Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Oil Leak from transmission

3G,

Just so we all keep the same terminology, the part that has the hole in it is referred to by MMC as the Centre Drive Bell (Part #2). See the red arrow below. This Centre Drive Bell bolts directly to the rear of the S&S motor.

The transmission bell housing is behind that and the Flywheel Mounting plate (Part #4). There is no round hole on the bottom of the transmission bell housing.

No need to confuse matters.

Apologies for my misuse of terms.

Dan, can you post a schematic of the new drive shaft that is installed when the Centa upgrade kit is installed? It is this new shaft that seals against the main crank oil seal. This seal part is not specific to Morgan and I do not believe it is the culprit of all of the reported leaks and at least one catastrophic failure chronicled on this forum (saved by the horn). In my opinion it is this Centa specific crank shaft that is not made to the quality demanded of it's task.

I'm now very curious what the "Special Tool" is that Paul's dealer is referencing next. In my opinion it's this dealers communication strategy to put 'special' before other common words to avoid accuracy.

Please correct any terminology I may have misused.

3Gs, no, I think you've nailed it this time...

Here is a detailed Centa conversion from the old HD compensator. JVS did this, but I see that his pictures have been moved or deleted and no longer available. Just in case I copied them for future reference, or something like this...

JVS Centa Upgrade Install

Here are some of the pictures and I'll try to give my best guess as to what they represent. JV or someone else can correct me if necessary.

This is the old seal on the left and the new seal on the right. The new seal is larger on the ID.



This is the crank sleeve that bottoms out on the inner flange of the motor crankshaft and acts as the sealing surface for the crankcase seal.

This is a new larger sleeve for the Centa install to match the larger ID new seal.



This is how it came apart. The rotor is keyed to the crankshaft and you can see "some" centrifugal spun oil/grease on the inside. The stator is inside and bolts into the crankcase and centers around the crankcase flange that the seal is pressed into.

This could be the place for the "SPECIAL" tool, a seal driver. But other than that, I have tools in my home garage that would remove anything that JV has done here. Not all that "special" really.



This shows the wear that was created by the old style Harley compensator. When the inner lip on the drive collar/spline didn't get grease, nearly impossible by the way, the inner shoulder wore out and went up into the base of the compensator about .08". This let the compensator housing rub on the rotor causing all of the wear. NOT GOOD...



This is the new Centa motor side housing. The black part has a splined hub on the end. This is the hub that now goes inside the new seal and bottoms out onto the crankshaft flange. The new Centa kit comes with the new rotor and hub housing assembly.



Here is the assembly ready to be slid onto the crank and tightened down.



This is the old splined shaft that went into the HD compensator housing. It also has the flywheel bolt pattern on the wide flange that the clutch will eventually bolt up to.



Here's the end result with the new shaft that now only has a single key, not a spline like the old shaft. Also shown is the inner rubber rod holder part of the Centa compensator assembly.



Hope helps explain how the motor and Centa all couple up together. The only place for oil to leak out of the motor will be the seal around the Centa black hub that is splined to the crankshaft.

Those are great pics Dan, you can really get an idea of the internals in question here.

In the first pic showing the Centa black hub, you can almost see what looks to be metal lathe jaw marks (4 of them at 5 o'clock); similar marks on the next Centa black hub pic (2 of them at 8'clock).

Obviously any marks or irregularities on this high speed rotating / sealing surface will cause oil leak / seal failure issues.

Any chance there are close up or more detailed pictures of the Centa black hub part?

Paul, maybe you can get a good look (and some up-close pics) at your Centa black hub part when your M3W comes apart. Oh, and maybe a pic to the 'special tool'.

These pics are actually from JV in Florida when he did the Centa conversion. I actually have his old Harley style compensator along with the Mercedes rubber flex coupling and stub shaft with the flywheel bolt pattern. I took it apart and it was clear what goes bad on the early units. I did a picture thing on that some time ago.

So to answer your question about close ups, I've got nut'n...

Maybe Phil has taken some close up pics as he's been working in this area with his prototype urethane inserts.

I would have just linked you back to JV's post, but he's removed or moved his pics and the properties links are no longer valid for his pics. I try to copy everything I can quickly so if they go bye bye I've got them or can share them later.

Car should be ready this weekend hopefully. I want to get a detailed explanation on the work completed. Hope it resolves the issue.

If they did NOT pull the motor and replace the crankcase seal, you might want to print out the above pictures to show them that this IS THE ONLY place for oil to get into the adapter housing.

Hopefully they pulled the motor and replaced the seal. These are not normally a high failure item.

Let us know the details after you pick up your M3W.

Paul, did the dealer fix your leak? I also wanted to mention that I had spilled a lot of oil while changing it and it had dripped into the footwell, all around the transmission, etc. It’s been more than 3 months since the spill and still find occasional drips...

Hello, hopefully final update. Crankcase seal was changed and so far no leaks. M3W been sitting in the garage for about 24 hours now and everything looks dry.

As it should with a new crank seal...

Glad you're drip free.

Now go out there and wear out a set of tires!

Thanks for the update.