8 3/4 rear ends, both axle shafts adjustable end play?

[madmike]

'68 Charger, 8 3/4" rear end, 3:23 gears, open.  I bought the car as a roller, so I have no history on it.  This is the first time I've ever worked on the 8 3/4" rear end.  While looking at a leaking passenger side rear axle wheel seal, I noticed that the passenger side axle had an adjuster nut for setting bearing end play, and that the end play was very small.  The driver side did not have an adjuster, but the end play was significant, maybe almost an eighth inch.

I'm guessing that the car originally had a non-adjustable bearing on both sides, and someone in the past must've repaired one with excessive end play by installing an adjustable set up.  Shouldn't both sides have the adjuster nut for setting axle end play?

Since I have one side with an adjuster, and the other side needs to be fixed, can I just purchase an adjustable set up for that side as well?  What is the best rear axle wheel bearing set-up for a basic, every day driver Charger with a big block four speed, that I wouldn't mind baking the back tires with every now and then?

Thanks for any advice...

[resq302]

Mike,

Believe it or not, the factory set up only had one adjuster on the pass. side.  If you don't have a factory service manual, I strongly recommend that you get one.  They are invaluable pieces of literature and reference points.  Explained in the factory service manual is how to set up the axle end play and shows you the adjuster you are talking about.

[madmike]

You know, I do have the FSM, and I read through that section briefly, but when I did, I got the impression that the factory only had one side adjustable.  That's sort of why I asked the question.  Now, the problem is, I have excessive clearance on the driver side, and just right on the passenger side...  I'll have to read through that section again...

[b5blue]

You need to replace the drivers side bearing. (Possibly both sides) It's a pain in the butt so read and heed the FSM or change both sides to "Green Bearings" they press on and have no adjustment.    This all can be done without removing the center section if you do not move it while the axles are out.

[John_Kunkel]

Changing to Green bearings because you don't want to be bothered with (or understand) the adjustment is just plain loony.

On the tight side try smacking the end of the axle with a shot-filled hammer or brass hammer, if this loosens the clearance go ahead and tighten the adjuster to spec. The loose clearance on one side and tight on the other might also be due to a missing thrust button in the differential if it's a clutch-type Sure-Grip....it's common for them to fall out when the axles are removed.

[RallyeMike]

I though maybe too about the thrust button, but:

'68 Charger, 8 3/4" rear end, 3:23 gears, open.

If ensuring the bearings are not seating by gently tapping them does not do the trick, you'll have to dig into it.

Reaching here if that does not work: Perhaps somebody stuck short axle(s) in it? You might have to measure them as a last resort.
What is the casting number on the snout of the pumpkin? I'm curious if its a 741, 742, 489 or something from and early 60's car that may not be compatible with the correct 68 Charger axle lengths?

Shouldn't both sides have the adjuster nut for setting axle end play?

No. It sounds like what you have is totally stock. Read you shop manual again closely and make sure you are adjusting it the correct way.

What is the best rear axle wheel bearing set-up for a basic, every day driver Charger with a big block four speed

The stock tapered Timken bearings is one of the best set ups around. The adjusters and adjustment of the axles is easy once you are familiar with them.

[b5blue]

  My point about the "Green Bearings" was mistaken, with 1/8th inch of slop on the drivers side I really doubt there is any grease left in that bearing and adjusting it will not help in the long run.
  The weak point for the factory set up is there is no way to inspect or re-lubricate the bearings as they must be destroyed for removal. After 7 years of hard driving my Timkin's started giving me a slight growl and after removal sure enough the race was brindled and the grease contaminated. Greens are sealed, have a shop remove the old ones, press on new ones and bolt the attaching plates to the axle housing ends and move on. Yeh I know some gripe about side loading capability of the Greens, I'm testing a set right now and have had no issues in 3 years. I do have a factory service pack to replace them with "IF" they start to fail. Keep in mind Ford uses this setup on their trucks, I suspect the reported failures are have more to do with improper seating or abuse than an engineering fault.
  With that much play you better take a hard look at the backing plate, drum and rest of the brake parts as they have been dealing with that drum shifting in and out. (It pulls the shoes out and forces them against the backing plate going in.) 

[Musicman]

The weak point for the factory set up is there is no way to inspect or re-lubricate the bearings as they must be destroyed for removal.

Funny... I pull my axles, inspect the Timkens, re-lube them with fresh grease, and then reinstall them... piece of cake.

Changing to Green bearings because you don't want to be bothered with (or understand) the adjustment is just plain loony.

[RallyeMike]

Funny... I pull my axles, inspect the Timkens, re-lube them with fresh grease, and then reinstall them... piece of cake.

Same.

I'm curious what hard driving is done that ruins a Timkens in 7 years? Under hard conditions you should have inspected and lubed them. Perhaps it wasnt the bearing that failed, but the maintenance or installation. Properly adjusted and lubricated they are very stout and long lasting even under "hard driving".

[madmike]

Thanks for all the thoughts.  I should have done a search...  I did, later, and found lots of information.  I have a 741 center section, no Sure-Grip.  Someone mentioned measuring axle length, which I didn't do, but I guess I could check that as well.  I'll probably dig back into this over the weekend, because I do think the driver side bearing might be bad.  But, thanks again!

