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MG TD TF 1500 - Straight teeth on the flywheel ring gear

Hello,

I bought a new flywheel ring gear for my TC
engine at Beaulieu Autojumble a few years ago.
It was packed in (I think) the original cardboard box, so NOS.

I've shrinked it around the flywheel and the engine is completely rebuilt and placed in my MG TA-Qtype project
(See pic)

When I tried to activate the starterengine today, the engine turned around but also a terrible sound was heard.

Thinking about what can be the cause of this, I relised, that the ring gear has straight teeths, so not beveled edges.

Does anyone have a opinion on this?
Do all XPAG ring gears have beveled edges or can also straight ones be used?







Erik vanHardeveld

we cannot see the ring gear from this shot ;)

anyway, does the ring gear have bevels at all? I ask as maybe it is installed front to back? or is it back to front?


super car :)
mog

Its an interesting question. Certainly on a TF they normally have a bevel on one side - the side that faces the driving pinion. If however you replace the std starter motor with a more modern geared type, I think you will find it engages from the reverse side, where there is no bevel. I have done this and wonder if there are problems in store.
Dave H
Dave Hill

The bevel on the ring gear normally is on the side that is toward the clutch and transmission side as the starter drive engages from the rear side. It is possible to mount the ring gear "backwards". If you remove the starter, look in the opening, and if you see bevels on the gear, the ring gear is installed improperly.
... CR
C.R. Tyrell

I've got a hi-torque starter on my XPAG - it engages from the front. There was no need to reverse the flywheel to make it work and I know I've swapped flywheels around without a problem in the past.
I don't believe they were straight cut gears though.

http://www.britishstarters.com/MG.html
Gene Gillam

We commonly reversed the flywheel gear on many engines when the starter pinion had clashed so many time as to wear a significant portion away. Placing the straight side toward the starter pinion didn't seem to cause a problem.

Some International tractor engine ring gears have no tapered side, matbe because in different installations the starter may engage from the from or back.
JE Carroll

Hello,
I typed something wrong in my first thread: "relished" should be "realised", sorry for that.

The teeth on the ring gear are straight cut at both sides; do I understand, that this should not be a problem??
Erik vanHardeveld

I was given a tip to just rotate the ring as it usualy stops on a compression quadrant, at some point in its life you would hope it wears down all the way round, at least its being used and not in a display?


back to the problem, is it only when you start the engine it makes a noise? if you get it running with the starter off does it make a noise?
mog

Erik,

The ring gear should have a bevel on the clutch side, the starter pinon should have a bevel on one side for the correct direction of rotation and it should have the correct number of teeth, you need to check for a TC if 9 or 10 teeth. If any of the above is incorrect you will get erratic operation.

John
J Scragg

Correction

The ring gear should have a bevel on the engine side.
NOT clutch side.


John


J Scragg

Erik, Have you checked the mesh between the starter gear and the ring gear to see if the starter drive gear is bottoming out on the ring gear? Is it possible you have a larger diameter ring gear? Wouldn't have to be much, couple thousands if their normally close running gears. PJ
Paul S Jennings

Eric,
Are you sure that you don't have any bell housing bolts or clutch dowel pins that are too long, and scrapping as the flywheel turns??? You didn't mention if the noise continued after the engine was started, or it just made a noise as the starter was engaging,,
Jack up one rear wheel, pull the plugs, then rotate the engine with the crank to see if any noise is heard,,,


Steve
Steve Wincze

How can you remove the ring gear so you can turn it so a new section of teeth will engage with the starter? I had to fit a new ring gear to my TD a few years ago and the only way I could remove the old one was to drill a hole and then split the ring with a chisel. I tried warming it but the flywheel expanded as well and everything remained solid.

If Erik needs tapered teeth he could simply file the corners off or even use an angle grinder. Would be cheaper than fitting a new ring.

Jan T
J Targosz

tap it and unwrap it. or support the flywheel and heat the ring up all the way round and it will drop off.
mog

https://www.youtube.com/watch?v=ppqQga46LiI
mog

Hello,

Thank you all for your comment.

My initial question was if a ring gear with STRAIGHT edges on BOTH sides could be the cause of the sound that occurs if I try to turn the (unfinished) engine with the starter engine.

As I understand that reversed ring gears are used, this can't be the cause.

I will check if the starter gear is bottoming out allright on the flywheel and if the bolts in the bell house and in the flywheel don't interfere with something.

I cannot start the engine yet, because it is not finished.

I'll keep you all informed

Erik
Erik vanHardeveld

John, I think you had it right the first time. I just checked my original flywheel and the bevel is on the clutch disk, pressure plate side. It's actually an angled bevel.
Rich (TD 3983) Taylor

"How can you remove the ring gear so you can turn it so a new section of teeth will engage with the starter? I had to fit a new ring gear to my TD a few years ago and the only way I could remove the old one was to drill a hole and then split the ring with a chisel. I tried warming it but the flywheel expanded as well and everything remained solid."

Jan,

You heat it with an oxygen acetylene torch and tap it off with a hammer and drift. Installation is the reverse, make sure it bottoms all the way around before it cools and gets trapped.

Jim
JE Carroll

I seem to remember that the TC and TD/TF starters had different drive gears (number of teeth).They certainly have different part numbers. I also note 3 differing ring gears. Maybe a mismatch.
Ray TF 2884
Ray Lee

Hello all,

Problem solved.

I removed the gearbox from the engine today and found, that the two bearing retainers were lying on the bottom of the bellhouse causing the strange noise when activating the starter.

Thank you all for your help.

Erik
Erik vanHardeveld

This thread was discussed between 26/01/2015 and 28/01/2015

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