TR2/3/3A Ring gear shot?

[Jim_Stevens]

Trying to determine why my TR3 starter won’t engage. Symptoms: previously had a hi-torque starter on it, but after the rebuild, it became unreliable. It would make an awful sound, with the engine turning only a degree or so (as evidenced by the fan slightly turning. If I kept at it, it would eventually turn the engine over. I replaced it with a newly rebuilt bull-nose starter this morning, and now all I get is a grinding noise with no fan/engine movement. It is not a ground issue—I ran a jumper cable from the battery directly to the starter case.
After scouring the forums, I pulled the lower inspection cover and discovered the leading edges of the ring gear teeth bright and shiny. I suspect this is not good. Picture attached. Can I get some advice on what to do next? Jim

 

[Jim_Stevens]

This could be much worse than I thought... I pulled the plugs, took it out of gear and tried to rotate the engine by hand, and I can’t budge it! Normally, it rotates very nicely. I had it running (with the old starter) just the other day... good oil pressure, just started it for a weekly test...

 

[Jim_Stevens]

Update Two: I was able to free it (thank God), and the flywheel is turning, but there it sounds like the teeth from the starter motor are still engaged. I can hear them chattering against the bull gear! I‘m confused because the Bendix mechanism retracts the pinion out of the way. Indeed, right before I installed the new bull nose starter, I checked its motion. I’m gonna sit tight and wait for others to chime in!

 

[TRopic6]

Hi Jim, I'm partial to originality and still use the Lucas 'bomb' starter - complete with brute-force meshing and mechanical sounds. Check for this failure mode by removing the cap on the rear bracket and see if the armature has slipped forward. There should be a balk ring and cup at the front of the armature that keeps it from drifting forward; you can see the ring on the left armature and missing it on the right one. The pinion on the right armature either got stuck forward (return spring failed) or the stop ring failed and the pinion got chewed by the ring gear. This is a starter project and I'll use parts from both to produce a good spare.

Anyway, you'll need to pull the starter to fix. The rebuilders may not have realized what the ring at the front did, and left it off, or maybe the pinion bumped the ring out of the groove when inertia sent it forward. The ring gear gets beat up even when the inertia starter works as intended, so you may be able to clean up the pinion with a file, repair the starter and carry on!

The third picture shows the pinion stopped by the ring. 4th picture is where the armature can end up if the ring is missing. Last picture is with the end cap removed and armature in normal position. If you can't see it its too far forward.

Jeff

 

[Jim_Stevens]

Will do straight away! Had a martini before dinner, so I can’t do it tonight. I got a rebuilt from TRF, but it looked kinda beat up. Albert said it was bench tested before he sent it to me.... will be curious to check it out. It’s a lead, though!

 

[TRopic6]

TRF's pretty good so I doubt if they left it off. I'm sure they'll replace it since it failed do soon. I'm curious to know what happened so I can watch it when I do my rebuild.

 

[Graham H]

I have seen on other forums that there are ring gears and starter pinions with different numbers of teeth, did you check to confirm the new starter has the same number of teeth as the old one? I also had a problem with my hi-torque starter not engaging properly and found some thoughtful person had reversed the ring gear to account for the new starter pinion engaging from the front. what they didn't notice was the chamfered tooth pattern was on the wrong side of the teeth and made the engagement more difficult. I did get it sorted and it's all good now

Graham

 

[auprichard]

Graham is right about the different starters for different ring gears (press-on versus bolt-on), but your first posting said the problem started with the hi-torq starter, so I am thinking it could be the ring gear. It is my understanding that the flywheel tends to come to rest in the same position, so certain teeth take all the force of the starter. I recently put a hi-torq starter in a restoration where I obviously didn't check the condition of the ring gear - it lasted about a week. See pic

 

[sp53]

Yes the pre 60K and the post 60K take different high torque starters. I think it is 10 teeth for one and 11 for the other. Perhaps in your case with original starter the rubber sleeve spun free and broke so the starter just spins free.

 

[sp53]

Part 46 in the drawing is the rubber sleeve. I would say that is the problem and the way to test it is to pull the armature out of the case and twist it with your hands. It should hold at the end of the twist by the rubber sleeve. If it does not then the rubber has sheared, a real pain to install, but doable.

 

[Graham H]

My, that ring gear got really chopped up I wouldn't like to be trying to start a nice shiny car in a public place with all that grinding going on?

Graham

 

[mctriumph]

That my friend is a Tr2 flywheel ,popular for its low weight. You Must replace the ring
as it is beveled for the early starter which faces forward, count the teeth !! get the
modern gear drive starter that fits it.
MD(mad dog)

 

[CJD]

I can't see the picture that well, but what I see of your ring gear looks good to me. It will always have some wear on the leading edges.

I suspect the old bomb nosed starter may be a bit sticky if it sat for several years. I would spray the Bendix assembly with carb cleaner and then re-lube it well with a light oil.

 

[karls59tr]

While we are on the subject of starters ...when I start my 3A there seems to be quite a hesitation and slow cranking before the starter(not bomb type) kicks in and starts. The battery has a full charge and I checked all the ground points. I'm thinking that after 62 years of faithful service that maybe it's time for a rebuild or hi torque starter. Just read where sp53 says there are two types of hi torque starter. I did not know that. Are there different suppliers for the non bomb type hi torque starter?

 

[CJD]

While we are on the subject of starters ...when I start my 3A there seems to be quite a hesitation and slow cranking before the starter(not bomb type) kicks in and starts. The battery has a full charge and I checked all the ground points. I'm thinking that after 62 years of faithful service that maybe it's time for a rebuild or hi torque starter. Just read where sp53 says there are two types of hi torque starter. I did not know that. Are there different suppliers for the non bomb type hi torque starter?

Usually when I encounter a delay in the starter engaging it is caused by the solenoid switch. If it isn't used regularly I think the contacts get a thin layer of tarnish that has to be burned through before it makes a good contact. Regular use keeps the contacts clean. That said...every switch has its limit, so the solenoid could be near worn out too.

 

[poolboy]

If you think it's the teeth on the ring gear you might try a 'different approach'

Inertia starter conversion - 6-Pack Car Club of the Americas

I have been having problems with starting my 74 TR6. About half the time the starter just spins the pinion against the flywheel ring gear. I replaced the Lucas starter because the teeth were showing wear. The new high torque starter does the same thing. So I figure that the problem is worn teeth...

forums.6-pack.org

 

[karls59tr]

Usually when I encounter a delay in the starter engaging it is caused by the solenoid switch. If it isn't used regularly I think the contacts get a thin layer of tarnish that has to be burned through before it makes a good contact. Regular use keeps the contacts clean. That said...every switch has its limit, so the solenoid could be near worn out too.

Just wondering if it's possible to take the solenoid apart and clean the contacts? I'd rather do that if possible than get a repo.

 

[Graham H]

Jim, I would go back and have a look at your Hi-torque starter, a common fault with them is the fittings on the pinion end tend to work loose and need a good thread locker to keep them firmly fixed, and as you said it did work before the rebuild.

Graham

 

[DavidApp]

I seem to recall that when I got my Hi Torque started from Brutish starters they asked about the ring gear type (bolt on or pressed on) and the starter type already on the car so they could get the correct number of teeth on the starter.

David

 

[Jim_Stevens]

Okay boys, here’s the latest.
pulled the TRF rebuild... it’s a Lucas 3M100 dated 10/73! (Maybe the rewind date?). 11 teeth. No wonder it was grinding and locking up the engine on hand-turning.
The hi-torque replacement has a 9 tooth pinion which I believe is correct for a press-on ring gear. Can anyone validate that?
After I’m done stewing over Albert, I’ll reinstall the hi-torque starter. I did find that I had painted the mounting surface of the starter when I resprayed the block, so maybe that was causing the poor ground. Cleaned it up and will give it a try.