Diy for diff replacement?

[euroZ06]

Is there one? I cat find it. Ive never done it, but good at following directions.

[John_Kunkel]

The FSM has all the info you need, you can download one for your car at:

http://www.mymopar.com/index.php?pid=109

[Cooter]

Depends on which diff and what you are doing as to skill level. I certainly wouldn't suggest a newbie jump into setting up a Dana 60, or even an 8 3/4 chunk. However, just replacing the entire center section can be done by beginners just hafta pay close attention to axle bearing end play.

[440]

Not to sidetrack but has anything ever gone seriously wrong here by a "beginner"?

[John_Kunkel]

Everybody here was a "beginner" once; to discourage beginners from attempting to raise their status defeats the purpose of these forums.

[Lord Warlock]

Not to sidetrack but has anything ever gone seriously wrong here by a "beginner"?

When I was a beginner, I stripped out all but two trans bolts from the transmission pan.  Its one of the reasons why it replaced it with the matching number trans that went with the motor I have now.  Think that counts as seriously wrong.

[Cooter]

Not to sidetrack but has anything ever gone seriously wrong here by a "beginner"?

When I was a beginner, I stripped out all but two trans bolts from the transmission pan.  Its one of the reasons why it replaced it with the matching number trans that went with the motor I have now.  Think that counts as seriously wrong.

Although some here would have you believe trying to steer people away from putting a big ol "D" up their own ass (after all, there's enough threads about how someone got hosed taking their car to joe blows body shop for restoration right?)
THIS is what these forums are truly for. Why even ask the question if you do not care about getting screwed? Helping others avoid the pitfals that come with experience is what these forums are truly about.
otherwise, you'd have Ron and Challenger340 never answering questions, just posting: "I know all, I've done all, send me your engine and I'll make your junk fly".....

We already have enough pompous 'businessmen' here that love to post dyno sheets about how badass their builds are, but refuse to help when it counts. Not that anyone's asking for the gold key to the crapper, but damn, is EVERYTHING in your posts "proprietary"

As for myself, was a beginner and if it wasn't for my autoshop teacher in HS (yes, we didn't have Google to get ourselves into trouble, or pull us out of it) there was so many things that if his experience hadn't stepped in, Ida f*coed my 65 up royally.

[John_Kunkel]

When I was a beginner, I stripped out all but two trans bolts from the transmission pan.

That's the first thing you did wrong, the second thing you did wrong was to replace the whole trans rather than buy a $30 Heli-Coil kit to repair the existing trans in the car.

[Lord Warlock]

30+ years ago when I did it, no one had a solution besides drilling new holes and tapping new threads, which we did try, still leaked afterwards even with a lot of silicon sealer, the engine made up my mind for me, blew up the 440 and had put a 383 in, and drove it like the 440 till it broke and I got a 3rd 440/727 combo out of another 69 charger r/t locally, and swapped both into my car. All by myself in the parents garage.  After two engine swaps and a trans swap, I vowed not to do that again unless forced to, and the drivetrain I got had 69k original miles and was a numbers matching 69 RT charger, figured I'd never get another motor as close to correct as I have, so stuck it in storage and let it age. 

[ws23rt]

We were all beginners. We all made mistakes and that's how we learned.
One can be told something important but there is nothing like learning why the old fashioned way.
I learned about left hand lug nuts with my first car (57 Desoto).  I broke off three before my friend told me about them. 

Not long ago my old friends wife (He has passed) called me to help with a homemade trailer that needed tires. The tire place she took it to stripped the threads on two lugs and gave up.

The first thing I saw was the left hand threads on the studs. (just by looking at the exposed threads). If I had not had the early learning experience I could have been miffed as well.

My point on this is that the things we learn when we really need to learn them will last like no other.

I for one appreciate those like cooter that want to share our/their hard learned experience.

A newbe to these cars that has little experience with them has come to the right place. We are many and with the stories and scars on our hands and ego to show for it.

The main reason I come back here a lot is to learn about how the cars of my passion can be upgraded.  Their is something to be learned from every one.

