All,

Had a friend over last night with what I believe is a late 99 SD 7.3. He has about 215k on it now, and thought he had a rear seal leaking. Looks pretty wet to me on the back/top of the engine, and his intercooler boots are just soaked with oil. I believe he needs a new set of O rings for his turbo, but looking to get some input here first.

Second issue he has, is the speedo quit working and his OD light is flashing. I am pretty sure I read something here about which module causes that, but can't find it nor remember it, any help would be greatly appreciated.

Thanks, Tom

 

The oil could be coming from any number of places... you'll need to clean up the valley of the motor as best you can and try to determine if it's coming from the front or rear of the motor.
The second issue is probably a faulty RABS (VSS) sensor- on top of the rear diff. Pull it out and wipe it off, and make sure there are no large chunks of metal on it (fine gray fuzz is normal). If wiping it off doesn't work, a new one is about $25.

 

I did type a post for this, but it got lost on here some how. Chase said the same thing I said.

 

Yea, rear main leaks are almost non existant on the 7.3l. Clean up the top of the motor, around the turbo especially, and run it and watch for oil. Be sure to have a flashlight handy.