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ea tranny rebuild diy


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my tranny just got destroyed today and i got a ftawd d/r tranny i wanna put back in my rx, but when i drained the oil was very grey and sparkly, with a bit of shavings on the magnetic plug and a lot of input shaft play and leaky seals, so the question is where would i get parts such as bearings and what not if all the parts seem good? and is there anything special about doing this task?

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usually when you post something and no one responds it means they want you to search it.

 

the search function is kinda weird so what do is use google and put ultimate subaru after it

 

like "transmission bearing replacement, ultimate subaru"

if i knew anything about the inner workings of the transmission i would help but im just as in the dark as you.

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Subaru will have those parts.

 

search for "input shaft bearing"

 

Gloyale is a user here who has a nice write up on a transmission tear down...I forget what he was replacing but I think it was an input shaft bearing? Subaru transmissions are largely similar since the later 1980's to now so expect similar overall process.

 

you can't use 3 letter terms in the search here. but you can search via username and select "thread started by" to see what threads they started. enter Gloyale into that box and click "started by" and a search string..."input shaft bearing" or something and see if you can find his trhead.

 

google is a good option, do the search you want and then google will provide a link under one of our search hits that says something like "more results from ultimate subaru...." click that link.

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It's a very expensive proposition typically. I rebuild transmissions quite a bit and parts costs can often kill the viability of it. Used transmissions are almost always cheaper. Most of the parts have to be ordered through Subaru as they are not generic. The prices will astound you I'm sure. The last EJ 5MT I did a full bearing/synchro job on was something like $800 in parts. For a turbo race transmission with a front LSD this isn't an issue. For an EA dual range its way out of the price range of viability.

 

You'll need a press, bearing splitters, and pullers/drivers, etc at a minimum to do a rebuild on a transmission.

 

GD

Edited by GeneralDisorder
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  • 2 weeks later...

GD a good trick I and others I know in the rally preparation business use with the Brass Cone Borg warner style syncros is to tape up the sections on the gear you dont want blasted and glass bead the syncro cones and the matching section on the gear.

 

Often when the syncro is lazy rather than damaged on the little gear teeth glass beading to give a satin type finish will bring the syncro action back to as new for years of road use.

 

Even in the rally cars they are generally good for a couple of seasons with a good driver,Bad drivers on the other hand can destroy a gearbox in one event.

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I ussually just do the 4 main bearings. 5 with a D/R, and all the seals.

 

unless there is obvious damage to anything else.

 

runs about $350 from the dealership.

 

It's a slippery slope though if you haven't got first hand experience with the transmission. If you have driven it and know the syncro's to be good then I can see going that route but if you are rebuilding one that's unknown I tend to just replace them all.

 

And even at $350 - you can usually find a good used one for half that.

 

Interesting option with the bead blasting. Though when I've seen bad syncro's they often have all the ridges worn flat and I'm not sure those could be saved.

 

With respect to "bad" syncro's - try the Subaru Extra-S gear oil first. I've had that clean up a lot of transmissions with a grind here or there. It's well worth the entry price. I stock it at my shop so anyone in my area can get a gallon of it for less than the online sources that sell it in liters.

 

GD

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i have 25 tranys apart if you need a specific part only two awd units for rx and one from xt 6

 

do you have the dr quill shaft/ball bearing holder, mine broke on the press due to me not looking for all the snap rings and getting in a rush.

 

anyways ive looked at everything and cleaned parts up in a solvent tank and all the syncros "appear" fine just 2-3 one is a little jammy

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Do you know what a good synchro is supposed to look like? How do you define its appearance as being "good"? What characteristics comprise a good appearance vs. a bad one?

 

Have you removed them from the shaft? You can't inspect the syncros without complete shaft disassembly.

 

I've had luck with Extra-S in conjunction with shifter bushings solving some instances where the transmission pops out of gear. Most recently I solved a 2nd gear popping problem on an '06 WRX.

 

GD

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well i suppose i made a bad call i just knew that it shifted fine except into 3rd i couldn't shift very fast because it wouldn't go, just kinda jam. I just kinda spun the parts on the shafts and would try sliding the collar on the 3rd gear one and i would have to wiggle things to get it to slide on. The little teeth on all of them have the same shape to them with the triangular ends on one side. All the other gears i just free spun them and quickly slid the collar and they would engage just 2-3 is a little weird. This is the first time doing anything to a tranny, so im trying to learn

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The teeth on the outside of the synchro are never worn since those aren't what do the work - those are just the drive teeth or "shift dogs". The "teeth" that need to be inspected are on the inside diameter of the synchro and cannot be seen or inspected without removing them from the shaft. These are a very tiny (1/32"-1/16") series of SHARP ridges that run around the inside diameter and have a cross-section like a saw blade. They engage with the matching cone of the freewheeling gear and pull it up to speed durring the shift. These are what cause grinding and poor shifting behavior when worn because if they are not sharp and defined they will not grab the gear and spin it up to speed before the shift collar engages the dogs - causing them to grind into each other rather than smoothly engage.

 

You can tell absolutely nothing without shaft disassembly but the forces required to disassemble many of the components will apply force through the rolling elements of bearings - generally requiring their replacement as that is not acceptable bearing protocol.

 

GD

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