Might need new trans??

I've searched thru a bunch of old threads on the subject. Car is an '01 C4 manual, trans only grinds when downshifting into second when cold. Fine when hot, all other times fine, all upshifting fine. So it's the syncro. But, drove 100miles north this w/e, and heard a couple times a medium pitched whine when under throttle between 3k-3.2k when at 70-75 mph, would disappear, then come back for 3 seconds, then gone... Would be hard to nice if the radio had been on or anything. Bearings? Now I'm more scared about impending doom. Waaah. Thoughts on longevity, when to fix, etc? I doubt the oil has ever been changed, it's got 49k+ on the clock. Going to replace straight away (I got the car a 2mo ago). What is the Shell oil Porsche recommends? Id like to get it locally if I can, so I can do this ASAP. (I've decided not to do the Redline or Swepco). Swallowing $3.2k+ for a rebuild might be in the picture, but that's a real hard pill to swallow, while also needing the swallow the clutch/flywheel, and (cause I want to), the IMS bearing upgrade. I will do the work myself on a buddy's lift, but that's still a $4.5k tab in parts alone. Uggg. Anyone have a core 31 trans for a C4 I could have for cheap? Lol! But having a spare ready would be nice, and get that rebuilt. I've heard real good things about Gbox, and Erik over there talked to me at length this morning. Seems like a real quality shop and rebuild. Anyone with experience with them? Thanks for any input, advice, info, kind words, unkind words, whatever.

You can drive it for many many more miles if it is a small whine, trust me I know!! Mine was finally howling like a banshee and popping out of first gear by the time I had it rebuilt!! Pete

I think Oklahoma Foreign has one for a 3.4 for sale now. If it comes to that of course.

peavy.... sorry for your troubles. Trannies are usually on the bottom of the list that goes bad. Keep us posted.... a DIY would be awesome. Write one up and you will be god on this forum.

I have swapped a tranny on a C2 - its not bad at all, the only thing I found "wierd" is the tranny didnt slide into place like other cars I have done... we had to draw it upwith the bolts which made us think the splines on the shaft were not aligned with the clutch... but that was just the way it when in... it wasnt the most comforting feeling, but worked perfect ! - sorry about the issues...you are right, any "grinding" doesnt sound right.

Thanks for the condolences, folks. It is a bummer. The more I read about it, the more I'm finding folks with the same issue. The whine is very slight, and I've only heard it that once. The grinding I can make completely go away by just not downshifting into second quickly when cold (I can do it with no grinding if I ease the stick in). It's fine all other times. So all in all, I don't think it's major (yet), and hopefully an oil change will help. But, in the end, I will have to do something at some point. When? Like pszikla said, it might be a long time. But we'll see. With no more bonuses or raises at work these days, finding a chunk of change like that is harder. As for the DIY, sure thing. If/when I do this, I'll DIY the trans removal, clutch, flywheel, IMS bearing, install, bla bla bla. One thing: I've heard from a couple folks now that it's much easier to R&R the trans by dropping the whole engine/trans as a pair, R&R the trans, and putting everything back. Anyone have an opinion here? Maybe I'll start another thread on just that. But I'm assuming Ed didn't have to when he said he did the C2's. I can't imagine it being easier with all the A/C, coolant plumbing, fuel lines, and electrical that needs to be disconnected.

Be careful not to throw the baby out with the bath water. Your comment about ‘not downshifting into second quickly when cold‘ ; it might be just a clutch related component

Ok, so P dealers want upwards of $40/qt for 75W-90 transaxle oil!! This is on Pelican, from Fuchs who is an OEM Porsche supplier. Is this oil any good? Right weight, but is this oil crap or something? Only $12/qt. I knew Shell is what P uses, right? What kind of Shell? http://www.pelicanparts.com/cgi-bin/...ear%20Diff.%29

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Take a step back though and think of the service interval that Porsche uses though; 90k, and you only need a couple I think for a C2; you can half that and it still makes financial sense. You can but a larger quantity for a smaller /quart cost and do several with a few other guys; that’s what we did locally.

