Flywheel Issue?4d55

[Jmuirhead9]

Heyo,

In the last month or so when starting, sometimes I'll get a GRIND and no start.(maybe 1 in 20) Usually will fire up next try with a little nudge to the truck. Pulled the starter, teeth look fine to me and should be getting full power.

Trying to look at the flywheel but it's a little hard to see...But also doesn't look significantly worn down or messed up. The inner wheel does show some sign of wear, and there was some buildup of metal shards in the housing.

Thoughts?

[geezer101]

Check your starter motor. Yes it sounds like an obvious one but if the throw solenoid is getting tired or is fouled up it will cause gear engagement issues. The starter motor does a hefty job but it can't do it forever. Also check your grounds and main positive lead to the starter motor - anything that can cause a drop in current. Your flywheel teeth look o.k. to me. I've seen worse ones that have still engaged.

[Uncle Spence]

I've had similar issues with semi's and pick-up's alike over the years. It's weird how just rocking it in gear will usually resolve the issue. One diesel mechanic once told me that it is usually one of two things... The starter is just getting tired and goopy (like what geezer said), and second that the starter is most likely after market and that the spacing can be a bit off and it can get bound up. That's why rocking it in gear or hitting it with a hammer seems to loosing things up again and it can spin freely. The same guy suggested using shims if it is sitting in too far. I once killed a big rig in the middle of an intersection and it did this to me. It took a loader to come nudge me so that the dumb thing would turn over again.

[skullzaflare]

My 2.6 did the exact same thing, on it it was the bearings in the snout of the starter wore out. disengaged you could move the gear side to side 1/4", engaged you could move side to side 1/2"

[geezer101]

My 2.6 did the exact same thing, on it it was the bearings in the snout of the starter wore out. disengaged you could move the gear side to side 1/4", engaged you could move side to side 1/2"

:shock:that is a lot of play. The end of the armature shaft must've been badly beat on too.

[skullzaflare]

:shock:that is a lot of play. The end of the armature shaft must've been badly beat on too.
Yea it was a ton of play lol. No there was no damage to the teeth at all surprisingly lol

[claych]

...oops latency... see post #8

[claych]

Jmuirhead9
Have You examined the complete Flywheel Ring Gear ???
Not saying the starter (or starter sub parts) are not the issue,
Looks to Me, from the second pic as there is significant wear
on the ring gear & a broken tooth !!!
I (mho) would use whatever method works for You & examine the complete
ring gear.

Edit,
Yep blew the pic up to the max, & most certainly a broken tooth !
Hopefully the ring gear can be replaced ---

[Jmuirhead9]

Took starter down to local shop and tested it there. The gear flew out and spun like it should...and teeth were fine.

Yeah claych, I think you're right about the gear wear and broken tooth.(By ring gear do you mean the inner ring?) Figure that must be the problem. According to some, the flywheel stops in 4 different spots, so there must be a bad spot that it sometimes lands on.

Hopefully it doesn't get too much worse cause I can't really afford to drop my tranny just to replace it.

Cheers, and thanks for the feedback!

[claych]

No prob, happy to help !!

This failure is one I am VERY familiar with,
The Fleet I work on has units that make up too 300 starts
per day !!!
So replacing flex plates/ring gears is a fairly common repair for Us.

Here's a trick We use to help with gear life, we apply MOLYPASTE
to the ring gear teeth !! there is a noticeable increase in gear life,
and this can't but help for Your worn gear--- read save $---

Also, it is true the flywheel stops in 4 spots --- IF--- the crankshaft
is a 90 deg rod journal configuration. I think???Your 4D is 180 though ???
No matter, this is rule of thumb as evidenced by a FULL ring gear :)

Anywho, apply the MOLYPASTE, it can't but help !!!

[camoit]

If you think it's a ring gear. Just make sure you have a way of rotating the engine over by hand. Then when the starter grinds just pop the hood and turn the engine about 1/8 rotation and try the starter again. If it catches your looking at the ring gear.

[pennyman1]

Geronimo had a similar problem years ago - occasionally the starter would make a ripping sound like it was tearing off or grinding the ring gear. It turned out the bendix was worn out and slipping causing the noise - it moved back and forth fine.