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j3k5d4
10-05-2017, 11:02 PM
My TR6 wasn't turning over, but the new starter was spinning like it should. Had a hunch it might be the flywheel, and pulled the starter to view the ring gears this evening. It turns out the ring gear had slid back a good bit, making sure the starter wouldn't reach. I have never had to deal with a ring gear repair, but my question is whether I should try to slide the old one back forward, or go ahead and replace it. I haven't pulled it off the engine yet, so can't tell the true condition on the ring gear. Just wanted to know if using the old ring gear is wise, or just being cheap. Thanks for the advice.

Gliderman8
10-06-2017, 06:32 AM
I had the same problem with my TR6. As long as you have to pull the flywheel I suggest that you should replace the ring gear. If you move the old one back into position and it moves again then you're going to have to pull the flywheel out again which is a big job. I believe the ring gear is around $30... a small price when compared with doing the job twice.

Rut
10-06-2017, 07:36 AM
I had the same problem with my TR6. As long as you have to pull the flywheel I suggest that you should replace the ring gear. If you move the old one back into position and it moves again then you're going to have to pull the flywheel out again which is a big job. I believe the ring gear is around $30... a small price when compared with doing the job twice.

Replacement is the best way to go and this will give you a good chance to inspect the flywheel and have it resurfaced if needed. Are you going to install the ring gear yourself or have it installed? If so, I’ve had good luck (Bugeye and Mgb) with heating it on the gas grill/in the oven and putting the flywheel in the freezer.
Rut

dklawson
10-06-2017, 08:57 AM
Rut, how quickly do you have to work to seat the replacement ring gear when it is heated and the flywheel is frozen? Do you think it would be any easier if you improvised a freezer compartment with styrofoam and filled it with dry ice?

mgedit
10-06-2017, 09:29 AM
Many years ago I had the same issue after rebuiling my engine and transmission. Took ring gear and flywheel to local welder to have heated and shruck back on. At same time, had him tack weld the ring gear in 4 equadistant place to make sure it did not move again. Maybe not ideal, but no issues over the last 10 years or so. Cheers, Mike

j3k5d4
10-06-2017, 09:36 AM
I will be taking it to shop to get the ring gear slide back on, I just dont have the tools or space currently to get this job done. MGEdit, how did getting it tacked back in place work for you, that sounds like a good idea to save a headache later.

Joe Schlosser
10-06-2017, 10:21 AM
Please correct me if I am wrong here but the stock TR6 starter is the standard Lucas Bendix pull in unit. Did you replace your starter with a gear reduction unit that pushes towards the flywheel??
You said that the pinion would not reach the gear so I am assuming this is the case.
If so then you need something to make sure the gear does not get slowly driven off the flywheel by repeated impact from the starter pinion.
If steel on steel then I agree that a small spot weld would work. For steel on an Al flywheel a lot of people have a machine shop drill and tap both the flywheel and gear ( half and half) and add a small button head screw to hold the gear on.
For me it was embarrassing to be on the false grid and hit the starter and nothing happened due to the same issue

poolboy
10-06-2017, 12:55 PM
There may have been some 69 TR6's that still had the "inertia" starters, but the rest had 'pre-engaged' starters

TOC
10-06-2017, 01:10 PM
On my "other" cars, this is a big problem.
Flathead Fords.
Had a small ridge to hold the gear in place, but, if you just drove the ring gear off to replace, you peeled that ring off.
Then, if you "upgraded" to 12V, of which the battleship grade starters six volt worked just fine, you would walk the ring gear off (forward). I have seen in more modern cars changing from "pull-in" Bendix to "push-out" drives do the same.
My fix, at least on the flatties, was to set the ring gear fully into place, carefully mark off six or even 8 equally spaced points around the ring gear, drill (parallel to the main line bore) between ring gear (1/2 the hole) and flywheel (other half of the hole), tap for 1/4:, and locktite in allen set screws. They never came loose again.

I had the machine shop balance the flywheel and ring gear afterwards.

j3k5d4
10-06-2017, 04:16 PM
The old starter I replaced was a "push-out" drive, but that does mean the PO made the change before me. In looking elsewhere and responses here it seems like most people either tack-weld or screw the ring gear down for extra security, and the only difference between the two methods is preference.

poolboy
10-06-2017, 04:24 PM
"Push out" = pre engaged starter
"Pull in" = inertia starter
https://www.youtube.com/watch?v=ITFW2PkqXWw&index=49&list=PL203268D84EE9ADD8

dklawson
10-06-2017, 05:10 PM
... it seems like most people either tack-weld or screw the ring gear down for extra security, and the only difference between the two methods is preference.

I would say it is a matter of convenience more than preference. Tack welding is quick and easy while the screws or set screws require a bit more time and effort. The screw method is a bit more suitable for future maintenance and repair if required.

mgedit
10-06-2017, 06:28 PM
MGEdit, how did getting it tacked back in place work for you, that sounds like a good idea to save a headache later.

Been at least 10 yrs with no issues. Was concerned about balance. Welder was very good and equally placed 4 identical one inch welds around ring gear. Cheers, Mike

Rut
10-07-2017, 08:55 AM
Rut, how quickly do you have to work to seat the replacement ring gear when it is heated and the flywheel is frozen? Do you think it would be any easier if you improvised a freezer compartment with styrofoam and filled it with dry ice?

Doug,
Our kitchen is adjacent to the grill area and I moved the flywheel to a small outdoor table next to the grill once the ring gear was hot. The grill gets to 600* and once it reached that temp I let it cook for about 10 minutes more. I would guess that it took less than a minute to move the flywheel to the table and drop the ring gear on. My previous attempts were with a room temp flywheel and a mapp torch and that didnít work so good.
Rut