GoFast Driveshafts ???

VintageIronFab · Post by **VintageIronFab** » Sun Mar 27, 2016 7:08 am

Hello All,
Most of my experience with driveshafts come in the 66-77 Bronco world. Where if you buy a shaft from someone other than the Tom Woods or Hi-Angle type shops/eople you have bind so damn bad early on in the travel that you simply have a very expensive limiting strap aka the driveshaft. My question is in regards to my F150 - I swapped transfer cases from a slip yoke to a flange style and am hoping to get the max travel out of the rear end- hoping 20"+ if that's even possible. There's a nice driveline place here in MO but do I need a special driveshaft on a F150 to be able to pull those kinds of travel numbers?

Thx for the help,
Matt

cs_drums · Post by **cs_drums** » Sun Mar 27, 2016 2:17 pm

I wouldn't think so. I have 22" of travel with the stock drive shaft on my bronco.

VintageIronFab · Post by **VintageIronFab** » Sun Mar 27, 2016 3:10 pm

Any porting or just right out of the box?

cs_drums · Post by **cs_drums** » Sun Mar 27, 2016 3:54 pm

Yeah I did a bit.

Tchajagos · Post by **Tchajagos** » Sun Mar 27, 2016 6:09 pm

the bronco drive shaft has a double cardan joint which will let it drop more. You will need a slip joint in the driveshaft if you took out the slip at the xfer case. You can always get a bronco drive shaft lengthened. You shouldn't have a problem getting those numbers on an f150.

VintageIronFab · Post by **VintageIronFab** » Sun Mar 27, 2016 7:30 pm

It's a bronco transfer case

Rmc · Post by **Rmc** » Sun Mar 27, 2016 7:52 pm

So do the string trick and measure plunge. This will show you a lot about what your Axel is going to be doing through the total travel distance. Also strip the leaf packs to the longest leafs, block them and cycle. This will show you pinion angle changes. What's very important is to have allowable plunge in the drive shaft. This may require a custom drive line but regardless a slip joint in the driveline is a must same as factory bronco style. Depending on length and total angle a double cardigan may be required as well.

Rmc · Post by **Rmc** » Sun Mar 27, 2016 7:53 pm

For more info on the string trick look on the ranger station or look in a thread I started years ago called suspension design links there's lots of info there as well.

VintageIronFab · Post by **VintageIronFab** » Sun Mar 27, 2016 8:00 pm

Yea I know about the cycling I was mainly wondering if go fast rigs as a rule need much more than the proper length shaft-- I'm just going to get a shaft made local it sounds like

VintageIronFab · Post by **VintageIronFab** » Sun Mar 27, 2016 8:04 pm

I'll look at that info

Rmc · Post by **Rmc** » Sun Mar 27, 2016 8:43 pm

Well one big advantage you have is the transfer case. On the 2wd race trucks when you get into big travel numbers custom drive lines are required as well as having the trans custom built with a fixed output shaft to put the plunge telescopically into the drive line vs having the plunge on the output shaft or the slip joint in the transmission. Basically once you get into the higher degrees of usable range in the driveshaft it will plunge it's way right through the transmission tail housing breaking the casting. In your case though you already have the Benifit of the tcase fixing the output shaft so your golden. It only boils down to usable degree range at this point and the string trick in combination with cycling will show you total plunge numbers. As long as you have enough usable plunge in the drive line it will keep the trans safe, which is a good thing and the rest boils down to total I binding usable angle in the u joints. Basically go to tuck and rotate by hand and do the same at droop. If it binds restrict the total travel numbers in tuck and droop as needed. The double cardigan is an option as well but a drive line guy must be consulted accordingly.