I have a '99 F150 with the V6, 3.55 gear, and a manual tranny. I want to be able to tow more without buying a new truck. The manual says the tow limit for a manual trans is low, like 2500lbs. What is the limiting factor with these transmissions? Is it the clutch, or is the whole trans unable to handle more load? If I were to change out the clutch to something stronger (recommendations?), what would my new towing limit be? If replacing the clutch won't do the trick, what are my options? BTW, I'd like to be able to tow a lightweight toy-hauler, perhaps 6,500lbs tops loaded. Thank you.

 

Actually... it's the tranny. The clutch isn't too bad actually. However, I've done quite a bit of investigating, and the max I could ever see the M5OD being capable of handling is roughly 6,000 lbs, severely modded that is.

You can raise the towing somewhat by changing out the rear end ring and pinion to 4.10s... but you'd be only good for about 4,800 lbs... maybe 5,500 lbs if done carefully.

The breaking point in these transmissions is the input shaft off of the clutch.

Now I'm not saying it can't be done... I've towed 6,000 lbs successfully many times. Does tranny like it? No. However, if you are a proficient stick driver, you should be fine as long as you don't try to do speed racer while towing. Letting off the clutch slower while accelerating will help you. Sure it wears the clutch a little more, but it takes a lot of that strain off the input shaft, especially during shifting, which is usually when they snap. Oh yeah, and stay out of 5th... towing in 5th is a big no-no with the M5OD.

Hope this helps.

 

Thank you for the excellent response, I was worried about the trans itself being the weak point. I guess I'll have to rethink my trailer plans.

 

I don't think it's just the clutch that limits the towing rating. It's the trans itself. I believe the truck is rated at 3500 lbs towing.