Im getting ready to tear apart both axles on my 85 BJ70 and Im considering putting it back together with center sections from a 78 FJ40.
I dont see any issues to address besides the driveshaft bolt pattern is different between the two. I dont think this is much of an issue though because I can use the end from a FJ40 shaft on each of the 70 shafts to mate to the 40 diffs.
The main reasons to use the 40 parts.
1. The stock BJ70 diffs are 3.70 and the rear needs a rebuild - the 40 diffs are 4:10. The 70 needs diff work and lower gearing would be nice.
2. I already have the 40 diffs and they are in good shape with one of them rebuilt and the other a little used front diff. This would save $ vs rebuilding the 70 parts.
What am I missing? Why shouldnt I use the 40 diffs for the 70?
Chris
I dont see any issues to address besides the driveshaft bolt pattern is different between the two. I dont think this is much of an issue though because I can use the end from a FJ40 shaft on each of the 70 shafts to mate to the 40 diffs.
The main reasons to use the 40 parts.
1. The stock BJ70 diffs are 3.70 and the rear needs a rebuild - the 40 diffs are 4:10. The 70 needs diff work and lower gearing would be nice.
2. I already have the 40 diffs and they are in good shape with one of them rebuilt and the other a little used front diff. This would save $ vs rebuilding the 70 parts.
What am I missing? Why shouldnt I use the 40 diffs for the 70?
Chris