Help with 4.10 gear install

[crom]

I plan on installing my 4.10 gears myself with a little help with some folks who work in the base auto hobby shop. I've been told by quite a few folks that ford gears are pretty straight fwd as far as install. My MM has 15,000 miles on the clock. I'm looking for any tips and if possible if someone could pm me or reply here, with the Tq specs etc. required to do the install. Any assistance would be greatly appreciated.

[hdwrench]

id be interested in learning more about this too... im sure it is not all that hard but i dont have a service manual or anything...

[BillyGman]

I've installed the Ford gears in my Marauder. You can perform this job yourself, but you had better be meticulous about making the required measurements, and shiming the pinion and the differential properly!! I was successfull at it twice, so I know there are others here that are mechanically inclined who can do this successfully as well. I performed the job twice because after installing the 4.10 gears, I wasn't satisfied, and I decided to install the 4.56's.


Ford gears are the way to go. They usually do NOT require any change of shims for the new pinion gear(you can usually use the old shim), but the pinion depth should be checked anyway with a depth micrometer. You also need to check the pinion depth of the old pinion right after removing the ring gear and differential, and BEFORE loosening the pinion nut. That will enable you to make a comparisant of the depth measurements from the old and new pinions. They should be within 3 or 4 thousandths of an inch.And whatever you do, do NOT neglect to check the gear contact pattern with the white marking compound!!! That's very important that you see the correct marking patterns on the teeth of the ring gear!!!! You should get a good manual which shows you pics of how it should look, or go to a website that shows that. If you don't get that correct then you could literally blow-up your rear end so badly that the housing comes apart in pieces!!! I've never had that happen, but I've been in communication w/those who have. And they said it wasn't pretty.

I can give you more advice on this, but it's just too lengthy to write out. So whoever is interested, please feel free to write to me, and I'll have you call me and I can explain some things over the phone. For those of you who have worked on cars before, and are mechanically inclined, you really shouldn't feel intimidated about performing a gear swap. However, you shouldn't be careless about it either, and you really do need to do your homework, and pay attention to detail, and be willing to take your time on the job. This isn't something that should be done in a rush during the first couple times that you tackle this!!!!! One more thing.......you should forget about using the original pinion bearings again even if your car has only a couple hundred miles on it. particularly the large pinion bearing since it has to be pressed off of the pinion shaft. And the clamshell tool that has to be used to press the bearing off of the pinion shaft distorts the cage of the bearing. Oh, and another thing.....when you're removing the differential from the housing, you'll have to pry it out of there. There's a trick to doing that w/out the whole thing flying out of the housing all at once, and onto your head. I can explain this to you over the phone also. But while you're removing it, you need to pay close attention to which shims are on the righthand side, and which ones are on the lefthand side of the differential, since different ones will be on each side, and you'll most likely need to replace those same shims on each side again once you get pinion gear, installed, and the ring gear bolted onto the differential.

BTW, the torque on the differential bearing cap bolts is 65-77 FT/LBS. And the ring gear bolts should be torqued to 65 FT/LBS. But you shouldn't use the original ring gear bolts. Instead use the ones that come with the ring $ pinion gear set since they're case hardened. And you should use red lock-tite on the ring gear bolts. That's very important!!!!! The driveshaft bolts should be torqued to 83 FT/LBS. and you'll ned a wheel puller to press-off the driveshaft flange, and an inch/LBS DIAL torque wrench to measure the pre-load on the new pinion bearings (very IMPORTANT!!!!)(the pre-load should be set to 25 inch/LBS for new pinion bearings). The housing cover bolts should be torqued to 30 FT/LBS.

If you're following the advice of anyone who tells you that any of these things I've mentioned can be overlooked, then you're listening to the wrong person, and you're headed for trouble. You can do this job, but it's nothing to be taken lightly!!!

[BillyGman]

Below you'll find some pics of diagrams that relate to a gear swap in the Ford 8.8" rear end (which ofcourse is what Marauders and Mustangs have). The first pic is an exploded view which you'll notice has each part numbered. The second pic is the part names listing w/the corresponding numbers from the first pic. Note that in the third pic you'll find a a dial indicator being mounted w/a magnetized block onto the rear end housing in order to measure the backlash which is absolutely what you'll have to do in order to make sure the backlash is correct (.008" to .012" is the usual spec for the Ford 8.8" rear, although the Ford Manual calls for a slightly tighter spec of .010" to .012" for the CV. GM, amnd Marauder ).


