5.7l cobra on a 3.0l cobra

[ieagreg1]

Will a 5.7L cobra bolt up to a 3.0L cobra? I know the gear ratio's are different but I just need something I get get around with. The drive I have chewed up the bearings and shaft in the upper gear case. There's only a few weeks of boating left so I'm running out of time. <br />Thank you

 

[rbezdon]

Re: 5.7l cobra on a 3.0l cobra

I think not. I am pretty sure the upper is different and I even think the number of splines are different but hopefully one of the experts can comment. My concern would be the gear ratio. The 3.0 takes a roughly 2 to one and the 5.7 a 1.5 to one and that would make the 3.0 lug so bad that I would be concerned about engine damage even just running for the few weeks left in the season. In fact. I am not sure you would even get up on plane.

 

[ieagreg1]

Re: 5.7l cobra on a 3.0l cobra

Ron<br />I suspected as much thanks for the insite. I ordered the new bearings, seals and water pump kit before I realized the shaft was damaged. I just ordered the new shaft and it should arrive by this weekend. My main conserns are removing the large bearing and carier as well as shimming it to set the correct preload. Any advise? My next concern is the lower unit (how much of the bearing made it into it) I can turn the lower unit over by the prop and when its in gear it has a notchy feeling in forward and reverse is this normal?

 

[rbezdon]

Re: 5.7l cobra on a 3.0l cobra

greg, I am a shade tree guy and have very limited experience inside of the drive. Most of my experience was under an old Chevy so I am very comfortable with all the stuff inside the boat but cant give too much advice outside except what I ave learned here and on mine. I know you need some "special" tools to do the job your are looking at to get it apart and back together. I sure hope you have an OEM manual in front of you. It will tell you what to do for the most part. With it and a few specific questions here I am sure it is very doable. On the "notchy" I am certain that cant be a good thing. Did you change/remove the oil?? What did it look like, metal flake paint??

 

[ieagreg1]

Re: 5.7l cobra on a 3.0l cobra

I'll give a little history on this drive and engine. I bought them on ebay and the owner said there was a bad prop seal and he would just change the oil every few hours of use. This is where I come in I install the engine and drive in a home built CC barrel back I ran the engine with ear muffs several times and found water in the oil and relized the water pump seal was bad. But figured I could get away with one test run of about five minutes. It did have a bad vibration. The next day there was white oil running out of the water intake and when I checked it the oil level (or should I say the water level) was all the way to the top and was pure white and foamy I drained it but didnt see any metal shavings these seam to be trapped in the upper housing. The water pump bearing was completely destroyed the outer race was cracked thru and the inner race had seized itself to the shaft. I do know one thing this was not done in just that single run. and yes I do have a manual. The notchyness doesnt feel bad it feels more like just the gears meshing but I'm not sure.

 

[4.3sunbird]

Re: 5.7l cobra on a 3.0l cobra

If you need a 3.0 out drive I have one on my boat ..I could use a 5.7 one <br /><br />redsttype@cox.net if any interest

 

[ieagreg1]

Re: 5.7l cobra on a 3.0l cobra

The 5.7 is currently on ebay for 300 bucks the only reason I was considering buying it was price and its with in driving distance.