[b5blue]

  Well let's see page 3-28  Fig. 6 of my 70 FSM shows notching the bearing retainer collar for it's removal, got more of them? Page 3-29 Chiseling off the end of the roller retainer then grinding off the inner cone, removing the bearing rollers then cutting out the roller bearing retainer....you reusing that too?  Madmike was told to check his FSM and that's what he will see for replacement.
Lighten up OK? I beat the crap out of my Charger on a regular basis for 7 years. Driving to work construction at times for an hour each way, driving on muddy, rocky, uncleared job sites hauling tools around, (I can fit a 6' 6" framers level inside the trunk if I poke one edge into the rear of the back seat.) the trunk so full of mechanical and construction tools it looked like a low rider in the back for years on end, every day rain or shine it earned it's keep, this was AFTER 8 years of drag racing from the guy I bought it from. How about 2 day 1,000 mile road trips loaded to the hilt for moving and sill running 100+ MPH whenever Smokey wasn't around. Pissing off BMW and Mercedes on the interstate by stomping on it @ 75 MPH and shooting up to 120 leaving them in my dust while they    wondering why that big ugly car won't let them cut him off. My Charger and I did what we had to to raise my family, work. You want to shoot some grease in the bearings go right ahead. The FSM shows tear them up and take them off and replace them.
I'm not seeing any sign Madmike knows what's in there much less has a dial indicator to set .008-.018 axle shaft end play so Green's are the least expensive and simplest option for him right now and that's all I'm saying.
With a set of bearings that far out (1/8th of an inch!) the bearing has been riding unseated on the race, slung all it's grease and started spindling the race's face on the load surface while giving the brake shoes lateral stresses against the backing plate, the seal is shot from all this action also.   

[RallyeMike]

Lighten up OK?

I'm light, so wind down.



A total of 15 years on the bearings with that abuse and never checked/cleaned/lubed? I'm not surprised they were growling.

Every time an axle is pulled you have to chisel the retainer off, etc to inspect the bearing? Not quite, by a long shot: You can quite easily clean the bearings out with degreaser, blow them out with air, check for wear, re-lube them and put the axles back in with bearings intact if they are in good shape. If the bearing is no good, then you turn to page 3-28  Fig. 6 of your 70 FSM and go to town. If you are hard on your cars, checking them and maintaining them should be done as a maintenance item. Done this 100 times as well as most every mopar hound I know, service techs, and just every day folk who have common mechanical sense. I clean, inspect and repack the axle and front bearings on every car I pick up because I don't know the history of them.

I will agree that if Mike's car has been running with slop, he should clean and check the bearings, NOT needing to destroy the bearings just to check them, and if they are going south, replace them ........................... with Timkins  

Post Edit: I thought perhaps you were Autocrossing or something, which was the nature of my question reagrding "hard driving".

[John_Kunkel]

I'm not seeing any sign Madmike knows what's in there much less has a dial indicator to set .008-.018 axle shaft end play

You don't need any kind of measuring device to properly set the end play.

so Green's are the least expensive and simplest option for him right now and that's all I'm saying.

So, following that logic, would you recommend that somebody swap out their solid cam because they don't know how to adjust solid lifters?

[b5blue]

  John my advise is just that advise. "Get in there and know what you have" (So you don't tear anything up) when rebuilding a car. I mean NOTHING negative to Madmike in any way, nor am I implying he can't learn or do anything.
  So to your first question: The correct procedure in the FSM is to tighten the adjuster till snug and back off 4 notches right? THEN verify .008 to .018 play with dial indicator right? My POINT is this assembly can't be removed to see the races like front wheel bearings can. These bearings are critical to proper brake functioning hence safety so why not start fresh? The shop I had replace my bearings on the 1/2 shafts said in their opinion just clean and repack them, I pointed out that the seal between the hub and bearing (mounted on the retaining or adjusting plate) was another concern of mine along with what I know I heard. After installing the Green's I came and picked up my 1/2 shafts and Chuck said he thought I "Jumped the gun" and this operation wasn't needed. I took the old races over to his parts washer, cleaned them well and sure enough found a 1/2 mark on the race that was galled from the side I suspected. Know exactly what you have and move on.
  Second question: Your just being argumentative John, this has nothing to do with axles or helping Madmike IN this topic. (Start a topic on this, PM me and I'll join in.     )
  John please know I respect your advise and opinions, your a great help to all. There are times when I notice you have replied in a thread I really have little interest in but I check in to see what you have to say on that subject.       

[John_Kunkel]

These bearings are critical to proper brake functioning hence safety so why not start fresh?

Sure, so why not start fresh with a fresh set of A7 Timkens?

Second question: Your just being argumentative John, this has nothing to do with axles or helping Madmike IN this topic.

I disagree, it has to do with advising somebody to replace superior Timkens with marginal Greens simply because the Timkens are more hassle. "It's a pain in the butt" in your words thus my analogy to changing solid/hydro cams simply because one is less hassle to maintain.

[Musicman]

Sure, so why not start fresh with a fresh set of A7 Timkens?

If your talking about bearing replacement, use the superior product.

[terrible one]

I replaced my axle bearings with a new set of Timkens as well and I truly don't understand why so many think they are a hassle. There really isn't anything tough about replacing the bearings or setting the end play in my opinion.

[A383Wing]

I have heard of more people having "issues" with the longevity and reliability of the "green" bearings than the OE style....

It's not all that hard to adjust OE bearings....usually a simple "feel" will tell you if it's right or not.

Again, service manual will be your best friend here