We found the vibration!

[Aunt Bee]

We pulled the chunk apart this weekend. It was easy because the pinion nut was torqued to "FINGER TIGHT". Imagine my husband's surprise as he equipped himself for battle with a 3/4" drive breaker bar in hand, and as he repositioned the chunk to get a better grip, he watched the bar swing from 10:00 to 6:00, with the assistance of gravity only.

Well, the ring gear has done some interior excavation work on the case, as has the pinion gear. And, the crush sleeve is in its original, 'uncrushed' specifications. Looks like the last person who worked on this rear forgot an important step...or two...or more!

We're real happy we had decided already to get all new parts, (true trac, gears, axles, crush sleeve eliminator, bearings, etc), as we're not going to trust anything that's here. Will measure the axle housings to make sure they're round before re-assembly, too. Can't wait to have her back on the road and fully functional! Says a lot about an 8 3/4, and what they'll put up with without breaking!

 

[RustyRatRod]

Crush sleeve eliminator. SMART move.

 

[Dan]

Green Bearings are not recommended for street use as they won't take side loading very well, made for straight line runs only.

 

[Aunt Bee]

Green Bearings are not recommended for street use as they won't take side loading very well, made for straight line runs only.

We chose to go with Timkens and the passenger side adjuster. If we have all of our parts, tools and information together, we should be able to get it all assembled next weekend!

 

[RustyRatRod]

Sorry Dan, I'm not trying to start an arguement, but that's incorrect information. Millions of cars made today use green style bearings and on the front where the bearings pull the car, as well as steer it. I cannot think of a single car made today that has tapered roller bearings on the front and precious few on the rear. Even most trucks have gone to the green style bearings. This is a rumor that has persisted and is simply not true. The green bearings are simply a different style of bearing. That's all there is to it.

Green Bearings are not recommended for street use as they won't take side loading very well, made for straight line runs only.

 

[daredevil]

We pulled the chunk apart this weekend. It was easy because the pinion nut was torqued to "FINGER TIGHT". Imagine my husband's surprise as he equipped himself for battle with a 3/4" drive breaker bar in hand, and as he repositioned the chunk to get a better grip, he watched the bar swing from 10:00 to 6:00, with the assistance of gravity only.

Well, the ring gear has done some interior excavation work on the case, as has the pinion gear. And, the crush sleeve is in its original, 'uncrushed' specifications. Looks like the last person who worked on this rear forgot an important step...or two...or more!

We're real happy we had decided already to get all new parts, (true trac, gears, axles, crush sleeve eliminator, bearings, etc), as we're not going to trust anything that's here. Will measure the axle housings to make sure they're round before re-assembly, too. Can't wait to have her back on the road and fully functional! Says a lot about an 8 3/4, and what they'll put up with without breaking!

Glad to see you found it. I have watched this thread with interest to see what the cause was. I didnt feel it was the axle but whos to say. So I sat back and watched.

 

[Aunt Bee]

Glad to see you found it. I have watched this thread with interest to see what the cause was. I didnt feel it was the axle but whos to say. So I sat back and watched.

What we first saw was just a symptom of a greater issue, that's for sure! We're grateful for all the opinions here, it's helping us to learn our way around the Bee.

After rebuilding the clutch linkage, installing a new clutch, doing a complete rebuild on the trans, installing new u-joints and rebalancing the driveshaft, we were anxious to enjoy the summer cruise-ins. We knew the rear needed a rebuild, too, based on the age and wear we found on the other parts we'd already refurbished. The vibration we felt only occurred at times, and we were sure it came from the rear...but, we couldn't have predicted we'd find this. New parts, installed correctly, are gonna feel real good!!!

 

[Dan]

Taken from Mopar acton mag. web site

Tech Question
Ray Block, Columbus, OH, 1992 Dodge Dakota 318

In installment 2 of Savvy Savoy, you said you do not recommend Green bearings for anything other than drag racing while you do seem to be recommending the "sealed cartridge type used on some 1980's ford pickups".

If these have been around since the '80's and are superior to the Green bearings, I'm wondering if my CRS has been working overtime or if no one has actually mentioned them before? Naturally curious which/why that might be?

The aftermarket axle companies I've looked at all offer the Green bearings but not (obviously anyway) the Ford bearings. Sooo, of course, I went with the Green when I swapped an 8 3/4 into my Dakota 6 years ago.

So far so good after 13,000 miles and 1,200 drag strip passes but you make me wonder if (why) I should switch to the Ford bearings anytime soon?

As always...you da man! Enlighten me please.
Thanks, Ray

Ray, the Greens are low-capacity ball bearings...maybe 1/10 the side-load capacity of the stock Timkens. They are fine for drag racing, pretty lousy on the street, and pretty scary if you're into cornering or towing! (Admittedly, I've never personally seen one catastrophically fail, but I've seen plenty get noisy and sloppy).

The Fords are sealed rollers, way better than balls. The reason why you don't see more of 'em is 'cause they require you to weld on custom axle housing "ends". I have featured these earlier in the mag, as a way to dump the C-clips on 8.25 and 9.25" axles.

I also must add that, except that they require more care during assembly (packing with lube, endplay adjustment, etc.) the stock Timken tapered roller setup is about as good as it gets.

Rick

 

[RustyRatRod]

Glad to see you found it. I have watched this thread with interest to see what the cause was. I didnt feel it was the axle but whos to say. So I sat back and watched.

That's exactly right. Who is to know? Especially when we are all electronically separated by this here internet thingie.

To the OP: Glad yall did find it though. A quick tip I always use......BESIDES a crush sleeve eliminator, I also "stake" the nut to the pinion shaft after the final tightening. This will help assure the nut will NOT back off. I don't know why it is that this is such a common problem for Mopars, but it certainly is. We see it quite frequently.

 

[Garys1969RR]

I just bought a complete 741 case with 3.91 posi in it for 180.00. The guy s mechanic said the tooth contact pattern was bad, and it would whine, unless I shimmed the pinion closer to the ring gear. Well it had alot of backlash, and I set it to .010", installed it in the housing, and it works fine! No howling. So you never know, I just do my best with what I have, and things work pretty well, Usually Lol. These 8 3/4 rear ends are super strong! Good luck!

 

[RustyRatRod]

...and Gary, that 741 is plenty strong, despite what you might read. To those who say otherwise, I simply ask, "How many broken 741s have you ever seen?" If they are honest, they will say very few or none. Because any other answer is simply untrue.

 

[Aunt Bee]

If I had ordered the right parts (sorry, sometimes I'm such a girl!), we would have accomplished a lot more this past weekend...hopefully, next weekend is more productive!!! We'll keep you updated...

 

[idrivemopar]

My axle shafts look the same. In the picture below, you can also see my old shaft on the right, which had shorter splines, the ones in am installing are from a 71, my old ones are from my 73, and you can see why i replaced them, broken spline.

- - - Updated - - -

We pulled the chunk apart this weekend. It was easy because the pinion nut was torqued to "FINGER TIGHT". Imagine my husband's surprise as he equipped himself for battle with a 3/4" drive breaker bar in hand, and as he repositioned the chunk to get a better grip, he watched the bar swing from 10:00 to 6:00, with the assistance of gravity only.

Well, the ring gear has done some interior excavation work on the case, as has the pinion gear. And, the crush sleeve is in its original, 'uncrushed' specifications. Looks like the last person who worked on this rear forgot an important step...or two...or more!

We're real happy we had decided already to get all new parts, (true trac, gears, axles, crush sleeve eliminator, bearings, etc), as we're not going to trust anything that's here. Will measure the axle housings to make sure they're round before re-assembly, too. Can't wait to have her back on the road and fully functional! Says a lot about an 8 3/4, and what they'll put up with without breaking!

Sounds exactly what i have done to mine as well, true trac with new ring and pinion (3.55), billet shimmed crush sleeve, i guess you could call it an elminator, new timkens, and new housing ends, mine were severely scored.

So does anyone know how to get the axle shaft end play adjustment correct without using the recommended tools in the service manual? Looks like a micrometer attached to one of the lugs and the brake plate. It should be something like 8 to 10 thousands of an inch.

 

[68gtxman]

Don't forget to check the pinion nose angle against the transmission's angle. The whole rear will vibrate with speed if not within the correct range.

Best of luck!

 

[99ss]

What is a Green bearing?

 

[Aunt Bee]

So does anyone know how to get the axle shaft end play adjustment correct without using the recommended tools in the service manual? Looks like a micrometer attached to one of the lugs and the brake plate. It should be something like 8 to 10 thousands of an inch.

