Rearend and Driveshaft Questions

[marvin2]

My truck was an original 3 on the tree that was converted to a t18 floor shift by the previous owner. I am not sure whether the rear end in the truck is original or not, but it appears to be a 9" (round pumpkin). I need to check the VIN and tag on the rearend to decode it. Was the 9" even an option for 70? If it is a transplant from a dentside, how could I tell without decoding it?

The driveshaft installed now is made of two smaller driveshafts...any idea why that would be? Is there a single driveshaft out there that I should be looking for to replace it or would I be better off trying to have a custom one fabricated? Would a dentside driveshaft from a t18 / 9" truck work?

[willowbilly3]

single shaft was deemed to long for a long bed, stay with the 2 piece. All the F100s had 9 inch except for a few 67s that had Danas I guess.
If you had a later 9 inch the leaf spring pads would have been moved in.

[marvin2]

I guess I should have mentioned though that my truck is a short bed. The guy gave us a spare longer driveshaft when we bought the truck with the intention of having it shortened to fit. Do I need to do this or is there a stock one out there that will work for this application?

I will have to check the leaf spring mounting pads, though I doubt they have been moved...i bet its still the stock rearend.

[fordman]

is there a reason you want to put the single shaft in? is the old two piece shaft gone bad in some way? if its good why not leave it alone. shortening a driveshaft is kind of spendy. but if you have 150.00 or around there to do it go for it. the driveshaft has probably been put in there because it worked for them when they were putting the truck together.

[Alvin in AZ]

Off hand, when I hear guys having repeated problems with drive shaft stuff
either they have "lifts" or have vehicles with single drive shafts.
Just my experience. {shrug}

My '75 F150 T18 230k+ has had the drive shaft worked on twice and neither
time it was for U-joints. I bent it slightly going over a dirt embankment and
one time the carrier bearing was getting sloppy inside.

Alvin in AZ

[willowbilly3]

You have a short wheelbase and a carrier bearing? That seems really odd, not factory I don't think.

[BobbyFord]

SWB trucks have one-piece driveshafts. D0TZ-4602-AA

[fordman]

i see a bent driveshaft canbe a pain and cause lots of other problems down the line. those canbe fixed also with either putting a new tube in it. or replacing that half if it is a option for you. and or putting the single shaft in when its shortened. i do not know if the dentside driveshafts will fit for you or not. the way to tell is to measure from the center of the t 18 yoke on the transmission to the center of the yoke on the rearend. then when you are looking around for a driveshaft you will get a measurement from the driveshft that you think will fit and compare the two measurements. as long as both driveshfts have the samk yoke (bolt on or slip in) then the measurement is all you need to figure a new driveshaft length.