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I think I broke it, but what?

beamer

New member
I was getting on the interstate at about 3/4 throttle, and the car revved up higher than it should, and when I let of it banged real hard and now I am the proud owner of a car with park and a whole lot of neutral. My buddy said input shaft, I wanted to get a couple other ideas, and how much horse power can a stock trans take before they go boom? Thanks
 


So you have no 1st or 2nd manually?

Input shaft is a good guess if so, they can break on stock power but not likely. Figure they become weak past 300 hp or so at a guess.
 
That's correct, no gears at all runs great just free revs in all shifter positions, and i bought the car not running a few months ago and just got it running and after about 2 weeks this happened. but it does have some go fast parts so I think that might be my problem.
 
well if you end up needing parts I have a 4t65e-hd in Willoughby that needs rebuilt im selling for parts, let me know
 
Thanks, I am not sure if I should just get a replacement trans or try and do a rebuild. The problem is it should probably have a little better than a stock trans with the parts on it, but its so expensive and taking performance parts off just seems too ridiculous for me to do lol! and CTKGP09 do you have an input shaft?
 
I was getting on the interstate at about 3/4 throttle, and the car revved up higher than it should, and when I let of it banged real hard and now I am the proud owner of a car with park and a whole lot of neutral. My buddy said input shaft, I wanted to get a couple other ideas, and how much horse power can a stock trans take before they go boom? Thanks

Plenty of 3.1's and N/A 3.8's break trans's all the time. The best answer for how much horsepower a stock 4T65-E could well be "zero".

That said, check your CV axles and make sure you didnt just snap one... I remember Clay had the free revving problem in his Eldo and it was a broken axle... not a broken trans. One is $70, one is $500+
 


OK thanks for the info guys! and I like the 4t65e hd horse power rating of zero, I think that is a safe bet!
 
What a trans can handle is really more a question of how hard you drive an old transmission with mileage on it.

Plenty of guys have done it successfully and put good power down. Me, don't ask me about how to treat a trans...lol
 
That's the worst p[art my trans has less than 95,000 original miles and I usually don't drive it hard but you cant always keep your toys on the shelf without playing with them lol. What are the recommended pieces to upgrade to handle roughly 350 to 400 hp. I just want one that can survive with what I have now and maybe an inter-cooler....
 
Well.. since it has to come out. Likely you are going to find a broken input shaft. If so.. it's easy to replace and put back in.
 
That's good to hear, but the real question is what is causing the hard shifts and stupid high shift points in the first place, I feel like the new input shaft might just be a bandaid on the real problem. Or am I wrong in that thought?
 


Guess I didn't read anything in this thread that you had super hard shifts and high shift points all the time. Sounded like a one time thing when I read it.

That might indicate a tune or sensor etc related issue. Maybe even a wiring problem.
 
Yeah thats what I was afraid of something super difficult to hunt down I am sure lol O well we will get her and if not I will turn the motor sideways and put a T5 behind it lol
 
I have a high compression 400 small block chevy laying around lol but at that point I think getting a completely different platform to work from might be best lol.
 


BillBoost37 how bad is a trans rebuild on one of these? the last trans I did was a TH350 and a T5 and T45. And what would you recommend I throw in it when I rebuild it?
 
Depends what you wanna do. If you just wanna drive, I'd toss in a JY replacement for $200. Rebuild .. depends on what it needs. Bushings/seals suck majorly. Checking bearings and doing clutches is easy. Most of the magic is in the valve body and I'd recommend sending that to Triple Edge Performance. Dave does some great things with tools that it doesn't pay to buy.

Send me a pm with your email addy
 
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