There are a couple of tech articles we found on getting the 'feel' correct on the end play adjustment, I'll post the links when I get to the right computer . Uses someone else answers first!

 

[Cranky]

Green Bearings are not recommended for street use as they won't take side loading very well, made for straight line runs only.

Taken from Mopar acton mag. web site

Tech Question
Ray Block, Columbus, OH, 1992 Dodge Dakota 318

In installment 2 of Savvy Savoy, you said you do not recommend Green bearings for anything other than drag racing while you do seem to be recommending the "sealed cartridge type used on some 1980's ford pickups".

If these have been around since the '80's and are superior to the Green bearings, I'm wondering if my CRS has been working overtime or if no one has actually mentioned them before? Naturally curious which/why that might be?

The aftermarket axle companies I've looked at all offer the Green bearings but not (obviously anyway) the Ford bearings. Sooo, of course, I went with the Green when I swapped an 8 3/4 into my Dakota 6 years ago.

So far so good after 13,000 miles and 1,200 drag strip passes but you make me wonder if (why) I should switch to the Ford bearings anytime soon?

As always...you da man! Enlighten me please.
Thanks, Ray

Ray, the Greens are low-capacity ball bearings...maybe 1/10 the side-load capacity of the stock Timkens. They are fine for drag racing, pretty lousy on the street, and pretty scary if you're into cornering or towing! (Admittedly, I've never personally seen one catastrophically fail, but I've seen plenty get noisy and sloppy).

The Fords are sealed rollers, way better than balls. The reason why you don't see more of 'em is 'cause they require you to weld on custom axle housing "ends". I have featured these earlier in the mag, as a way to dump the C-clips on 8.25 and 9.25" axles.

I also must add that, except that they require more care during assembly (packing with lube, endplay adjustment, etc.) the stock Timken tapered roller setup is about as good as it gets.

Rick

Yeah, Timkens take much more side loading than any ball but with that said, they are overkill for a car that's used normally on the street. Ford has used a ball bearing on their rears for many years going way back but I don't know what they use in the modern times. I think pretty much everyone has gone to the needle roller using the axle itself as the inner race? Maybe not everyone but many have. And if the Greens were so low of a capacity bearing, they wouldn't hold up in drag racing very well either but one of the things that I have found is these bearings don't have much grease in them from the get go.

- - - Updated - - -

There are a couple of tech articles we found on getting the 'feel' correct on the end play adjustment, I'll post the links when I get to the right computer . Uses someone else answers first!

Meep Meep covers it pretty well in this post #6. Do you also have the adjuster retaining lock clip? It keeps the adjuster from moving once it's set.

http://www.forbbodiesonly.com/mopar...How-to-adjust-8-3-4-quot-axle-bearing-preload

 

[RustyRatRod]

What is a Green bearing?

The green bearings are sealed bearings similar to what is in modern front wheel drive cars. They are not tapered roller bearings.

 

[Aunt Bee]

Do you also have the adjuster retaining lock clip? It keeps the adjuster from moving once it's set.

Yes, we do. Thanks for the advice!

- - - Updated - - -

This weekend, we figured out that the parts I re-ordered had the same problem as the parts I thought I'd ordered incorrectly. The master install kit put together by Motive has the wrong carrier bearings...same wrong parts in both kits. I should have known it wasn't my mistake LOL!!!

So, our local Auto Zone provided us with the correct bearings today, the correct races are on order, and I have some returns to make. Yes, a detailed letter of explanation will be enclosed!!

Looks like we might be smiling by NEXT weekend...

 

[Aunt Bee]

No progress yet, except to find more problems with new parts. :angryfire: We received a Motive Ring and Pinion, 3.73 ratio. After finding they had supplied us with incorrect bearings in their master install kits, we weren't surprised to find that the pinion shaft is also wrong. It measures correctly in length, and the yolk fits onto it, but the shaft itself is .003 larger than the inner race of the top bearing. We checked the bearing number, and it IS correct. We also compared the measurement to our old pinion.

So, more parts to return, and we'll check into other suppliers. Summit told us that the only brand they carry in the 3.73 ratio is Motive (which is Richmond). We tried for 3.55's and were told they're on backorder until March. Really???

There's a local shop we used for our trans rebuild, and another parts dealer in Atlanta that we're going to check with. Family comes first for the next week (my Mom's 84th birthday :happy7, so we'll post up again after we get some answers!