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My son has a 700R4 transmission in his car. It has a shift kit and 2800 stall converter. He has a ZZ383 engine with Accel Super Ram and BK Trottle Body. The distributor was changed to a MSD. The car had been running fine then a shifting problem occurred not allowing a shift from first to second until the engine hit almost 5000rpms. His mechanic is baffled. The mechanic took the transmission apart replacing the bands and went to eight clutches. He may have done more but I don't know. Any suggestions? Thanks for any help.
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Re: 700R4 Problems
Martin, The VERY FIRST THING I would check is the TVS cable adjustment at the throttle body, to confirm it is adjusted correctly, ESPECIALLY with an Accel Super Ram. IF the TVS cable is adjusted correctly, sounds like the 1st gear shift valve is sticking in the valve body. Try starting out in 1st gear and shift it manually to 2nd gear at around 15 MPH. If it shifts manually, the problem is in the valve body. Probably sediment build up on 1st gear shift valve or in valve body shift valve bore. Hope this helps. Dave -
Re: 700R4 Problems
Martin; have a look at the governor. It is on the left side of the transmission under a cover held on with a "bale". If the nylon gear is stripped or the springs have come apart the transmission will act like you have described. JohnComment
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Re: 700R4 Problems
Dave and John, Thank you for the suggestions. I just called and spoke with my son. He tells me the car does not shift manually at 15mph. The mechanic has checked the valve body and the governor and continues to be dumfounded. Any other ideas? MartinComment
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Re: 700R4 Problems
I agree with John, look at the governor.Comment
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Re: 700R4 Problems
Martin, The only other thing's I can think of is the pump pressure is to low or the servo (applies band in 2 and and 4th gear, located on right hand side of case), has a damaged apply piston seal or the servo apply pin is not the correct length. DaveComment
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Re: 700R4 Problems
The TV cable adjustment is critical to the correct operation of a 700R4. Google 700R4 TV cable and you will find a wealth of info on this. If the cable is out of adjustment pump pressure will not be adequate and the trans will soon fail.
http://www.tciauto.com/Products/Inst...ust.htmhttp://Comment
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Re: 700R4 Problems
Dennis, That is why I stated it is the VERY FIRST THING I would check, especially with an Accel Super Ram. I don't remeber, for sure, if it was the positioning of the cable bracket or the bracket itself that cause's a problem getting the correct adjustment. DaveComment
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Re: 700R4 Problems
You are correct on both. As the link states, the distance the cable moves is dependent on the distance from the centerline of the linkage to the attachment of the cable. It has been my experience that everytime I make an assumption that something is adjusted correctly, well you know the rest.Comment
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