Custom driveshaft or use a oem

[lalojamesliz 56]

Hey guys,

I'm about to get my engine back and then I can measure for my required driveshaft finally.  

Are there any oem driveshafts that can handle a 408w or do I need to go custom? My engine guy didn't tell me the power it made since I'm supposed to go tomorrow or the next day to pick it up and then he'll run it and show me what it makes but he did say its over 550hp

I have a strange 9" with a 1350 end and I haven't measured my 4r70w.  I don't know if the end has been upgraded or if it can be. I'll measure that later today when I leave my job if I can remember. 

The driveshaft I was looking at now would cost me close to 500 after shipping and it's custom so it will already have the proper ends but if I can save a little then I'll try. 

I wish it was just a simple, ok with this trans and rear end you need a driveshaft x in length instead of having to measure....

Thanks guys. 

[jmlay 80]

Have you seen what a broken u-joint &/or a twisted off driveshaft cam do to the drive train and body of a car? You have spent on the performance upgrades for engine, trans and rear, not to mention all of the body work. My recommend would be to spend on the 1350 yoke and custom driveshaft to match the rest of the drivetrain.

[lalojamesliz 56]

I was thinking I might get a response like that.... I just didn't know if some oem driveshafts can withstand enough and more. I see a lot of people mention they used a explorer driveshaft with success.  

But yeah, I guess a custom driveshaft it is.  

I was looking at one from "street or track" for $350 plus shipping 

He told me he hasn't had one fail and they have been on more powerful engines than mine.

I was looking at one from Dennys driveshaft but they are more than double.  I haven't looked around locally 

[jmlay 80]

Do a search in your area. I'm sure there is one around that can make one for you.

[Rich Ackermann 174]

I have a 408 Cleveland with a Tremec TKO 500 5 spd that I bought from MDL. I have an Eaton True Track anti-slip with 3.70 gears and Yukon (N case like) casing. The Tremec and the Yukon have 1350s. When pushing 500+- HP,  MDL recommended the following (custom built) driveshaft... It was not cheap, but then again neither is the cost of repair should one blow up as a result of under sizing it.

Aluminum Driveshaft 3.5" tube, 31 spline forged yoke, 1350 U-joints (under 700hp up to 58") High speed balanced
* Drive shaft is measured and built once the transmission has been installed. 

[lalojamesliz 56]

Do you guys think a 3" aluminum driveshaft is strong enough or should I look for a 3.5"? 

My engine dynoed at 514lb-ft

I haven't checked the yolk size on my trans yet. If it's not a 1350 I wanted to switch to one. It should be already.....

It's supposed to be built but I have no way to verify. 4r70w bought used a few years back.  Big gamble but I wasn't thinking straight at the moment 

[RPM 1,190]

I think the 4R70W comes with a 1330 yoke, mine did anyway. Have you searched for one? Whether you have 400, 500, or 600 hp/tq, your weak link will be your tires, unless you run slicks with a hard launch. 

[Rich Ackermann 174]

4 hours ago, lalojamesliz said:

Do you guys think a 3" aluminum driveshaft is strong enough or should I look for a 3.5"? 

My engine dynoed at 514lb-ft

I haven't checked the yolk size on my trans yet. If it's not a 1350 I wanted to switch to one. It should be already.....

It's supposed to be built but I have no way to verify. 4r70w bought used a few years back.  Big gamble but I wasn't thinking straight at the moment 

I would go with a 3.5" Dia for sure.

[RPM 1,190]

That's a really good looking undercarriage there Rich.

[Rich Ackermann 174]

9 hours ago, RPM said:

That's a really good looking undercarriage there Rich.

Thanks Bob!

[lalojamesliz 56]

18 hours ago, RPM said:

I think the 4R70W comes with a 1330 yoke, mine did anyway. Have you searched for one? Whether you have 400, 500, or 600 hp/tq, your weak link will be your tires, unless you run slicks with a hard launch. 

Hey Bob how are you doing? 

I was exhausted from my job yesterday and had company when I got home so i didn't check.  I should be able to today though.  

Where did you say you got your driveshaft made? Somewhere up north right? 

I went with some Falken Azenis 615K+ tires so I should have decent grip but yeah, I know what you mean about the slicks 

[lalojamesliz 56]

17 hours ago, Rich Ackermann said:

I would go with a 3.5" Dia for sure.

Damn that's a big shaft...... hahaha

My goal on this car was to have a almost bullet proof drivetrain so I'll look into the 3.5"

[RPM 1,190]

On 1/5/2022 at 12:14 PM, Rich Ackermann said:

I would go with a 3.5" Dia for sure.

Eddie, my Exploder drive shaft is 3.5", so...

I'm doing fine. Put new pistons, rings, and bearings in the 393. Awaiting heads to get surfaced from AMS in Fresno. Have the complete dash removed for air conditioning and new lower dash. Pray for me.  :)

[lalojamesliz 56]

Why did you rebuild it? I thought you sorted out the problems? 

Did you bore it out more or just hit it with the dingleberry tool on the walls?

Makes me wonder if I should look into a explorer driveshaft too..... 

What year, model, and other stuff should I look for?  Pick a part here has never really been any good to me but I've never looked for ford parts either

[RPM 1,190]

Had some detonation and broke a couple of pistons. Long story, but operator error. Edumication is not free. 

Cylinder walls were fine, and yes, hit them with the dingo ball hone. No detonation damage to the bearings but replaced them anyway. 

On a good note, it ran and sounded really well, until it didn't :)

[lalojamesliz 56]

Oh crap, thats some bad luck.

luckily you have the knowledge. 

[1969vert 55]

Yes new shaft would be needed for that hp. Stock 50 year old rubber coupler would not be happy with that power.