Fireindc

iTrader: (13)

I used to flog on my little 1.6 diff. No real launches(well, i've done maybe 3 total EVER. And they were mild), but many many pulls at around 180-200whp (10psi greddy). Now the cars apart and I'm swapping in a torsen. I still have my cute little diff intact.

Underway

Just lost mine at just under 68K. '93 running 7psi and 215 rears. HPDE and AX.

If I had to do something different, I'd switch the diff oil EVERY track event. When the pinion finally let go I was actually just taking it easy cruising to a friends so I figure the oil condition and heavy use just fatigued it.

I'll working on a pic of the oil.

Underway

Gear oil (mobil 1) after 2 Roebling track days and probably 8K daily.

Beautiful in a horribly expensive/ non lubricating way.

Now I'm working on my swap.

bikersam717

iTrader: (5)

Would very short differential fluid change intervals help prolong the life of a 1.6 diff? I have access to a lot of 80w90 and 75w90/75w140synthetic gear oil. Which would be best?

Underway

I think it would have helped mine.

There's no way all that metal in my oil wasn't causing excessive heat and more friction.

IIRC 75/90 is what is called for. Don't think the synthetics will make that big a difference IMO, it's more about flushing the contaminates out then the life cycle of the gear oil.

Linh

Good info... Sure the 215 tires didn't help. Btw how much whp/trq at 7psi? And how did you treat it? How many miles boosted?

I've changed mine before I left on an Gulf coast trip to DC and back. Was 120k miles then. Now at 137k. Probably change it before I go turbo.

Keep the 1.6 diff experiences coming.

Underway

Just came back from the first run with the torsen. What a difference! My demon actually has a first gear! With the VLSD I would get a ton of passenger side tire spin, not any more! Should help a ton on the track. I do feel the torque loss from the 4.30 to the 4.10 but I'd be willing to bet the car is still quicker just because it can get power to the ground now. Also the Poly Carrier Bushing have made a awesome improvement it how smooth clutch engagement feels.

OK off my thread jack soap box.

I've had the car for about 20K miles at 7 psi. It was a used HPDE car when I bought it and needed a complete over haul. (I got all the way to the short block before I stopped finding broken parts) As far as I can tell it was the original rear end with a total of Just under 70K on it.

As far as #s go...I've never dyno'd the car. If I had to guess I'd say 170-180 range. Felt pretty quick at first but the boost bug is definitely starting to get the best of me.

I never really launched the car hard since first gear was relatively useless due to wheel spin. My wife and I did share the car for HPDEs so it was running two classes. Equivalent to twice the wear per weekend. This is why I think being better about fluids would have helped. 2 weekends = 4 to the car.

I do have bits and pieces that will be up for sale but don't have time to list them right now so if anyone is looking for something specific PM me and I'll see if I have extras.

Just out of curiosity, why the interest?

Linh

Just really intrigued to see some 1.6 diff last 80k miles and some just 8k miles. I wanted to pin point what was the cause of them failing.

My car is set up for street fun and no track, so I wanted to know for certain it can handle the street abuse. So far, the consensus is yes, a 1.6 diff can take street abuse for the most part. However, in racing events, I believe it won't. From your post, I'm guessing part of the 1.6 issue is heat!

Linh

Up for updates on everyone's 1.6 rear end.

Hows everything holding up?

Rallas

iTrader: (9)

I had over 210k miles on my 1.6 open diff before it grenaded. The last 8k had a na 1.8 and I drove it hard, but with sympathy. The last tank or two I was driving like an idiot with lots of 1st gear dumps and hard shifts to second. It only took a week or two to kill the tiny diff. I already had a 1.8 torsen laying around for a few years so it was no biggy. Seeing the two next to each other will make it clear why the puny 1.6 can't handle anything.

redturbomiata

iTrader: (5)

Mine went Thursday night at 178k miles. Looks like it chipped a couple teeth then shredded the rest of the ring gear. Finishing the Torsen install today.

krissetsfire

iTrader: (1)

Mine lasted about 500 miles after I turboed. I took it to the movie theater parking lot and went to town on it. It then cried at me for the next few hundred miles and finally died 2 blocks from my house one night.

I bought the car with 167k miles on it still had original clutch and all. the old man i bought it from was original owner and was very nice to it. I turbo'ed and killed the rear end/clutch before it hit 168.

Changing the rear end and axles is really very easy btw. You don't need too many tools. The only somewhat odd tool would be a socket for the axle nut. My car has been an Arizona car it's whole life and I still had trouble getting the nut off even after soaking it in penetrating oil. I didn't have anything to break it free at the time so took it to brake max. I just brought a 44oz coke with me and he took it off with an air chisel. If i hadn't had that hiccup it would have taken me slightly over an hour to swap the rear end out. I'm counting the time it takes to jack the car up, take the wheels off, drink a beer, stare at the wheel for a few because i really didn't feel like it, take the caliper off, drink another beer, etc...

there are actually a lot of really helpful things in the garage section at m.net and i'm sure there are some miata guys in your area willing to help you change it and will work for beer.

Photo 1 of album Differential Swap

Linh

I wish we have more local Miata enthusiast. We actually have a larger group of s2k members. Anyhow, I recently acquired a 99 type 2 Torsen. It's going in soon. Not sure before or after the rear end goes.