Not sure on the 4.44 and LSD as I havent taken apart the front KIA diffy. But with the 4.78 ring (KIA rear), the bolt holes wont line up to a stock 84-85 open diffy AND im not sure if it will fit a pre-S3 diffy either. Havent spend time on it since the RX-3 (where the 4.78 would go) will be out for next 2-3 months.

Didn't bother to take the time to read the whole thread, BUT...

I have the 4.78's from a Sportage in my '85.

It is important to use the FRONT pumpkin, since the rear diff is a different size.

The pumpkin was a direct bolt in replacement for my Series 3 rearend. The axle splines are the same (note: open diff) and the driveshaft flange was the same. All of the pumpkin to housing bolts are the same length, meaning you will need to have one extra "short" bolt, or a huge stack of washers for the "long" bolt. Huge stacks of washers suck, get a bolt of the correct length.

The rear had a bunch of noise on deceleration. I pulled the pumpkin out to investigate the noise and found the factory was very sloppy in how they assembled it, and backlash was twice what it should have been. The gears had practically no wear pattern in them yet, so when I installed the limited slip from the original rearend (184k and everything was in "as new" spec, just needed some glaze removed!) I set the backlash to the tight end of specs. The gears whined a lot until they broke in, now they're almost silent. I suspect that if I didn't have a suspension link going right from the center of the housing, to directly under my ear inside the cabin, the noise would be nonexistent.

Again, you use the front diff, as the rear is a 7.5" and will not work.

OTOH, the whole Kia rear axle assembly looks like it might go into an RX-7 with minor work, and is already set up for a Panhard rod and 3 link :)

Didn't the 83's have two different housing sizes? i swear the 82 diff I replace mine with doesn't fit right. The pumpkin doesn't seem to mate with the housing correctly to take some of the load off of the housing bolts. But, The axles are small bearing so what does this mean?

On a similar note, I found a 97 miata in our local playground. Its an open 4.10 diffy. What a waste of time.

You have the small axle so the 3rd member swap wont work.

The pumpkin will be a direct fit. It's a *tight* fit to get it in there, but it'll go in.

'83-earlier rears all have the small axles, so you either need to swap the differential out or change the side gears with ones from a small-axle open diff.

Changing the differential is trivial if you're patient and have a calipers and a dial indicator. The dial indicator is for measuring backlash, the calipers are to measure housing spread, which is kinda important. The way I did it, since the manuals never specified how much bearing preload there should be, was to stick bolts into the bearing caps (the holes for the adjuster retainer bolts) and measure the distance, then loosen one of the caps, loosen the adjuster until bearing preload was gone, then tighten the cap back down and re-measure. This gives you two ways to re-set the carrier bearing preload, by absolute measurement and by relative spread.

Too busy so I paid $150 to a local gear/trans rebuilt shop to replace the stock GSL's 3.90 R&P with a KIA 4.44 R&P. Installed it last night with GM LSD additive/Royal Puple Gear Oil. I havent taken it on the freeway, but today, this fucker launches harder than my prior SE 4.10 gears and with the LSD.

Im running 15x7 panas with 205 tires in the rear. We will see how it will perform at the canyons tomorrow @ annual SOCALRX run.


I cant wait to get my RX-3 back from the body shop. New 13-B P-Port, 51.5 IDA and a newly acquired KIA 4.78 gears

Thanks for the update, let us know how the run goes.

so witch kia had the 4.77 in it?

^ yea, and will this work for my '85 GS?

Gee, I don't know maybe reading the thread tittle and thread might give you an answer.

I think he ment the years.

hummm pics of kia sportage gear and pinion...dose not tell me what yr the 4.77 is in..i read the thread and it says early 90's but wackeyracer said his gear is a 4.44 so there most be a diff in the yrs if 1 has a 4.77 and the other has a 4.44

so seeing as you said you dont know..and you told me to read the thread to get the answer..and its not in the thread from what i have read maybe you should reread it? :) but thanks for helping

No Sportage ever had 4.44's.

The 4.44 was from a certain 80's Mazda 4x4 pickup.

Go to www.solomiata.com and scope out the drivetrain section.

thanks peejay that is very useful :)

this is why i said 4.44

I don't want to be left out.. what will fit into the '82s w/LSD??

any of the ring and pinion will....its just not a str8 bolt in you have to pull your 3rd member and take to the ma place to get set up :) or you can do it your self if you have to tools and know how

Im surprised myself and a little disappointed that its only a 4.44, not a 4.78. At this point, it doesnt matter...I got a 4.44 for dirt cheap. I guess solomiata is WRONG like the threadstarter that said, rear diffy will fit a S3. Remember my other post??? KIA sportage rear diffy with 4.78. that was a waste of time and $$$. The ring is larger than our stock ring.

Then 3 weeks ago, went to another junkyard and found another sportage. Pulled out the front diffy, whallllllllllaaaaaaaaaaaaaa, its a 4.78.

what yr was that kia that had the 4.78 in it????

It was a 94

thanks wacky

4.10's going back in. 4.44 or higher is good for low end but the sucky on top end.

Awwwwwwww come on Mel. My truck has factory 4.625 and I buzz along the freeway just fine.

You really should not be doing 150+ on the freeways anyways :)

Of course I have taller 245/50/15 meats on the back....

I dunno, I kinda like not having to downshift on the highway. :) Then again I never drive faster than 80-90mph, but there's still plenty left. I'd probably run out of power before running out of gear at the top end anyway.

PLUS, there's a boomy resonance with my exhaust at between maybe 3000 and maybe 3600rpm, the shorter gears get the RPM up out of that range, making the car MUCH more pleasant to drive on the highway. Much quieter at 3900, 4200, 4500! This is important if you spend half of your weekends sitting in the driver's seat, the fatigue from a noisy environment will wreck you!

so how exactly do you get your speedometer read correctly after a step up like this