Yep,

I cracked (2) t-cases in that very spot within a months time.

 

What diameter hole is that? I'd love to run some infinite life stress/strain analyses on the point of stress concentration, if someone would ever want to affix a strain guage to their TC.... (pretty please??)

...im such a dork... but my enginerd ears perked right up when you pointed out that that one point is where all Al tc's experience 'catastrophic failure from extreme torsional loading'.... does anyone who's more familiar with the platform that i know if that is, in actuality, where they usually break???

edit: anyone have the TC up in autocad, inventor, anything?? It would be awsome to make a model to run through ANSYS... could be very enlightening...

 

What diameter hole is that? I'd love to run some infinite life stress/strain analyses on the point of stress concentration, if someone would ever want to affix a strain guage to their TC.... (pretty please??)

...im such a dork... but my enginerd ears perked right up when you pointed out that that one point is where all Al tc's experience 'catastrophic failure from extreme torsional loading'.... does anyone who's more familiar with the platform that i know if that is, in actuality, where they usually break???

edit: anyone have the TC up in autocad, inventor, anything?? It would be awsome to make a model to run through ANSYS... could be very enlightening...

That is where most of them break. I believe some one has drawn a 3D model of the 1st gen t/c. the hole is about 6-7mm in in diameter.

 

Here are a couple of more shots of what those morons did. I just can't figure out what someone didn't look at it and say "hey don't you think that thing might fail if we drill a hole in the weakest area of the case."

 

Ugh, it's like Mitsubishi just didn't really care what they did with these cars when they put them together

On kind of an off-topic note Lane, what did you and Adam decide to do with your trans since it looked damn near pefect when he took it apart over here? That was kind of a weird one.

 

As far as I'm concerned, the whole 5-speed is a joke. It's like Getrag took Mitsubishi's own W5M33 (AWD DSM tranny) tossed their own undersized syncros on it, stamped GETRAG on the DSM transfer case, and put it in the car.

The 6-speed is just much more solid in every way, especially the transfer cases.

I suppose this design is fine for people who never take their car above 4500 RPM and drive like a 70 yr old retiree, but with the frequency of snapped and twisted output shafts, shattered 5-speed transfer cases, the lame ass syncros, and the fact that damn near all of these things leak at one time or another, I am far from impressed with either German or Japanese engineering.

On top of that, they won't even sell us parts to repair the damn things. That just adds insult to injury.

 

Am I the only one who suspects they didn't design the car to be launched at the track? Or is everyone here under the impression that their stock car is a drag car?

And considering the $50,000 price tag, I think they did actually expect the target demographic to drive "like a 70 year old reitree" most of the time.

 

As far as I'm concerned, the whole 5-speed is a joke. It's like Getrag took Mitsubishi's own W5M33 (AWD DSM tranny) tossed their own undersized syncros on it, stamped GETRAG on the DSM transfer case, and put it in the car

A DSM T-case would hold. Cast Iron. What I don't get is they put such big beefy gears inside the transmision and have weak t-case. If the gears weren't so oversized, the syncro's might stand a chance.

 

Am I the only one who suspects they didn't design the car to be launched at the track? Or is everyone here under the impression that their stock car is a drag car?

There is not a national safety recall in place because of isolated drag racing incidents.

 

soon this issue will be fixed, very soon

 

I love these threads.

Your car was built in the early 90's its now 2005. How many years of abuse has your car seen plus wear and tear?

You could have a brand new WRX that snaps the trannyat stock hp. Im pretty happy how well these things have held up to the abuse we toss at them.

 

There is not a national safety recall in place because of isolated drag racing incidents.

Maybe I'm confused, but it seemed to me the topic of this thread wasn't an oil leak.

Just look at it reasonably, very very few cars come from the factory with race ready engines, let alone a race ready drivetrain. I would bet the aluminum transfer case was to minimize the more common complaint of the car: it's weight. When designing the car, drag launches were probably at the very bottom of their list of concerns. Launching is hard on ANY car, 5 speed owners should feel somewhat lucky that the problem is isolated to the transfer case and early output shafts, all things considered that's a very minor problem to have compared to splitting an intermediary shaft or a differential.

 

In hindsight, I don't mean to rant or generally be an ass, I just find such complaints to be mildly irritating. If you're modding your car, you should be well aware that you are going to break parts that were never meant to handle that type of abuse. That's the name of the game when you're modding a car, you can't just strap on some big turbos and expect the stock equipment to suffice. If a problem is found somewhere in the stock parts, it needs to be addressed, not lamented about to the point of blaming engineers who were designing parts for a stock car and nothing more.

I know someone whos transmission, transfer case, and synchros have served him without a single failure in over 320,000 miles since he bough the car new in 91. Interestingly enough, the car doesn't have so much as a drop-in K&N air filter.

And that's what I have to say about that

 

In hindsight, I don't mean to rant or generally be an ass, I just find such complaints to be mildly irritating. If you're modding your car, you should be well aware that you are going to break parts that were never meant to handle that type of abuse. That's the name of the game when you're modding a car, you can't just strap on some big turbos and expect the stock equipment to suffice. If a problem is found somewhere in the stock parts, it needs to be addressed, not lamented about to the point of blaming engineers who were designing parts for a stock car and nothing more.

I know someone whos transmission, transfer case, and synchros have served him without a single failure in over 320,000 miles since he bough the car new in 91. Interestingly enough, the car doesn't have so much as a drop-in K&N air filter.

