Drive Shaft Is Too Long

[Ranger83]

I just bolted up my new tranny to the block. My drive shaft is extendable. I've made it as short as I can but it is too long. There is a nut on top of the differential where the drive shaft bolts to it with 4 bolts. This bolt is what is catching my drive shaft. I only need about a centimeter more room to get it on. I figure there is 3 ways to do this.

1. Cut and weld a shorter shaft
2. Grind down the nut a little bit
3. Jack up the rear end and pull the entire axle back

I do not have access to a welder. If anyone has any ideas to make this work. Please let me know. My truck is so close to moving again and I know it misses the road.

Also let me know if pictures would be helpful

 

[krugford]

What tranny did you swap in? If you can't get it to bolt up now, you may have to either shorten your current shaft, or get another from the junk yard.

I would avoid options 2 and 3, it's going to bind when the suspension compresses.

 

[Wicked_Sludge]

2 and 3 are not options.

your driveshaft isnt "extendable". it has a slip yoke on it which allows it to stretch and compress as the suspension cycles. if you jam the shaft on there with it fully compressed, the first time you hit a bump, you will damage something (t-case, differential, or the shaft itself).

you need to either find the proper length shaft from a stock pickup (there are lots of options since there were many different wheelbases and transmissions used in these trucks), or have your current shaft modified at a shop (this isnt something the average home mechanic is equipped for as the driveline needs to be perfectly centered and balanced after its shortened).

 

[Ranger83]

thanks for the info. The tranny is from an '89 Lincoln Town car.