Many questions about my rear end.

[fmontez1]

After much help from FBBO, I've gotten my 68 coronet, 318/904 going, and she runs great.

Of course, if it's it's not one thing, it's another, so the next thing to go seems to be something in the rear. From what I've been told on here, it's probably a wheel bearing.

Anyway, the rear end is the only chunk that has not been gone through/rebuilt or completely replaced.

I don't really want to have to take forever fixing this myself, I want to drive my car.

What I'd like to know, is what should I buy and take to my mechanic? It will be primarily a street car, some freeway driving, and I was wondering what gears you all think I should put in the back. I just want it to be fun, its a nice 318 with a 650 holley/alum intake/mild cam/headers/TTI H-pipe/mazzolini trans/ high stall converter. Nothing has been done to the rear end as long as I've owned it (About twenty years) but now the rear is starting to make a clunking noise.

I learned on here how to ID my rear, and its a 741 case, in case anybody here has parts.

Like I say, I'm not looking for diagnosis, the rear needs servicing now any way you slice it. But what are good parts, what should I pay, and whats a good gear ratio to slap in there?

Thanks for any info. It's 12/31 and I promised myself 2014 would be the year of the car, even though shes had a couple of good years recently. I want to finish this project. I'll probably look around till 1/15 then buy everything, so until then I'll consider any and all advice.

 

[Cranky]

The clunking could be u-joints or the bearings are going away on the pinion. Wheel bearings usually don't cause a clunking but will growl instead. When does it clunk? When you put it in gear or go from reverse into drive? Also, do you know what gear ratio is in it? And you might be better off just buying another chunk (3rd member) that's ready to bolt in and once you pull the axles for the swap, you can check the bearings.

 

[super-bee_ski]

Like Cranky says...look there because,
I just helped a guy re-build my 78 Gremlin rear-end with 500,000+ miles on it. Totally WORN out!
And, it never made a clunking noise...
It did "whine"

 

[fmontez1]

Like Cranky says...look there because,
I just helped a guy re-build my 78 Gremlin rear-end with 500,000+ miles on it. Totally WORN out!
And, it never made a clunking noise...
It did "whine"

I meant the clunking is wheel bearings, but Im going to have my rear end gone through anyway. Im not saying the clunking comes from the diff, I just want to rebuild the rear end because its not done yet.

The u joints and driveshaft are new.

It clunks on deceleration, sounds like a loose lug nut but its not. Dont really feel any play in the rear axles, but like I say, I'm gong to go through this anyway. Also going to get new leaf springs while I'm there, but I think I can figure that part out too.

Thanks again.

Edit: BTW It does whine a little bit, more on decel. I've heard bad rear ends, mine doesn't sound terrible, but I want to refresh it either way. Its the only weak link I have right now.

Edit 2: Call me crazy, but I'd love to keep my original center section too. I want to keep anything I have original to the car. Already too late for engine trans.

 

[wedge69]

If it Clunks when you go from park to drive or Drive to reverse I would look into the carrier. You spiders could be worn or your cross pin seat in the carrier itself. If thats the case a newer posi would be in oreder !?!?
If its not Growling or Whinning I would say you pinion bearing and axle bearings ar Not the problem.
Also I had one here that did that and found the Carrier bearing them self failed and it was flopping the ring on and off the pinnion. SO you won't know what you need till it on the bench .

 

[terzmo]

I meant the clunking is wheel bearings, but Im going to have my rear end gone through anyway. Im not saying the clunking comes from the diff, I just want to rebuild the rear end because its not done yet.

The u joints and driveshaft are new.

It clunks on deceleration, sounds like a loose lug nut but its not. Dont really feel any play in the rear axles, but like I say, I'm gong to go through this anyway. Also going to get new leaf springs while I'm there, but I think I can figure that part out too.

Thanks again.

Edit: BTW It does whine a little bit, more on decel. I've heard bad rear ends, mine doesn't sound terrible, but I want to refresh it either way. Its the only weak link I have right now.

