Son breaks rear end..dad fixes

[maddzz1]

Okay

I pulled the cover ..don't see anything stamped on the ring gear but the tag on the exterior has numbers that I can read just barely. anyone know what these indicate?

 

895 3004682

3 55 605324-5

 

I assume the 89 in the top line indicates year1989 and 3 55 in the bottom line means it is a 3.55 gear ratio?

Is that all I need to know? :dunno:

 

Yes craigslist has a couple w/in 100 miles though I need to verify they are suitable for swap.And I have a call in to the local junkyard

brian

 

I don't think any manual transmissions came with 3.55's, only automatics. Is there a chance the previous owner swapped the axles?

 

None of the 6yl, M/T came with the 3.55's. LINK

 

 

I didnt see that on that link. The only thing it said was that 93-94 XJ's w/ the tow package got 3.73's. MJ's werent made in 93-94. I think all MJ's with the automatic transmission (AW4) got 3.55's Someone correct me if I'm wrong about this.

[bigalpha]

Okay

I pulled the cover ..don't see anything stamped on the ring gear but the tag on the exterior has numbers that I can read just barely. anyone know what these indicate?

 

895 3004682

3 55 605324-5

 

I assume the 89 in the top line indicates year1989 and 3 55 in the bottom line means it is a 3.55 gear ratio?

Is that all I need to know? :dunno:

 

Yes craigslist has a couple w/in 100 miles though I need to verify they are suitable for swap.And I have a call in to the local junkyard

brian

 

I don't think any manual transmissions came with 3.55's, only automatics. Is there a chance the previous owner swapped the axles?

 

None of the 6yl, M/T came with the 3.55's. LINK

 

 

I didnt see that on that link. The only thing it said was that 93-94 XJ's w/ the tow package got 3.73's. MJ's werent made in 93-94. I think all MJ's with the automatic transmission (AW4) got 3.55's Someone correct me if I'm wrong about this.

 

None of the 6 cylinder engines with the manual transmission are listed as having the 3.55's.

[maddzz1]

My bad. When you wrote M/T I thought you meant Metic Tonne package. :doh:

[bigalpha]

My bad. When you wrote M/T I thought you meant Metic Tonne package. :doh:

 

Nope, sorry. :cheers:

[wannabeMJ]

Image Not Found

 

this is your ring gear

a good way to find out your ratio is to find out how many time your drive shaft turn for a complete wheel turn

roughly 3.5 drive shaftturn for a full rotation of your tire gives you a 3.56

a bit more then 4 turn would give you a 4.11 ratio

[ParadiseMJ]

...the repairs over the years are turning him into a pretty good backyard mechanic.

brian

 

I'm pretty sure that's how I got into this...My dad did my brakes on my 64 Chevy...made me watch...then he took it all apart and said "now you do it!"

 

That was 40 years ago (damn I'm starting to get old!!)

 

Look for a MJ in a junkyard, with an automatic (AW4), likely it's got a D35 with 3.55's...take the kid with you for muscle.

[Eagle]

Look for a MJ in a junkyard, with an automatic (AW4), likely it's got a D35 with 3.55's...take the kid with you for muscle.

Why should he look for a 3.55 axle when the front axle (unless it has been changed) is a 3.07? He has a 4.0L with a 5-speed transmission. Those did not "usually" have 3.07 gears ... they ALWAYS had 3.07 gears. The tow package with 3.73 gearing was only available with the AW4 automatic transmission. Jeep didn't want people towing more than 2000 pounds with the 5-speed.

 

Before doing anything here, it will be essential to determine what the front axle ratio is. The ratio of the replacement rear axle has to match the front axle.

[ParadiseMJ]

Why should he look for a 3.55 axle

 

:dunno: Oops, I thought we were talking about a 3.55...I can read but not well.

[pilotblake]

damn how does this sagga end :popcorn: :popcorn: :popcorn:

[HOrnbrod]

damn how does this saga end

 

I was just thinking the same thing...............

 

Pull cover, count the freeking teeth on the ring and pinion, divide.

[brian]

first of all to the last poster; I can't turn my wheel to count driveshaft revolutions since the gears are busted and the drive no longer engages. Good idea though.

I'm thinkin' maybe the front gears don't match the rear as was suggested.And yeah, sure that could cause something to snap.

So now that I have access to this site and some of you can read the codes stamped on the housing tags, I'll get the numbers from my front axle tag.

If this wasn't my kids fault but was a result of some dumbass previous owner :fs2: putting in the wrong rear end...well....hmmmm, I think I'll still let the boy pay for the new one. What's he got to spend his money on anyway?

I'll be back with those numbers.

brian

[bigalpha]

first of all to the last poster; I can't turn my wheel to count driveshaft revolutions since the gears are busted and the drive no longer engages. Good idea though.

I'm thinkin' maybe the front gears don't match the rear as was suggested.And yeah, sure that could cause something to snap.

So now that I have access to this site and some of you can read the codes stamped on the housing tags, I'll get the numbers from my front axle tag.

If this wasn't my kids fault but was a result of some dumbass previous owner :fs2: putting in the wrong rear end...well....hmmmm, I think I'll still let the boy pay for the new one. What's he got to spend his money on anyway?

I'll be back with those numbers.

brian

 

I think they mean count the revolutions on the front axle. But, if you have a data tag on the axle housing that should work too.

[jimoshel]

When we got married me and the wife had a discussion. Kids or Jeeps but not both. Flipped a coin, Jeeps won. We lived happily ever after, or until she found the 2 headed coin in my dresser drawer. :rotf:

[brian]

sorry I posted that last one not realizing there were 3 pages of posts already. I only read the 1st two.

ok I'm gonna find the tag on the fron axle and also count the teeth on the rear although the pinion gears are in pieces so counting may be tough. I'm wondering how this ends myself!

