AWD launch...clunk

[DiamondStarCar]

Ok I have only had my 1g awd for about a week now, and I was wondering if I have a problem with my t case or something. I got the awd because I heard about how you can launce these things at 5,000rpms and they just shoot forward. Well, I've been kind of carefull by only launching my car at 3 or 4,000rpms. When I drop the clutch, there is some bogging and a clunk coming from the front of the car. I think I may be dropping the clutch to fast and need to be more steady...but I should be able to launch these things pretty hard right? Please tell me if this "clunk" is just me letting off the clutch too fast or if it's a real problem I need to worry about.
Also, the car's clutch has 35k miles if that helps...it's not slipping. When I am already accelerating from a roll, it grips great and takes off fast. However, I sold my Fwd and got this Awd because I like the faster launch. Please help.

 

[selmerguy]

I dont think it is th TCASE. Cause even with the tcase the car would pull with the front wheels when you pressed the gas. I bet you tosted that 2100.

 

[Mike1992]

+1 for a broken rear axle

 

[Eagle18g]

well I'm pretty sure it wasn't the clutch because its not brand new it has at least 1000 miles on it. And when i dumped it there was defiantly one loud thud so I'm assuming some sort of gear along the drive train just exploded. And it doesn't feel like a clutch because i just had my clutch go bad 1000 miles ago and i know how it feels. Can anyone explain to me if it's not the clutch why it is slipping like a broken clutch?

 

[selmerguy]

well I’m pretty sure it wasn’t the clutch because its not brand new it has at least 1000 miles on it. And when i dumped it there was defiantly one loud thud so I’m assuming some sort of gear along the drive train just exploded. And it doesn’t feel like a clutch because i just had my clutch go bad 1000 miles ago and i know how it feels. Can anyone explain to me if it’s not the clutch why it is slipping like a broken clutch?

Maybe cause there is no gear there???? Did you check all the gears and see if one worked?

 

[Eagle18g]

yeah every gear works i drove home. but are there other friction surfaces besides the clutch? like anythinn else that could slip? i am very puzled as to what could be going on!

 

[absolute_DSM]

(just wanted to do some sweet launches and stuff)

WTF Im sorry.


If you dont see any broken axles, no leaking from your CV boots, and if you say its coming from your rear diff, I would suspect a "spider" gear to be gone.

 

[GVR4592]

I wouldn't be driving the car around anymore until you find the problem. It does seem like you broke an axle, have you checked anything yet?

 

[Eagle18g]

Not yet I'm going to open up the rear end tomorrow and see if there are metal shavings in there. Otherwise I guess I'm going to have the shop check it out next Thursday but I don't want to weight that long!!!! But do you know why it could be slipping like I described its the one thing that has me stumped.

 

[1stGenRocks]

sounds like a broken rear axle to me.

the reason it feels like a slipping clutch is the viscous coupling that connects the front half to the rear half. when they spin a different speed it locks together so whats happening is you floor it and the broken part spins real fast because theres no resistance. then the viscous starts to lock it all together and then it feels normalish again.

 

[StR8sPo0Ln]

sounds like a broken rear axle to me.

the reason it feels like a slipping clutch is the viscous coupling that connects the front half to the rear half. when they spin a different speed it locks together so whats happening is you floor it and the broken part spins real fast because theres no resistance. then the viscous starts to lock it all together and then it feels normalish again.

I agree, But also i would check the rear of the car to. drain the oil out from your rear and see if there are shaving of metal and how much. You could have done more than just blow an axle.

 

[BISHILVR]

Front diff, front axle, center diff. Is what I would think.

 

[silver bullit]

No wonder DSM's get a bad rep for reliablity cause people cant drive, and practice 6k drops into first with a new clutch and the driver not knowing what the hell they are doing.

 

[cc4ever]

Come on now, no reason to be mad at him. I launch at 5.5K and always in first ... also 1,000 miles is fine for break in as long as they aren't all highway miles. And he has learned what not to do, maybe he even knew not to drop it so hard before and it was an accident. Atleast he admits what he did wrong and knows not to do it again. No real racer never makes a mistake.

 

[GVR4592]

Not yet I’m going to open up the rear end tomorrow and see if there are metal shavings in there. Otherwise I guess I’m going to have the shop check it out next Thursday but I don’t want to weight that long!!!! But do you know why it could be slipping like I described its the one thing that has me stumped.

Why don't you just look under the car and see if you have a broken axle?

 

[Eagle18g]

I'm going to check everything I can see after school today 1stgenrocks made a really good point about the vicious coupling. Yeah and it was pretty stupid to launch at 6,000 rpms. I didn't rev it and hold it at a certain rpm I just floored it and dumped the clutch and by the time I got the clutch out it was at 6,000 which is pretty stupid, Plus my clutch adjustment is out of whack and it doesn't engage till about 5 inches off the floor. But what happened, happened. Anyone know any good places where I can buy used rear ends, or differentials.

 

[1stGenRocks]

I dont think the 6k launch is what broke it. More likely just a part that was wearing out and that was the last straw.

Hell, I launched mine off the 7500 rpm rev limiter once. I was sitting on the link stutterbox at 5500 and the car creep forward just a hair and tripped the speed sensor bumping it up to 7500 right as the lights dropped. Slipped it out hard and spun most of the way through first gear and chirped 2nd.

Lucky for me the track prep was shit since it was a friday night and it was cold out.

 

[compression]

sounds like something ive been through, when i shattered my center differential it acted exactly the way you are describing. and i have also had many broken rear axles, and i know when i break a rear axle because then im fwd and i can see hear and smell the front tires burning. just go check the rear axles and try turning the driveshaft by hand just go check it out.

 

[Eagle18g]

Ok well today I visually checked everything out. Everything looks fine from the outside. I jacked up the driver's side and took off the parking brake and I could spin the tire easily. So I guess that would mean that I shattered the spider gears in my rear differential. I hope that is all I broke I am hopefully going to take off the rear diff later tonight and I will share my findings. Anyways is it possible i broke anything else? and does anyone know any good places to buy a cheap rear differential.

 

[Killer_TSI]

Spider gear definately

 

[Eagle18g]

Thanks for posting your first post telling me what i just said. Let me be the first to say welcome to DSM tuners!!! Having a little trouble with the rear diff anyone know what size the bolts are that mount it to the frame in the rear of the vehicle? I cant get a socket on there so I'm going to go to craftsman and get a wrench I think it is 21 mm but I'm not 100% sure.

 

[c4uldr0n]

sounds like you need to get a SAE/METRIC kit from sears...

 

[pottersgst]

well if it was only the spyder gear that broke then you would just have to watch that no pieces broke off an got jammed anyhere else. Let us know what you find

 

[Eagle18g]

yeah I'm in the process of getting the rear differential out. All the bolts on my suspension are royally rusted in so I hope I don't break anything when trying to free up and axle! ill let you know how it all turns out

 

[1g_tsi_awd]

+1 for rear axle.

 

[DSM_Zak]

Thats shitty.
Hopfully its nothing catestrophic.
My best educated guess is a rear axle.
But who knows it could be anything throughout the drivetrain.