My 93 E4OD has developed a Whinning sound that directly follows engine RPM (not vehicle speed). It is not very loud, and the transmission is still shifting perfectly. From my research, this is either a convertor (unlikely) or pump issue. As it is a 93, I must have the undesireable "E9" pump casting. If I replace the pump, can I use the later "F5" or "F7" pump castings without having to change anything else? I am also interested in swapping in a later revision VB if it will add any useful updates.

How this might have happened:

Fuel pump went out several weeks ago and a buddy had to tow me home a short distance. He started pulling before I got the transmission in N. When I hurried to get it in N it banged pretty loud. The whinning started about 2 weeks after that. I have no other transmission issues.

No ECU codes, but my ABS light has been on for a while. Is there chance that could cause the whinning?

 

the transfer case needed to be placed in neutral along with the tranny. have you replaced the fluid and filter yet?

 

I've still got the push-button t-case so I couldn't do that. He didn't pull me too hard, but I still wasn't happy. Haven't changed the fluid yet, as its not that old. I'm not expecting to find any parts in the pan if thats why your asking.