Update: Driveline Noise

[insite]

well, after replacing three of four CV joints, i took my car by precision porsche & they are telling me that the knocking noise is my transmission. this thing is KILLING me this year.

anybody got a used 5-speed w/ a 2.5L gear set? ugh. this will be the third time i've had the transmission out and the fifth time i've had the axles out in the last eight weeks.

[rsfeller]

No offense but is sure sounds like you were just throwing money at the CV w/o really inspecting them. C/V always have tell tale failure signs that you can diagnosis before you spend all the money.

Additionally, if you have had the transmission out before is there not some other issue from negligence to be the current cause? Bad rebuild, fluid change, ect?

[Topless]

well, after replacing three of four CV joints, i took my car by precision porsche & they are telling me that the knocking noise is my transmission. this thing is KILLING me this year.

anybody got a used 5-speed w/ a 2.5L gear set? ugh. this will be the third time i've had the transmission out and the fifth time i've had the axles out in the last eight weeks.

Sorry man. Driving season is here and your track car is still down. I know that hurts. Do get a second opinion on that tranny. A knocking noise is unusual and there are few things more frustrating than changing expensive parts that don't fix the problem. Did you miss anything with the clutch/flywheel upgrade? If I remember right you used some custom made components. Possible mismatch somewhere? Good luck.

[insite]

No offense but is sure sounds like you were just throwing money at the CV w/o really inspecting them. C/V always have tell tale failure signs that you can diagnosis before you spend all the money.

Additionally, if you have had the transmission out before is there not some other issue from negligence to be the current cause? Bad rebuild, fluid change, ect?

the CV's were inspected. i started with IR temp readings at each joint along w/ checking the play in each one. i started with the first most likely suspect & proceeded in order to the least likely. it was difficult to tell where the sound was coming from; not an obvious thing. i suspected my transmission, but my automotive knowledge really ends there.

of course something could have gone wrong when i had the trans out to replace the clutch. i did change the fluid at that point for Redline. fluid level was checked per OEM shop manual procedure.

just as likely though that it is just worn out; i race the car & it has 130k miles on it.

[rsfeller]

I do recall from your previous post now that you raced the car and used the inferred to detect the failure posibility of the CV. Obviously no wasted money since you race them, but I was concerned for a daily driver. Most road cars give very specific signs of CV failure that are a bit elusive at first. My CV failure on my porsche was just like my vanagon (with a transaxle too) and you could hear the sound (click) on sweaping turns, but it was hard to determine which one was to blame.

Good luck and I hope it's nothing detrimental with the tranny. Keep your eyes peeled for the Porsche demantler on Ebay from Oklahoma as I've seen him have engine/trans combos before and I feel his prices are very resonable.

[insite]

I do recall from your previous post now that you raced the car and used the inferred to detect the failure posibility of the CV. Obviously no wasted money since you race them, but I was concerned for a daily driver. Most road cars give very specific signs of CV failure that are a bit elusive at first. My CV failure on my porsche was just like my vanagon (with a transaxle too) and you could hear the sound (click) on sweaping turns, but it was hard to determine which one was to blame.

Good luck and I hope it's nothing detrimental with the tranny. Keep your eyes peeled for the Porsche demantler on Ebay from Oklahoma as I've seen him have engine/trans combos before and I feel his prices are very resonable.

i kind of suspected it was the tranny to begin with, but was in a bit of denial since i'd just spent beaucoup bucks on a custom clutch, flywheel, exhaust, etc. two of the three CV joints i replaced had excessive play anyhow & i'm okay with having replaced them.

my symptoms occured whether i was going straight or turning. direction of the turn did not matter. this made me think it might be the trans. i, however, know very little about transmissions & was hesitant to diagnose it as the problem without an opinion from a tranny guy. initial diagnosis seems to be that the diff & possibly the pinion gear are shot. i was steered away from just replacing the diff w/ aftermarket toward a replacement tranny. i found one from german auto dismantlers about 1.5h from me for $1,500, so i'll go pick that up tomorrow. ugh.

[insite]

well, after replacing three of four CV joints, i took my car by precision porsche & they are telling me that the knocking noise is my transmission. this thing is KILLING me this year.

anybody got a used 5-speed w/ a 2.5L gear set? ugh. this will be the third time i've had the transmission out and the fifth time i've had the axles out in the last eight weeks.

Sorry man. Driving season is here and your track car is still down. I know that hurts. Do get a second opinion on that tranny. A knocking noise is unusual and there are few things more frustrating than changing expensive parts that don't fix the problem. Did you miss anything with the clutch/flywheel upgrade? If I remember right you used some custom made components. Possible mismatch somewhere? Good luck.

yeah, it sucks to be down during track season. trying to get everything buttoned up for may 1st; we have the track reserved that day. as for the knocking, the tranny guys i've spoken with today say that the knock is a common symptom of a dying diff.

[rsfeller]

I envy you ability to race a Porsche! but I believe you fall into the same category as us "boaters", you're never allow to complain about the cost of maintenance of an elective money pit!!

I to think tranmissions are voodoo and know little of their interworkings. Although many speak of this being a solid 5 speed from Vw/Porsche I'm curious of it's record at being thrashed on the track expecially with soup'd up engines. Are guys running blowers or 3.xL killing them?

[rsfeller]

i found one from german auto dismantlers about 1.5h from me for $1,500, so i'll go pick that up tomorrow. ugh.

That seems like a good price. How quick and you drop a trans and swap it w/o having to redo all your custom items? Do you have a pit or lift or the fun of doing it with ramps in the garage?

Always curious about DIY work. I'm waiting for the day I will have to learn how to do a clutch/flywheel on my own. Never had to replace one EVER in a car I've owned!

[insite]

i found one from german auto dismantlers about 1.5h from me for $1,500, so i'll go pick that up tomorrow. ugh.

That seems like a good price. How quick and you drop a trans and swap it w/o having to redo all your custom items? Do you have a pit or lift or the fun of doing it with ramps in the garage?

Always curious about DIY work. I'm waiting for the day I will have to learn how to do a clutch/flywheel on my own. Never had to replace one EVER in a car I've owned!

it's actually fairly easy on the boxster. i don't use a lift, just jack stands. it will take me about 1.5h to get it out and another 2h to get it back in and running. i'll pull it this evening so i can trade in my core when i pick up the replacement. none of my custom stuff is affected by the job. since the clutch, FW, axles, etc are all new, it's just a simple R&R.

it should go really quickly since i had to do the job twice when i did my clutch. spec originally sent the wrong clutch disk & i had to pull the tranny a second time.