727 to getrag driveshaft problems
 

Almost done with my 2wd getrag swap. I'm having serious issues with my driveshaft. It seems like it's too long. The front of the truck is lifted up with a jack just enough that the tires don't come off the ground. The transmission is not in the crossmember yet so it might be lifted up. I measured the getrag from bellhousing to yoke and it was 31.25 inches. My 727 measured around 28.5. Also my truck is a 1991 with the two piece drive shaft. From reading all the 727 to getrag threads I though everything was more or less bolt on. Could lifting the front and not having the trans on the crossmember cause the driveshaft to not fit?

Exactly what are you referring to by "not fit?" Try counting the splines on the pieces you are attempting to mate up. IIRC, the rag has a higher spline count somewhere, but not sure.

When trying to install my driveshaft i cannot lift it up all the way to the center support or the drive shaft will bind and not move anywhere. I can lift it up to about 4" down from the center support and 3" from the left of the support. It seems like the drive shaft or getrag is too long or I just have the getrag at a very bad angle where the driveshaft won't fit properly


What do you mean by counting splines? On the yoke?

Yes, I'd at least start by fitting each end - separately if necessary - to confirm the parts are going to mate correctly. I would have thought the Getrag was overall shorter than the 727, requiring a longer shaft, but what do I know?

^ That right there says you need to shorten your driveshaft.

That's the part I don't get. I read more than a dozen 727 to getrag threads and none of them mention shortening the driveshaft. But it seems the 2wd versions are different from each other. I measured the front driveshaft length. This is front carrier bearing to center of u joint: 35.5" for the one I have now and 32" for the correct one. Don't have the crossmember in just yet since I'm waiting on the mount for the getrag version. So the proposed new length might change

I looked up '90 D250 driveshaft on car-part.com and it shows a different part for auto or manual on diesel.

Yea found a salvage yard that has 2 rear drive shafts for $75. Thought the 2 transmission would be the same for the 2wd guess that's not the case. Only for the 4wd. Sucks to find out this way. Thanks guys

Not sure how to edit my posts so apologies for the double post but would a d350 driveshaft work? I read this one thread posted below about how the guy had a getrag d250 with no drive shaft, bought a drive shaft out of a getrag d350 and was 4 inches too big. Then he bought a drive shaft out of a 727 d250 and it was the right size. All trucks were single cab like mine. There is a d250 drive shaft 2 hours from me and a d350 shaft an hour from me would like to get the d350 since it's closer but I'm afraid it's going to be too long.

driveshaft questions - Dodge Diesel - Diesel Truck Resource Forums

Too many wheelbase possibilities to assume anything. How about having the sellers use a tape measure?