Johnrude V4 Lower Unit Repair/Rebuild - 1983 140

[Chinewalker]

I am in the middle of accumulating parts to build up an early 1980s 140 crossflow for a project boat I am redoing (18-foot Starcraft American) and just acquired one of the needed parts - a lower unit! However, the upper splines are shot (spun out of the crankshaft). Now, I have two other gearcases with chewed up gears, but the driveshafts look to be alright. They are the 2-piece style with the pin to hold them together.

Now the question: which is recommended - replacing the entire driveshaft as a single assembly, or swapping out the top section with one of the good ones from the other units? Any other pitfalls I should look out for when putting one of these back together? I already have the OEM service manual and a big, heavy honking pair of snap-ring pliers. I will also be installing a seal kit while I've got it all apart.

Thanks!
- Scott

 

[OBJ]

Re: Johnrude V4 Lower Unit Repair/Rebuild - 1983 140

I really don't know Scott!! Never tried it before. Take an end to end measurement on one that's together and see what the measurement is once you change it around. Can't recall anything that says you can't mix and match.....Got a year? I can check the parts manual and see if it's a matched set or if they have different PN's.

Other than that, nothing I can think of in the way of bugaboos to watch out for. Shoot.....ya' got the snap ring pliers....that's the hard part.

 

[Chinewalker]

Re: Johnrude V4 Lower Unit Repair/Rebuild - 1983 140

Thanks OBJ,
Yeah, my Father-in-Law is a retired tool & die maker. He whipped these pliers up in an evening in his shop out of plate steel. They weigh about 2 lbs., but they work great! Certainly do the job better than the biggest pair I could find at Sears - the L/U snap rings folded the tips over first time I tried to use them... They weren't cheap, either!
All of the critical dimensions are in the lower driveshaft - bearing surfaces, etc., so I think just swapping the upper will do the trick.
- Scott

 

[OBJ]

Re: Johnrude V4 Lower Unit Repair/Rebuild - 1983 140

Let us know how it works out Scott.....be interested to know.

By the by......I tried a couple different types of snap ring pliers way back when......finally broke down and spent the money for the good ones. Was a good investment.

 

[DHPMARINE]

Re: Johnrude V4 Lower Unit Repair/Rebuild - 1983 140

For anyone looking,the OMC/BRP pliers are made by OTC and you can by from your local bearing/seal supplier. Gonna cost around $110.00 ,but NICE.

DHP

but if your father-in law .........

 

[Chinewalker]

Re: Johnrude V4 Lower Unit Repair/Rebuild - 1983 140

I got my gearcase back on Friday with the driveshaft depth set for gear lash. I finished the assembly myself on Saturday morning, installing a seal kit and waterpump kit in the process. I now have a drivetrain! On to the powerhead...

Block I had was determined to be beyond boring - scoring at exhaust ports was too deep to bore out. I bought another complete 140 that was supposed to be running, so hopefully that will yield a rebuildable block....

- Scott