Changing the rear end on the Bee

[WM23N1G1]

Hi guys,

I may soon have some money to change the rear end of the Bee (think it's a 3.91 suregrip  in a 489).  
Last time I had a look inside, it was filled with filings, and seemed to have been adjusted with a sledgehammer.  
The yoke is a small one, so I will have to change it too. I don't want to get a lot of hassle about adjusting a new set of gears with a new suregrip.
I think I'll just get a new third member, and bolt it into the 489. Maybe I should have a look at the axles and green wheel bearings too...
I just don't know where to buy, who to trust. For the moment, I just spotted these :
http://www.marketworks.com/StoreFrontProfiles/DeluxeSFItemDetail.aspx?sid=1&sfid=92390&c=68053&i=18365877
http://members.aol.com/doctordiff/8.75.html
http://www.outrageouslyvintage.com/
http://www.jimsautoparts.com/mopar_performance_drivetrain.htm
http://chucker54.stores.yahoo.net/comcen.html
http://www.bobmazzoliniracing.com/bm_parts.htm#REAR%20END%20PARTS%A0
BTW, I will need a new fan and clutch fan too...

FYI, the car will never see the strip, I'm not so good at it. If this makes a difference (shipping costs), I live overseas.

Where would you buy, and why?

I'll try to get the rear axle of the car in a week or two and then post pics here (I am really busy with 1YO twins).  

[RD]

FIRST, WHATEVER YOU DO, DO NOT BUY FROM JIM'S AUTOPARTS

secondly, buy from doctor diff or mancini

if you change to the larger yoke, you will need to get a combination u joint (precision 347) or just buy a new driveshaft that has the 7290 size yokes.

[WM23N1G1]

Thanks for the tips.
I've been told of a 1350 yoke too, seems bigger than the 7290. 
I still don't know if I'll buy a complete driveshaft, or just a yoke and make it weld in France on my old driveshaft. 

[RECHRGD]

Randy's Ring and Pinion.

[WM23N1G1]

Thanks, I'll keep Doctor Diff, Mancini and Randy's Ring and Pinion in the list. 

http://members.aol.com/doctordiff/8.75.html
http://chucker54.stores.yahoo.net/comcen.html
http://www.ringpinion.com/DiffDetails.aspx?DiffID=8&PartsLink=PartCats.aspx%3fSearchMode%3dDiff%26TypeID%3d2%26Type%3dChrysler%26DiffID%3d8%26DiffName%3dChrysler%2b8.75%2b(89%252c41%252c42)

[Chatt69chgr]

I would not buy from Randy's Ring and Pinion.  They are too high.  I would buy a new ring and pinion from Strange Engineering.  They are made in the USA----not China.  And they have the best price.  You can get the bearings from AutoZone.  They have Timken roller bearings.  On the 489, you can elect to go with a crush sleeve on the pinion or you can buy a spacer and shims now.  I think RAtech is the one that sells these items.  Actually, they have everything you need to rebuild in the way of bearings, seals, shims, etc.  If you want to upgrade to the 7290 from the 7260, as stated, you would have to use a cross over type u-joint.  If the rest of the driveshaft is using the 7260, then I don't see how you are gaining anything----a chain is only as strong as it's weakest link.  How much power are you making?  That would probably determine if you would even want to think about going to a stronger U-joint.  You don't need the 1300 series unless you are making tons of power.  You will want to replace the bearings and seals on the axles.  If you don't want to rebuild your unit, you can buy complete third members from several sources in 742 or 489 case with our without suregrip.  I don't know if they use the clutch type suregrip or the cone type.  I've heard that for normal everyday type driving, the cone type might actually be better.  But it can't be rebuilt-------least ways-------most can't rebuild it.  Some have machined the cones down and been able to return these to service.  There is usually someone in about every town that does rearends and everybody goes to them.  Start asking around at the local dragstrip or auto repair shops and you will soon find out who this is.  If you don't set the ring and pinion up, they won't last too long.  This might be money well spent. 

[WM23N1G1]

The problem is I'm not in the USA, so that there's no dragstrip, and no local rearend shop. Furthermore, I'm dumb as can be when doing anything mechanical. 
That's why I'd like a complete 8 3/4 thirdmember, just a bolt on if possible. Is there something to set up when you just change the centersection, or not?
My car isn't making lots of horsepower, it's just a souped up 440, maybe 420HP or so... I'd just like to install the thirdmember and forget it, even if I drive like I just stole the car .
Thanks for your detailed answer.

[RECHRGD]

Yea, Randy's is not cheap.  It was about 8 years ago that I got my 3.55 (489) suregrip unit from them.  It came all set up with a solid spacer (no crush sleeve to worry about) and ready to bolt on and forget it.  I'm sure the other company's out there do the same thing but Randy's is the only one I've dealt with and they stand behind their stuff.   Bob

[Nacho-RT74]

Randy's Ring and Pinion.

I know about someone else who has a noticeable BETTER PRICE than they, selling same stuff. INCLUDING SG UNITS

Moparts parts & services. some delay on shipping, but great guy
http://www.marketworks.com/StoreFrontProfiles/deluxeSFshop.aspx?Drivetrain&sfid=92390&c=68053

[WM23N1G1]

Thanks for the link... It was the first on the list in my first post. 
I'm not worried about the delays, the Charger now is winterized.

[Nacho-RT74]

ooops... sorry... I didn't recognize the link LOL.

Scott ( website owner ) is a great helpfull guy as far my experience.I got lot stuff from him, not just the SG unit.

BTW doctordiff is also A GREAT HELPFULL GUY. Also dealt with him.

[WM23N1G1]

No problem for the link, thanks for the testimony. 

[Ghoste]

I bought a centersection from Mancinis a few years back and it too, was ready to bolt in and go.  I don't know how they compare to the others on price but they stand behind their sales as well.

[WM23N1G1]

Thanks. Let the fun begin.

[WM23N1G1]

We disassembled the axle this afternoon. As strange as it may seem, it's a 742 (the pinion shaft is straight with 10 splines).

I would have liked a 3.73... Bad luck! 
http://www.ringpinion.com/ProductDetails.aspx?ProdID=1795

[Runner]

  the picture you posted looks like you have a 741 center.   are you still planning on just buying a ready to install 3rd member? drdiff is the only one i care to deal with.

[WM23N1G1]

Sorry, I thought I had a 742. I know nothing about diffs. 
How do you know it's a 741 and not 742? The casting numbers, or the type of pinion shaft?
I just don't know about the complete 3rd member. One of the my friends told me he wanted to rebuild the axle, even if he never did it.
If he can rebuild a 528 from scratch, he maybe can rebuild a rear end...  If he doesn't manage to rebuild it, I could even buy the parts a second time for less than a complete 3rd member... 
Thanks.

[Mopar2Ya]

I've bought from DTS & they were nice/helpful. I called Randy's before that & wasn't treated well. Your friend may be able to handle it if he gets all the info/tools he needs. Good luck.

[Runner]

the casting number on the side of the 3rd member. 2070741   the last three numbers tells you what diff you have.     im all for doing the job yourself.  remember the ring gear bolts are left hand threads.    good luck

[WM23N1G1]

Thanks for the info. Are the parts interchangeable between the 742 and 741? Is it a good idea to keep a 741 ("This assembly was typically used in low weight/low horsepower applications through low weight/medium horsepower and high weight/low horsepower applications.")?
I've got the '71 shop manual, and my friend has the '70 one. Should we look for another book to help us?

[Runner]

the carrier is interchangable, ring and pinion gears are not.  they are the weakest of the 8.75 3rd members but in alot of cases work fine.  im not sure if the carrier bearings are the same or not, i THINk that the pinion bearins are not the same.   you can usually find the info you need from the net and the manuals.

[Nacho-RT74]

http://www.autohobbydigest.com/8_75.html

ALL the info is there

[71 Bee Man]

I have just recently rebuilt the diff in my 71 Bee, and I can highly recommend Scott from Moparts P&S. Very helpful and fantastic on price. I'm not just saying that either - best by a long shot.
I got Yukon gears, 3.55 and a new sure grip center, as well as axle bearings and seals.

http://www.marketworks.com/StoreFrontProfiles/DeluxeSFItemDetail.aspx?sid=1&sfid=92390&c=68053&i=18365877

Peter.

[WM23N1G1]

Thanks, guys! 
I've asked  a quote to the Doctor, and will soon do with Scott. 

[WM23N1G1]

Hi,

The good news is DrDiff seems to be a very knowledgeable guy! 
The semi-bad news is the I will have to change the yoke too.

