ok, have some issues With my th700r4 (84 Camaro)




When driving in OD everything is Perfect,1,2,D shifting no problems,
but when i manually put the stick in 1or2orD the car moves forward,but when im speeding,the transmission slips and the RPM on the engine raising.
could it be stuck checkvalves or something?
is it hard to take down the Central without ***** and springs jumping
out everywhere?


the car have not be used for many years, but works when parked.


TV cable checked,New filter and oil.


Nils
Norway

 

The main difference between D4 and manual 3rd is that in manual 3rd, 2nd, and 1st, the over-run clutches are engaged. I'd guess that there is a leak in that circuit or a stuck valve that is bleeding off line pressure.

A pressure gauge on the main line test port would confirm this. At a minimum, don't use any of the manual 3, 2, or 1st positions until this is fixed. Otherwise the transmission will be needing a full rebuild.

> is it hard to take down the Central without ***** and springs jumping
> out everywhere?

You can drop the pan, be sure to use a large drain pan under it as a lot of fluid will drain out. If you drop the valve body (big cast iron piece that holds the valves and such), the check ***** will fall out of the case. There are also ones in the valve body that if tipped enough those too will roll out.

No springs will let loose as they and the valves are retained by roll pins.

RBob.

 

Thanks 😀 Ill try check the line pressure.

 

I thought that the overrun clutches are to there only to provide engine braking when coasting (off the throttle) in manual 1st, 2nd and 3rd (D) by preventing the forward clutch from being overrun.

I don't think the overrun clutches has any effect when accelerating (on throttle). The OP seems to be describing an on-throttle issue and not an off-throttle issue.

 

Yes, but if the overrun clutch piston seal is leaking like a sieve the line pressure won't be high enough to clamp the other clutches. This could be the reason the trans is slipping in manual 3, 2 and 1.

A line pressure test will tell the tale.

RBob.

 

If that's case, the OP doesn't have to check line pressure. All he needs to do is check to see if he has or doesn't have engine braking in manual 3rd, 2nd, and 1st.