4.0 bolting to 2.9 trans

[Boggin]

I have a friend who is saying the 4.0 wont bolt to the 2.9 trans, i am sure that at LEAST pre-95 4.0s bolt to a 2.9 transmission. i just want some extra proof from the hundred of people on here that done so. I know they usually wont last espically like an fm145, but I have a 2.9 m5od so that will be plenty strong.

 

[heptofite]

4.0 might break it with the power, but all 2.8/2.9/4.0 transmissions have the exact same input shaft spline count and bell housing bolt patterns.

 

[Andres629]

A lot of guys want the 2.9 M5OD on a 4.0 for the lower first. Personally, I like having a closer 2nd and 3rd of the 4.0 one...
*edit* Besides, if the 2.9 trans didn't fit on a 4.0, why does a 4.0 trans fit on a 2.9?

 

[Boggin]

he is saying that 4.0s have 2 more bell housing bolts which need to be there?

 

[Andres629]

He is right, they do, BUT do not need to be there. The two lowest bellhousing bolts actually bolt on to the oil pan on a 4.0. Go figure...

 

[Boggin]

ok, cool

 

[BlackBII]

I have the 2.9 M5OD on my 4.0. Works great. 1st gear is rather low.

Like previously mentioned, 2.8,2.9 and 4.0 all have the same bellhousing bolt pattern.

Don't worry about the lower two bolts. No biggie.

 

[adsm08]

Realistically speaking, if you get the good and tight, you only need 2 bell housing bolts in there opposite each other.

The dowel pins take up the rotational force of the engine and keep the trans case from spinning. The bell bolts only keep the trans from moving backwards off the engine.

 

[mhughes165]

Realistically speaking, if you get the good and tight, you only need 2 bell housing bolts in there opposite each other.

The dowel pins take up the rotational force of the engine and keep the trans case from spinning. The bell bolts only keep the trans from moving backwards off the engine.

i invite u to test that theory lol....

like has already been answered boggin yes, just put a fm146 into a explorer the other day, damn that thing hauls ass with stock tires on it and 3.73's LOL

 

[Andres629]

i invite u to test that theory lol....

I already did... Had a 2.0 Ranger and the PO broke 3 out of 6 bolts in the block... dissimilar metal corrosion or somethng I guess. I ran it like that til I sold it, and its still runnin' around.

 

[mhughes165]

3 is one more bolt then 2 lol