[euroZ06]

Depends on which diff and what you are doing as to skill level. I certainly wouldn't suggest a newbie jump into setting up a Dana 60, or even an 8 3/4 chunk. However, just replacing the entire center section can be done by beginners just hafta pay close attention to axle bearing end play.

Thanks.

I tried opening the file, but my tablet is unable to open zip file

I know my driver side axel is bad, and i need to replace it, the guy that was originally going to help me had a spare one, but after last project we did together declined to help. So im on my own now.

So drain diff fluid, unbolt the driveshaft, unbolt the bolts holding the diff, and it should pop out?

Currently i have 741 case with 3.91 posi, i found 489 case with 3.23 and posi. Do i need to make any other modifications or have things handy? Will it bolt right up?

[Lord Warlock]

The axles come off from the housings, you can rent the tool from autozone and get them off in about 10 minutes each.  I had another one of those teaching moments while trying to cut a frozen rear drum off...cut the axle flange too...hence replacing one side, replaced 2nd side because they weren't that expensive and had ordered a pair.  May be able to dig up a link somewhere.

I was replacing the brakes and one side was stuck on, extended that project by several weeks while waiting for parts to arrive in the mail.  Now have two new axles. 

Only reason to mess with the chunk in the middle would be if you're swapping gears or have a posi problem.  Yanking the axles meant you didn't have to drain any fluid, much less remove the driveshaft.  I doubt the gear portion of the housing will just drop out, wouldn't be surprised if there was a trick to it. 

For the axles, you'll rent a 3 or 4 prong wheel puller and slide hammer, it'll take about 5 good whacks with the slide hammer to pull the axle/seal out of the housing, more if it decides to get stubborn.  I pulled my factory axles out pretty quick once I got the drum brake drum off.

[euroZ06]

The axles come off from the housings, you can rent the tool from autozone and get them off in about 10 minutes each.  I had another one of those teaching moments while trying to cut a frozen rear drum off...cut the axle flange too...hence replacing one side, replaced 2nd side because they weren't that expensive and had ordered a pair.  May be able to dig up a link somewhere.

I was replacing the brakes and one side was stuck on, extended that project by several weeks while waiting for parts to arrive in the mail.  Now have two new axles. 

Only reason to mess with the chunk in the middle would be if you're swapping gears or have a posi problem.  Yanking the axles meant you didn't have to drain any fluid, much less remove the driveshaft.  I doubt the gear portion of the housing will just drop out, wouldn't be surprised if there was a trick to it. 

For the axles, you'll rent a 3 or 4 prong wheel puller and slide hammer, it'll take about 5 good whacks with the slide hammer to pull the axle/seal out of the housing, more if it decides to get stubborn.  I pulled my factory axles out pretty quick once I got the drum brake drum off.

Im replacing it cause i got orders to go to germany and want to take the car with me. Currently i am at 3k rpm at 50mph and at 8mpg. So i think 3.23 will be much better for the autobahn, so i can cruise at 80mph or so... Is my lodgic flawed?

So to pop axels i need to rent a special tool, ok. What do i have to do with the brakes again?

[Lord Warlock]

If you are swapping the gear ratio, you're swapping the main gears in the chunk in the middle, but you may have to pull the axles out a few inches so you can get the middle piece out.  Haven't done that in a while.  Did a 66 mustang gear change once, since then its one of those cheap things to pay a shop to do.  I paid a shop to do the gears on my 2000 GT mustang and it cost about 200 in labor. 

If you have any gears higher than 3.73, I'd probably go with the 3.23's to ease the strain of driving at 80.  I've always had 3.23's in my RTSE, and it isn't bad on the interstate.  I only checked gas mileage on mine twice first time was with the original motor, stock everything and and was getting 6-8mpg city and 14 on the highway, so your gas mileage won't save you much.  Got 15 on the highway with the 383 installed.  Your logic isn't flawed, the lower gears will make it rev less at highway speeds.  After realizing how bad the gas mileage was, I thought a moment, and came to the conclusion that I didn't buy the car for gas mileage, and didn't really care to ever measure it again afterwards. 

