Mercruiser 4.3L Alpha One; lower unit part information

[jasonbrodsky]

I have a 93 4.3LMercruiser stern drive. I have a question about a part that is located attached on the lower unit. It has the gear lever coming through it and what looks like a vent tube.. Can anyone tell me what this part is called? The vent tube broke and I either need to jerry rig it or replace it if it isn't too expensive.

 

[boatguya1]

Re: Mercruiser 4.3L Alpha One; lower unit part information

I have a 93 4.3LMercruiser stern drive. I have a question about a part that is located attached on the lower unit. It has the gear lever coming through it and what looks like a vent tube.. Can anyone tell me what this part is called? The vent tube broke and I either need to jerry rig it or replace it if it isn't too expensive.

View attachment 137129

I'm thinking you are talking about the seal/bshg for the shift shaft and the part you are calling a vent tube is your speedo pickup hose connection. If the speedo hose is the only problem you can run as is, if the bshg is broken near the seal you could lose drive oil.

If I remeber correctly the old white coupler for those could be unscrewed from the bshg. I don't think they are available from merc anymore , but some dealers still have them. Otherwise you have to split the upper and lower and replace the whole bshg with the new style and change couplers on the end of the hose.

James

 

[jasonbrodsky]

Re: Mercruiser 4.3L Alpha One; lower unit part information

I'm thinking you are talking about the seal/bshg for the shift shaft and the part you are calling a vent tube is your speedo pickup hose connection. If the speedo hose is the only problem you can run as is, if the bshg is broken near the seal you could lose drive oil.

If I remeber correctly the old white coupler for those could be unscrewed from the bshg. I don't think they are available from merc anymore , but some dealers still have them. Otherwise you have to split the upper and lower and replace the whole bshg with the new style and change couplers on the end of the hose.

James

OK.. I figured out the name of the part...

Shift rod bushing assembly.. There is a little nipple on it, speedomter pickup fitting. This part is broken.. Is this vaccum feed? If I have to replace the entire assembly.. How hard is it?

 

[cr2k]

Re: Mercruiser 4.3L Alpha One; lower unit part information

Unless you want to hook the speedo back up to it it is fine as is. There is a little hole along the front of the lower drive that feeds this water under pressure from forward movement. That pressure is taken to the speedo by a plastic tube and is converted to MPH by the gauge.
If you have a speedo you can just add a Pitot pickup on the transom and hook to it.