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MG TD TF 1500 - Ring Gear replacement

I know this has come up quite a few times and there is a lot in the Archives about this and that is the worry for me.
I received a new Ring Gear and Starter motor with my TF at the time I thought they were odd spares to have on hand particularly the Ring Gear but when I took the sump off to do the gaskets I could see that the ring gear had some damage in one section over a length of about six inches.
Some the posts in the archives worry me and paint a bleak picture in doing this job, particularly with the engine still in the car.
I am worried that if I remove the flywheel I won't be able to get it back on or it is going to be very difficult and beyond my physical capabilities, so at this point I am wondering if I should just leave it and only replace the starter motor.
Looking for any advice / help on this matter please.

Regards

George
G Mills

George.
It is a simple thing to replace the ring gear.I use a blunt chisel to knock the old one off.
Put the flywheel into your freezer or use dry ice to shrink it a little bit. This will not damage the flywheel in any way. Whyen it is good and cold put the new ring gear into your oven and riun it up to 450 degrees.
Get everything ready with a couple of wood blocks on the floor. Take the flywheel thats good and cold by now and set it on the blocks then put the ring gear on the flywheel and with a brass or copper hammer knock it back in place going all around. Not just in one spot.
Be certain to orient the chamfered teeth on ring gear on the clutch face side as they help the starter to engage.
Sound like a big job but it actually isn't.
Sandy
ss sanders

G/day Sandy, thanks for that, appreciated, but it is the actual removal and replacement of the Flywheel that has me worried seeing the engine is in the car.
G Mills

George - first of all, how does your car start? Is the starter pinion jamming against the teeth with regularity, or does it start fine? There is a lot of slop to this gear interaction, and a lot of wear can take place before you need to do or replace anything. Original starters have a square drive end just for this reason - when it jams, turn the square end with a wrench and the pinion pops out and un-jams.

Second, in order to change the ring gear the flywheel has to come off. But to remove the flywheel, the sump has to come off. I have never removed a flywheel with the engine in place; it has always proven that there are things that can be profitably done to the engine while out. Among these are a thorough cleaning and re-painting, cleaning out the cooling passages, checking the cam and followers for wear, checking the condition of the big- and little-end bearings, replacing the steel core plugs with brass, and removing sludge and small bits from the sump and oil pick-up screen.

IF you are having starting problems, pull the engine and do it right - you will save countless hours of contortion and distortion to your body! If you have no starting problems, wait, is my advice. Changing the starter motor is the matter of an hour, so that can be done any time.

Tom Lange
MGT Repair
t lange

Thanks again Tom for your input, I really have not had an issue with starting, it has not jammed on me yet or spun on the teeth it is just that as I have the sump off I thought I may replace the ring gear seeing I have one, but maybe your right just leave it and if it plays up pull the engine and do everything.
G Mills

George - I think you are being overly cautious. If it ain't broke, don't fix it!

In order to change the ring gear with the engine in place. you will have to remove the transmission, which means you have to remove carpets, seats, trans tunnel, floor boards and then the trans - no small job. IMHO it is better n the long run to remove both engine and trans, and do everything your car needs, all at once.

If you have no problems starting, don't worry. You can now see the condition of the starter pinion teeth, so that will tell you whether you would feel better replacing it now. I don't think I would bother if you are having no problems.

Tom Lange
MGT Repair
t lange

Am I remembering correctly that even if you do have a worn spot on your ring gear that you can extend the life of it by rotating the flywheel by ninety degrees due to the engine always stopping in one of two positions?

Kirk
Kirk Trigg

George,

Since you have your engine out and you are worried about your ring gear, here's a precautionary suggestion.

First before fussing with the ring gear, using a lumber stick or tire marker, mark both the flywheel and the ring gear with segment marks at each 90°interval. We're going to remove and rotate just the existing ring gear.

Each time you operate your engine and stop it, it always completes an engine cycle and stops at the same place. This is a result of residual engine compression and the kinetic energy remaining in the rotating mass.

This means that your starter always engages the same teeth each time you start your engine.

Using the method that Sandy has outlined above (or below, as the case may be), rotate your ring gear only 90°, This will expose a fresh set of teeth to the bendix gear and extend the life of your ring gear. 10 years from now, rotate it another 90°.

The ring gear will probably outlive you!

