I just recently bought a 1991 F150 with a 5.0V8, 4x4, 5 speed, reg. cab long bed with only 103k miles.

I have a few questions as I have never owned one of these trucks.

Is the rear axle an 8.8? If no, what do I have.

If yes, what spline count?

What kind of 5 speeds come in these trucks, and how well do they take abuse?

Any help is great. Thanks.

Yes. 31 spline 8.8.

Trans is the M5OD. 5spd, no granny gear. Its ok i guess, nothing special.

odds are its a 8.8 31 spl rear, its a M5od tranny, and that don't take abuse veyr well in a 1/2 ton as they are are more or less a 1/4 ton tranny

I had a 92' f150 with a 4.9l and 270k before I finally lost the tranny. Im not sure for 91' but in 92' they offered two 5-speeds for it one was a mazda and the other was a mitisubishi.

Yes. 31 spline 8.8.

Trans is the M5OD. 5spd, no granny gear. Its ok i guess, nothing special.
Hardly "nothing special". Its a hunk of fucking shit thats only worth its weight in scap aluminum.

I had a 92' f150 with a 4.9l and 270k before I finally lost the tranny. Im not sure for 91' but in 92' they offered two 5-speeds for it one was a mazda and the other was a mitisubishi.


AFAIK the only 5 speeds for larger trucks were the M5OD and the ZF- 5speed. I think mitsus were for rangers and shit.

Hardly "nothing special". Its a hunk of fucking shit thats only worth its weight in scap aluminum.



Wow. That's reassuring.

Wow. That's reassuring.

Even so if you have it already and want to use it go ahead. I am unsure about length but I think a ZF out of 3/4 and 1 tons is a direct bolt in swap if you waste the M5.

The mazda 5 speeds are fine on road and for light towing/offroading so long as you keep them full of fluid. they have a couple of rubber plugs in the case that tend to dry out over time and when they do, they start leaking and when they leak is when things go down hill FAST.

If you have a trans leak you're better off replacing the plugs sooner than later because later will probably mean you'll be replacing the whole trans with the plugs.

Only bad thing here is the plugs only leak when the truck is being driven. Look under the trucks for signs of ATF all over the floorboards/crossmember.

Justin

Wow. That's reassuring.

I put under 10,000 miles on my truck before the m5od locked up on me going down the highway. That was a scary fucking ride :eek:

i have the mazda 5 speed in my truck... 180,000 on the clock, no problems with it yet (other than the nice bearing noises:laughing:)

30,000+ miles were with 37s or bigger, and my driving... but yes, they are tiny little trannys. and only should have been put in rangers. :flipoff2:

i have the mazda 5 speed in my truck... 180,000 on the clock, no problems with it yet (other than the nice bearing noises:laughing:)

30,000+ miles were with 37s or bigger, and my driving... but yes, they are tiny little trannys. and only should have been put in rangers. :flipoff2:

Yeah...but you dont have V-8 POWA :flipoff2: