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Mopar Rear End?


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Hello all MJ owners. Joined a couple years ago, but have never made a post. What thoughts and or experence does anyone have with using a mopar 8 3/4 rear end for off road. I allready have this complete assy in my garage. Thought about using the 8 3/4 when i converted my 88 MJ from a 2wd to a 4wd some day. Width is good and has 3.55 gears w/ clutch type posi. Is using a 1pc type axle housing good or bad for off road. This will not be used for hard off roading. Doesnt seem like anyone uses a 1pc housing very often. Any way thanks, like this web site and enjoy reading about your MJ projects. Thanks Paul

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I called last week on a 8.75 that was in a 66 Fury, WMS to WMS is 62 and the bolt pattern is 5 on 4.5

 

 

The guy selling said he uses them in his drag cars.......he wants $350 for it......I passed.

 

But later did some digging and apparently they are robust and Chrysler used them in full sized and some muscle cars in the 60s and 70s.

 

They are supported with aftermarket and I like the removable center section.

 

Still on my list of possibilities.........will not be cheap though. Some sites I visited referred to them as a Dana 60.

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I am kicking my self big time......before I looked into this

Ii did not realize i have seen at least 2 of these that were virtually free bees......check the list I posted....if they were tough enough to take on a 440 wedge.....or a 500 pony Hemi...... :doh:

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The 8 3/4 is really strong. It is not as popular as the 9" ford but it gives up nothing to it IMHO. I used one in a 4,300# bracket car that would pull the front wheels and it was dandy even after 11 seasons. The clutch-type posi is a plus over the cone-type, as well. These were the rear ends that came in even 440/automatic Mopar muscle cars. The best years of the 440/4-speeds and all of the best years of the Hemi auto/4spd got a semi-float D60 of the same width and bolt pattern. Someone has one under his MJ and I would love to find one of them!

 

A downside might be the pinion. IIRC it is a touch lower than some others but so is the 9". But if hardcore off-roading isn't your goal I can't see where that would be a problem if at all. 

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Yes. The 8.8 has c-clips that retain the axles. The 8 3/4 has bolt-in axles. Bolt-in is a big advantage. C-clips have a history of breaking/coming off and when they do the axle shaft leaves the car and takes the tire and brakes with it...almost assuring body damage as well as, well, you lost a wheel maybe at speed. To run a c-clip rear end with slicks in NHRA requires that you install c-clip eliminators to make the axles bolt-in, for example.

 

The 8.8 has an advantage in that you can get them with factory disc brakes and there is more support in the form of after-market lockers, etc... Everything is a trade-off it seems.

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875rearend.jpg

 

 

 

 

Yeah.

 

Centered and removable center section, not offset as the POS Ford is.

 

Axle housing is more like the Ford9  in that it's a one piece unit, not tubes inserted into the center of the housing.

 

 

Comes in multiple lengths depending on application.

I'm getting different WMS to WMS surface measurements or axle widths depending on the source of info....but........62" seems to be consistent. A 63" is also listed.

 

I'm going to find some old ones to measure for myself in the coming month.

I'd much rather gain an inch at each wheel without using spacers.

 

I'd also imagine that like the D44 or nonC D35 the disc brake conversion will be similar.

 

Also, I'd like to keep the drive train in the family.

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Yes. The 8.8 has c-clips that retain the axles. The 8 3/4 has bolt-in axles. Bolt-in is a big advantage. C-clips have a history of breaking/coming off and when they do the axle shaft leaves the car and takes the tire and brakes with it...almost assuring body damage as well as, well, you lost a wheel maybe at speed. To run a c-clip rear end with slicks in NHRA requires that you install c-clip eliminators to make the axles bolt-in, for example.

 

The 8.8 has an advantage in that you can get them with factory disc brakes and there is more support in the form of after-market lockers, etc... Everything is a trade-off it seems.

 

 

Everything that is available for the 8.8 is available for the 8.75.

 

I searched around for a couple of hours a week ago and I did not bookmark any of the sites........don't have time now.........but everything and anything you want is out there.

 

http://www.drivetrainshop.com/Chrysler_8_75_s/82.htm

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Yes. The 8.8 has c-clips that retain the axles. The 8 3/4 has bolt-in axles. Bolt-in is a big advantage. C-clips have a history of breaking/coming off

 

 

the list of individuals that have managed to break an 8.8 shaft is very small indeed.  :D 

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Yes. The 8.8 has c-clips that retain the axles. The 8 3/4 has bolt-in axles. Bolt-in is a big advantage. C-clips have a history of breaking/coming off

 

 

 

the list of individuals that have managed to break an 8.8 shaft is very small indeed.  :D

Above and beyond that, the 8.8 if equipped with discs has every advantage that a non c clip does. The discs function. As secondary retainers at low speeds.

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Yes. The 8.8 has c-clips that retain the axles. The 8 3/4 has bolt-in axles. Bolt-in is a big advantage. C-clips have a history of breaking/coming off

 

 

the list of individuals that have managed to break an 8.8 shaft is very small indeed.  :D

 

In the off-road world you are probably right although I have seen this. Luckily it was a disc-brake 8.8 and the caliper retained the axle. In racing, which is admittedly a different beast, they do break/come off. If it is a weakness on the track then it seems to follow that it would be a weakness anywhere once the same threshold is reached. NHRA doesn't mandate that they be replaced for no reason. I will say that this is much, much less likely on an 8.8 then the pretty crappy GM c-clip rear axles, especially most versions of the 10-bolt. Those things broke regularly. 

 

I thought that the 9" does have a separate housing and axle tubes...just that the seam is pretty far out from the center-section??? Time passes...memories blur... :hmm:

 

I have not priced 8 3/4 stuff in a long long time. Lockers, etc...used to be pretty pricey for them. Glad there are more and more reasonable options out there. There are a lot of these axles sitting around that can probably be had very cheaply with about the right width and the right bolt-pattern.

 

I am not sure how it would work, if at all, in a jeep application but the 8 3/4 has a bolt-on adjustable pinion snubber available that is an easy and cheap fix for spring wrap in a performance car.

 

Oh...remember that there are different versions of the 8 3/4. They have a stamp on the drop-out center section. If it says "741" it has a pretty smallish pinion shaft. The "742" is larger and is more desirable. The "489" is the biggest of the three and is the most desirable.  Even the "741" isn't weak but it is weaker than the others. You have to know the stamping number to get the correct gear set should you change ratios. 

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They're good axles,

the housing can bend if you beat it enough,

but adding a brace will take care of that.

Also, you'll need the little insert that goes between the axle shafts if you keep the stock, tapered style wheel bearings that require preload.

Aftermarket axles like Mosers usually come with non-preload style 'green' bearings, that don't use the insert-spacer,

but some have complained about lower load capability of them.

 

B-body Mopars late 1960's-1970= ~59.5"

later B's are wider

& E bodies are around 61"

 

I've had a 69' B-body Mopar  Dana 60 with green bearings in my MJ since 1999 or so,

bearings have held up fine & the slightly narrower width isn't a big deal.

 

(D60 was the factory upgrade axle over the 8.75 when a 4spd was used behind a Hemi, or 440,

axle width & wheel bearings/brakes were the same as the Mopar 8.75)

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Thanks for all the input about this axle. I was mostly concerned with the axle housing and its strength. Thinking about some of the ford 9" housings used on Broncos and F150's they held up very good so i don't think i need to worry. I have no plans to offroad hard so i feel its going to work good. Thanks

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