MV Tooth Extraction, at Weare Rally - Transmission Problems

[Phil Waterman]

Hi All

Title caught your eye? Well it was not my tooth that needed extraction but BEAUTY my 1942 Pattern 13 C60S that just had a tooth extraction. On the way to our MV Clubs 26th Annual Summer Rally, BEAUTY developed a new load ticking or tapping sound when I down shifted down into 3rd gear. This was a new sound as I had the truck out the previous weekend for an antique car show and had not noticed any noise, could feel a little vibration as well in the gear shift lever. As the truck was all loaded and had the generator in tow with every thing I needed for the week at the Rally I did the brave or stupid thing and kept going and just didn’t use 3rd gear. Having learned to not try and fix things when tired or hot and definitely to not go taking things apart until thinking through the problem, I parked the truck were it would could sit for the week of the Rally next to the registration tent and went home to come back in the morning with my HUP.

In the morning when I got back I had a plan of attack:

• First confirm that the noise/problem was only present 3rd gear. Quick drive around the field confirmed that.
• Drain the transmission through a filter to check for partials. Did this with the improvised funnel with a paint filter and a magnet. Very little in the way of metal or any kind of dirt in the gear oil. Gear oil was last changed 4 years ago when I changed engines. (Plastic liquor bottles make handy disposable funnels)
• Inserted one of those extendable magnet wands through the drain plug hole and Extracted One Gear Tooth. No other debris came out, which was a good thing.
• Removed the PTO side cover plate to look for damage. Up until this point I figured I three options if everything was OK, plan A accept for 3rd gear I’d just clean out the case replace the gasket, PTO cover and refill the transmission and drive home at the end of the Rally not using 3rd gear. Or plan B go home remove the transmission from my other truck and do a field replacement of the transmission. Plan C was go home on a wrecker hook.
• It turned out that the tooth had broken off 3rd gear of the lower cluster and luckily just dropped to the bottom of the transmission with out doing any other damage. So went with Plan A

The trip home was uneventful in fact it turned out that I drove most of the way only using 2nd and 4th gears. What is strange is I think I actually got better gas mileage coming home than driving over.

Returning home I loaded more of the gear for “camping” and the rally in to the HUP than it had coming to the Rally and it actually seamed much happier, smoother riding, and quieter with a full load of gear than running empty.

I’ll be posting more information on the Rally in the near future and will post the link to photos and videos here on MLU.


Cheers Phil

[Bob Carriere]

How much time was needed to empty the vodka bottle to make a funnel ????

Very lucky indeed that the broken piece did not get flung aorund the innard of the tranny...... warm weather.... light oil.... heavy chunk just sank to the bottom.

Is there any way to check for such failure....possible cracks..... when doing a rebuild....... or maybe yours was just one of those bad Friday afternoon assembly.....chance in a million.

Bob

[Lynn Eades]

The failure looks fresh enough. Maybe just bad heat treatment and 70 years of use.
Phill, is the whole cluster junk, or does it press apart?

[Ganmain Tony]

It looks very, very clean inside the gearbox and the everything looks to be in great shape (apart from the broken tooth on third)... a credit to your maintenance Phil.

Noticed from your photo's the front drive shaft is obviously installed. You don't leave it out for driving on sealed roads?

As a general rule we do down under, mainly for less wear and tear. May also help with fuel mileage (but if I worried about that, I wouldn't own a 1941 truck)..

[Bob Carriere]

.....will help you out if you need one or two.......

Bob C.

[lssah2025]

That sucks believe me.... Well I will see you your tooth and raise you multiple teeth.. Pics from the transfer case to the front drive of my HSC.. Looks like the previous squaddie couldn't shift it into AWD...

[Richard Farrant]

Originally Posted by Ganmain Tony

Noticed from your photo's the front drive shaft is obviously installed. You don't leave it out for driving on sealed roads?

As a general rule we do down under, mainly for less wear and tear. May also help with fuel mileage (but if I worried about that, I wouldn't own a 1941 truck)..

Hi Tony,
Removing front propshaft will make little difference to fuel economy as the front wheels are still rotating the drive shafts and diff in the front axle, this is where the drag occurs. Unless someone can produce a free wheeling hub, there is no practical solution unless you are prepared to remove the front drive shafts.

regards, Richard

[lssah2025]

Phil, yes my transmission and transfer case were rebuilt and other gears were sourced. That was last year that they were replaced. But I definitely feel for you. Almost having a complete restoration and then finding out about the darn toofeshhesss royally sucked. Had to take off the floor plates and rebuild everything so I think yours is probably easier to replace then mine was. As for the Humber it is usually in rear wheel drive and then only the front are engaged for off road traction. So someone probably jammed it into awd without knowing what they were doing. Bob, that is what I was worried about having all the little teeth and fragments come into contact with the other gears and viola they all get screwed.