Gord Clark
Rockburn, Qué.
Gordon A Clark

I have a new ring gear it came with the car, my problem is the thought of removing the flywheel if I do that I am not sure I can get it back on correctly,
my engine is in the car, sump is off (renewing gaskets) seats are out floor boards are out (cleaning up and freeing seized seat runners, so it all boils down to the fact am I capable of doing this job, who's actually done this I ask.


thank you

George
G Mills

Hi George,
Put jack stands to hold up the engine block, disconnect the propshaft, unpin the clutch rod, remove the rear mount nut and rubbers, take off the speedodrive and remove the gearbox.Take note of the position of the mount rubbers as they only fit one way
Unwire and undo the flywheel bolts gently tap off the flywheel while turning the engine.Then follow Sandy's instructions.
The fly wheel will only go back one way as the bolt holes are asymmetric. Tighten to 50 foot/pounds and rewire.
Ray TF 2884
Ray Lee

George, To remove the flywheel the pins must be removed for clearance to drop the flywheel down and out of the block. This can be tricky. I always install the crank with the flywheel attached to avoid this fight. It can be done but lots of work under the car for all you get. Tom
tom scott

The castings may vary engine to engine bur I have never had a problem removing flywheels with just the sump removed.
See a bunch of old fools doing just that at youtube " MG Y Type oil leak".
We were trying to find the source of a rear oil leak that had fooled us a few times. It was the rear oil thrower plate warped.
We had the sump and flywheel off three times that day between test runs.
Ray TF 2884
Ray Lee

So the pins come out with the flywheel? and when reinstalling the flywheel you what? bolt it up loosely then knock the pins in then tighten up, right ?
G Mills

Ray can you send me a Hi email so I can get your address I wish to email you

Regards

george
G Mills

George - exactly right. Screw in the flywheel bolts finger tight, hammer in the pins, then tighten and torque the flywheel.

Tom Lange
MGT Repair
t lange

GREAT I will be into it today

Thanks

George
G Mills

This is also the very best time to check the clutch pieces, especially the throw-out bearing, and the flywheel surface. Have you considered lightening the flywheel at the same time? Plenty in the Archives...

I hope you are doing this because you enjoy the work, because based on what you write - no starting problems at all - I certainly don't see any overwhelming need for it.

Tom Lange
MGT Repair
t lange

Quite the opposite Tom I would rather be doing something else less traumatic but the thing is I have only started the car a few times and had no problems lucky I guess, today I had a good look at the ring gear there is a section of about 18 teeth that look real bad, burred over then another section of about 20 teeth where you can see that the started drive cog has been skimming (for use of a better word) on it.
Anyway all the hanging on stuff is disconnected now to support the engine and remove the gearbox bolts.
Yes will check everything before I put it all back.


Thanks

Regards

George
G Mills

In that case, be sure to check the spring condition and lubricate the starter pinion - if the return is sluggish the starter pinion teeth will drag on the ring gear, wearing out both.

Tom
t lange

Well took gearbox out, no problems with that put a piece of flat board across the chassis rails inside the cab and just heaved it back slid right on, clutch off easy as well, flywheel well the pesky little dowels did not want to clear the crankshaft, lightly tapping back and forth gave them the message I wasn't foolin and within 5 minutes off it came.
Clutch plate looks good, pressure plate bit hard to say with my limited knowledge of them, anyway to be sure to be sure the complete clutch will be off to the Clutch man Monday morning for a going over, will definitely get the flywheel skimmed at the very least as someone in the past 60 years has taken to the face with a hammer and it wasn't me.
Anyway thanks to everyone that gave their two bobs worth to advise and help me, without that I doubt I would have even attempted it and I shudder to think what it would cost in the specialist garage @ $100 min an Hour.
Happy chappie is now about to have a beer.

Cheers to all


George
G Mills

Hi George,
You don't have a listed email so I can't mail you.
just remove the words 'dot' from mine and replace with a typed dot. I believe this keeps automatic readers from spamming me.
Ray TF 2884
Ray Lee

George, you can save yourself a good bit of hassle installing the gearbox by a simple 'trick'. Screw a couple of studs into the top two holes in the bell housing. Use them as guides to slide the gearbox into place. Any of the 8mm x 1mm studs work fine, such as the ones that hold the manifolds on, or the valve cover. There are recent threads showing this. Bud
Bud Krueger

I buy a pair of 8x1.0 bolts, cut off the head and saw a screwdriver groove. Always in my box of special tools, and always used!

Tom lange
t lange

Checked the clutch shaft today even though the bush in the housing was ok there was a lot of movement in the arm that connects to the clutch rod, on close examination I discovered that there was no pin in the arm pinning it to the shaft, inserted a roll pin and all is good again.


Regards


George
G Mills

All done, relatively easy job, clutch checked out ok, pressure plate needed slight adjustment on the finger height and had the flywheel skimmed.


regards

george
G Mills

In regard to pinion lubrication...mechanics school taught me no lubrication..clean and dry as any fluid lubricants will gather dirt and cause the pinion to bind. There have been advances in the past..god has it been 40 years since I entered school..how did THAT happen? But I digress. ...in lubricant so I now use a dry, greaseless, oil less lubricant. Regards, Tom
tm peterson

If your talking about the Bronze spigot bush then I heard that as well.

Thanks


george
G Mills

This thread was discussed between 02/05/2014 and 07/05/2014

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