We have always wondered why so much attention has been paid to the warpage of the valve body on the 68RFE and none to the pump! Transmission builders across the country (those that have access to surface plates) have known for years that the 68RFE pump is prone to warpage. Just like the valve body, the pump too doesn’t have a gasket and relies on perfectly flat mating surfaces to seal properly. When the pump is new these surfaces seal pretty good but after hundreds or thousands of heat cycles warpage becomes a huge issue. We have seen used pump bodies with up to .020” warpage and nearly every pump we inspect has a moderate amount.
Warped pump bodies can give a wide range of failures or complaints including:
- Erratic actual line pressure, especially on trucks running additional line pressure.
- Unexplained Overdrive Clutch failure
- Unexplained Underdrive Clutch failure
- Increased transmission operating temperatures
- Gauling of the pump separator plate
- Excessive pump gear wear
- Damaged pump body at the gear face location
- Pump seal failure
- P0868, P0933,P0934 loss of transmission prime, low line pressure or high line pressure
- P0740, Converter dragging or staying engaged when coming to a stop
Some builders have thought they had a solution to this issue. They have attempted to resurface the pump body by flat sanding or stoning it. This absolutely will make it flat again but it causes another bigger issue. By sanding down the pump body you also decrease the clearance from the pump separator plate to the top of the pump gears. A new factory pump has .002-.003” clearance in this area. Considering that most pump bodies have over .005” warpage this means that by the time the resurfacing has taken place the gears are now in constant contact if not binding against the separator plate. This decreases pump life and will contribute to previously undiagnosed transmission failure. The good news is the stator half of the pump can be conventionally resurfaced and be reused so long as the valve train has been inspected to make sure excess wear isn’t observed. Our pump body will work with any new, used or rebuild pump stator assembly. This body can be used on stock 68RFE’s and with any brand aftermarket 68RFE. It is also highly advised to replace your used pump separator plate with our coated version or a new OEM plate.
The RevMax 68RFE ZeroFlex Billet Transmission Oil Pump Body should be deemed an essential minimum part on even a stock 68RFE rebuild. It has many features that the factory part even when new does not.
- Billet 6061 construction
- Revised worm tracks to more efficiently move oil
- 5 Axis CNC milled gear and face profile
- Nearly 3x thicker than an OEM pump
- Will not warp even under the most grueling conditions
- Surface is flat within .0003”
- Fits 2007.5-2018 68RFE transmissions
- No core required