Which Starter do I use

[lilfordrunner]

Hey y'all,

In the middle of swapping out a 2.9 for a 4.0 what starter do I use?

The 2.9 is from an 87 ford ranger with a manual transmission. The trans is staying, thus so is the flywheel

The 4.0 is from a 93 ford explorer with an automatic transmission.

I've gotten conflicting information on which starter I need to use, since one is for a flywheel and the other for a flexplate.

I am trying to put this in TODAY or go and buy the right one (Depending on the answer) Any help would be appreciated.

 

[monsterchuck]

My guess would be the 2.9 starter would be the one you want to use. The 4.0 is going to hold the flywheel in the same spot, and the starter bolts to the trans. so the starter should behave the same with either engine bolted in place.

 

[adsm08]

My guess would be the 2.9 starter would be the one you want to use.

You would be guessing incorrectly.


There are three things to consider here.

1) A 2.9 starter doesn't have the balls to live up to turning a 4.0. It will work for a while, but won't last.

2) What transmission are you using?

3) The 4.0 had two different starters.



So here is the real run down.

The 2.9 used one starter, the 4.0 used two. The 2.9L had an 8 2/3" flywheel for a manual trans and the flex plate for the auto trans was the same width.

The 4.0 had a 10" flywheel but retained the smaller flex plate from the 2.9. This means the 4.0 has one starter for a manual trans and one for an auto, the difference being the location of the drive pinion, which is located appropriately to engage the ring gear.

Now I am hoping that you were not dumb enough to attempt to use a 2.9L clutch on a 4.0 engine, since that is just asking to toast the clutch. If you were smart enough to use the right clutch you need to go get a 4.0 manual starter.

If you were dumb/cheap enough to try using the small clutch the 4.0 auto starter will mate up and engage correctly, but will need to be wired correctly to work for as long as the clutch lasts.

If you put the Explorer trans in the truck along with the engine, then use the 4.0 starter, which will still need to be wired in correctly.

But at the end of the day, you need a 4.0 starter for any sort of long-term service.

 

[dj1075]

either starter will work. preformed the same swap a couple of months ago on my nephews 89. I'm in the process of a 4.0 swap on my 88 now. The 4.0 starter is lighter and easier to work with due to its smaller size. Be sure to look at a wiring diagram for the 4.0 it has the solenoid on the inner fender and the one one the starter. Another switch wire has to be ran.

 

[adsm08]

either starter will work.

Unless he used the 4.0 clutch. Then the 2.9 starter will not work.