so my friend rear-ended my car
 

Cosmetically, the car isn't bad at all. only a couple stone chip sized marks. But here is the bad news... i drove about a mile and then it started making some horrible noises. I stopped immediately, looked it over and found the differential pumpkin was hanging a little funny.

If you need a new carrier I have one, from a an rx7 that will never break like that.

where'd he hit you? removing the diff and replacing the winged portion is a couple hour job at most.

i guess now i am in the market for a new diff, appropriate speedometer gear, axles, and possibly some other parts, once i dig in there and see what else is broken.

This is currently a 4.30 with a 5speed. do you think a 3.9 would be a little too tall to keep this car's sprightly nature. Will my begi s kit be enough to offset the taller ratio?

hit square in the rear. i have no clue how that impact did this, but i don't see any other cause

I'm also not sure a hit to the rear would do this unless it he really plowed you. What kind of car was he driving? How fast? I have been rear ended twice in the past year and both were much worse than yours:

http://www.mdbbox.com/images/miata/9...earoutside.jpg

http://www.mdbbox.com/images/miata/97m/hit2/rear.jpg

First was from a restored '69 Nova. The Nova did not drive away, I did). The second was from an '01 Cherokee. She had only a ding on her bumper, but it was a much slower impact.

Neither of these accidents even got me an alignment, even after several arguments with the adjuster. I honestly haven't looked at my diff, but I've heard nothing odd since either of the accidents.

I don't even see any damage to your car! I'd say this is just a coincidence, hasn't this been known to happen before? I'm not going to go through the entire build diary, but I think Keith's 7 broke a diff wing. Entirely different chassis of course, but it has happened before, I believe to others as well.

I have nothing useful to add, other than you might want to rethink your thread titles because of perverted people like me

Lol.

if the car was in gear with the brake off, it might have tweaked it somehow.

hah, i didn't even notice that until you brought it up. :fixed it:

He was driving a 92 prelude @<10mph Those do look much worse than mine. You can't even see the cosmetic damage on mu car unless you are really are looking for it. Both him and myself can't understand the physics behind the diff housing getting busted, yet there is little cosmetic damage to speak of. I haven't disassembled anything yet, so i don't even know of anything else that is damaged other than the diff carrier, and probably the axles (where all the awful noise was coming from when i tried to move the car and had no power to the wheels)

I might just have to take you up on that, i will pm you later this week.

it was in 1st with light brake applied

Thats one way that it could have happen, now what i want to know is how do you driver your car. Like burn out shows, some good wheel hop, or pop the clutch one too many times. Not saying you do but we had a women who cam in for an exhaust leak and we found her diff hanging which pulled her exhaust down and made it leak. Now we know she drove her car hard and the diff ripped off the her uni-body. The car was a 1999 bmw m roadster turns out its a common problem when driven hard. So i think you had a crack in your housing and the hit caused it to fully crack and drop.

well i am no grandma when i drive, but the most wheel spin i apply on dry roads is approx. 2 full wheel revolutions.
I am not a drag racing fast n furious attention grubbing wannabe.

I am much more interested in getting to my destination as quickly and quietly as possible, and perfecting a rev matched double clutched downshift. Heck i have only been to two autocross events.

I think you had a hairline crack and the hit caused it to brake fully if you were hit harder then i could see it happening. then again i have also seen a diff grenade itself by ripping the e-brake.:giggle:

i don't deny the hairline crack, that does seem like a good possibility. It is even possible that this crack could have existed before i even bought the car 2 years ago. In any case, it is broken. Is there anything that i should keep an eye out for that could also possibly be broken as a result of diff dropping? Frame damage, axle, drive shaft, wheel hub?

Should i just replace the diff housing and other broken hardware? Or should i just simplify the situation by swapping the whole diff?

Get the broken diff out inspect and if any thing looks bad or damaged replace. I myself would look into the offer on that rx7 housing.

What other broken hardware do you think there will be?

Same thing happened to my friend Jason's 01. He was hit in the back by a NA not even going that fast. There was a little crack in the bumper, but nothing really bad. But the diff wing was cracked and it needed a new carrier. He said he knew something was broken by the position of the shifter.

The diff wings have a relief notch in them so that the wing breaks as opposed to the internals of the diff upon impact. The diff is most likely fine so just find a new housing and swap out the pumpkin.

Happened on my old 90 but I did get run over by an 18 wheeler so my impact was slightly greater. ;)

Frank