Driveshaft length after 4tr/3tc conv.

[Western Slope]

In process of adding 4 speed transmission to 3 spd. T/C of the '72. I've several questions about what will have to be done to presumably correct the resultant problem of incorrect driveshaft length. Any and all help to size up this problem would be appreciated.

Can specialty shops lengthen and shorten these?
Is the change a known amount for this conversion?
Can it simply be measured with tape or is it more critical that that?
Do I need to worry about reorienting them on vehicle correctly or does rebalancing them eliminate that need?

Thanks again.

 

[woody]

easiest? get a set of stock 4-speed shafts and drop them in...you'll need to change pinion flanges at both axles too, but you gain the stronger-larger u-joints with the later shafts.

Most driveshaft shops can work with them, but they are metric-diameter tubing and not all carry it (well, my local ones don't...)

So long at the joints are in phase, it's balanced...any shop that changes lengths "should" automatically rebalance them

 

[CRZRJames]

There are several places in Dallas that can do the work of either shortening or lengthening a driveshaft. The last time I had it done it cost me $85 each. One was lengthened and one was shortened.

It will cost more to balance it. There is no need to balance the front unless you drive on the highway in 4WD. There is no need to balance either if it's a dedicated trail rig.

Best way to measure is from center of flange to center of flange. Take your old driveshafts in and give them the measurements and they will know what to do.

Good Luck,

James