Alpha Gen 1 Gimbal Transom Plate Swap

[peters715]

I have a 1969 MC-1 120 that I would like/need to replace the gimbal transom plate.

The parts manual for this series lists the part number as 45702A1. Any hints as to where I might find this part and/or are there ways to identify gimbal transom plates that are interchangeable with this?

I've looked on eBay and some sellers will list the cast number. All the units I am seeing have later gimbal rings that have the trim sensors mounted on the ring. I am not sure if this gimbal ring design would require the gimbal transom to be changed.

Anyway, any thoughts or suggestions would be greatly appreciated.

Skål!

 

[matt167]

Do you mean the part that is held in by the pins that the outdrive bolts to? If so I’m pretty sure they are different for the drives with nail type pins vs the screw in pins

 

[peters715]

This is the unit I am looking to replace.
The gimbal pins are held in by nails/stainless steel wire.

 

[dubs283]

Pic post #3 shows the mc-1 gimbal housing. NLA new and no aftermarket products ever made (afaik)

Your only option is to purchase used oem. Any vintage mc-1 will work but you may have limitations regarding the trim system. There were some changes over the years regarding the trim pump and hose routing

You may be able to utilize a newer style r/mr/alpha one transom assembly and trim pump using the existing/old inner transom plate and drive however I personally have no experience putting something like that together

 

[peters715]

Pic post #3 shows the mc-1 gimbal housing. NLA new and no aftermarket products ever made (afaik)

Your only option is to purchase used oem. Any vintage mc-1 will work but you may have limitations regarding the trim system. There were some changes over the years regarding the trim pump and hose routing

You may be able to utilize a newer style r/mr/alpha one transom assembly and trim pump using the existing/old inner transom plate and drive however I personally have no experience putting something like that together

Thank you for the info. I keep looking for an MC-1.

 

[Scott06]

Thank you for the info. I keep looking for an MC-1.

this is listed as pre alpha, there are others listed on ebay as well.

U4 Mercruiser Alpha 1 Pre Alpha transom gimbal ring housing Pre 1982 | eBay

Fresh water, Good condition, Steering Tight.

www.ebay.com

 

[peters715]

this is listed as pre alpha, there are others listed on ebay as well.

U4 Mercruiser Alpha 1 Pre Alpha transom gimbal ring housing Pre 1982 | eBay

Fresh water, Good condition, Steering Tight.

www.ebay.com

Thank for the research on Ebay.

Any thoughts on if this would be compatible with the MC-1 transom plate? I don't really need the gimbal ring or bell housing.

 

[Drivewayboater2]

Here’s one showing the part number. Might be a match if you can see he part number on your existing unit

 

[Scott06]

Thank for the research on Ebay.

Any thoughts on if this would be compatible with the MC-1 transom plate? I don't really need the gimbal ring or bell housing.

That is a Mc1 housing so should fit no issue in one of the pics is the transom housing serial number 5 xxxxx. You can put this in the parts drawings on marine engine.com or similar site and compare the compatible part numbers vs your existing transom serial.

 

[peters715]

That is a Mc1 housing so should fit no issue in one of the pics is the transom housing serial number 5 xxxxx. You can put this in the parts drawings on marine engine.com or similar site and compare the compatible part numbers vs your existing transom serial.

OK, I have ordered the unit. Thank you all so very, very much for the info!

I may yet get this out on the river this summer!