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Thanks Whitey, and per your previous post, I really do hope it's something clutch-related and not inside the trans! Fingers crossed. My C4 supposedly take s 2.7L in the transaxle, but I heard someone needed 3.2L in the end. And my front diff needs 1.5L. That adds up. As to the service interval, that's a whole other thread with opines o' flyin! P also recommends 15k engine oil changes, which almost everyone has agreed is way way too long. 90k is way too long IMO for a gear oil change too, if for no other reason than just the particulates in the oil from component wear that needs to be taken out. I'm a 30k guy myself on high performance cars, but to each his own.

I'm waivering on oil again!!!!! Crap. Originally I was gonna use Redline NS (no slip) that doesn't contain any friction modifiers which would make the syncros come to speed quicker. I don't have an LSD so don't "need" modifiers. Here's a desciption of the Redline 75W-90NS taken from the Porsche Shoppe in the UK. I doubt this was designed FOR the P-car, they just want to sell more of it. Regardless, I've heard good things about this oil. "Redline 75/90ns 1 Quart Specifically developed for Porsche gearboxes. This GL-5-type gear oil doesn't contain the friction modifiers for limited-slip hypoid differntials. Makes syncros come to equal speeds more quickly, allowing faster shifting & much easier low-temperature shifting. Can also be used in racing limited-slip differentials." Thoughts? Other than "Porsche used the oil they chose for a reason" answer. (I believe they've made choices on certain things based on factors other than pure engineering). Could it make my syncros wear even faster?!

Food for though. I did not wait until 90k; I was @ ~ 42k. Trans fluid looked better than I thought it would; the front diff though was near black, and see the metal in the plug . Re: oil - you'll pull your hair out. Check the OM and pick an approved oil that falls into the viscosity range appropriate fro your climate and use a good interval, time or mileage, that correlates to your usage. HTH

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Thanks Whitey, that does help. I was more worried about my transaxle than front diff, but now really want to get that oil out of both and quick. Thanks for the pict. Oh yes, oil. We'll definitely NOT talk about engine oil on this thread. Lol!!

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Peavy, IMHO I'm sure it would be fine, however it may not last for 100k like the OEM stuff. IF by some chance it fixes your problem, just count on changing it again at the shortest recommended interval.

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Awesome, thanks for the input Medtech. I think I'm gonna give it a shot. I'll probably also change it every two years JIC, since you're right about the service interval being affected most likely. I talked with another shop, and they seemed on board too. I'll let everyone know how it goes after I do the drain/fill. Here's more to think about : adding a small amount of ATF. (dont' scream yet!) Some folk's indies have done this during the fill and say it's wonderful. Even the shop I talked to this morning say they've done it with good results. I'm thinking of adding about 10oz, but not until about a month before I drain this new Redline (a year from now) to let the detergents in the ATF clean it up a bit inside, then do a refill with pure gear oil again. Thoughts? Comments? Flames?

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I'd advise before having tranny rebuilt to have tranny/diff fluid changed and clutch hydraulic system flushed and pressure bled. My 02 Boxster was starting to shift with difficulty when cold I had to skip from first to 3rd when tranny cold. Once warmed up shifting ok. After fluid change (at dealer) shifting much better. Took me a while to unlearn the skipping from 1st to 3rd technique though. Had the tranny fluid changed couple of times now. Tranny has over 225K miles on it. Shifts as good today as it ever has. Fluid. Have it changed. Don't skimp. Have Porsche dealership service department do the fluid change and use the Porsche fluid. I have done this several times and I see no reason to risk using some tranny fluid du jour to save a few bucks. Sincerely, Macster.

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Macster, thanks for the input! That's very hopeful news. I did do a clutch bleed when I did a brake bleed a couple weeks back (using a Motive bleeder). I'll report after I do the fluid change. I'm real glad to hear your experience (and congrats on not needing a new tranny and for having such a high millage B!). I hope I have the same happy ending.