Poate intereseaza pe cineva :
Comentariu interesant de la un "subaru tech" :
Hey, a bunch of questions I'm qualified to answer as a subaru tech.
First off, this 2014 OB's TR580 was the 2nd year of the existence of the 580. The powerflow and components inside of it are quite different from the TR690, which became the "big boy" transmission but was also the first model, which debuted in the 2010-12 legacy/outback. The primary issue the early TR690s would face is chain slip, which generally is caused by a dip of fluid pressure. Through years of iteration and improvements, these problems have largely been corrected as long as the vehicle load is kept on the lower end. (Ascent problems notwithstanding.) The common fail point in the TR580 by contrast is usually a valve body solenoid failure, either the torque converter lockup solenoid (which is basically always applied) or the transfer clutch solenoid (aka "awd" or "center diff"). In either case, the valve body is a serviceable component, with a new one in the ~$700 range MSRP. the 580 has also gone through a number of revisions and updates through the years and has landed at a fairly stable place nowadays.
@2:08 how many 4EAT/5EAT transmissions had problems? Less than these early CVTs, but definitely not zero either. It took a solid 5-6 years-worth of recalls and bulletins before the 4EAT landed in a stable place. The 5EAT was only used behind the higher-output engines (EZ30/36 in a tribeca, for example) and was pretty solid but occasionally would have 3-4 or 3-2 slip issues.
@2:20 the tailshaft cup is missing, looks super weird without it>
The transmission is designed to be serviced when it's stood up on its snout, would have had an easier time that way lol.
@4:14 yes, it was. That's the transfer clutch drum, aka the center diff. As the piston you're holding squishes, it sends power out to the rear driveshaft, which splines onto the end you pushed through.
@5:18 you don't need to take that nut off, as I assume you're about to discover. That is the pinion shaft, and will lead to the front differential.
@5:51 this is where you'd find the aforementioned valve body. It is accessible in the car relatively easily without having to move anything; there's just enough space in the transmission tunnel to sneak in there and remove this cover plate. I assume the valve body was removed so that it could be rebuilt.
@6:11 this cover is primarily just a chain that runs from the torque converter to the oil pump. This cover is a very common source of leaks on newer TR690s, and occasionally a leak point on TR580s. An indexing prybar is the ideal tool to remove this.
@7:42 thank you for bringing this up -- because a differential will always have some metal-on-metal wear and therefore metal in the fluid, I think one reason subaru CVTs are more robust than their jatco/nissan counterparts is because of this fluid separation. (In the nissan transmissions, the diff is lubricated by the trans fluid.) Also, I'll put this blurb here, but Subaru does not have a required interval for diff fluid service, only an "inspect and replace as necessary" every 30k, but in my experience it'll already look pretty gross at 30k (from break-in) and then be fine until 90/150/210/etc. from there on out. Subaru calls the CVT fluid a "lifetime" fluid, and I'm sure you have an opinion on that, but their criteria for it being failed is if it is no longer translucent. While the stuff coming out of this trans is quite dark, it does not appear to be murky, and so in Subaru's eyes would be considered "ok." (Most technicians would agree doing them on a 60k interval is fine for normal use. Subaru does say replacement at ~30k miles if you "tow regularly" -- and does not elaborate what that means.)
@8:49 this is a serviceable part but it's called a "strainer" not a filter, and it's more akin to the pickup screen in your engine's oil intake. The amount of metal on that magnet is average to less-than-average. That fluid view at 9:00 though, is not normal.
@10:35 early-00's and older subarus also used a double-roll-pin axle with stub shafts in the front. Company23 makes an excellent punch tool for servicing those.
@11:21 I have literally never seen or even heard of a leaking shift shaft seal on any subaru auto transmission. (They all use a very similar design.)
@12:16 and this is about as far as we're supposed to do teardowns at the dealer level. While the chains/sheaves/etc. parts are available in the parts catalog, subaru does not provide the special tools necessary to decompress the sheave and remove the chain set. However, all master techs do a full disassembly and reassembly of a CVT as part of the training program, so I suppose someday we might be doing rebuilds.
@13:06 subaru calls this the "manual valve" and it's connected to the shift selector you elegantly removed -- this hydraulically controls shifting through the valve body. Should note here everything from the selector lever in the car all the way to the valve body is all physically linked; no electronic shifter gizmos in any subaru (so far).
@13:30 this is the step where the sheave would be separated -- you'd need essentially a huge 2-jaw or 3-jaw puller on the big side to release the chain from the sheave. There's a really good youtube video from a Kennedy Transmissions shop in St Paul, MN doing a teardown of an early TR690 -- he shows the puller in use.
@13:48 that chain guide probably popped out during disassembly -- if it popped out during operation it would be all chewed up or broken -- but inspecting that chain guide was part of the WRK recall process for the 19-21 Ascent.
@16:30 this is the forward/reverse clutch drum and planetary set. In the TR580, when you pick R, everything after this set spins "backwards" -- chain and sheaves included -- and then when you select "D" all of that stuff needs to change direction. This means, if you own a TR580, **do not shift from R to D while the car is still rolling.** One of the major differences between this and the TR690 is that the D/R planetary set comes after the chain/sheaves.
@17:18 the smell comes from the air trapped in the bolt holes, it's like a stale, fishy, crabapple blossom-y kind of smell. You'll get it when pulling the engines apart too.
@18:00 very good, yes those rotating cups set the pre-load. They're also basically impossible to remove once corrosion sets in on the case, even with the correct special tools.
@20:53 those diff bearings don't look tooooo bad. We've had more than a few cases where a "quick oil change* place will try to do a front diff fluid service, drain it, and then use the wrong port to try to "fill" it. They dump 1.4 qt of gear oil into the trans and leave the f diff empty, which means they get to buy a new trans for the customer.
@22:45 looks like we're taking apart the transfer clutch. There is a current TSB for the Ascent for this clutch having some pretty bad wear in the drum and causing a binding, which leads to wheel chatter around turns. Haven't seen that failure in any other CVT though. It was a somewhat-common problem in early 4EAT transmissions. You can see just a little bit of wear at 23:01 on the sides of the drum.
@25:40 never thought to take apart a chain that way, lol, interesting technique. Hoping you'll show us the faces of the sheaves here, as if this was experiencing "chain slip" you'd see some scoring on the faces of the sheaves. @22:67 yeah i'm not seeing anything obvious in there.
Not really sure what failed in this one that necessitated replacement tbh. Could have been from bearing noise or could be misdiagnosis.
Anyway, I'm a very regular contributor at r/subaru, if you or anyone else has any questions feel free to post up
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