count perhaps?
 

GoToGuy

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Did you read the beginning post? What input?
 

88Coopertruck

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I have been compiling this info for a while, finally got around to posting it. I could not find a thread on here that outlined the actual differences in the automatic transmissions of our trucks. Feel free to comment or ask questions if you need anything. I BELIEVE all this is correct, but feel free to correct me if i have made a mistake or overlooked something. Maybe this will help everyone figure out what will and will not work between years.

1988, 89, and 90- 700r4 trans. Nothing changed

1991, 92- Name changed to 4l60. No changes were made from the 700r4.

1993- first year for the 4l60-E. In its simplest terms, it is an electrically controlled 700r4. No PWM. 11 pin connector

1994- NOTHING changed between 93 and 94. Transmissions are directly interchangeable. No PWM. 11 pin connector

1995- Stand alone year. First year for PWM. Has an extra solinoid to control the PWM. 3-2 shift AND TCC are PWM in this trans. Has a different 3-2 control solonoid, and a extra wire in the harness to facilitate the PWM TCC lockup. Addition of a trans mounted neutral safety switch. If you put a 95 trans in a 94, it will not recognise the PWM circuits and will go in to limp mode. If you put a 94 trans in a 95, the check engine light will stay on, and the TCC and the 3-2 clutch pack will burn up after just a few miles. If you put a 96 trans in a 95, the 3-2 clutch pack will also burn up after a few miles. 95 has a 10-15 ohm TCC solenoid and a 10-15 ohm 3-2 solenoid. 12 pin connector.

1996- 3-2 shift is NON-PWM. It was changed back to a on/off arrangement. The 3-2 solenoid was changed to a 20-31 ohm unit. The 3-2 control valve was changed to "design 2". TCC is still PWM and uses the same 10-15 ohm solenoid as a 95. You can create a 95 trans out of a 96 or vice versa, but you have to change the 3-2 solenoid, the valve body, and the separator plate. If only the 3-2 solenoid is changed (and not the valve body casting), the transmission will 'cut loose' on 3-2 downshifts (shift from 3rd to neutral, then to 2nd as the accelerator is released). 12 pin connector.

1997 (one piece bell housing)- Identical to 1996. Direct swap. 12 pin connector.
1997 (two piece bell housing)- Identical to 1996 EXCEPT the addition of a transmission ground wire in the harness. This was done to address poor transmission grounding issues on the previous models. Can be interchanged with the 1 piece bell housing, but the ground wire should be added to the harness if you are using the 2 piece. 2 piece bell housing models also had hardened sun shells to address the sun shell fracture issue common to the previous model automatic transmissions. Identical in fit, function, and design, the material just changed. 13 pin connector.

1998- Identical to 1997 2 piece bell housing.

1999-up Identical to 1998 and 1997 2 piece bell housing
Is the 700r4 what came in 88 K2500 4.3L V6 w/5 speed Manual?
Someone mentioned an NV3500. Which one would be correct tranny for that year? Thanks
 

Erik the Awful

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The HM290 is the early name for the NV3500, but I don't know if there were any differences. I do know that early HM290s have differences from the NV3500, but I don't know if the name changed with the physical changes.
 

618 Syndicate

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The HM290 is the early name for the NV3500, but I don't know if there were any differences. I do know that early HM290s have differences from the NV3500, but I don't know if the name changed with the physical changes.
Cases are very similar but the guts are different. NV's have one shift rail, HM has 4.
 
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