OMC 400 upper gearcase help needed

[BIGTUCK]

got a 1975 omc 400 electric shift that the upper gearcase was trashed in so I bought another gearcase got it all together and there is no steering. From what I can from diagrams this one I just bought is missing the worm gear for the steering. Was there a different gearcase that didn't come with the worm gear for steering. The one that was originally on the boat had the worm gear I suppose because it has a gear that is attached to the exhaust cap.

any help is appreciated thanks, tucker

 

[KaGee]

Re: OMC 400 upper gearcase help needed

I believe you bought a gearcase for a drive older than yours. The older drives were steered by an arm that ran through the transom. Your old gearcase was set up for tru-course steering. I'm not sure what year that was introduced.

 

[BIGTUCK]

Re: OMC 400 upper gearcase help needed

I believe you bought a gearcase for a drive older than yours. The older drives were steered by an arm that ran through the transom. Your old gearcase was set up for tru-course steering. I'm not sure what year that was introduced.

Yeah the gearcase I received is for the tru-course steering, it has the same gear on the front side of the upper gearcase and it turns when you turn the steering wheel just the lower unit doesn't swivel. It appears to me that the worm gear has been removed for some reason. I just want to make sure that there were no other gear cases that had the gear on the front for the trucourse steering but didnt have a worm gear that meshes with the exhaust cap and turns the lower unit.

 

[BIGTUCK]

Re: OMC 400 upper gearcase help needed

So I just pulled the cap off the top of the gearcase and the worm gear is just missing. What bearings,bushings, or shims should also be there?

 

[Lyndy]

Re: OMC 400 upper gearcase help needed

As you continue with your project, you will probably be needing parts. Saying that, Model 400 was not available in 1975. 1978 would be a closer year. Below is a picture of a typical 1975-77 Low Profile Outdrive and then an Upper Section of a Model 400.

 

[Lyndy]

Re: OMC 400 upper gearcase help needed

Yeah the gearcase I received is for the tru-course steering, it has the same gear on the front side of the upper gearcase and it turns when you turn the steering wheel just the lower unit doesn't swivel. It appears to me that the worm gear has been removed for some reason.

Just for S & G, have you contacted the folks you got that upper from and asked them why the gear was missing?