FM145 strength and how much power it can take

[Shran]

The FM-145 in my stepside truck suffered from massive leakage at the shifter housing when I got it... because all the bolts had backed out about 1/4"

Personally I like the lower 1-2-3 gear ratios in the FM transmissions... the 4 cylinder and 2.9 M5ODs are just about the same and just where I like them. I'm looking forward to building one for use in my Explorer, I'm not real fond of how high those three gears are in the 4.0 transmissions.

 

[rusty ol ranger]

The FM-145 in my stepside truck suffered from massive leakage at the shifter housing when I got it... because all the bolts had backed out about 1/4"

Personally I like the lower 1-2-3 gear ratios in the FM transmissions... the 4 cylinder and 2.9 M5ODs are just about the same and just where I like them. I'm looking forward to building one for use in my Explorer, I'm not real fond of how high those three gears are in the 4.0 transmissions.

What was the first in the FM's? The TK's had a 3.96:1 1st but there seems to be a decent drop between 2nd-3rd then 3rd to 4th, but 4th to 5th is barely noticable.

 

[Shran]

1st: 3.769
2nd: 2.210
3rd: 1.516

3.96:1 would be awesome.

 

[4x4junkie]

To be fair, the fact that they used ball bearings rather than roller bearings is a pretty big issue in and of itself.

And is why I pointed out that they are ball bearings. Roller bearings indeed are far superior.

The FM146 that was originally under my BII lost it's output shaft bearing at around 150K miles. I managed to get it out of service before any other parts were damaged. I may rebuild it some day. I did like the way it shifted better than the more-trucklike M5OD.

FWIW, overfilling the trans by about a half-quart seems to help it live a bit easier (better oil flow, especially to that 5th-gear & output shaft bearings).

 

[ford4wd08]

My first truck had a M5OD behind the 4.9 straight six in a F150. It was rebuilt after 140,000 miles. It never did seem like it belonged in that heavy of a truck to me. It would literally jump out of first when you tried to take off and then it would lock up where you couldn't shift it to any gear. I wished I had a lower geared trans in that truck it didn't like 31's at all.

 

[rusty ol ranger]

1st: 3.769
2nd: 2.210
3rd: 1.516

3.96:1 would be awesome.

Yeah the 3.96:1 with a 2.9 makes a fun little launcher.

TK 5 ratios...
1st: 3.96

2nd: 2.07

3rd: 1.39

4th: 1.00

5th: 0.84

Theres big drops between the gears, ive never driven a 4 cylinder TK truck but i imagine the drop offs really hurt them.

My first truck had a M5OD behind the 4.9 straight six in a F150. It was rebuilt after 140,000 miles. It never did seem like it belonged in that heavy of a truck to me. It would literally jump out of first when you tried to take off and then it would lock up where you couldn't shift it to any gear. I wished I had a lower geared trans in that truck it didn't like 31's at all.

Best trans ever in an F150 was the BW T18. I had one in an 83 mated to a 300 with a 4.10 rear. Thing would pull a house over.

 

[ford4wd08]

Best trans ever in an F150 was the BW T18. I had one in an 83 mated to a 300 with a 4.10 rear. Thing would pull a house over.

Yeah mine wouldn't pull a wet string out of a cat's ass. But it was a 95. Towards the end for the 300, 302, & 351. The end of the pushrod era in F150's.

 

[rusty ol ranger]

Yeah mine wouldn't pull a wet string out of a cat's ass. But it was a 95. Towards the end for the 300, 302, & 351. The end of the pushrod era in F150's.

Ive had a 93 with the M5OD with a 3.08 rear and a 300. It literally got double the fuel mileage of my 83 and would actually run 70 mph comfortably. But yeah, it wouldnt pull very good.

 

[ford4wd08]

Ive had a 93 with the M5OD with a 3.08 rear and a 300. It literally got double the fuel mileage of my 83 and would actually run 70 mph comfortably. But yeah, it wouldnt pull very good.

That was my rig! Lol

 

[Shran]

I really liked the T19 in my old '85 F250. Basically the same as a T18 but it had synchronized 1st gear. That thing was a tank and it shifted nice too.

 

[rusty ol ranger]

I really liked the T19 in my old '85 F250. Basically the same as a T18 but it had synchronized 1st gear. That thing was a tank and it shifted nice too.

Never had a rig with the T 19. Had a couple of the T18s, one in that 83 and one in a 78 F350 dually bolted to a massaged 400 with a 4.30 rear, talk about a pullin sumbitch.

The unsynced 1st never bugged me, id just float it into 1st on a roll if i needed to grab 1 st on a roll.