Perkins 4.236 - Velvet drive (71C 2.11:1) questions

[evm1024]

There is more oil in the bilge that I like and I'm not quite sure from where it is coming. Likely it is coming from both the engine and the transmission.

I've got the velvet drive off and will be getting it rebuilt. It appears to have an oil leak. Or rather is has atf on it and is seriously oily and rusty. Go figure.

Inside the engine's bell housing appears to be mostly oil free. There is a little in the drain hole but it actually looks quite "clean" on the damper plate and inner housing.

I had assumed that I would be taking the ball housing off, replacing the damper plate and replacing the rear main seal. But if the main seal is not leaking I may not mess with it.

I've removed all the bolts that hold the bell housing in place, removed the started but left the studs in and the bell housing does not budge. It looks like that there are 2 locater pins as well.

Before I go all BFI (brute force and ignorance) on it is there a "trick to removing the 4.236 bell housing? I guess this is the question!

With the transmission out I have better access to clean the bilge. After it is clean I'll fab up a drip pan to go under the engine to try to keep any oil out of the bilge.

[evm1024]

So far from some research it appears that there is no hidden bolt and that the dowel pins are what is holding the bell housing on.

I'll be on the boat later today and use a bit more force.

Another question: Does anyone have a recommendation of a shop to rebuild a Velvet Drive between Portland and Bellingham?

At the moment I am thinking about Harbor Marine in Everett. Anyone know them?

Regards!

[meridian28]

Where is the leak on the trans? If is leaking at the splines it just needs some RTV sealant and a new nut

[evm1024]

The whole transmission is filthy - rust, oil and who knows what else. That is part of the reason that I had planned on rebuilding it. Sending it off to a shop is as much my being lazy as wanting the shop to clean it and paint it.

It is hard to tell where the oil is coming from. See the photo below to get an idea of how it looks.

It does shift fine And if I knew that there would be no problems for the next 5 years I would be tempted to let things lie where they are.

I do have a full rebuild gasket/disc kit so now that it is out...

[evm1024]

I did get the ball housing off. The primary cause for it not coming right off was the sealant used on the gasket. That and the single locating dowel was tight. I ended up getting a 2 x 4 and playing Atlas to break the seal.

Wow, that flywheel is massive. Mostly I've built Fiat Spider 124 engines (1.8 l and 2 l) to Guy Croft fast road specs. The flywheel is tiny in comparison.

No rust on the flywheel, almost no oil on the bell housing. I think that we can say that the rear seal if good.

This photo shows the inside of the bell housing. The drain hole is on the right.

[evm1024]

One last photo. This is the flywheel - I got some water on it so I've wipled it down with Boeshield to keep it nice looking. This is more or less how it looked when pulling off the bell housing.

With the transmission off I will have room to move the bilge pumps around, replace their hose and fit a drip pan under the engine.

[Cat36Mahalo]

My recommendation is Harbor Marine. Let us know how it goes. I have a sailing buddy with a Perkins 107 and Velvet V drive that’s weepy

[Cat36Mahalo]

Is this in a Cal also??

[evm1024]

The transmission is up at Harbor Marine. Let you know how it goes after the rebuild and after a few hours running.

It is from a Gulfstar.

[evm1024]

I picked up a set of replacement nuts and bolts for mounting the bell housing and transmission. Most grade 8.

I am having trouble sourcing the transmission mounting studs. There are 6 studs sized 7/16-20 3-5/8" long. They are tap end studs and all mu google searches comes up with nothing. Of course I'll keep looking but If you know of a source please share it with me.

The original studs and nuts are quite rusty and pitted. Worst case I'll reuse them till I find a replacement.

Only about 2 weeks till I get the transmission back.

[evm1024]

Never did find studs of the right length so I used cap screws. A bit overkill I suppose but easy to source. I used 2 of the old studs for alignment then removed them.

Had new hoses built and replaced the oil cooler. The replacement has a zinc and the old one is now a spare.

Had to replace the input shaft. That ugly rust on the transmission has eaten away into the shaft and through the seal. Looks like it was sprayed with hot acid. Wonder what caused it.

I did not do the rear oil seal on the engine. There was no oil in the bell housing and I went back and forth and if it ain't broke don't fix it won.

Here is what it looks like now.

[skwanderer]

Hi, curious to hear, how much did the velvet drive rebuild cost? Last evening as I was docking, my transmission "went out". I have a very tricky approach to my slip, with side winds and strong cross currents, so I have to jockey my boat (Lancer 44 with twin Perkins 4.236 and velvet drives), going forward and reverse somewhat quickly (have feathering props as well), to get in close to the dock (I prefer stern in). Anyways, as I was in reverse, I heard a loud thunk/crank (definitely not a good sound), and as a result I only have now forward, no reverse, not even neutral (ended up re-entering the slip bow end in and pinballing into place) Horrifying, but I feel lucky it happened at home and not out elsewhere.
I am trying to guesstimate just what a rebuild on a velvet drive looks like, cost wise and also any common issues. Thanks for any help you can reply with. Cheers, Lee

[evm1024]

Hi Lee,

I have the bill in hand. The total was $2683 before taxes.

I used Harbor Marine in Everett WA who has a transmission shop and a bunch of BW on the shelf as well as other brands. They do a lot of marine transmission repair.

A year later and the rebuild is still trouble free.

Mine was an AS3-71CR RH

Glad you made it back to the slip with minimum of drama.

Harbor Marine's number is 425-259-3285 but I'm sure you can find a local shop. They were helpful on the phone and via email.

Regards!

[oldcal46skipper]

I am located on the Gulf Coast, Pensacola, FL and have been rebuilding BW Velvet Drives and others for over 40 years. I have several rebuilds that are ready to ship, Redux 1-1, 1.5-1, 1.9-1, 2,5-1 &3-1.
I have a Perkins 4.236, BW 1-1 and a 3-1 V drive in my Cal 46.



Let me know if I can help.