MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Starter Jammed Again

I have a '67 BGT. The engine is from a '73, but the starter is the older style with the big spring end that sticks through the bellhousing. For the second time in four years, the starter jammed in the ring gear this morning. I'm thinking about getting a different kind of starter. Is the later model starter also prone to this problem? How about the modern gear-reduction replacement?

I had never heard of a starter jamming in the ring gear before I got this car. I was very surprised to read instructions in the manual that began with, "If the starter should jam . . . ."

It's not that I mind spending a couple hours removing and replacning the starter. What I mind is the raised eyebrows of wife who has to take me to work and/or boss if I arrive late.
Glenn G

It does happen with the old style to unjam it put the trans in 4th (ign. off) and rock the car backwards handbrake off it should unjam

I have a gear reduction on my V8 and no problems

Bob

Bob Fisher

Glenn,

Some starters, not MG that I'm aware of, had to be adjusted to get the starter gear and ring gear in proper relationship to each other. It may be that your gears are a little too close to each other, and so causing them to jam. You might be able to slightly oval the mounting holes to give a little more gear clearance.

Check with someone who knows for sure, but I don't think you can put the other style starter on unless you also change the flywheel or ring gear. I think they engage from opposite sides.

Charley
C R Huff

Yes the inertia starters do tend to jam as they get older. The "in-gear" rocking usually does the trick but if it persists it'sasign something needs doing. The next time you have the starter out have good look at the pinion gear and the ring gear. Wear on either won't help, but sometimes it's just that the helix gets clogged with clutch dust and oil vapour. A good de-greasing with petrol or similar, drying off and lubricating with a touch of graphite (soft pencil lead will do) should restore things if the gear and pinion are not too worn.
Allan Reeling

I had this same problem with my '67 Tourer. It is a poor design. I converted to a 4 synchro trans from a '72 and used the starter, backing plate and flywheel from the later car. Never had a problem again. However, in your case this is a bit of an extreme remedy for your problem. When the engine is shut off, it stops in one of 2 places on a 4 cylinder engine. Therefore, the chances of wearing out the teeth, in these 2 places, is greatly increased. The easiest, and overall cheapest solution, would be to get a gear reduction starter. This unit engages the flywheel from the front of the car where the teeth have no wear on them. The back of the flywheel is where the original style starter engages and it has probably damaged the ring gear after 40+ years of use. To replace the ring gear itself is inexpensive, if the flywheel is out of the car, but to replace it without anything else needing work would be cost prohibitive and the engine would need to be removed. RAY
rjm RAY

Thanks for the comments, guys. I may investigate the gear reduction starter. I haven't had much luck trying to rock the car by hand, but I was trying to rock it forward. Will have to try rocking it backward next time.

I pulled the starter this evening and was reminded that I cannot remove it from the car because of insufficient clearance. Looks like the easiest improvement to clearance would be to remove the clutch hose. That would add at least an hour to the job, so I lay under the car and cleaned the shaft and pinion with the starter wedged between frame and engine. The shaft and gear were dirty, but the helix looked very clean, so I didn't have much to do there. Two hours later, the car is back in action.
Glenn G

Glenn, many years ago (would you believe about 35!), my '65 MGB would do the same as yours. I also never had any success rocking the car back and forth in gear to release the starter. As I recall, there's a square shaped nut on the front end of the starter motor. I used to carry a large adjustable spanner with me and got very adept at releasing the starter twisting this nut. (I no longer recall which direction I twisted it, but it should become obvious when you try.)
Ultimately I bit the bullet and fitted a new ring gear, which solved the problem. About two years ago, when the engine and gearbox was out anyway I fitted another ring gear again. After 220,000 miles, I'm still using the original (but serviced) starter motor, and ring gear #3 has about 10,000 miles on it, with no issues.
rjm Ray's description of the underlying problem, with the flywheel wearing at two places is correct. Bad design? That's how they did it back then.Sure 40 years later, knowledge and designs have improved. Mine however still works fine with the original arrangement.
Tom Aczel
T Aczel

They *do* jam and always have, which is why the more expensive pre-engaged starter was developed. Conventional wisdom is that the bendix gear should be scrupulously clean and not lubricated. However after three bouts of jamming many years ago an old hand told me to put just a drop of oil on the spiral and after that it was fine. Graphite powder as Allen mentions used for lubricating locks is probably even better, you can buy it, but I have scraped the tip of a pencil onto paper and used that with good results - in locks anyway.
PaulH Solihull

You can rotate the flywheel by 60 deg to get out of the old worn areas where the engine stops.
Art Pearse

Workshop Manuals say the flywheel must be fitted with the 1/4 mark at the top when pistons 1 and 4 are at the top.
PaulH Solihull

This thread was discussed between 16/12/2010 and 18/12/2010

MG MGB Technical index

This thread is from the archives. Join the live MG MGB Technical BBS now