2wd lift and axle length

[Feintmotion86]

Hey all...need your input. I just had a re-gear done on my 97 tahoe, and the shop ( just so happens to be a driveshaft shop) is wanting me to be aware that the driveshaft needs a certain amount of bite onto the spines of the trans, and that I'm outside of that spec. Makes sense, since the rear is lifted about 3-3.5". I consider it to be a relatively mild lift, as I know some of you have gone much higher than that. Any problems? Or perhaps is there a known limit to the rear lift before a longer driveshaft is in order?

Also to note...he was indicating that if they built me a longer custom driveshaft, that there would be a clearance issue with the crossmember. He claims that the diameter of the tubing would have to be bigger than stock and would contact the crossmember, so that some cutting would be needed.

 

[SUBURBAN5]

Idk if it helps but I lifted my suburban with the rc 4" lift and my components are all stock. I've been wanting to get my driveshaft rebalanced and new u joints, but other then that nothing scrapes and nothing has indicated being too short......

 

[Nad_Yvalhosert]

I've got a 2wd 3/4 ton. 4.5" lift knuckles up front and regeared the rear ro 4.88. When I reinstalled the 14 bolt, I put on a set of 4" tapered blocks. The carrier bearing in the 2 piece driveshaft stayed in the OE location. The rear section pulled out 3/8" of the slip. That to me is inconsequential being that the entire spline section is over 4".

How big of a rear block are you installing? 3"? Tell the shop "Thanks for your concern. I'm good with the stock driveshaft."

 

[Feintmotion86]

I have a rear add a leaf and a 1.5" block. I think its a total of about 3", 4" max.

I think they were just telling me as a safety precaution because they HAVE to tell me for liability reasons. I took a look myself though and like both of you mentioned, there seems to be plenty of meat left on the spline that its biting.

my guess is, 6" or more and you probably need a longer driveshaft (on 2wd). Thanks for the input guys.

 

[OBS Oregon]

I have a 96 C1500 silverado that had 3in blocks under the rear springs. Stock drive shaft. Didn't notice any issues...