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Can I rebuild my own 5MT?


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Have a 91 legacy 4WD s/w with 190,000Km on the clock and shot syncro's on the 4-->3 downshift. I plan to pull the gearbox over the holiday (or thereabouts) and take it in to the subaru independent mechanic for a rebuild.

 

He says it is a fairly simple job, and new main bearings and syncro kit are only a couple hundred dollars. However he books 8 hours labour for the job which he says is 'mostly cleaning' plus a little work at the press of course. Total cost about $600. A used gearbox from the wrecker is $500 with a 'replace if defective' warrantee but no cover for the labour to swap.

 

I can clean. Why can't I do everything except the bearing mount and setup myself? Has anybody done this job successfully and maybe have a few pointers about what to watch for or warnings not to do it?

 

Chris

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I have a 93 legacy 5mt which needed a rebuild due to the shot 1-2 syncro. I pulled it myself and would have liked to rebuild it myself, but that presented several issues. First of all, the gears and syncros are press-fit on the main and drive pinion shafts. It takes a hydralic press to get them apart. I am not shure about your 91, but I would think its the same. It took the tranny shop, which has done subie's before, three hours to get it apart. Aside from that, there are clearances that must be measured and properly sized snap rings, shims and such must be fitted.

 

I am pretty ballsy when it comes to taking my car apart, but I left that one to the proffessionals. Total cost for the rebiuld was $1182 which included a one year warranty. They did not replace any of the four big bearings since there was only ninety some thousand on the car at the time, and they cost $80-120 apeice,:eek: . I figure I saved $600-800 by taking it in and out myself, which included a new clutch, resurfaced flywheel, new aluminum plate on the back of the engine to replace the plastic one that leaked, and other gaskets and such.

 

I looked into having someone do just the pressing for me, but I couldn't find anyone that knew how to do it and only perfom that part of the work. It mad me mad because I had the tranny apart and both the shafts sitting on my work bench. If you can find someone to do it, I say go for it, and I'd be jeleous:boohoo:

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trannys and some of it depends on how much time you have to read the books and run back and fourth to places with presses and the like.

Another tough part is being able to tell a still usable part from one that will go just down the road.

On the subaru I would probably farm it out these days as I have more time than money.

When I was a kid I just got two or three cores for next to nothing and mixed parts till I got all the best looking bit in one case.

Thats when you find out that often transmissions have the same weak point.

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Thanks for all the info. I am in New Zealand for only 10 months -- I usually live in Victoria, Canada and all my tools are at home:( This would be a limiting factor in a complete DIY rebuild.

 

My plan was to pull the gearbox, clean it up on the outside, open it up and clean up all the sealing surfaces (no gaskets as far as I can tell) and then take the package to the mechanic to do the pressing and setup of shims and whatnot. However, I don't want to wreck any diagnostic info in doing so -- sounds like that will not be a problem.

 

My mechanic will replace the two sets of syncros and the main bearings. He said that after the bearings are pressed off, they still look and feel good, but he has had rebuilds come back after a short period with failed mains when they reuse them -- figures that the press stresses them in some way.

 

I have only a basic set of wrenches here, a hammer, few screwdrivers and for some reason the house I rented has an excellent floor jack and, I just found out, a pair of axle stands! I like messing around with my car and I like to be independent: so far I've rebuilt both front driveaxles (including outer CV R&R) and replaced the steering rack. I have no concerns about pulling the gearbox. FWIW I've found the subaru to be a well put together and sensibly engineered car. My vehicles at home are Mercedes and I would NOT say the same about them. But they are interesting to work on!

 

I'll keep you posted on what happens. Thanks again, and feel free to offer up any other advice that seems to have been missed. Chris

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My brother in law in Queenstown runs the Pegasus agency and knows a lot of folks in the trades.

I have been in New Zealand myself rebuilding the cars I used to own there, and found Kiwi mechanics and machineists to be incredably helpful.

They had ways to save parts we would throw away in disgust in the states as totaly gone.

My Anglia van had an Escort engine that was bored to the third oversize on the mains. We would toss it here if it needed one.

That van also had parts from three junkyard cores in the tranny.

I put the best stuff I had from all the trannies I could find and it ran three months all over Kiwi untill it was time to go home.

Had one radiator hose fail in all that time climbing up a mountain.

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I would change the internal transmission bearings even if they appear good. Noisy 5MT bearings are a fairly common occurance, usually starting to appear at around 200,000 km or so, but highly variable on how the transmission is treated by the owner, and whether the synchros have failed or not.

 

You don't want to skip changing any potentially worn parts that you pull out and then have to pull the tranny apart again in a year or so. Gears and synchros are somewhat easy to inspect and keep, but the bearings often give no indication of an upcoming failure.

 

BTW: most bearings start to get noisy not all that long after the synchros start to misbehave. Shavings from the synchros get into the bearings accelerating wear, and the additional vibration and stress of a "synchro-less" shift can also harm them.

 

Two Subaru transmissions have done this to me, the 5-4 synchro stops working, and about a year later the middle bearings get noisy. In both cases I ran the noisy, grinding transmissions for another 200,000 km or more, I had easy access to spare transmissions at the time. I was trying to get as much life out of the clutch as possible, but the clutch kept going and going.

 

When I looked at rebuilding the transmission it was going to be an expensive and tedious process, as all of the parts are not avaible and you don't know what you need until you pull the tranmission apart. I managed to secure a used 5mt with only 40,000 km on it for less than $500 CAD including shipping. I have noted that the 5MT prices have shot up quite a bit recently though, it is now hard to find one for under $1000CAD.

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If he is spending only several more months in kiwi a patch job may be fine. A transmission will make noise for a long time.

At the end of that time you sell it for what you can get.

If the job came out great then fine, you get a bit more for the car. If it howls you get less.

To use the example of my Anglia van I was offered $1,000 kiwi from the guy I bought it from.

The windshield was broken by a rock on the trip so we took that much off.

For an expenture of $800 US I got a car for three months that I could sleep in. Fair enough.

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Cookie points out

 

When I was a kid I just got two or three cores for next to nothing and mixed parts till I got all the best looking bit in one case.

Thats when you find out that often transmissions have the same weak point.

 

Yep, that's an unfortunate fact about used parts. Component failures are much less random that one would hope.

 

Bye the way, I am in Hamilton NZ, since you asked. And I agree, the mechanics here are terrific and very resourceful, not that I've really needed one yet. I find them really easygoing about giving advice and they don't seem to mind stopping work for a few minutes to explain something to you if you get stuck (within reason of course!).

 

alias20035:

I managed to secure a used 5mt with only 40,000 km on it for less than $500 CAD including shipping. I have noted that the 5MT prices have shot up quite a bit recently though, it is now hard to find one for under $1000CAD.

 

Owch! I think I mentioned that the going rate down here is $500NZ or about $400 canadian. But the trick is to find one. With all the turbo subaru cars down here, the gearboxes are mostly in very bad shape even at low mileage. Also, I think the turbo gearbox needs some modification to work (clutch different?).

 

Chris

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to you if you are in hammytown.

Nice place though.

A friend of mine swore he had bought every available transmission in Hawai for his BRAT. He got tranny after tranny to have the bearings fail.

Needless to say he does not drive a Subie today.

The advice about the main bearings may be well taken.

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