89 Cobra, Is there any salvation?

[olbuddyjack]

89 Cobra 5.7, No forward or reverse.

I pulled the lower and found the drive shaft broken right behind the pinion gear.

Now for the big problem, How can I get it apart?

In order to get the pinion gear out I need to turn the driveshaft to remove the pinion nut and theres just nothing to get ahold of. It can't come out with the nut and shaft stub together and the prop shaft and gear won't come past the pinoin.

It looks repairable, I can't see any gear damage or such but I need to get the parts out to make a good inspection.
Plus I want to find out why it broke. No strike or prop damage. The engine just freewheeled pulling to plane.

I have means to weld the case if I need to drill or cut the bullit anywhere to get the parts out.

If anybody has any experience or ideas I'm all ears!

 

[DHPMARINE]

Re: 89 Cobra, Is there any salvation?

Only idea right now ... can you grab the nut,with the unit in gear,probably forward so you can get at the nut .... and unscrew it by turning the propshaft ?

Kinda be easier if it was in front of me so I could look at it.I've done similar jobs by welding a nut to the broken shaft,but I feel in this case the welding is too deep in the housing to be feasable.

DHP

 

[Limited-Time]

Re: 89 Cobra, Is there any salvation?

Maybe drill 2 holes in the broken off shaft, drive a couple of hardened dowel pins and use those to drive off.

 

[lilmandavis]

Re: 89 Cobra, Is there any salvation?

IF your real good with a oxy torch.... cut the nut in 2 spots 180 from each other. it will fall right off. its all got ta come apart anyways. its got ta be re shimmed and pre loaded properly. you could cut a piece of tin to shove down under the gear if your worried about burning it up.

 

[calwldlif]

Re: 89 Cobra, Is there any salvation?

Nut Cracker (sweet)

 

[cobra 3.0]

Re: 89 Cobra, Is there any salvation?

What pinion nut? Take a look at this schematic. Can you be more specific, I'm trying to picture your problem, but am not quite there.

http://www.sterndrive.info/id17.html

 

[lilmandavis]

Re: 89 Cobra, Is there any salvation?

he is talking about the nut that holds the gear on the drive shaft in the upper unit.

 

[seahorse5]

Re: 89 Cobra, Is there any salvation?

A broken lower driveshaft makes removing the pinion nut more difficult, but it can be done.

Shift the unit into forward gear and "lock" the propshaft with a rag cushioning a pair of vice grips with the handle facing down.

Use a long chisel or an air chisel to loosen the pinion nut and remove the pinion nut.

You may have to leave the nut at the end of the threads, wedge a large screwdriver or chisel between the propshaft and the nut, then strike the propshaft upwards with a brass hammer to "pop" the taper loose from the pinion and driveshaft..

I do this several times a year on all types of gearcases.

 

[olbuddyjack]

Re: 89 Cobra, Is there any salvation?

Thanks for everybodys response!

Sorry I didn't get back sooner but I was busy this weekend boating. I figured you guy would understand.8)

T.C.Electronics site has a procedure where you drill the housing and knock the roll pin out of the clutch dog. http://www.sterndrive.info/omc_cobra_repair_techniques.html
That way you can remove the prop shaft and everything else should be accesable.

I'm gonna give that a try first. I'll let you guys know how it goes.

Thanks again for your suggestions!