lafnlt1

iTrader: (4)

I have an AWD 05 serria denali crew cab and going to start my swap soon to a 4L80E

I have almost everything I need but I am looking to do the swap in 2 days and not 2 weeks. The only thing left is the drive shafts. I know the best way is to measure when the trans is installed but i dont have the time to wait. From the swap thread that kysilverado did it looks like you can use a front shaft from a 2500HD, I decoded the VIN and it was a 03 2500HD 4X4 Ex Cab LQ4 6.0L part number 15182094

My wheel base is 143.5 just like the extended cabs

What are the lengths of the front and rear drive shafts that you guys used??

kbracing96

iTrader: (26)

It is my understanding from KYSilverado's thread is the 4l80e 4x4 tranny is 30mm or 1.18" longer then the 4l60e 4x4 tranny, so that should be how much longer/shorter the shafts need to be.

Also, I not sure if your aware or not, but the awd t-cases are not the same as the 4x4 t-cases, and you need a different input gear for it, or the smaller 4l60e output shaft they make for the 4l80e, but that would be some what counter productive from a strength perspective.

lafnlt1

iTrader: (4)

i thought with his measurements it would make it 1.6825" longer

KySilverado

iTrader: (7)

The rear DS will be shorter. The front longer and smaller diameter.

With all the variables, ride heights, pinion angles, and potential measurement errors by hurried people (my disclaimer) ... I recommend getting it done, measure, and then order the shafts.

lafnlt1

iTrader: (4)

belive me, this is not my way of doing things but i dont have a choice now, before it would not be a problem but now things around me shop are really tight. i dont have the capacity to do the swap in my garage so it will have to be done at the shop. i cant have my truck holding up a bay, pushing it around in the snow would be imposible

if its the only way then ill have to do that but would rather not, i might have to hold out till the weather turns

KySilverado

iTrader: (7)

Understand you position.

Based upon the the good measurement I got on the front DS's. The old was 30mm shorter than the new that fit perfectly and corresponds with the measurements I made of the transmissions. Can't really use the measurements of my new rear DS because of the joint swap.

A 30mm longer front shaft and a 30mm shorter rear shaft would be pretty darn close if you use the same u-joints.

lafnlt1

iTrader: (4)

i think i got that one covered for the front, just wanted to get an average for the rear and if there is not enough info, ill do it the long way

kbracing96

iTrader: (26)

Well, Here's what I know about mine... I measure the stock shaft and subtracted 30mm, and it was right around 65 1/2-3/4 u-joint C to C. I had Thunder550 measure his (he already has done the swap and our trucks are Identical year to year and same drop) and he's shaft in his truck was also 65 1/2-3/4. So that's what I'm going to have made for mine.

KySilverado

iTrader: (7)

And the point I was trying to make with the 2500 HD front shaft being 30mm longer stock and fitting perfectly. The transfer case moved back 30mm which also matched my rough measures of the transmissions. Subtract 30mm from your rear shaft length and it is going to be darn close.

howard quick

My 98 Burb needed to have the rear driveshaft shortened by 42mm.
I measured from the face of the bellhousing (where it bolts to the motor) to the mounting face of the NP243 transfer case (so....including the transmission to transfer case adaptors...which are different widths)and the difference between the two was 42mm.
This was perfect for mine.
Front drive shaft on the OBS's has a fair amount of 'telescopic' movement in it and didn't need altering.