'89 F150 transmission issue

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

Jim Tiberio - 26 Aug 2005 14:35 GMT

I've got an '89 F150 with a 5.0 EFI and three speed auto. The problem is
that it is now a two speed. I leveled off the fluid but that didn't do the
trick. The truck is rarely ever driven at 55 MPH since I only use it for
local dump and Home Depot type runs. Last night I had to move a couch for a
friend, I got on the highway and realized it wasn't engaging third gear.
The previous owner had it re-built 20,000 miles ago. Is there a problem
inherent with these trannsmissions or the re-build of them that would cause
this? I just want to know a little about what I'm talking about before I
bring this $500 truck in for repair and get told it will be a $1000 fix.

Reply to this Message

TranSurgeon - 26 Aug 2005 14:39 GMT

check vac modulator line

unhooked/leaking - no third

> I've got an '89 F150 with a 5.0 EFI and three speed auto. The problem is
> that it is now a two speed. I leveled off the fluid but that didn't do the
[quoted text clipped - 5 lines]
> this? I just want to know a little about what I'm talking about before I
> bring this $500 truck in for repair and get told it will be a $1000 fix.

Reply to this Message

Jim Tiberio - 26 Aug 2005 14:42 GMT

> check vac modulator line
>
> unhooked/leaking - no third

Thanks for the quick response, I'll do it when I get home. Sooo, uhhh
where exactly is the vac modulator line?

>> I've got an '89 F150 with a 5.0 EFI and three speed auto. The problem is
>> that it is now a two speed. I leveled off the fluid but that didn't do
[quoted text clipped - 9 lines]
>> this? I just want to know a little about what I'm talking about before I
>> bring this $500 truck in for repair and get told it will be a $1000 fix.

Reply to this Message

TranSurgeon - 26 Aug 2005 16:19 GMT

modulator is thelittle can thing sticking out at right rear of transmission,
on the back edge

line goes from there to manifold vac source

> > check vac modulator line
> >
[quoted text clipped - 16 lines]
> >> this? I just want to know a little about what I'm talking about before I
> >> bring this $500 truck in for repair and get told it will be a $1000 fix.

Reply to this Message

lugnut - 26 Aug 2005 18:31 GMT

>I've got an '89 F150 with a 5.0 EFI and three speed auto. The problem is
>that it is now a two speed. I leveled off the fluid but that didn't do the
[quoted text clipped - 5 lines]
>this? I just want to know a little about what I'm talking about before I
>bring this $500 truck in for repair and get told it will be a $1000 fix.

I am assuming you mean it is not upshifting as opposed to
going to "nuetral" in which case you have an entirely
different problem. If it is a 3 speed, you may have a stuck
road speed governor. It is located in the tailshaft
housing. IIRC, it can be service (unstuck) by removing the
ts housing. It is not a 10 minute job, but, it is not too
bad or complicated if you have a few tools and are willing
to learn as you go. You might also want to check your
kickdown to be sure it is not stuck at full throttle
position for some reason.

Lugnut

Reply to this Message

Rate this thread: