TR2/3/3A Starter/ring gear engagement

[Jim_Stevens]

Hi-
Still having problems with starting. All grounds re-checked, solenoid replaced. Starter motor turns but crankshaft only a tad, if at all. I had thought that the starter pinion is normally retracted from ring gear, and that upon current, it flies forward to engage, then retreats when started. (Retired military… hence the terms…!).

However, look at the picture, taken from underneath the bell housing. Looks to me like when the current hits, the pinion flies forward, mostly missing the ring gear. WOSP gear reduction starter, number of teeth correct. I have a buddy coming over in the morning to push the start button while I observe from underneath. (Car on ramps, not jack stands). What am I not getting? Jim

Jim Stevens
TS44067L”O”

 

[charleyf]

Hi-
Still having problems with starting. All grounds re-checked, solenoid replaced. Starter motor turns but crankshaft only a tad, if at all. I had thought that the starter pinion is normally retracted from ring gear, and that upon current, it flies forward to engage, then retreats when started. (Retired military… hence the terms…!).

However, look at the picture, taken from underneath the bell housing. Looks to me like when the current hits, the pinion flies forward, mostly missing the ring gear. WOSP gear reduction starter, number of teeth correct. I have a buddy coming over in the morning to push the start button while I observe from underneath. (Car on ramps, not jack stands). What am I not getting? Jim

View attachment 71420

Jim Stevens
TS44067L”O”

Jim, can you give us a background?
Has this set up run before?
Which starter and which ring gear do you have?
Charley

 

[CJD]

I am still a bit confused...is the pinion hitting and then locking up solid, or does it spin without doing anything?

 

[Gliderman8]

Hi-
Still having problems with starting. All grounds re-checked, solenoid replaced. Starter motor turns but crankshaft only a tad, if at all. I had thought that the starter pinion is normally retracted from ring gear, and that upon current, it flies forward to engage, then retreats when started. (Retired military… hence the terms…!).

However, look at the picture, taken from underneath the bell housing. Looks to me like when the current hits, the pinion flies forward, mostly missing the ring gear. WOSP gear reduction starter, number of teeth correct. I have a buddy coming over in the morning to push the start button while I observe from underneath. (Car on ramps, not jack stands). What am I not getting? Jim


Jim Stevens
TS44067L”O”

If I am understanding your post, the starter is spinning but missing the ring gear.... correct?
If this is what's happening, I had a similar problem on my TR6. A new gear reduction starter would spin but not engage the ring gear. It turned out that the ring gear had moved quite a bit off of the flywheel.
The photo on the left shows how much the ring gear moved off of the shoulder of the flywheel (red arrow).
The photo on the right is after I installed a new ring gear... the gear now sits against the flywheel shoulder.

 

[Jim_Stevens]

Thanks all. I’m waiting for a buddy to come over so I can get under the car while starting.
To recap: Symptoms are the starter motor turns but the crankshaft turns weakly or not at all. Previously, this had been only after a spirited run fully warming up the engine, but now it’s all the time. This started after the body restoration, during which the engine sat. A previous gear-reduction starter worked fine before the restoration.
Because of the fresh paint and hot engine conditions, I thought that it was a grounding issue, but I’m running a strap from the battery to the block (scraped clean). The starter motor flange on the block was also cleaned. Starter motor and exhaust pipe were wrapped. Also just yesterday I tried a very high current battery, thinking I had a weak battery. So I’ve exhausted all the electrical possibilities.

Now the working theory is ring gear engagement, hence the look through the bell housing. As I wrote yesterday, I was surprised to see the pinion already in “meshed“ position. And I noticed a misstatement in my description, since the starter faces aft, the pinion is thrown aft upon current flow.

I’m actually encouraged by Elliott’s photo— maybe we’re homing in on it? More after we crank it with me underneath. Jim

 

[Jim_Stevens]

Studying Elliot‘s photo compared to mine from the inspection port, my ring gear is flush with the after-edge of the flywheel, i.e., if the two flywheels were similar, the little red arrow on mine is even longer than his.

 

[Gliderman8]

Studying Elliot‘s photo compared to mine from the inspection port, my ring gear is flush with the after-edge of the flywheel, i.e., if the two flywheels were similar, the little red arrow on mine is even longer than his.

You may have found the problem.
Rotate the engine so you can see more sections of the ring gear.

 

[Jim_Stevens]

That was it indeed! The ring gear is spinning like mad on the flywheel. That only took six months… oh, well. Experience is the best teacher. Off to buy a ring gear, and maybe a flywheel too. Thanks all

Jim Stevens
TS 44067L”O”

 

[Gliderman8]

That was it indeed! The ring gear is spinning like mad on the flywheel. That only took six months… oh, well. Experience is the best teacher. Off to buy a ring gear, and maybe a flywheel too. Thanks all

Jim Stevens
TS 44067L”O”

It drove me crazy too! I rebuilt my original starter first then bought a new gear reduction starter all with the same results.... starter spun but engine didn’t.
Ring gear was cheap but pulling the transmission was a PITA. Get her done!

 

[sp53]

Yes I was awestruck the first time I installed a ring gear with the shrink to fit on the flywheel. I put the flywheel in the freezer and ring gear in the hot water and the ring gear slid on then shrunk tight. I wonder if those new starters have too much torque at the beginning for the shrink to fit ring gears. I am looking for an older flywheel if you go new.

steve

 

[CJD]

If you have the older bomb nosed starter, is sounds like your rubber isolator has shredded...a common problem with those starters. Since it is a gear drive, there is no other way the starter could turn fast and the flywheel not turn at the same relative speed without a whole lotta grinding. They call the part a "sleeve" in the moss starter breakdown...item 46

 

[Jim_Stevens]

Yes I was awestruck the first time I installed a ring gear with the shrink to fit on the flywheel. I put the flywheel in the freezer and ring gear in the hot water and the ring gear slid on then shrunk tight. I wonder if those new starters have too much torque at the beginning for the shrink to fit ring gears. I am looking for an older flywheel if you go new.

steve

The more I think about it, the more I agree with you.