V4 omc gearcase hop ups

**76horizon** · 01-16-2017, 05:35 PM

I'm building a 14" cross flow for my mirage cheetah .pictures are on hpbcanada if you want to see it. I'm looking for gearcase help for this project. Does anyone make a billet bearing carrier for this motor or a way to convert it to 15 spline. Does anyone have any other suggestions for some gearcase mods . Monty will be cutting Drive shaft and I am am installing a modified bobs cone.

**ultrafast** · 01-16-2017, 05:51 PM

The early V6 prop shaft fits in the gear case giving you a 15 spline shaft really opens up the possibilities as long as you use a 14 inch diameter or smaller prop

**ultrafast** · 01-16-2017, 05:52 PM

Pretty sure a 14 & A Quarter inch prop will fit but it's tight

**ultrafast** · 01-16-2017, 05:54 PM

The nose cone to use on Netgear case is a bombs made for an inline 6

**76horizon** · 01-16-2017, 06:01 PM

Do you know part number of prop shaft or what years of v6?

**oldschoolltv** · 01-16-2017, 06:54 PM

On my old 140 looper I went with a v-6 gear case so I had the 1:86 gearing.

**Umassot50** · 01-18-2017, 02:01 AM

Find a 1973 135hp gear set. Its 1.86:1. Not 2:1. Lets you spin lower pitch props faster. Where the 13 spline usually runs out of high pitch props. If you go 15 spline. The prop bodies are larger than the case unless you run a small hub prop.

**76horizon** · 01-20-2017, 08:56 PM

I would love to switch it to 1.86 . I will keep my eye out for a donor case. Still would like to do a 15 spline conversion . Trying to source a early 80s v6 shaft this weekend for fitting. Does anyone make a billet carrier possibly double bearing for a 4" case?

**BarryStrawn** · 01-20-2017, 11:54 PM

The 73-76 135 and 77 140 gearset is 13:25 or 1.92:1, not 1.86:1. To use in a mechanical shift case you have to machine/remove the drive for the hydraulic shift assist from the front of the forward gear.

I believe any V6 propshaft requires machining to fit the V4 carrier bearings and gears. Diameter is larger. None are just bolt in.

**olboatman** · 01-21-2017, 07:46 AM

Originally Posted by BarryStrawn

The 73-76 135 and 77 140 gearset is 13:25 or 1.92:1, not 1.86:1. To use in a mechanical shift case you have to machine/remove the drive for the hydraulic shift assist from the front of the forward gear.

I believe any V6 propshaft requires machining to fit the V4 carrier bearings and gears. Diameter is larger. None are just bolt in.

These are the facts that make a BIG difference deciding whether or not the conversion is a worth while project. IMO Thanks Gary

**brussrude** · 01-22-2017, 04:43 PM

Originally Posted by BarryStrawn

The 73-76 135 and 77 140 gearset is 13:25 or 1.92:1, not 1.86:1. To use in a mechanical shift case you have to machine/remove the drive for the hydraulic shift assist from the front of the forward gear.

I believe any V6 propshaft requires machining to fit the V4 carrier bearings and gears. Diameter is larger. None are just bolt in.

I think there are more mods needed before the gears will fit into the case, its not only the drive

bruss

**BarryStrawn** · 01-22-2017, 05:04 PM

Originally Posted by brussrude

I think there are more mods needed before the gears will fit into the case, its not only the drive

bruss

I assumed this was about using the V4 gears inside the V4 case but with 15 spline V6 propshaft. I have two of those from the early '80s and both use propshafts made or modified by Land and Sea and 13:26 gears.

A few folks have posted over the years about using an early V6 shaft but I've never seen how that could work without significant machine work.

Don't recall hearing of anyone modifying V6 gears to fit inside the V4 case.

**brussrude** · 01-22-2017, 05:33 PM

Originally Posted by BarryStrawn

I assumed this was about using the V4 gears inside the V4 case but with 15 spline V6 propshaft. I have two of those from the early '80s and both use propshafts made or modified by Land and Sea and 13:26 gears.

A few folks have posted over the years about using an early V6 shaft but I've never seen how that could work without significant machine work.

Don't recall hearing of anyone modifying V6 gears to fit inside the V4 case.

you're right on the V6 gears in V4 case.
I was referring to the early V4 gears 13:25 with pump drive on fwd gear. To get these gears in the newer style case without oil pump( I think '77 & up) there are more modifications needed . Removing the pump drive on the gears is one of them.

Bruss

**BarryStrawn** · 01-22-2017, 06:30 PM

OK and agreed, I see that was what you meant after reading more carefully.

Although V6 gears in the little V4 case would be pretty cool.

**upyours** · 01-23-2017, 11:01 PM

I am running two of them now only 1 year shaft that works 77 175-200 only other mods required is bore reverse gear and install v6 same yr Berrings in rear of carrier