Oh, the tools you'd need to pop axles is just a flange that bolts to the wheel studs, and a slide hammer to tap them out. any parts store sells them, but autozone will lend it to you for free (refundable deposit)  The brakes, rear drums I assume, wouldn't really have to be messed with, the drum cover has to come off to get to the flange, but it isn't connected to the brake parts so you can pull it straight out.  I had mine disassembled for a rebuild with new parts, but the axle has a bearing that is press fitted into the axle housing and a slide hammer makes the job go quicker getting it out.  Getting the back in is reversed, slip them in and slowly turn until they fit the teeth of the differential, and tap in with a hammer on the flange till seated, or the bearing is all the way in.
If I was being deployed soon, I'd pay someone to swap the gears out for me, it takes someone with the right equipment a couple hours, it would take me all weekend.  Nowadays I don't mind doing auto work, but lately don't like crawling on the concrete floor, can't afford a lift so have to farm it out.     

After pulling the axles out, it is mainly unhooking driveshaft, ujoint, and getting the gears themselves out of the axle housing.  I've never had my rear axle opened up, so can't help on how to get them apart.  I'd have to look it up.

[John_Kunkel]

You don't need a special tool to pop the axle shafts out, just install the brake drum backwards and install 3 lug nuts a couple of threads on....then use the drum as a slap-hammer.

If your center section has a clutch-type Sure-Grip, be aware that the thrust buttons in the center often fall out when the axles are removed.

Replacing 3rd members will usually require readjusting the axle end play, again the FSM has all the info needed.

[Lord Warlock]

that's an innovative way to get them out, didn't think of that.  Will remember that for next time, if there is a next time. 

[69wannabe]

We were all beginners. We all made mistakes and that's how we learned.
One can be told something important but there is nothing like learning why the old fashioned way.
I learned about left hand lug nuts with my first car (57 Desoto).  I broke off three before my friend told me about them. 

Not long ago my old friends wife (He has passed) called me to help with a homemade trailer that needed tires. The tire place she took it to stripped the threads on two lugs and gave up.

The first thing I saw was the left hand threads on the studs. (just by looking at the exposed threads). If I had not had the early learning experience I could have been miffed as well.

My point on this is that the things we learn when we really need to learn them will last like no other.

I for one appreciate those like cooter that want to share our/their hard learned experience.

A newbe to these cars that has little experience with them has come to the right place. We are many and with the stories and scars on our hands and ego to show for it.

The main reason I come back here a lot is to learn about how the cars of my passion can be upgraded.  Their is something to be learned from every one.

I would like to learn how to set up a differential myself!!! Rear gears and the parts are so expensive that it is something you really do not want to mess up!!!! I have learned alot from this forum and some of the good guy's on here. If I can help with any of my experience I always try to share some of my knowledge and upgrades that I have done on my charger but it seems some members on here seem to want to mock or make fun of others trying to help out or recommend what to try to fix a problem. I do not know all but I try to help out anybody I can, thank goodness for Ron and Pete. Both these fellow's have been very helpful and friendly when I run up on a engine or electrical problem. Like said above their is something to be learned from every one!!!

[John_Kunkel]

In my youth (late fifties), lack of money was the motivating factor that necessitated me learning to do everything myself. With the exception of my auto shop teacher, who was never there when I needed "in the trenches" help, my only reference was an aged Motors Auto Repair Manual...that's why I recommend "the book" for all tyros.

Since the OP is about differentials, I successfully set up my first ring & pinion using the above mentioned Motors Manual, a torque wrench (my own) and a borrowed dial indicator. With the current availability of downloadable FSM's there's no excuse not to have "the book" for your car and it contains most of the info anybody will require for the more complex operations.

[Cooter]

Depends on which diff and what you are doing as to skill level. I certainly wouldn't suggest a newbie jump into setting up a Dana 60, or even an 8 3/4 chunk. However, just replacing the entire center section can be done by beginners just hafta pay close attention to axle bearing end play.

Thanks.

