Starter Ring Gear

[Goswell]

I replaced my starter motor, as the old one was struggling to connect to the flywheel.

Upgraded to a high torque one and everything seemed great.

Used it about 20 times, whilst tuning up the engine, Butterflies, tappets etc over the winter.

Took it for it's first run, 3 miles, only to find that it then wouldn't start, with the bendix seemingly just spinning against the ring gear. Even when turning over the engine manually to find a better less worn area of the ring

Checked the starter motor, out of the car, and everything seems ok.

I've assumed the starter motor has failed so I called Moss and spoke to Geoff who has offered to test the motor but did suggest that maybe the ring has moved away from the flange on the flywheel.

I've measured the gap, and it's at least, 3mm against a spec of less than 1mm.

Measuring the distance the Bendix has to travel, it appears it will only overlap the ring for 5mm, not fully over the ring as I would have thought. With the 3mm gap this overlap is reduced and with the wear in the ring I can only assume this is the cause of the failure.

I'm wondering if the new motor has pushed hard against the worn ring and made it move.

However it worked fine before taking it for a drive, so I'm still in diagnostic mode.

Is it possible the Bendix solendoid has gone soft, despite it being vitually new ?

Is it possible the motor starts spinning before engaging, I've seen some points raised in the Forum before ?

If I'm going to change the ring, then so be it, any advise re doing it. I assume you can a ring hot enough, in an oven, to get it on the flywheel ?

[PILKIE]

Hi Goswell.

 

Having had to do mine due to the almost catastrophic failure of it nearly falling off,

I also thought it was the starter motor,but on checking saw it was about to fall off the

flywheel!!

Has the edge of the ring gear you can easily see got the tapered edge nearest the flywheel

or is it on the rear "clutch" side?

It should be on the front facing the starter so it gathers the starter bendix cog into it,otherwise

it will tend to hammer at it and eventually knock it off like mine had!

The only way is box out,clutch and flywheel off!!

Cut the old one off,heat up the new ring in the oven on hot for 1/2 hr put the flywheel

in the freezer,then make sure you drop the ring gear on the right way round,as you drop it

on the taper edge should be pointing downwards to the flywheel.

Good luck!

 

Dave

[Mike C]

Hi,

I did a ring gear replacement to a Morris Minor about 30 years ago.I heated the ring gear with an oxy and kept checking the inside diameter of the ring gear against the OD of the flywheel with calipers to make absolutely sure the ring gear would fit before I started the process.

I was obsessed with the ring gear shrinking on to the flywheel before it was properly fitted.As I saw it if it shrank on too early there was no way to get them apart as they could not be independently heated again.

Anyway I kept checking and wnen I was sure they would fit I quickly did the assembly with some light tapping.It worked perfectly.

Regards,

[KEL]

hi guys same happened to me with my 6 a few years ago the lead nut came loose and the starter fired up whilst i was driving along knocked the gear off the whole lot had to come out a real pain as i can remember.

 

 

my tr6v8 is now stripped & ready for painting i have cut the surround of the lights off a tr7 the rimm\surround \raised section welded them on filled in the sides with metal the lights look great if i can get a picture to reduce ill post a pic regards kel

[Mike Graham]

"It should be on the front facing the starter so it gathers the starter bendix cog into it,otherwise

it will tend to hammer at it and eventually knock it off like mine had!"

 

I agree that the ring gear should be faced this way, but I think that they were often installed the opposite way (that is how they are done on the TR4 I believe as the starter pulls "in" to engage rather than "out"). When I rebuilt my engine and transmission, I too made sure the ring was reinstalled the "correct" way with bevel facing the starter. Shortly after I got the car back together the ring gear came off. No damage but quite a clatter. Fortunately, it happen in the driveway. Took the transmission back out, removed the flywheel, reinstalled the ring gear, and took it to a local welder who tacked it in place on the flywheel. I've had not problems since. May not be the ideal solution, but it has worked well and I've not had to take the transmission out again ... other than to install a j-type OD :-)

 

Cheers, Mike