Replacing Starter Motor

[Liam_H]

So my 2004 4.0L TJ is having troubles starting 50% of the time. Sometimes starts right away, sometimes just has an audible click like the starter is seized and trying to move when I turn the key, happens about 5-10 turns then finally turns over and starts.
Looking online the noises relate to starter on its way out, battery seem fine as holding 12v and headlights/radio plays fine with no dimming.
So my question is, looking for a used starter motor as they are less than half the price of new, and I find a lot of them from a 2.5l TJ.
Would I be able to use a 2.5L starter motor in my 4.0 TJ, or are they not compatible?
Thank you

 

[Jerry Bransford]

Before assuming you have a bad starter motor, do this... remove both battery connections and use a wire battery brush to get the battery posts and the insides of the connectors bright and shiny clean. Then reinstall them tightly enough that you can't move the connectors around on the posts with even considerable hand pressure.

Loose/dirty/corroded battery connections are more than capable of causing your starter issue even when they look perfectly fine.

 

[Liam_H]

Okay thanks, the terminals look okay but I'll definitely give that a try now.

 

[Rubicon88]

So my 2004 4.0L TJ is having troubles starting 50% of the time. Sometimes starts right away, sometimes just has an audible click like the starter is seized and trying to move when I turn the key, happens about 5-10 turns then finally turns over and starts.
Looking online the noises relate to starter on its way out, battery seem fine as holding 12v and headlights/radio plays fine with no dimming.
So my question is, looking for a used starter motor as they are less than half the price of new, and I find a lot of them from a 2.5l TJ.
Would I be able to use a 2.5L starter motor in my 4.0 TJ, or are they not compatible?
Thank you

Voltage is only part of the story..
12 volts to run a radio or lights without the alternator is nothing.

A starter on the other hand needs 12 volts but also needs a lot of amperage to turn that bitch.

Try turning your engine wtth a ratchet and socket and see just how hard it is.
Yet this little cylinder spins the engine no problem....provided you've got the amps to spin it.

75 percent of "bad electrical anything" here at the shop we see can be attributed to piss poor connections.

 

[SSTJ]

So what happened in the end?