Edit 2: Call me crazy, but I'd love to keep my original center section too. I want to keep anything I have original to the car. Already too late for engine trans.

if it's not broke..why do it...Under normal driving conditions, I never heard of a rearend going bad as long as it kept it's lube....wheel bearings...yes...8 3/4 nope

 

[super-bee_ski]

X2

Again, my 78 Gremlin has 500,000+ miles and I HAD to rebuild cuz it was whining....

I would LIKE to think a 8 3/4 rear end would hold up on a 318 car for a long while.

 

[bigmanjbmopar]

I'm still laughing at this one "Many questions about my rear end" lol are you asking if your *** looks big? That sounds like my wife lmao

Anyway, the guys are right, when you do you hear the clunk? while moving forward slowly or high speed on the freeway? or when you drop into drive or reverse? If your going to have your *** gone through (lmfao) then you should replace the u-joints anyway as a preventive maintenance item.

Sorry for funnin' on you man just kidding.



I have 3:55 gears and run around 2500 rpm at 60 mph 2800 @ 65 so depending on what you want t do with your care like just cruising then go with 3:23 gears so your not reving as high. Go to Mancini Racing for good factory parts. http://chucker54.stores.yahoo.net/ma493ci440fl.html

 

[69Bee]

X2 ^^^ First thought I had too... :eusa_dance:

 

[wedge69]

Hay look at the rear I put in my runner ! Now thats a BIG *** REAR !!!!

 

[Seax440Dodge]

My wife used to ask me questions about her rear end.... I told her if she kept asking I was going to "check her diff fluid".... she quit asking for some reason

 

[NJRR]

I was waiting for R/C to be the first one to bring that up !!! LOL

I'm still laughing at this one "Many questions about my rear end" lol are you asking if your *** looks big? That sounds like my wife lmao

Anyway, the guys are right, when you do you hear the clunk? while moving forward slowly or high speed on the freeway? or when you drop into drive or reverse? If your going to have your *** gone through (lmfao) then you should replace the u-joints anyway as a preventive maintenance item.

Sorry for funnin' on you man just kidding.



I have 3:55 gears and run around 2500 rpm at 60 mph 2800 @ 65 so depending on what you want t do with your care like just cruising then go with 3:23 gears so your not reving as high. Go to Mancini Racing for good factory parts. http://chucker54.stores.yahoo.net/ma493ci440fl.html

 

[fmontez1]

I swear. Every time I open my mouf. Haha let's keep my *** out of this and focus on the nuts and bolts here. Right here.

Okay, kidding aside, the yoke was a little wet when I put the driveshaft in, so I know some type of seal in the front facing part, the seal where the yoke is, is probably bad. I don't think it's ever lost all it's lube, at least not in my possession (man, the rear end joke potential here is nasty)

As for the clunk, I don't mind getting new u joints again, it's not the end of the world. Makes sense too cause it does kinda sound in time with the tires. It's on deceleration, it goes away when I hit the brakes. I thought maybe loose parking brake. It works, but not that great. It'll hold the car in drive on level ground, but on a slope in drive, it'll roll. I think I'll also grab a trans mount while I'm there.

Thanks for the advice! A couple of you guys have helped me a lot in the past too. Appreciate it, and the car does too.

 

[bigmanjbmopar]

The yoke has a plug in the center like a freeze plug and they leak some times just replaced mine over the summer.

 

[Texpar]

another thing you might double check is to make sure your rear shocks are tight and not moving. The slightest movement will cause noise. usually its the top that causes issues. They could chatter or clunk with deceleration until the brakes are hit and a load is put back on them again.

Oh and on gear size if your primarly going to cruise and not a lot of long trips I would go with 3:55. It will help make up for small block torqe (or lack of). You siad you put a high stall converter in? how high? if you went real high you dont want to put too small of a gear in or the converter is kind of in stall mode all the time.

 

[fmontez1]

Yaknow, I bought the tranny and torque converter a long time ago, it was the street strip level trans, and a hughes converter, from Bob Mazzolini. I told him what I had, and he gave me the parts.
Tell ya what, Im gonna try and call him today and see if he keeps those kinds of records. 3:55 sounds about right too, from what I've read. I doubt I have those in there now. Were the different gears an option back in the day? Or was it based on engine setup?

Edit: Just got off the phone with Mazzolini, sounds like I either have a Hughes 2000 or 2500, nothing fancy he said.