AMC 15 interchange?

[jnordness]

Hi everyone. New to the forum. I don't have an Eagle, but I have a 78 AMX I've been looking to do some upgrades on. It's a 258, 4 speed car with manual everything. One of the things I'd like to change is the gear ratio. It currently has the AMC 15 with 2.53 gears, with posi.

Doing research, I have inferred that the AMC 15 is essentially the same as the Dana 35. Will a Dana 35 ring and pinion combination in 3.31 work on my carrier? I know the 3.31's are as rare as hens teeth, but I found a set on e-bay for the Dana 35 and asked the guy (Drivetrain parts) if it would fit and he said no. Now it's sold. I'm confuzzed.

[MaskNMI]

Never heard of 2.53 ratio in these cars, unless you mean 2.35 or 2.73....I've only really looked at the axles the Eagle uses though...

Yes, from what I'm finding out, most carriers are essentially the same, although the 2.35 carrier (2.53? who knows, probably also an obsolete carrier ) is different and obsolete along with the gear set to fit in it, and what a crappy ratio, as you well know....the tubes are different, though as AMC axle has a wierd  setup for the axle retention and wheel bearing where the wheel bearing is sealed off from the gear oil and runs in grease with a second seal to hold the grease in...or in my case you get a brake drum full of greasy oil....also the wheel bearing comes off by removing the hub and sliding the wheel bearing off the opposite way you would from almost any other semi-floating axle (don't even get me started on the 2-piece axle...)

He probably said no cause you asked him if it would fit in an axle he knew nothing about....AMC 15 is not exactly a well-known or well-respected axle

If you can get the 3.31's in there (I don't see why not unless it's a really odd ball tooth combination), that still doesn't solve your problem of getting the same ratio for your Dana 30 up front

My personal advice (and many hardcore AMC people will probably feel like flaming me for this, go ahead...) is to not waste your money building an axle with a troublesome 2-piece axle design that have been known to snap off the studs holding the hub/drum/wheel assy on the car...and get a real Dana 35 or something even better.

[BenM]

2.53 is a valid AMC ratio for D35/AMC 15 rears. It's rare though, so few people run across it. I have heard rumor that 80 Eagles may have had 2.53 axles, but I can't find any records that it was available for the D30 yet.

Code K for Open, V for Twin-Grip.   The 2.53 is 17:43.

Edit:Read chart wrong. AFIK, late and early are the same code on this ratio.

[68AMXGOPAC]

Mask: Not to step on ye toes, but he has an AMX wich is 2wd. , I think that is also why it has the odd ratio , not normal to our 4wd. eagles ??

[jnordness]

That's correct GOPAK, it's a 2wd car. I know this is an eagle forum but it seems that people here know better than anywhere else on the internets about this.

I understand that the AMC 15 and Dana 35 are 'similar', the Dana 35 being stronger and more modern, but I'm still cloudy about whether the ring & pinion from a 35 will fit on the 15's carrier. It also seems that the ratio I have (2.53) is in the nether region, since 2.35 is a different carrier, and all of the ratios I know about for the 35 start at 2.73, so I don't even know if my carrier will work for steeper gears, assuming the ring & pinions DO swap.

Thanks for helping me out guys.

[IowaEagle]

Here is the link to our parts catalog section on '79 - '83 AMC cars.  It may be of some help in your research:

http://www.amceaglesden.com/~iowaeagl/guide/index.php?title=Group_9_Axles_--_Propeller_Shafts


This image shows the ratios and codes LLD = less locking differential and WLD = with locking differential:

[duane2171]

Hey Jnordness!!  Do you have any pics of your AMX?  What color is it and what interior does it have?

I also have a 78 AMX.   It was originally a 304 car.  It now sports a 401/727 combo with an AMC 20 rear and an Auburn.

[jnordness]

Yes Duane! Check out this link from the AMC forum:

http://amccars.net/cgi/yabb2/YaBB.pl?num=1267829065/30#30

It's black, with black interior, and it has the 79 graphics kit on it, with a rear spoiler from a Ford Probe, of all things. It looks stock on the back.

Yeah, I definitely want to hop it up, but having trouble deciding on how to do it. I may just swap in an AMC 20 and be done with it, and not worry about the old 15. I plan on running a 304 with Jeep 4.0l slugs, a solid cam and a T-5.

Have any pics of your ride?

[duane2171]

Check out this link for pics of mine.
http://www.amcalberta.ca/Gallery/AMX/AMX.html

Black with black vinyl as well.  Was yours on flebay before?  I'm sure I've  seen pics of it.

[jnordness]

Sweet ride. Correct color!

I don't think it was on e-bay ever. I bought it from an AMC guy near Cincinnati (Cincijeff), and I think he's had some pics online and in a couple of magazines before. I don't have the trim, but I think it looks good without it anyways.

[MaskNMI]

Mask: Not to step on ye toes, but he has an AMX wich is 2wd. , I think that is also why it has the odd ratio , not normal to our 4wd. eagles ??

LOL, didn't think that one through did I?!? 
[it's funny cause I remember realizing we were talking not about an Eagle and ACTUALLY GOING BACK and changing the first sentence...]

jnordness:
lol, sorry about that I guess you can pretty well run 3.33 and 1/3's if you can find the gearset  and iirc, it was a matter of the physical case size (I dunno, I've never seen this 2.35 case), not different bearings, so maybe you can machine to fit???

AMC 20 would be WAY better for you if you want to run an AMC axle, and i can certainly understand that if you have a nice AMX...this is an axle people won't give you a quizzical look over when you ask for parts for it, and is well-respected in some circles....i have no experience with it, can't tell you a thing about it, maybe you already in the know by the sound of it.

you can always go pull a semifloating D35 out of an XJ through '89 (many have stock LSD) and put your gears in there (you might find some that are 3.55 stock iirc...also, have to move  shock mounts) and then you can take your time building yourself a sweet little AMC 20

[MaskNMI]

duane: that looks like one bad-@$$ little amx you've got!!! how do you like that Auburn, I am thinking of going with one?!?

[duane2171]

I remember Googling 78 AMXs a couple years ago and coming across your AMX.  I thought the spoiler looked like it totally belonged
on the car.  I'm pretty sure I was talking to the owner at the time as well, cuz it was for sale at the time.  I am a member of the AMC forum as well.
It's one great looking AMX.

Thanks MaskNMI!  I love driving it now that I got it on the road.  I love the Auburn, problem free and hooks up like a charm.  I also have a line-loc on it.  I have a 650 Edelbrock on it for a carb and it was supposed to be almost new when I got it.  But I'm having problems getting it set up properly.  I'm thinking of just going to a Holley or a Demon to save myself some headaches cuz I don't seem to have any luck with Edelbrock.  Also another tip....if you're thinking of using the Edelbrock shorty headers....don't....they don't fit without a lot of tube customizing.  They are supposed to be a direct replacement for stock, but they are 1 1/2" wider than stock and they won't fit between the steering shaft on the driver's side and also rubs hard on the passenger side.  That was an expensive lesson I learned as I didn't want to bash in the header tube ot make it fit.  I'll just use them on one of my J trucks I guess.

[jnordness]

Well, it's been a while since my OP, but I finally digested the link posted by IowaEagle. It looks like my AMC 15 carrier that has 2:53's will be able to take up to 3.58's. Does anyone know if this is correct?

Joel

[SX/290]

  I've NEVER had any issues with AM-20's 

Mike