Ive got a worn ring gear on my BMC 1800, which is starting to cause some trouble now with the starter not catching the flywheel, since the engine usually stops at the same point, i have been told in the past that you can just unbolt the flexiplate and turn the engine about 1/2 a turn and bolt it back up, is this the most practical way around it without removing the engine!
falcon15,
Aug 27, 1:22am
you will still need to remove gearbox to do this. If you have the gearbox out you might as well replace the ring gear
purple666,
Aug 27, 1:36am
Are you sure it is the ring gear! Had same problem with my jag, turned out to be a problem with the starter motor (and belive me that is the short version of said saga)
nzoomed,
Aug 27, 1:49am
No you dont have to remove the gearbox, its front wheel drive, and you can get to the 4 bolts that hold the flexi plate in place through the hole where the starter goes.
well, if i stick a screwdriver in there and turn the engine a little, it will turn over, or else the starter motor just spins without turning the engine.
jmma,
Aug 27, 1:52am
In theory, it sounds ok, Give it a go. Have you checked the bendix spring on the starter!
4piggy,
Aug 27, 2:03am
dont change by 1/2 a turn as the 2 main spots it will stop on are 1/2 a turn apart ,change by 1/4 a turn
nzoomed,
Aug 27, 2:20am
last time i had it out it was all good
supernova2,
Aug 27, 3:17am
I struck one of those once where the big spring had vanished.That was back in the 80's and even then it was damn near impossible to find another spring.Next time it dont work pull the starter and have a look at the teeth on the ringgear thru the hole.If they machined off then thats you problem.Turning the flexplate 1/4 turn might help.Those bolts you can see are they the flexplatye to converter or flexplate to crank!If they to converter it wont help.Often a flex plate will only fit in one position - dont know about bmc1800.If the ringgear not all chewed then you have a problem with the starter bendix sticking.Give it a good wash in kero, blow it dryand fit it back with no oil. From memory you can pull those bendix to bits without special tools just a vise and some care.
bigfatmat1,
Aug 27, 3:46am
turn it quarter of a turn. I am pretty sure you could change the drive to 11 tooth to help overcome the problem of your worn ring piece!
NZTools,
Aug 27, 3:48am
The 4 bolts you can access through the starter motor hole hold the flexiplate to the torque converter, not hold the flexiplate to the engine. You need to undo the bolts that hold the flexiplate to the crankshaft, which is not quite that easy.
nzoomed,
Aug 27, 6:15am
Yes, it is the torque converter that needs turning, so if i unbolt it, turn the engine 1 quarter and bolt it back, it should all be good. It bolts on in any position, as all the holes are evenly spaced, but yeah ill check the starter motor first.
motorboy2011,
Aug 27, 6:34am
are you sure! in my head if you turn the torque converter, it wont change the position on the flex plate, and therefore the ring gear in relation to the engine/crankshaft, and with therefore still stop in the same place
nzoomed,
Aug 27, 4:50pm
ive had these apart before, the flexi plate is just a thin steel plate thats bolted onto the crankshaft, the torque converter then bolts onto that with 4 bolts from memory.
Fix it properly. If you turn it a quarter turn, and it stops one day in an unusual point in the rotation, you won't be able to start the car, or turn the ring gear by rocking the motor, so you will be stuck in a carpark somewhere. What you are proposing would be an option(not a very good one) if it were manual.
jmma,
Aug 27, 5:15pm
Ring gear on torque converter, 1/4 turn and it sounds like you're away, goodluck (o:
upnorth,
Aug 28, 3:25am
And what if this trick has already been done!
gammelvind,
Aug 28, 3:43am
Unlikely to have all 4 positions done, so move it again lol
cowlover,
Aug 28, 3:47am
+1 Also from hazey memory the ring gear is part of the converter and not the flex plate so the 1/4 turn trick will work.Can you stil buy an 11 tooth pinion for the s/motor!
nzoomed,
Aug 28, 4:15am
dont know about changing the pinion on the starter motor, and yes the ring gear is on the torque converter. Should work fine.
bigfatmat1,
Aug 28, 4:56am
if its inertia type not pre engaged change to either 10 or 11 tooth cant remember now at least 8 years since i replaced one. this was common practise for meshing problems you can still by the pinnion but neet a spring compressor to take it off. if its a re engaged this will not work
mrfxit,
Aug 28, 3:55pm
At 1 stage, I was doing so many of those bendix starters that I built my own mini spring compressor & still have it somewhere here. In regards to the ring gear, may as well do it right 1st time, it WILL be a pain again even if you fluke it right this time. Ring gear AND beniix needs replacing at the same time. May as well pop in a new set of brush's at the same time. Been there done all this, not worth the constant stress & hassles of doing this particular job halfway
bryshaw,
Aug 28, 7:10pm
Good old BMC.built difficult for garages to fix.
brokebloke1,
Aug 29, 3:08am
ring gears are so easy to replace ive just done mine on my capri took me about 15 mins with a gas torch. Average engineering shop should be able to fit one to a flywheel for about $30-$40 if you supply the new ring gear
doctor_evil99,
Aug 29, 3:12am
Darren Hughes, he got a worn ring as well.
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