I decided a few weeks back to change the gear ratio from 3.55 to 4.10 due to my new towing requirements concerning the increased weight of our new TT. I've decided to start with the front as it's always the worst one when it comes to the amount of work involved and the fact that there may be plenty of parts that need replacement. I've got it broke down already, as of 1500 today, and found a couple of things, nothing too serious though. I have an outer u-joint that is frozen, there are two ball joints that are loose but I had planned to install new ones during this process anyway. I also have to figure out why one of the MM stainless manual hubs is just spinning when you lock it, unlocking it works fine. I'm sure the c-clip is out.

The differential bearings are good, as are the pinion bearings so I'm not even changing those. I left the beams installed, just pulled the center "chunk" from the beam and will be setting up the R&P on the bench.

As for the rear, I have to swap the rear leaf springs out as they are twisted for some reason (probably a previous accident from an old owner) and I'll be installing used F350 springs and blocks. Anyone know if I'll need the shackles to go with or can I use my factory ones?

I believe this whole endeavor will only cost me $500. Both R&P units are used in very good condition and the setup kits totaled $100. The ball joints I had from another truck I sold before I installed them and really, it's just fluids and an alignment after that.

Can't wait to drive it after the install.

 

Do you have the "chunk" from the donor TTB gears? I think it would bolt in, no gears to set up.

The F250 and 350 rear shackles are the same.

 

R&P came out of a straight axle D50 so no.

 

Nice. Am curious to see how hard it you find this task.

Do you plan to put a drain plug in the chunck or front "cover"? Seems Ford forgot one...

 

I've done four of these swaps in SD trucks. I've finished the front axle today, it went very fast with the chunk removed from the truck. I'm waiting on an outer u-joint to finish the front and I'll start on the rear axle tomorrow.

I'm not installing a drain. I have a vacuum pump to remove fluid.