On my third starter...

SmashOgre · **Posted:** Wed Mar 25, 2020 2:26 pm

Hi, has anyone else experienced weak solenoids on their replacement starters? I bought my Liberty CRD used and afternoon a few months it began mid-starting. The symptom would usually show up first thing in the morning where the starter would begin turning but the bendix seemly did not engage the flywheel. Then as time progressed, the starter solenoid would begin dropping out during starting until it finally failed to stay engaged with the flywheel long enough to start the jeep. I contacted Advance Auto and arranged to replace the Carquest starter. Oh, I discovered the last tech to replace the starter left out the third bolt, you know the one - behind the solenoid. Anyway, I replaced the starter and the symptom went away for - wait for it - one day. The new starter began the mid-start thing first and once a day progressing quickly again. Before replacing the starter again, I removed it, checked the bendix and the flywheel teeth- all good, checked the starter function with jumper cables and a remote start switch - all good, put it back on the Jeep with a new third bolt and used remote start switch - same symptom of solenoid failed to keep the bendix engaged, performed voltage drop tests (both, battery to starter cable - no loss and start trigger circuit - no loss), so I replaced the starter again... new again Carquest starter and for now, no problems. Yeah... oh yeah, this is day two.

flash7210 · **Posted:** Wed Mar 25, 2020 6:48 pm

Is oil leaking onto or into the starter?

Had the exact same problem on my friends XJ.
And all the replacement starters were from Auto Zone.
And they all bench tested good.
I thought maybe it was because of the oil leak soaking the starter but we eventually got a new starter that worked properly.

Maybe auto zone is just crap.

WolverineFW · **Posted:** Wed Mar 25, 2020 10:40 pm

If it happens again.....I would try and source an OEM starter. I think Denso made them. Probably find a reman.

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Billybob · **Posted:** Thu Mar 26, 2020 3:36 am

If the solenoid is not getting maximum current it could be failing to engage properly.

Not actually a "Bendix" as far as I know...a Bendix flies out as it rotates and engages the flywheel. Then when power is dropped it falls back under spring action.

I believe this solenoid has a forked arm that pulls the small gear out to engage the flywheel and then drops back under spring load. The solenoid also makes a large contact inside itself which spins the starter motor up....these contacts can get burnt and make bad contact so sometimes only the solenoid needs replacing. Over the years I have opened many a solenoid and carefully filed down the contacts so as to make a firm even contact..lubricated the moving parts and put it all together.
Nowadays we simply replace everything!

Does not matter which system is used...main thing is that the whole system receives good current.
I will read up on exactly what system our Jeeps use!

The connectors on the solenoid and starter motor must be clean and tight.
The battery connections must be clean and tight and the negative battery lead going to chassis must be clean and tight. The straps grounding the engine to chassis....one on the CRD and two on the Gasser...must be clean and tight.

Worth swapping out the Starter Relay in the box under the hood.

Strange that you are having these problems....the Starter Motors on these Jeeps are generally pretty reliable!....hopefully the teeth on the flywheel are in good condition :roll:

TKB4 · **Posted:** Thu Mar 26, 2020 3:43 pm

agree they are very reliable I have had none give a problem on 6 crds buy I never drove the parts one but that doesn't help if yours isn't working.

WWDiesel · **Posted:** Thu Mar 26, 2020 4:49 pm

Question? Is the starter motor itself failing or is it the starter solenoid on top the the starter motor?
Need to determine if the problem is electrical or mechanical.

You definitely need to connect a voltmeter to the positive lug on the starter and see how low the voltage is dropping to when the starter motor is engaged.
Amps go up exponentially as battery voltage drops, so a low voltage situation could be killing the starters.

As the battery voltage drops, it’s internal resistance increases due to chemical actions of the battery plates. This battery resistance increase limits the available battery current and reduces the amount of power delivered to the starter motor. Now the starter motor is not getting the voltage that it is designed for, so it starts dragging (arcing across the armature windings) and repeated occurrences will shorten the life of the starter motor very quickly. Weak batteries will destroy starter motors over time because of the excessive current draw and armature arcing due to low cranking voltage. The wires going from the battery to the starter motor also have resistance that adds to the impedance of current flow in low voltage situations.

