So I have a new-to-me 1989 F150 4x4 with a 5.0 and manual transmission.

The gear box is doing some crazy stuff. While driving, the gear shift seems to almost pop out of gear, then things start grinding like CRAZY. Very loud and noisy.

Seems to to be the upper gears mostly, but it's done in 2nd if I recall correctly.

PO said he had the transmission evaluated by a shop and that it was fine. They did "something" to the.....shift forks, maybe? He wasn't sure, and neither am I.

SO - to begin - which tranny is that I'm dealing with? Likely the Mazda M5R2? How do I being to identify it?

And once I know which tranny I have - where to from there? Where should I start to begin solving this noisy dilemma?

Huge thanks in advance. I'm anxious to hear what you all think.

In the meantime, I'll start doing some searchin' and reading. I'm sure this isn't the first time someone has posted about this issue....

Thanks -

 

Here's a pic of the ol' gal....just as dirty and raw as when I first saw her.

Got plenty to do - but she's a great start!

Any input would be greatly appreciated....

 

1) post a picture of the transmission

2) there is a transmission code on the driver's side "B" pillar. The M5OD is code "M".

 

If it pops out of gear I would suspect worn synchro rings on the main shaft. Common byproduct of resting your hand on the shifter and applying unnecessary weight to the shifter forks.

 

So I checked the door pillar....

Tag shows trans as "M" and axle as "19"

I'll post a pic of the tag as soon as I can. Crazy slow internet here tonight.

Knowing that - is the tranny a M5OD? Or the M5R2? Or are those the same tranny?

I'm pretty ignorant about all of this. Just jumping right on in.

I'll grab that tranny pic as well and get it posted.

Da_Lariat - if it's the syncho rings, is that a complete R&R of the transmission? Should I just start scrounging up a tranny? Are those synchro rings readily available?

What's the story with the shifter repair kit? Seems plausible, being that the PO said he had the tranny looked at, and it was supposedly great on the inside. I have NOTHING to verify any of that - simply what he said to me. He did say that they did something that lasted for maybe a month, and then it was right back to its antics. Just putting that out there for whatever that's worth.

Hey - thanks for all the input so far! We're moving forward...

Boy oh boy! This ought to be a fun little experiment.....I'm hoping it's going to be worth tackling.

 

M5OD-R2

I did the shifter repair kit on mine. The kit helps with the slop in the shifter. It was hard to find the gears because there was so much play.

 

Replacing synchro rings basically requires pulling out the main shaft on this transmission, and if you're forced to go that far, you may as well rebuild the whole thing while you're in there.

If this was my situation and I didn't feel comfortable rebuilding it myself (not the case, I love transmissions!) then take it to a good rebuilder and let them have their time with it. It's usually more economical to get a rebuilt unit but I'm a big believer in keeping the original units on the vehicle it came from and rebuilding if possible.

 

The shifter repair kit is an affordable way to get started; I'll scratch that off the list and see what happens from there.

@Da_Lariat - what you're saying makes perfect sense to me. If you've got to get into it that far, may as well do it right, yeah?

I have a feeling that my bushings are gone as well. She doesn't have many miles on her, but I think she's pretty tired all the same. I'll get that kit ordered pronto and then we'll see what things look like when I pop the boot on that thing...

Thanks all - the help is invaluable.

 

Here are a few quick pics of the tranny from underneath.

Just want to make sure it is in fact the M5OD before I order the wrong parts....

 

This tag is on the left side:

 

Right side

 

One more photo -

 

Looks like an M5 to me

 

Awesome - thanks Lead.

I'm going to get that shift kit ordered today; I need to get moving on this ol' girl. If it's going to take more than the shift kit to make her behave - and it's likely that it will - then I'd rather know sooner than later.

 

Looks like Fred has been in there before.