The fourth pic is a tool that you'll have to make out of band iron by drilling two holes in it which will line-up with two of the four holes on the driveshaft flange. This tool will have to be bolted to the flange using two of the four driveshaft flange bolts in order to prevent the pinion from turning while torqueing the pinion nut to compress the crush collar until the preload of 25 inch/LBS is on the pinion bearings. This will take about a good 175 FT/LBS of force to turn the pinion nut the last two turns or so. I used a four foot plumbing pipe slid over a big ratchet to perform this task. This is the fun part of the job and takes a little muscle. ;)

And in the fifth pic you'll see a diagram of how you'll need to use a prybar and a thin piece of wood (or anything lese that's softer than the iron housing) to pry the differential out of the housing once you've loosened the differential bearing cap bolts. Like I said, there's a trick to doing this w/out having the whole differential come flying out on top of your head!!! If you're intersted, then you'll have to write to me since these two posts have been long enough.

[crom]

Billy, Thanks for all the info. I just received my gear set. It did not come with new bolts. It had a set of shims, crush collar and pinion nut. I'll see if I can order the bolts from my dealer along with the pinion bearings. I've also got a couple of guys here at the base auto hobby shop who have done alot of gear installs that said they will help me. I work on aircraft also, have been doing it for 20 years in the Marine Corps. Again, thank you for your reply and sharing/passing on this info to me, mucho appreciated brother!

[Bradley G]

Hey crom,

congrats on the patience on the 4:10's I have had mine for a month (programmed)I did not have the correct tools and courage to tackle this mod.I was thankful I had the resources to have a experienced wrench install them.He was very through and warned me accordingly about potential noise and vibration and of course voiding the warranty on the Rear end.Which I learned here first .Good luck Let us know what you think.You have to Reprogram the EEC to correct speedo there are Vendors here to help you with that .If you want any suggestions from someone who experienced the learning curve first hand Pm me and I'll save you some grief.
Bradley G

[BillyGman]

You'll defonately need either a chip, or a handheld tuner to correct for speedometer changes that the new gear ratio will create. And you can go to summitracing to order the installation kit online or over the telephone which includes all the bearings along w/the ring gear bolts and also the pinion oil sel which you'll also need. Here's the link to that...


http://store.summitracing.com/default.asp?target=partdetail. asp&part=RAT%2D305K&applid=%7BD6223085%2D6AD9%2D43 5D%2DBF0C%2D0E6F5D58F50C%7D

[crom]

I ordered the hand held tuner from Dennis so I'm covered there. I saw that kit on Summit but from what I've seen said here and by the folks who are helping me with the install I shouldn't need all of the stuff that comes in the install kit. I talked to the parts guys at my dealership and other than the shims ( which came with the gears) they said I can order the pinion bearings, bolts and seals from them. In fact most of it they have on hand already. It would be nice to have the install kit, but I'm on a tight budget. Not trying to cut corners mind you (before you say it Billy) just trying to kep the cost down. That's one reason I'm doing the install myself, plus I've done similiar things and then some on all types of aircraft. That and the enjoyment and satisfaction of doing it yourself not to mention the knowledge and experience gained. Oh yea, I almost forgot. I work part time here at a local auto parts store so I'll look into ordering the stuff from there since I get a 20% employee discount :D

[BillyGman]

naw, I wouldn't say that you're cutting corners for not purchasing the complete installation kit. That's understandable because it is true that you don't need everything in that kit. And yes, you can just purchase the specific things you need. You should get both the large and small pinion bearings, pinion oil seal, and ring gear bolts along w/some permananet Loc-tite (red) for using on the ring gear bolts. You'll also need some black permatex gasket sealant as well as a cover gasket. other than the ring & pinion gears that's all you'll need. You don't need to replace the original differential bearings unless they look bad. let me know how it turns out. ;)