And that's what I have to say about that



Maybe I'm confused, but it seemed to me the topic of this thread wasn't an oil leak.

I'm just pointing out what I feel is a serious design flaw. It is stupid to drill a hold through the thinnest portion of the T/C housing.It is begging for failure. It is also stupid that once the T/C starts to fail to try to fix the problem with a bandaid cheesy little bracket. Poor engineering. The oil seals also represent poor engineering. Like I said I'm surprised that this portion of the T/C housing holds up as well as it does. And yes the engineers should consider that many times a 40k sports car is going to get driven very hard. What ever they design should handle sprited driving. Many people with stock cars have suffered T/C failure under regular driving that is why they started installing the OEM T/C brackets. I suspect the change in transmissions from 5 speed to 6 speed and change in T/C to cast iron in 94 was the attempt to solve the problems cause by bad engineering on the early model trannys and transfer cases.
The engineers didn't worry about adding a couple of pounds to beef up the 94 T/C because they learned from their earlier engineering mistakes.

The Topic of this thread is German Engineering? And the shitty T/C oil seal would diffenatly fall into that category.

When your work results in a national safty recall you have probably done a poor job. If you like to excuse engineering failures then a Yugo would be a great car for you.

 

soon this issue will be fixed, very soon

I sincerly hope so. The reason this part of my extra T/C case is disassembled is to look into the possibilty of hand machining a steel replacement part. I'm just waiting to see if you are sucessful. Hopfully you will save me the time and expense of doing it by hand. I have my fingers crossed.

 

me too, im afraid to launch my car, lol (not really)...one more thing, i think if the engineers were smarter they would have put a oil seal on the output shaft where is goes into the tcase spool. That way it would always be lubed and pretty much never wear the splines...that way i wouldnt have just had to spend 500 bucks to buy a new shaft and spool with seals...btw i'm talking to the guy tmrw, so hopefully he has time this week to model it
- matt

 

Maybe I'm confused, but it seemed to me the topic of this thread wasn't an oil leak.

As has already been said, the thread is about the overall engineering of the case. Oil leaks fall into the same category as cracked housings. They could very likely be related. The case flexes, oil leaks. The case flexes too much, it cracks.

The change to the massive 6-speed housing in 94 was not simply for asthetics. They had to have had a very good reason for not just changing it, but radically altering the size and material.

Don't think that I expect the car to be "race ready". I don't. But as I said in my original post, the fact that we've uncovered engineering deficiencies, even in near stock form, says something. At the very least we should have been allowed to purchase suitable replacement parts from day one. I challenge anyone on this board to give me even one credible reason for the facts that we had to battle with Mitsu for years to clear release of rebuild parts, and why I had to spend a couple months translating Mitsubishi's own rebuild documentation into English just so we'd have service specs on the damn thing.

 

In respect to your reference to German Engineering, I believe in the old days they were known to make highly innovative and strurdy designs and got the reputation as master craftsmen. I have considerable experience with BMWs in particular and although at first glance they appear to be built very well, I believe many things are overly complicated which only serve to raise the price of the car and do not in any way increase their reliability over the more common ways of achieving the same end goal. Often times, they introduce amny more parts into the equation then they really need to. On the other hand, in the US, we are always striving to make things cheaper,simpler and more durable and the reduction of parts is often the main goal, and quality and craftsmanship takes a back seat.
However, I think the evolution of the 3s platform has addressed all the really weak parts as far as stock power levels are concerned. You cant expect an engineer to produce a product with cost restraints that will be able to handle repeated abuse from double and triple the initital de3signed parameters. On the other hand, the whole transfer case design is really an awkward poorly engineered part. Its a part which causes catastrophic/dangerous failure when run dry, but the owner is never given any warning when it does run dry by some light or gauge. The main shaft is not lubricated in any way and requires periodic inspection and lubrication, but its not spelled out in the maintenance schedule given to the owner. Also, its fluid capacity is so small, its empty before an owner would even realize it. They really could have avoided alot of their obligation or responsibility by telling the owner to change the case fluid every year sort of like guys with the active diffs in the EVOs have to do, but I guess they treated the TC like people do with rear diffs---just keep running the car and never look at or change the fluid for 100,000 miles. I know I had many RWD cars without a posi, and I never changed the diff fluid and I never had an issue because it didn't leak, but if it did, as an owner, I would be the only one to blame because I was not aware of the maintanance issues with my own car.

Sam

 

The problem is not that one hole is not located well it is that 2 holes are not located well.

The two holes are right next to each, one to hold to cover on, the other to hold the transfer case to the mid housing.

When I blow my transfer case I am just going to replace it with a 6 speed combo tansaxle and transfercase, with MR Jspec gears of course.

You can see the two holes in the lower RH corner of this picture.

Some pictures of a broken transaxle housing that I sectioned with a bandsaw

I had a team of my design engineers look at this design and they didn't like it
http://www.monninengineering.com/images/Transaxle/Team.jpg

 

^^ Haha... reminds me of when I try to do my homework...

 

John your an animal with all ur 3d renderings.

 

Your engineers look very professional

 

I agree with John Monnin it is really two poorly placed holes that significantly reduce the overall strength of the T/C case. If the case is indeed cast in iron I would like to see at least the hole that is picture with wire in it in my picture repositioned. Of couse the GETRAG lid would also need to be redesigned also.