'for those of you wondering why I'm so dense...too many things on my mind. I hadn't thought this through and i've never even opend up a diferential before.All those teeth! scary!

brian

[HOrnbrod]

Axle housing stamped numbers or tags don't mean squat if the gears have been changed. To be absolutely sure:

 

Pull cover, count the freeking teeth on the ring and pinion, divide.

 

No offense mate. :cheers:

[brian]

ok you bunch of old dogs

I just crawled out from under the front end. the tag on the front housing which looks to be untouched by human hands says 3.07 just like you all figured. So untill I can piece together the busted pinion gears and do a count I'm leaning toward the theory that someone replaced the rear end with a 3.55 while the front end is a 3.07. This also explains why the rear brake control valve(bias) was hooked up wrong when I bought the rig.

What an education I'm getting!

 

Now what do I tell my son?? :oops: Let's see...allow him to continue feeling bad orgive him a break /

brian

[pilotblake]

Your son depending on age, took a nice young lady a little toooooo far out to that special place and found himself in a place to sticky to get out in 2wd.....and being close to curfew snapped into super jeep mode to save the day....only for dad to have equiped him with a snapfu drivetrain. Sorry dad, fess up, and if your son is as interested in mechanics, and smarter than you somehow :nuts:will roll his eyes and have learned something as well.

[brian]

Ha aha. there was no girl involved he was surfing and confessed he was cutting cookies on the beach with the jeep when it broke so I' not so inclined to let him off completely

Brian

[pilotblake]

:cheers: Good stuff..... :rotfl2:. Sooooooo he got stuck in the sand :dunno:

[brian]

no ,he put it in four wheel drive and drove part way home with the front end doing all the work while the rear chattered and banged.

Finally he pulled over and called the old man to come tow him.

thank god my wife has AAA

brian

[mvusse]

You may not have to count the teeth. The ring gear should have the number of teeth on both the ring gear and the pinion gear stamped on the outside. That is as fool proof as counting teeth.

[bigalpha]

Well if your son was driving home with it in 4WD and it was clanking and stuff - I say let it ride a while longer. What transfer case do you have?

 

Do you have a "Full Time" or "Part Time" option?

[Wildman]

 

Jacking up and turning the wheel is Not a fool proof way to find the gear ratio :shake:

 

The gear ratio is stamped on the ring gear, the first 2 sets of numbers will be the tooth count on the ring / pinion, just divide the 2 numbers = gear ratio.

 

Note: That is something the previous owner did not do, that got you up to 4 pages here now :roll:

 

So........lets say that the PO did install the wrong gear ratio axle, and for the past (how many years) you owned this MJ had no idea, things worked fine, until........

 

1) Son should not have drove on hard payment in 4wd (could have taken the transfer case out and you still would not know about the axle differences)

 

2) Son might have found a defect that would have gone undetected for the life of this MJ.

 

3) Teaching Son that if something brakes, you just can't call Superman, and blink, and the problem is solved.......without spending time and $$$$

 

4) You have learned that coming here first, and letting us lead you in a direction that just might solve several problems, with a little extra work, might save you time and $$$ in the future, by just not sticking an ole axle under there, and causing additional problems.

 

5) There is no reason for you to put your tail between the legs, Son had vehicle in hands, something went wrong, it broke, you jumped to the wrong conclusion (at first) and now Both of you need to get dirty to fix problem........

 

Just another day in the lessons of life.......

 

So, now.......You need to find the correct D35 MJ axle, with 3.07 gears, now if you were near me, I got a couple sitting here, but your not. So maybe some one on the left coast near you can jump on this for you :D

 

The chance of finding an XJ (Cherokee) with 3.07's in slim, because most XJ's had automatic's, and finding a MJ axle is getting harder.

 

You can do a quick search on car-parts.com in your area / state and see what comes up.

(I just did a quick search and found 3 in that area)

 

Or.......you can upgrade to the 8.8 and do the additional work required, or, have some shop that specializes in gears, replace the ring and pinion in the axle you have now, but note, the cost is going to be about $400-$500 for that option.

[Eagle]

I wish we weren't on opposite ends of the continent, because I'm pretty certain I have a 3.07 MJ rear axle out in the pile. In fact, that may be the one that put me in the hospital four years ago when the pile shifted and mashed my ankle. Unfortunately, axles are heavy and shipping from CT to OR would be "pricey."

 

Anyhoo, I'm glad we have zeroed in on some important information and helped you focus your search in the appropriate direction.

 

By the way, if all else fails you could regear the existing housing. Setting up gears requires a bit of patience and double-checking, but it can be done in the back yard. If the truck is a beater and won't see lots of high speed highway miles, you and your son could learn a LOT about how a differential works by slapping a set of new (or even used) gears in the existing housing.

 

Does anyone remember where the carrier break is for the D35? Would a new/different carrier be required going from 3.55 to 3.07?

 

Last but not least, check www.car-part.com for used axles. You can limit the search to a region, or just to your state.

[brian]

Lots o' good, reasonable advice. Thanks all. to bigalpha; my jeep has part time awheel , or so the dash light indicates. :dunno:

 

now I'm wondering if there was damage to the tranny. My kid says when this 1st happened the engine shut down .When he re-started it it lugged down and died again. So he put it in 4low and drove forward for a while (in the sand).

Sounds to me like the busted gears had the rear end siezed up until he forced the truck forward with 4wheel dr. Then the gears got broken into many small pieces and the rear end rolled freely.sort of.

 

A strain like that would surely play hell with the tranny. :(

I guess I'll look into that . meanwhile I gotta find a rear end with 3.07 gears and from an mj

still gonna let the kid pay for it. :fool:

Brian