Thread: Oil Pump problems in a 700 R4 Trans

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Hi folks,
1. Question:
My pump rotor went with a bang a couple of weeks ago (yes it broke just like that, taking the slide with it), so I had to take the trans out and I installed a new 13 vane rotor with new slide, rings and all that's needed (into the old pump housing). But now I'm having pressure problems (pressure far too low) . The pump flanges aren't onehundred percent flat (I guess a breaking rotor could do some damage there) Does any one know firstly what can cause a rotor to crack and break and secondly whether it's advisible to rebuild the pump or is it possible that it's beyond repair?

2. Question:
My converter needs to be pulled about half an inch out of the transmission til it reaches the flexplate (of a normal SBC 350 block). How can I change that condition?
There are marks on my old rotor the indicate that the converter coupling didn't completely cover the depth of the rotor, i.e. those two notches on the converter only gripped the rotor by about 4 mm, and not the whole 7mm.
HELP !!!

Although i'm no expert on Transmision's,,i would guess that your pump failure could have been caused by the main input shaft bearing failing,,causing a great deal of flex and wobble on the shaft,,this can also be amplified by flex plate warpage,,,causing your torque converter to amplify the out of ballance state,,and on through your input shaft.
These condition's are more common than you would think,,

As to your torque converter problem,,are you sure you are running the proper torque converter and flex plate for your vehicle?

If you need to shim inbetween your torque converter and your flex plate to reduce the amount of distance your torque converter must travel to bolt up to the flex plate,,,first make sure that your flex plate is not cracked or warped,,,then get some suitable shim's or washer's to mount between yout torque converter and flex plate,,,Important,,,if you are going to do this,,i would weigh each of my shim's and make sure they are all the same weight,,or you are going to cause things to go out of ballance. Also make sure the shim's are of the same thickness.
A spinning torque converter with all that hydraulic fluid inside can be very unfriendly to your state of mind if it is spinning in an unballanced state.

When i look at your problem through my mind's eye,,,,,i can see your torque converter too far out of the tranny,,and the flex plate not running true,,,causing a great deal of harm to your input shaft seal and bearing.
Anyone want to take over from here?

you are loosing your pump pressure some where, eather in the pump or the gasket under the pump. that dont sound like to much space from the conv. to the flex plate when it is all the way in. i really dont know what your talking about on the pump. if i had a pump problen id put a new pump in. if the pump gears were broke then something broke them, like a loose trans. loose or cracked flex plate or the conv. came apart inside. the pump gears shouldnt brake on their own. didnt you have a viberation in your drive line a while back? if i pulled my trans down and the pump gears was busted id put at least a new pump, conv. and flex plate. if i couldnt see what caused it i think i would go with another trans, conv. and flex plate. ive never had any luck with using shims on a conv.