SmashOgre · **Posted:** Sun Apr 05, 2020 5:21 pm

Brand new battery as of fall last year, yes solenoid is failing not the starter motor, yes all connections are clean and tight, verified vehicle electrical is functioning normally (performed voltage drop tests), teeth of flywheel inspected - no damage (yet), third starter working beautifully with no hint of faulty solenoid. I think it was a bad line of starters at Carquest. The (3rd) new starter sounds different than the last two.

Method of engagement aside, I’ve always known the small gear with the one-way clutch on the output shaft of the starter to be called a bendix. I have a Triumph Spitfire and it’s starter bendix is engaged with the flywheel by centrifugal force, so familiar with both.

WWDiesel · **Posted:** Sun Apr 05, 2020 10:17 pm

FYI,
Bendix is a misnomer, it was the brand name of a starter drive used for many years in the US.
The Bendix Corporation built starter drives for many, many years.
So most old timers simply called starter drives a "Bendix" when in fact the correct name is a "starter drive". :ROTFL:

Billybob · **Posted:** Mon Apr 06, 2020 7:27 am

WWDiesel wrote:

FYI,
Bendix is a misnomer, it was the brand name of a starter drive used for many years in the US.
The Bendix Corporation built starter drives for many, many years.
So most old timers simply called starter drives a "Bendix" when in fact the correct name is a "starter drive". :ROTFL:

This is exactly correct.
Most ofthe first starter drives were made by Bendix and it was in fact a centrifugal gear that shot outwards to engage the flywheel. There was a one-way clutch on this small gear so that as the engine fired the Bendix would freewheel.

It became normal to call these little gears a "Bendix" while in actual fact most manufactures started using a fork on the solenoid to push the little gear outwards to engage the flywheel while at the same time making a large copper contact to energize the Starter Motor windings, then it would return back into place under spring action.

I have not seen these types of starter for many years and as an Old Timer myself do not refer to them as a "Bendix"....might be made by someone else!

The basic rules still apply no matter what type is used...powerful battery with good grounding and firm connections, good brass commutator on the starter motor with no dead windings, clean carbon brushes that have not worn down too much etc.

Years ago I had to take apart a solenoid and file down the large brass contacts so that they made good firm contact to provide the high current that the starter motor drew...on an old BMW I think :wink:

WWDiesel · **Posted:** Mon Apr 06, 2020 3:50 pm

Watched a very good video the other day of a mechanic diagnosing a poor performance starter motor issue.
As it turned out he found more than one problem that was causing the problem.

The owner had just replaced the starter with a new unit after the old one had completely died.
The new starter motor turned the engine over very slowly. So he got another new starter thinking the one the owner had installed was a bad one right out of the box.
The second new starter motor still spun the engine over at only about 2/3 of normal speed it should have.

What he ended up finding:
Measured battery voltage with a digital volt meter at the starter motor connection with starter engaged and it measured only a little over 8 volts.
Measured it at battery + positive cable clamp connection and at starter motor connection without starter being engaged and it read 12.4 volts. (normal)
Then measured it at battery + positive cable clamp while engaging starter motor and voltage dropped to 8.7 volts.
Found + battery cable clamp was corroded around battery post even though the clamp was tight and looked OK. Removed cable clamp, cleaned and reinstalled it.
Tried starter and it was still not spinning engine at normal speed.

Next started measuring voltage drop on ground side of battery.
Battery had a ground wire that went to the chassis first and then a strap that went from the chassis to the engine block.
Battery (-) negative clamp to chassis measured 0.03v voltage drop with starter engaged.
Battery (-) negative clamp to engine block voltage drop measured 02.8v with starter engaged.
Found battery negative cable to block had a poor connection (slightly loose) where it was attached to the side of the engine block.
Removed, cleaned, installed new bolt and reattached to engine block.
Starter motor then performed perfect spinning at normal speed.

Takeaways from this:
A good digital voltage meter can be your best friend when trying to diagnose starter performance issues.
Not only for purely measuring static voltage, but also for measuring voltage drops on a wire, cable, or between point A and point B.

layback40 · **Posted:** Mon Apr 06, 2020 7:06 pm

My XJ diesel developed starter issues like the OP describes.
It was the overrun clutch slipping.
I disassembled the overrun clutch.
Yes it was a non serviceable part, roughened the grip surfaces & rollers & stretched the springs.
This fixed it for a few years.
When it started to play up again I obtained a new overrun clutch & never had another problem.
I dont know if this could be done to a CRD.

On my third starter...

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