I am totally vexed!!! Ever since I finished my 351 swap, I have had this belt squeal problem. I have new idler and tensioner pulleys, smog pump eliminator pulley, new water pump, new power steering pump and pulley, plus a new belt. When I start the engine, the belt screeches and the alternator doesn't show a charge. It'll read 10.2 volts. Now I can pull the alternator plug and the screech goes away. Or I can use my battery charger and while the engine is running, move the selector switch up two clicks from 2 amps/trickle charge to 40 amps and the belt screeching stops and the voltmeter will read 14.6 volts. I have replaced the alternator three times(new units, not reman) and this time I even tried replacing the voltage regulator to a soft start unit and still have the same belt screech problem.....I'm really lost at this point..please help!!!!

 

I would suspect you must have a wiring problem. And I think that 5 speed manual was never used behind a 351 because its torque rating isn't high enough.

 

Try reading this.....What kind of abuse can the M5OD 5spd real world handle???? - Ford Bronco Forum

 

I've owned two trucks with the M5OD. Both were/is great. I'm happy with their performance.

I had a '99 F150 SCAB when I was a kid, and I beat the heck out of it... towing, burnouts, racing, etc. Held up fine.

I got a '07 F150 Reg Cab, and the only thing I haven't done with this one is burnouts and racing (kind of grew out that...), but it has towed and hauled some impressive items.

Though I've learned that the key piece to making it last is NOT to dump the clutch or be jerky with it. If you can operate your left foot correctly, the transmission will last a long time.

Also, my '07 came with 3.55s, and I swapped them out to 4.10s. What a HUGE difference driving it, especially while towing. I don't even have to rev it to get it going in 1st. Talk about a clutch saver. It's much easier on the transmission. I also get much better fuel economy with the 4.10 ratio.

The most known issue is the slave cylinder going. However, that's not from "overloading" it.

 

I drive my truck pretty conservatively....no clutch dumping or burnouts so I'm pretty sure that my M5OD gearbox should last at least the life of the 351....after all it has outlasted the 300 six.

 

I think you'll be fine.

There was a guy on here that used to put M5OD's behind either a Triton V10 or V8... can't remember without searching it... but he used to off road and and probably once a month he'd have to repair his M5OD. He was very familiar with the workings of one.

I'm still surprised there wasn't a market for "bullet proofing" the M5OD since it was a transmission that was used behind so many vehicles. Now a days, I don't see why not, especially with the advent of 3d printers and CNC machines. Kind of weird.

 

That's JMC, he has one behind a Procharged 5.4.

 

Ahh, yes, JMC.

Thank glc.

 

In response to the squealing problem, I can tell you with near certainty that your harmonic balancer pulley is slipping on the hub and needs to be replaced sooner rather than later. I had the same problem with the 4.9 and changed all the same things you did. Also engine coolant temp would try to run high in the hot weather.. after the harmonic balancer failed and I replaced it , all the squealing and temp issues ceased. My harmonic balancer was so bad that when I pulled it off it was in 2 pieces. Now you dan hardly hear the engine running at idle.