I tried opening the file, but my tablet is unable to open zip file

I know my driver side axel is bad, and i need to replace it, the guy that was originally going to help me had a spare one, but after last project we did together declined to help. So im on my own now.

So drain diff fluid, unbolt the driveshaft, unbolt the bolts holding the diff, and it should pop out?

Currently i have 741 case with 3.91 posi, i found 489 case with 3.23 and posi. Do i need to make any other modifications or have things handy? Will it bolt right up?

Pull the axles, be careful to remove them completely as many times if left hanging in the rear there's a chance the seals can become damaged, once driveshaft is removed make sure yoked are correct and take the same U joints, remove nuts holding center section in, remove partially to drain flu uhh d as there's no drain plug, check to be sure some dumbass didn't lose the thrust buttons inside rear if so equipped, RE install reverse order and set axle end play.

[Sublime/Sixpack]

Everyone has their own preferred way of doing tasks, with that said I agree no special puller is needed to pull the axles loose from the housing (I just use my fingers to yank on them and they generally pop out of place) of course you have to remove the nuts on the retainers first.
If replacing the 3rd member only I pull the axles out about 8 inches on each side so they clear the 3rd member. Once the driveshaft is unbolted and moved out of the way,  the center section nuts can be removed so it can be dropped out. Tip: remove all but the top four nuts then with a drain pan under the 3rd member loosen the top four nuts (this way the remaining nuts will act sort of like a hinge), then push up on the yolk to break the gasket seal so the gear oil can drain out before removing 3rd member. Much less messy that way. Keep in mind that the 3rd member is fairly heavy.
If removing axles be careful that you don't touch the seals in the housing with the splines of the axle ends (the splines are sharp enough to cut the seals). Actually this would be a good time to check the seals and replace if necessary.
Also, the 489 case (3rd member) will have a wider yoke than your 741 case so you'll need a special u-joint to mate your driveshaft to the 489 case yoke.
Hope this makes sense to you, and take into consideration some of the tips others have offered about proper axle end play adjustment, etc.

[John_Kunkel]

Also, the 489 case (3rd member) will have a wider yoke than your 741 case so you'll need a special u-joint to mate your driveshaft to the 489 case yoke.

Not necessarily, the 489 used both the 7260 and 7290 u-joint.

[Sublime/Sixpack]

Also, the 489 case (3rd member) will have a wider yoke than your 741 case so you'll need a special u-joint to mate your driveshaft to the 489 case yoke.

Not necessarily, the 489 used both the 7260 and 7290 u-joint.

My statement was based on all the 489 case 3rd members I've had.  I figured if there was a chance that my statement was the least bit incorrect you'd jump in and correct me. Thank you.

[John_Kunkel]

I almost added to my first post "the majority of the 489's that I've had had the 7260 yoke" but that's the dubious value of anecdotal experience.

[ws23rt]

Just revisited this thread and agree with all the added advice. Most of all what John added at the beginning.

My beginnings with doing stuff myself started with the old motor manuals like chiltons (for example). I soon had questions that those books couldn't help me with and the extra detail the FSM had took care of that.

So with the proper information one is only left with following the instructions. My roadblocks in following instructions came mostly from not having the correct or proper tool for a particular task. This is where a bit of logic and practical thinking helps. Most of the special tools called for are nothing more that ideal. Understanding what needs to be done and a time out is usually enough to overcome those things. Experimenting with hammers and wedges seldom works out well.

The first dif I worked on was a 51 cad.  I had it in pieces when a friend/mechanic (we were both about 17)  asked wtf are you doing? --- Fixing it.--- You never worked on one before and therefore are making a mistake.---Hmm I fixed whatever the problem was using basic hand tools and a chiltons manual. 

Being reluctant to work on something new comes from fear of causing damage/expense. Not working on something new only causes extra expense (paying to have it done).  A big part of the car hobby for me is the satisfaction to be had from doing stuff myself.

[euroZ06]

So any word on how to adjust axel end play?

Also, should i mae a new thread orrrrr can u guys tell me how to replace motor mounts? On that note, car was originally a 400 and now has a 440, should i order 440 mounts?