There are no more 10 splines pinion for the 741. 

[WM23N1G1]

We"re near the (rear) end! 

741 3.73 ring and pinion                     $185
Bearing/seal/shim kit                        $100
Set ring gear bolts                        $15
Pair "Green" wheel bearings                     $60
Pair inner axle seals                        $10
Power-lock clutch pack                        $55
Bottle friction modifier additive                  $5
New 29 spline 7290 yoke                     $100
7290/7260 conversion U-joint                  $25
ring gear bolts                           $15
1/2" dia lug studs                        $20
pinion snubber                           $15

Had to buy a standard pinion snubber, because mine is :
The U-bolts are tired, I don't know if I will make something for the threads, or just buy new ones :
The cleaning of the pumpkin is coming nicely :

[WM23N1G1]

$610 later, the parts are on their way. 

[Nacho-RT74]

the carrier is interchangable, ring and pinion gears are not.

I have to say I'm a little bit disagree on that... I know has been told by the experts they have to be a matching set, and I definitelly not an expert but I just can say as a testimonial I have a 741 case with 3:23. Got a NOS 489 pinion and gear set AND GEAR IS THE SAME PN than the one I found on my 741. In fact really close built ( machined ) date too.

Anyway I know all what has been said about the matching set. That can be matched again with the shims  and carrier adjusting bearing nuts thought, need to be done from the first instance like on factory, when they label the offset needed on every piece. However, aftermarket pieces I have seen ARE NOT labeled, son need to be done anyway!

they are the weakest of the 8.75

well, yeah, but that doesn't mean is not strong enough. Never have seen one broken... maybe they can get broke on serious racing. Even in that way, they still got the 10 spline option , that does mean something

[WM23N1G1]

Mine wasn't broken, but the pinion "ate" the gear.

[Nacho-RT74]

well thats a diff stuff and is not in relation with case kind really

[Belgium R/T -68]

Also beeing from overseas, RD: what's wrong with jimsautoparts? They seems to have a huge stock and inventory. 

[mikesbbody]

whats wrong with jims? service or lack of but i have never dealt with jims.

[WM23N1G1]

I received yesterday one parcel:

new studs and bolts:

U-joint, new yoke :

Bearings and gaskets:




pinion snubber


I think I will get the other parcel tomorrow.

[WM23N1G1]

Hi guys,

I know I should be ashamed, but the rear end has not yet been rebuilt.
Well, I just can't do it by myself because I know nothing about anything...
The friend of mine who could have done it faced some serious issues, and I do have lots of problems too. 
Anyway, another friend of mine found a guy who is really good at mechanics, but who mainly deals with GM cars. He already has rebuilt the rear end of his wife's '71 Charger (not a 8 3/4), but he doesn't seem too confident about rebuilding mine...
I found a conversation with Dr Diff in my email related to High Performance MOPAR Magazine, May 1997, PGS 28-30. I just can't find any file on my system related to that:

I sell a shim kit that is used to restore the tolerances between the side
gear and spider gears.  This kit is used after machining 0.040" off the base
of the cones to restore traction to a worn out sure-grip.

Does anyone have pics of these pages, or any documentation related to that process? If you ever have any documentation about rebuilding a 8 3/4, I'm really interested!

TIA!

[WM23N1G1]

We're almost reaching the end...  
Still have to change the drum springs , put the oil in, and frighten the old ladies in the streets.  

[WM23N1G1]

Still have to fix a fuel issue, but the Bee made its first meters by itself a few days ago.
We're seeing the light at the end of the tunnel.

[68RED4SPEED]

http://www.moparmusclemagazine.com/howto/mopp_0308_mopar_rear_end_gears_set_up/photo_01.html

[WM23N1G1]

Thanks for the link, I do hope I won't need to remove once again the rear end to adjust the settings...

[68RED4SPEED]

Hehe my fault, answered the last post at page 1 and didnt see there where a page 2 until it was to late, anyway now you got it.
Sven

[WM23N1G1]

Hi,

made 20 miles last saturday, and kaboom, away went the propeller shaft. 
Apparently, one of the clamps on the rear axle flange broke, and the assembly... disassembled.
I managed to park, get the shaft before someone hits it, and put it in the trunk. No one was hurt, and the shaft still looks good.
I suppose something blocked in the rear end, and the weaker part of the assembly went south...