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Snapped Input Shaft

BrokenRhythm

BrokenRhythm

New member
:th_angry2: I was taking a ride the other day and decided to punch the car a little bit in performance mode. next thing i know i hear a "boom!' and lost all gears.
Not the most fun but i guess i found another weak point in the trans. Just ordered the upgraded shaft from zzp. (and a dp and a whisper resonator) Ill take pics of the carnage when i go to the shop.

just figured i would share another failing 4T65E-HD story for you all.



pics soon!
 


Snapped a turbine shaft with a 3.4" pulley? Wow, that sux, sorry to hear it.

What does built trans in your sig mean if you had a stock input shaft?
 
You may also have a broken drive chain which causes a lot of carnage when it goes. Typically the input shaft will only break on a hard launch or during a very hard 1-2 shift, while the chains will give way pretty much any time you are WOT and typically at higher rpms.
 
First reading the post and seeing his mods, I was wondering if he was sure it was the input shaft. I'd be more inclined to believe it was the chains, since they're a wear item while the shaft is not.
 


unfortunately the input shaft was one thing i just couldnt afford when i rebuilt the trans.. gotta love how things catch up to you in the end. went to the shop yesterday that previously built my trans. and yes, the input shaft snapped right in half.

this is what was in the trans before:
TSP-651 INTENSE™ Street/Strip Performance Shift Pak
4CS-289 Heavy Duty Fourth Clutch Shaft 1
PSK-65E 4T65E/-HD Pawl-Style Input and 3rd Sprag Kit
CKO-100 Overdrive Clutch Kit
CK2-100 Improved 2nd Clutch Kit
GMH-PCS 1997 - 2002 Pressure Control Solenoid
GMH-TCCS Torque Converter Clutch Solenoid
GMH-SHS Shift Solenoid
GMH-TFPS Transaxle Fluid Pressure Manifold Switch
BVK-831 Improved Boost Valve and Sleeve Kit
TNST-TBC Coast Band for the 4T65E Transaxle
TNST-TBF Forward Band for the 4T65E Transaxle
TNST-TBR Reverse Band for the 4T65E Transaxle
And the upgraded 3rd gear clutch.

im just gonna do a single chain setup now too while im at it.

does anyone else know of any weak links that i should be cautious of?
im not exactly putting down much hp, but it would be nice to know that if i started to go into one of my crazy modifying binges that it would hold up
 
Don't get an 11/16 th's chain. Get a 7/8's. The 11/16 th's are garbage.
 
how hard is it to replace the chain by myself? im not a trans guy, im more of engine/whatever guy. just curious if it is possible to do while the trans in in the car
 
I'm doing one right now. Out of the car. And I must say I would never attempt it in the car. But that's just me. It's pretty straight foward. It was mainly me being scared because I have never been in an automatic before.
 


Don't fear the gear. Go 3.69's. I wish I did although for most people 3.29's are MORE than enough. ESPECIALLY if they do a lot of highway driving.
 
Don't fear the gear. Go 3.69's.
Click to expand...
3.69s are not fun (besides breaking loose from higher MPH) and I would not recommend them on a daily driver usually. Besides the fact that it kills gas milage... it makes 1st gear completely useless (especially with a turbo) and 2nd to 1st downshifts are even worse. Of course, with slicks thats all a different story.

Also, third gear tops out between 120-125mph or so.
 
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BrokenRhythm said:
when converting to 3.29's? was there a noticable difference in performance? and how annoying is it that the speedo is off?
Click to expand...

The speedo shouldn't be off, when you do a conversion you need to get the computer reprogrammed for the new gearing, otherwise the shifting would be all screwed up, too. You could also just get a different reluctor wheel to fool the computer, but I don't know if anyone actually does that anymore.
 


Right. I had put a cam and a lot of other stuff in at the same time. So i'm not sure exactly what i was feeling but yes there was a difference in acceleration.


A lot of peoples issues with breaking the tires loose is greatly dependant on the type of street tire there using. I use a street tire with around a 280 TR rating. That's probably i did not have to much of a traction issue.. All i could do is chirp second real good.


A turbo is different though.
 
BrokenRhythm said:
when converting to 3.29's? was there a noticable difference in performance? and how annoying is it that the speedo is off?
Click to expand...

It won't affect your speedo since the reluctor wheel is on the diff, which isn't being changed out. You do need to have the PCM reprogrammed so it will shift at the right points. Also, without PCM programming the PCM will think the tranny is slipping (since there's more reduction with 3.29 instead of the stock 2.93).
 
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