[euroZ06]

I also would need to refill it with oil, is the there an oil plug? What oil should i use?

[John_Kunkel]

You state that you can't open Zip files on your computer, why not download a FREE zip file opener and use it download a FSM from the site I posted earlier?

http://fyzip.com/download/free-fyzip-download.php?pk=463

You REALLY need a book.

[euroZ06]

Hello,

I just wanted to thank you all for valuable advice! I have successfuly installed my dif in my little car port! Looking back at it, it was an easy job. I picked up refurbished 3.23 posi 489 case. It looked so fresh, i couldnt resist and decided to do the work myself! I tried reading that manual u guys advised on, and that thing kind of confused me, so i asked the guy i bought the dif from for some tips.

So here is how to set the axel end play (if anyone else is going to be searching for it):

Before u pull out the axels, tug on them, the little movement back and fourth is end play. It should be minor, but should be there (to avoid premature wear of bearings). One of the axels (usually the right one, but mine was on the left) will have a tightening ring. After u re-instal the axels (and bolt everything up), tug on the axels again. If play is more than what it was before, ull need to tighten it. The way u do it is using a flat head screw driver ad a hammer. Set the screw driver in one of the groves on the ring and tap until the ring turns a few ticks. Dont over do it, there should be some play, but not too much. Right is tight, left is loose. Thats it! Really simple!


Overall im extremelly happy i went from 3.91's to 3.23's! I wish ive done it sooner! Car feels so much better cruising around town and especially on the highway. I no longer have to hold up traffic in the left lane and can move with general flow. The whole "but its so much faster with 3.91's" is not noticable in normal driving. I got on it a few times and it still pulls like a train! I easily hit 110mph, without having my engine scream at 6k rpm.... Speaking of which, anyone knows what is the top speed with 3.23 and a833? Car should have enough power (425hp/500tq). Once again, ill be takingit to germany, so no issues with speed limits.

[euroZ06]

Also, how bad is it to drive it at high rpm's? Say if i take it to said 100-120mph? 5k rpm or so... Not for long, just a sprint to it. Not sure how reliable these engines are. Mine has mild cam, some aftermarket valve springs, some other minor stuff (440).

[euroZ06]

Everyone has their own preferred way of doing tasks, with that said I agree no special puller is needed to pull the axles loose from the housing (I just use my fingers to yank on them and they generally pop out of place) of course you have to remove the nuts on the retainers first.
If replacing the 3rd member only I pull the axles out about 8 inches on each side so they clear the 3rd member. Once the driveshaft is unbolted and moved out of the way,  the center section nuts can be removed so it can be dropped out. Tip: remove all but the top four nuts then with a drain pan under the 3rd member loosen the top four nuts (this way the remaining nuts will act sort of like a hinge), then push up on the yolk to break the gasket seal so the gear oil can drain out before removing 3rd member. Much less messy that way. Keep in mind that the 3rd member is fairly heavy.
If removing axles be careful that you don't touch the seals in the housing with the splines of the axle ends (the splines are sharp enough to cut the seals). Actually this would be a good time to check the seals and replace if necessary.
Also, the 489 case (3rd member) will have a wider yoke than your 741 case so you'll need a special u-joint to mate your driveshaft to the 489 case yoke.
Hope this makes sense to you, and take into consideration some of the tips others have offered about proper axle end play adjustment, etc.

Damn it, forgot to pull the axels all the way out, hope i didnt damage anything. My right axel seems to be leaking, so prob one of the seals or gaskets has been busted (its been like that for a while). A local guy has a spare axel, so perhaps just replace the whole thing to avoid chasing the issue?

My 741 had a large yoke, so it fit perfectly (3 3/4).

[John_Kunkel]

Resting the weight of the axle shaft on aged stiff seals is a good way to leave a permanent "divot" in the seal lip...guaranteed leak.

[euroZ06]

Is that seal hard to buy and replace? My one axel had a leak for a while now, so i wonder if its from that seal. What else could be leaking in there?