Damage 3.25

[milner351]

Vue V6 is a Honda fo sho.

I don't like dealers, regardless of brand.

[SuperBuickGuy]

back to tech - why would a tremec keep eating synchros?

[Beagle]

Driver needs a woman passenger to put his hand on her leg instead of resting it on the shifter.

[dieselgeek]

back to tech - why would a tremec keep eating synchros?

poor trans alignment perhaps? I know this can cause all kinds of screwed up problems.

[milner351]

^^^ YUP - Bellhousing alignment can cause all sorts of issues, putting the input shaft in a bind, it slows down quicker than the output shaft which is tied to the wheels and changes speeds more slowly. The difference in speeds from input to output is what strains synchro's as I understand it. Could also be a wrong lube / not enough lube problem - but certainly the dealership can get that simple stuff done correctly?
(Lots of ATF required 5 speeds got mistakenly refilled with 90w in the 80's-90's)

[TC]

Every manual transmission bellhousing that I've seen had "dowels" on the back of the block that lined up the transmission, also the input shaft is supported by a bearing in the middle of the Crankshaft, which gives 3 points of alignment.........Basically it is almost impossible to for the trans not to be line up correctly, unless you have some hack that doesn't make sure the trans is seated properly against the engine.......

[SuperBuickGuy]

Given what Scott and John said (which make a lot of sense) - is it possible that the problems with the hydraulic clutch system relates to this? to remind - the clutch fluid keeps becoming burned (descriptors are failing me here) - the fluid smells burned. I've changed it once, and it's again burned. It is the clutch the car came with from the factory 48k miles. The other issue is when you're really pushing the car (power shift), the clutch within 2 shifts fades to nothing (boiled fluid)... I have a new clutch/throwout bearing (which includes the slave cylinder)...

TC - GM is the owner of the problem (if this is what it is because the clutch hasn't been changed)

[dieselgeek]

Every manual transmission bellhousing that I've seen had "dowels" on the back of the block that lined up the transmission, also the input shaft is supported by a bearing in the middle of the Crankshaft, which gives 3 points of alignment.........Basically it is almost impossible to for the trans not to be line up correctly, unless you have some hack that doesn't make sure the trans is seated properly against the engine.......

You can't just bolt in any old trans combo to any engine it fits. You have to measure with a dial gauge to get the input shaft centered and parallel to the engine crankshaft, and this needs to be done on EVERY new combo, even factory ones.

They make Offset Dowel pins just for this application, so you can get the shafts to line up. When they don't line up, you can cause all sorts of problems including ruining the main bearings in the engine itself.

I used to not realize how big of a deal this was until I saw the process take place. Then I understood all those guys who just bolt up their new aftermarket transmissions without properly measuring, and wondering why their trans or engine got fragged.

in SBGs case though, it should be safely presumed that the trans/bellhousing/etc is already aligned from the factory, but maybe not?

[dieselgeek]

Some good reading on the subject:

http://www.camaros.org/bellhousings.shtml

That one caught my eye as I googled many pages-worth of "bellhousing alignment" topics. They show a picture of a throwout bearing that's seized up from heat. This sentence takes me to SBGs complaint of burnt fluid:

"This misalignment created excessive stress on the pilot tip of the input shaft, which eventually fatigued, broke off, and allowed the transmission input shaft to wobble extensively around in the crankshaft. This resulted in tremendous heat sufficient to cause the throw-out bearing to weld itself to the bearing retainer"


Definitely something worth looking into. I was reminded of this as the landspeed car we're working on required significant work to get the Liberty trans properly aligned with the Gen II Hemi block.

[TC]

Given what Scott and John said (which make a lot of sense) - is it possible that the problems with the hydraulic clutch system relates to this? to remind - the clutch fluid keeps becoming burned (descriptors are failing me here) - the fluid smells burned. I've changed it once, and it's again burned. It is the clutch the car came with from the factory 48k miles. The other issue is when you're really pushing the car (power shift), the clutch within 2 shifts fades to nothing (boiled fluid)... I have a new clutch/throwout bearing (which includes the slave cylinder)...

TC - GM is the owner of the problem (if this is what it is because the clutch hasn't been changed)

I can't see it being an alignment issue, if it was an older car that you did a manual swap on with an aftermarket bell housing or you have an engine that has been Align bored, then yes an alignment issue could be the problem, but since everything is factory and came with the car I don't see it being that........I would look more at the throwout bearing not being shimmed properly..........Basically being shimmed to tight, so it's like your driving around with your foot on the clutch...........

[dieselgeek]

TCs suggestion, I agree with, you HAVE to wonder how the factory got it wrong - since they made hundreds of thousands of these cars.

I agree that the heat issue with the fluid is a great clue - you may have to follow that lead yourself because automotive techs today just aren't what they used to be. I didn't really need to state that last sentence because this whole 12 page thread is a testament to Tech Service not being what it used to be!!!!!!!!!!!!!!!!!!!

[STINEY]

Factory tolerances are just that, tolerances. We'd like to think that all these new fancy expensive cars are better than what was turned out 30 years ago.............but PEOPLE still put them together (granted, fewer people, still)

Quite possible someone had a bad day, asleep at the wheel, or newbie in training didn't get the alignment quite right.

Also, offset alignment dowels can slip, putting things WAY WAY outta whack.


On the synchro thing, I have stripped the synchros off my sandrail. The cause: heavier-than-stock clutch disc. Just as John alludes to, the shafts cannot keep the proper speed for the proper time when there is a variable change.

His example = different viscosity fluid. Mine = different rotational inertia. Symptom is the same, eventually no more snychros.

[SuperBuickGuy]

while I can fault the transmission/rear end guy for a long list of things, I doubt even he would have screwed up the proper synthetic fluid that goes in the transmission.

...and I'm not throwing the tech under both back wheels of the bus - I think GM's "fix it, and we'll decide whether or not we're going to pay for it" is rubbish. Which is why I'm not 100% concerned about them fixing the throwout bearing. Reason number 2 (reason 1 is I don't trust them) for fixing the clutch and throwout myself is it will be the foundation of any case I'd bring against GM for failing to pay a valid claim.
The tech would testify they couldn't demonstrate
The experts would testify the part is failed
GM would not get the benefit of the doubt.

For every overreaching, there is a lawyer waiting to take their overreaching hand off at the shoulder blade.

[SuperBuickGuy]

funny coincidence me talking about shoulder-blades and such... got a call from GM's lawyer today

maybe I can convince....errr, yeah, we'll go with convince GM that they need to trust their mechanics and not put the general public at risk with their silly post-repair shinanigans.

that and I'll settle for a ZR-1 or 10.

[Deaf Bob]

Crap... Was so looking forward to getting my Dualie on the road... Took ti,me from derby cars to drop a motor in it (Crescent City winner) .. Getting the bell housing and motor to mate was a beeyouch! Untill I pushed the TO bearing back by hand.. Now no clutch.. Gonna take some time after Memorial day to monkey with it... Same set up u have on your car..