Page 1 of 1

Sudden loss of power on Mark VI

Posted: Thu Jan 20, 2022 7:04 pm
by JGwynne
Has anyone had experience with this? A friend and I were driving my 1950 MVI on a rough brick street near my home when it suddenly shut itself off, as if the battery died abruptly. But the battery was fully charged. We had it towed home and I took a good look under the bonnet for loose wires, blown fuses, anything that might be amiss. All I found that seemed out of place (?) was what looks like a large disconnected grounding wire double wrapped in tape set off to the side, above the inside of the right front (driver’s side) fender. The car starts now, but I’m reluctant to get on the road without knowing that I can prevent the same from happening in the future. Any thoughts?

Thanks all!

Posted: Thu Jan 20, 2022 7:55 pm
by Paul Bennett
This happened to me once.
It transpired that the High Tension Lead had come loose from its connector underneath the coil, (but was still attached therefore not obvious at first sight.)
Good luck with your car.

Posted: Fri Jan 21, 2022 9:35 am
by Christopher Carnley
There are several flat braided wire earthing (grounding) straps between the engine, gearbox, exhaust system and the chassis frame..
The engine/gearbox are supported on insulating (isolating) rubber components, and grease and dirt are dielectric.

Many straps are broken when parts are removed for service, and then there is no electrical circuit.

Check that the one between the lower rear of the gearbox housing and the frame is in good condition.

When the frame was being prepared, the holes for the earth strap attachment bolts were tinned with lead solder, to maintain the circuit.

Posted: Fri Jan 28, 2022 9:33 pm
by JGwynne
Thanks Paul! I’ll try to find it and check that it’s properly attached.

So sorry for the late reply; I failed to get a notification of yours in my inbox!

Posted: Fri Jan 28, 2022 9:42 pm
by JGwynne
Thanks so much Christopher; you have a wealth of knowledge about these vehicles! I’ll do my best to find what you’ve described.

Speaking of gearboxes; mine is *incredibly* sticky; takes all the strength that I have to get it into reverse and third gear. It likely requires servicing; do you think that that’s something that a novice can do after some study on the subject? Competent mechanics are damned hard to find here.

And sorry for the tardy response! For some reason I never received any notifications for these thoughtful replies!

Posted: Sat Jan 29, 2022 8:59 am
by John Robins
Is your car right or left hand drive? If lhd the gear linkage might require lubrication, that column change has lots of joints in it. If rhd, the alignment of the cross shaft can cause problems, especially the side to side movement which selects 1st/3rd/reverse. If the linkage/cross shaft are in good fettle, ask Christopher!

Cheers
John

Posted: Sat Jan 29, 2022 10:23 am
by Christopher Carnley
J.

It sounds like you have an internal breakage.

If you are intending tackling the job yourself with friends, arm yourself with the Workshop Manual, the Service Handbook, the Parts List and certain Service Bulletins.

All these can be downloaded from the "matey" RROCA site, Postwar Technical Library, FOC, no membership required.

A "thankyou" on their forum would be appreciated.
In the WM read Section "F" on how to get the thing out, then Section "G" on the box itself.

The Service Handbook provides a "fitters" precis on the actual process.

The section through the main shaft in the WM is an early and flawed type, so look for the later one in the Parts List.

My belief is that the thrust washer holding the 3rd speed driven gear has broken and fragmented, in your case.

This can cause a lot of damage, and make selection impossible.

You will see in "F" that the best way to get the thing out is to remove the front seats and floor panel. Then remove the prop shaft.

I shall be taking another gearbox and engine in today, for rebuilding, so unusually I shall take a few (!) pictures and if you intend having a GO, then I will post.
If you let me have your email address then I can send them more readily as the facility on the forum is a pain.
C.