Re: Transmission: 700R4 lurches into forward gear

Jul 25, 2003 1 Replies

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Whats your idle set at?

1990 Astrovan with 1986 rebuilt 700R4 transmission
>
> When I put the transmission into drive (forward) is lurches into gear. This
> seems to cause a undue amount of stress on the rear since I have to make
> sure that I have the brakes fully applied so not to bolt forward. This
> lurching action does not accurr when ingaging reverse gear.
>
> When the transmissin was rebuilt the value body was not touched. Only the
> clutches, seals and gaskets were replaced. The pump was upgraded from a 7
> vane to a 13 vane assemble. Prior the the rebuild the transmission was
> slipping in the low gears and had trouble shifting.
>
> The rebuild fixed the slipping and shifting problems.
>
> Question:
> Is there a pressure regulator that can be adjusted/replaced to control this
> lurching action?
>
>

You raise a good point. When I first start the engine the idle is a little high. I don't have a tachometer so I don't know the exact value. I idle does reach a low value after about 10 seconds. I will try to set the idle as low as possible. I'll have to do some research on how to do this. Do you know how? It is a 4.3 L engine with fuel injection into a manifold.

One thing that makes me think it something in the transmission if the following: If I drive in reverse for about 200 ft (length of my driveway) and then put it in forward the lurching action is sometime very slight. Even for the about the same RPMs. My thought was it maybe something like a weak spring in the value body area such as the accumulator assembly.

This older transmssion does not have the auxiliary value body. Any idea what this does?

Re: Transmission: 700R4 lurches into forward gear

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