2.9l starter problems

[Mylesp30]

I have a 1989 ranger with a manual transmission and I have been going through starters like crazy. Realized the remanufactured starters bolt holes get wider when they are sand blasted so I bought a brand new one off the Internet and it did great for about three months but now it is making a grinding noise like my previous starters. For some reason it seems to start hard and what I mean by that is that after it is running it’s like the starter still turns over for like a split second.

 

[RonD]

Welcome to the forum

You are correct and there are probably 100+ posts on grinding 2.9l starter motors just on this one forum

You can shim the starter bolt holes, even on a new one, using a cut up beer/coke can
Starter will shift/rotate overtime, each start, just enough so only the edges of its gear contact the ring gear, and grinding is heard

I think someone found bolts with bigger shoulders that fit the older worn holes or he drilled out the holes to fit new bolt's shoulder for a tight fit and no shifting

Also the block plate, thin metal plate between engine and trans, was there to stop the starter motor from shifting and for alignment with ring gear
The block plate was often left off after new clutch or ?? engine/trans work

In any case it is an alignment issue, and if you have a 2.9l engine long enough you will most likely have this issue



If you are getting "run on", starter seems to stay running, replace the starter relay on inner fender

 

[2 bronco 11s]

Take your bolt to a place like Fastenal or we have EBN who sells bolt . Tell them you want a Shouldered bolt . Hope I spelled that right ! They are metric . Make sure the starter sets inside the mounting hole . Try to find a factory starter and have it rebuilt if you can .

 

[Terry]

I fought this problem for a while. I tried everything suggested here only to have the problem come back. I ended up replacing the thin plate between the motor and trans. Never had the problem again.

 

[Mylesp30]

Welcome to the forum

You are correct and there are probably 100+ posts on grinding 2.9l starter motors just on this one forum

You can shim the starter bolt holes, even on a new one, using a cut up beer/coke can
Starter will shift/rotate overtime, each start, just enough so only the edges of its gear contact the ring gear, and grinding is heard

I think someone found bolts with bigger shoulders that fit the older worn holes or he drilled out the holes to fit new bolt's shoulder for a tight fit and no shifting

Also the block plate, thin metal plate between engine and trans, was there to stop the starter motor from shifting and for alignment with ring gear
The block plate was often left off after new clutch or ?? engine/trans work

In any case it is an alignment issue, and if you have a 2.9l engine long enough you will most likely have this issue



If you are getting "run on", starter seems to stay running, replace the starter relay on inner fender

Is the starter relay you are talking about the same thing as a solenoid? Or is it more like a fuse?

 

[RonD]

Yes, often called Starter Solenoid on Fords, but it's a relay
Has the 2 bigger posts and 1 or 2 smaller posts



Not that it matters
A relay connects electrical devices to power
A solenoid causes movement of something, a valve or other mechanical device

In an automatic transmission you might have a solenoid that moves a valve to change gears
Or EGR system has a solenoid valve that opens to apply vacuum to the EGR valve
Or power door locks use a solenoid to move the rods, but use relays to activate the door solenoids, lol

Relay may activate Dome light or Fog lights, or door locks
And in this case the starter motor, by connecting Battery Positive to starter motor

Solenoid came first as far as the name so it stuck, the word relay was applied later

 

[rusty ol ranger]

I had a 460 do exactly what your describing.

At first i blamed the cheap valucraft starters.

Until one day all i got was a "whirrrrrr" and pulled the starter and bench tested it and it was fine.

Anyway long story short the flexplate was cracked/broke right around where it bolts to the crank.

Might be worth looking into

 

[Mylesp30]

Yes, often called Starter Solenoid on Fords, but it's a relay
Has the 2 bigger posts and 1 or 2 smaller posts



Not that it matters
A relay connects electrical devices to power
A solenoid causes movement of something, a valve or other mechanical device

In an automatic transmission you might have a solenoid that moves a valve to change gears
Or EGR system has a solenoid valve that opens to apply vacuum to the EGR valve
Or power door locks use a solenoid to move the rods, but use relays to activate the door solenoids, lol

Relay may activate Dome light or Fog lights, or door locks
And in this case the starter motor, by connecting Battery Positive to starter motor

Solenoid came first as far as the name so it stuck, the word relay was applied later

I got a new starter bc of the warranty on the old one and it starts and doesn’t grind but it’s like the flywheel is catching the starter when I let off the key? Will a new solenoid help this or is it another issue?

 

[RonD]

Hook a test light up to the starter "solenoid's" larger post that has the one cable to starter motor
Start engine, light should be on only as long as the key is in START, if it stays on a second or two after releasing the key replace the starter "solenoid"


Yes, could be the starter gear is to close to ring gear so can't release when ring gear speed exceeds starter motor speed, binding, so needs to be shimmed out a tiny bit


Starter motors only crank engine over at 200RPMs, or less
In your model starter, like this one: https://www.motortrend.com/uploads/sites/21/2017/07/004-big-block-ford-starter-tech-starter-disassembly.jpg

The starter gear is forced outward by the torque of starter motors shaft when it first starts spinning, has a corkscrew on the shaft, like this: https://www.motortrend.com/uploads/sites/21/2017/07/007-big-block-ford-starter-tech-remove-bendix-drive.jpg?fit=around|875:492

When the engine/ring gears RPMs(250+RPMs) exceed starter motors RPMs the gear should twist backwards on the corkscrew and come back into the starter motor, unless it is binding with ring gear, which was not an uncommon issue


On newer starter motors a solenoid was added to the starter motor, has the round tube on the starter
Looks like this inside: https://www.carparts.com/blog/wp-content/uploads/2021/03/starter-motor-diagram.jpg
These were much less likely to bind or grind
The solenoid pushed the starter gear out and then pulled it back

 

[bcschief]

Do you have a block plate between the engine and the transmission bell housing?

 

[Mylesp30]

Yes I do and it looks like it’s not worn or anything like that in my opinion.