hey guys just need to pick sum brains here, i have an open diff and just bought a lsd and i want to swap them. 1, i allready searched and found and i quote "if you have to ask have a professional do it" I do have reall mechanics doing it but they wanted me do search for any tips or good ideas that will make it go easier. so i am wondering about how to do the swap and then their question was if i could find any info on what the backlash (correct me if i am saying it wrong) should be and stuff so please dont come back and tell me to search or this is the wrong forum all i would like is sum possitve feed back

 

You are planning on swapping the carriers...and whenever you are swapping carriers, the ring gear is being installed on the new carrier....AND you'll need to check backlash and the contact pattern on the ring gear.

To fully answer your question...WE NEED TO KNOW WHAT AXLE YOU ARE WORKING ON.

On a Ford 8.8", 11-16.
On a Ford 7.5", 11-16.

 

At first you say you want to swap them then your talking about the backlash which are you doing?
Changing out the whole axle or just the gears

Changing the axles would be a lot easier then changing the gears. And if a mechanic has to ask questions on a forum I don't think they should be working on your truck. Dont they have access to books with the numbers?

 

Here is my $.02

I have been setting rear ends for over 15 years and cant count how many I have done at this point.

If you use a Ford LSD or T-lok you can get away with just swapping the ring gear over from the open diff to the LSD and reinstall just the way it was,no reshimming.I have dont this 100's of times and as long as your using Ford parts I have never had a pattern change for the worse or had to change the backlash.

Reason for this is when Ford builds the 8.8 on a essembly line they dont have time to mess with changing shims and checking patterns.Everything is machined to exact tolerances so they can be thrown together as quick as possible.They use the same .028 pinion shim,carrier shims,bearings,races,etc in every rear that goes down the line and they all end up within spec.That being said if you remove a open diff and install a FMS Traction Lock diff {or one from another Ford 8.8}you can swap the ring gear from the open onto the new diff,add new Timken bearings and races and reinstall in the exact order it came apart in.Everyone I have done sets up perfect.I always double check on a customer vehicle to be safe but I havent bothered to check any of my own in a long time.

If your not using a Ford diff then throw all this out the window........

 

I will note: when my torsen limited slip diff didin't work with my 4.88 ring gear, i electedto put in a stock open carrier. My gear installer did the swap for me and i watched him do it....the mesh pattern and the backlash were still perfect w/o any additional carrier movement left to right(no extra shimming).




First and foremost....wtf is your 'mechanic' doing asking you do to research for them!?!?!?????

Secondly....Take this to a differential shop...should only run about $100 for carrier install and utilizing the stock gears. An axle shop would not ask you to do their research for them. Are you kidding me? Seriously?

 

Thats what I did about 10,000miles ago.

 

ok guys well the guys that are going to do the work for me work at monro and off the books they have done all the work on my truck since day one in 2003 so i trust them as for the dif it is a ford product lsd out of a used 8.8. so i am assuming that all info from deathbypsi is good then. just to clear things up my truck is an 2003 xlt 4x4 4.0 5sp supercab 8.8 rear open diff and i just want to change from open to the lsd. I also whole heartedly agree if a mech. has to ask i wouldnt let them do it but i know these guys all my life and trust them it is like my truck and our project lol . btw how did that work for ya goodysgotauda did it make a good improvement??