FJ 55 4spd conversion, drive shaft issue? (1 Viewer)

[marlow]

Hello,
I recently converted my 68' FJ 55 to a four speed transmission and transfer case, all went well except for the drive shaft issue. I have access to the original 4spd driveshaft, the only problem is the flanges on the 68's axles are the small bolt patter and the transfer case is now the large pattern. One thought is to use my 3spd transfer case and shorten/lengthen the original (3spd set up) drive shafts. The other option (not sure if this is possible) use the flanges from the 3spd transfer case on the 4spd transfer case and shorten/lengthen drive shafts. Any thought. would be greatly appreciated.

 

[hicruise55]

Using the 3 spd transfer on the 4 spd trans will net you a lower crawl ratio, but will require some more adapting.

Easiest thing to do is pull the slip yokes apart (splines) on the driveshafts then connect the two ends that you need, making sure the ujoints are still in phase- ujoints at same angle as the one on the other end.

 

[65swb45]

1. Welcome to MUD. I invite you to post more information about yourself and your rig at your earliest convenience. Pictures are also nice.

2. You have a third option, which is to acquire the larger pinion flanges that match the 4 speed driveshafts and install them on your diffs. This will net you flanges and driveshaft bolts that are far superior to cobbling a system together that retains the 68 driveshaft flanges and bolts.

3. Flanges are cheap. I should know. I sell them.

Best

Mark A.

 

[hicruise55]

I didnt know you could put the newer (larger) flanges on the older pinion shaft- thanks for the info Mark

 

[marlow]

Hi Mark,
That sounds like a good idea considering I have access to the drive shafts that came out of the donor 4sd vehicle 74'. How much are your flanges and what measurement do you need from me. The donor vehicle was a 74' and my truck is a 68'. Thanks