I'm having the occasional clunk from a dead stop, and hesitation at WOT shifts. Only occasionally, mind you, but they're there.

 

when you guys feel your transmissions start to go on you, and you get these clunks. do you guys actually get them from dead stops? I don't get those yet, but I do get clunks occasionally when I'm coasting to a red light, and then it turns green and I get back on the gas. I'm at just over 30,000 miles myself so I don't know what to think yet.

 

Mine has been both, usually from a dead stop though. I haven't lost a trans yet, though.

 

With the warranty is there any way for them to allow me to take the cost of the replacement tranny, and add it to my own $ and then install a better tranny and troque convertor?
Or is it simply if ur trans goes, GM will replace with only the regular trans and if you don't like that tough...?

 

I'd imagine you'd get a used GM trans in good condition.

 

Well..speaking of reaper...I have boggled the minds of TEP and PRJ and Cartuning..I have 58K on mine with the N2O and Turbo...although I havent ran any racing turbo runs, I have been tuning the hell out of it....I would say that I owe mine to a shift kit, tranny cooler and the dog bone with poly bushings and motor mount....

Now, I spray on a computer N2O controller...called an FJO...its a progressive, computer controller tied into the TPS. I can tell the computer to spray where I want it...I DONT SPRAY IN 1st GEAR!!! and not through shifts!! and mind you...this is all padding until I can get a tranny...Im making arrangements with TEP as we speak to build this dog up! The 7/8" chain thing sucks though...Im just going to stay 2.93 so they compliment eachother...3.29 a lil too much for the 7/8"

 

Wait. You've been running the turbo and or nitrous for over 50k miles on the stock trans???

 

"Im just going to stay 2.93 so they compliment eachother...3.29 a lil too much for the 7/8"".....Please explain

 

He does have the shift kit, so it's definately not stock. He's been tuning and using the window switch in his N2O controller.

The trans cooler is only necessary if you spend a lot of time at WOT or have a higher stall converter. I don't and I've never seen a trans temperature higher than my coolant temperaure. I'm not saying it's a bad idea or won't help, just that it's not necessary.

 

I've been doing some homework on the chain (thanks GXPJay for getting my gears turning), and it's the shock load that snaps the chain. When you go to 3.29's you increase the mechanical advantage the torque converter (and engine) have on the planetary gears, so during the shifts you see a higher jerk (time-rate change of acceleration) in the chain.

That's also why slicks are hard on the transmission. Street tires will break free easier during the shift, and since the torque generated by the tires is related to the torque on the chain and deceleration of the engine, you see a lower jerk in the chain during shifts when using street tires. It's the whole equal and opposite reaction thing (although there is compliance in the driveline).

I hope that helps. Maybe someone else can explain it better.

 

What is it that's actually failing in the stock transmission? Is there a common weak link that can be replaced before the stock trans goes?

 

Well, once you start seeing problems, something is already worn or damaged so I'm not sure if you can get away with just throwing a shift kit on it without taking it apart and inspecting everything. And as for fragging the torque converter, I can only guess the cause.

In a nutshell, a shift kit firms up the shifts mechanically. You can do the same thing with the pump, but when you raise the pressure you put more stress on the pump, the solenoids, and all of the seals. By firming the shifts up, you reduce wear on all of the clutches because they don't slip as much. You also reduce the heat generated by the clutches. Soft shifts are preferred by most people that buy cars, and they are easier on the axles and CV joints, but they are hard on the transmission.

When I started posting here I was suprised at how few people had installed one. They are used in RVs to keep the transmission alive hauling all of that mass, and my brother in law uses them all of the time when he yanks the V6 out of whatever full size Chevy he is currently driving and drops in a V8. My Dad always considered a shift mandatory in cruisers, and always put them in any heavy car he had.

By the way, what a guy like Dave at TEP does besides installing a shift kit and cleaning up your broken parts is the transmission equivalent of engine blueprinting.

 

Typically with the older units from the early 80's to late 90's, it was the pump shaft that would pit and tear up the bearing and drop the pump shaft and causing low pressure...Other times would be a los of all gears north of 2 when the reverse reaction drum would wear out.

If the people who's transmissions have failed would be kind enough to let us all know of the cause of thier failures, and not the total outcome, maybe we could have a a more meaningful discussion on this.

If you are burning all the clutches then its more likely an issue with the pump, pressure control soleniod, or just abuse. If it goes neutral, then its likely an issue with the valvebody, input clutch system, forward band system, or reverse band system. One could stress the forward and reverse servos without comming to a complete stop as all the mechanism is still energized.

But as I said in a different post, even if you put a on a K and N filtercharger, its enough to offset the calibration of the TCM and the shifts will not be timed and or pressured right, mainly at WOT, and if not right away, eventually. If the shifts are not timed and pressured right that can cause excess wear and or damage as well.

As far as breaking any hard driveline parts, that does not seem to be an issue. But also keep in mind that we do have a rather loose torque converter that masks alot of the shift feel. If you look at the tachometer and listen very closeley to the engine, you'll notice the shifts are hardly slow. One little tidbit, our V6 counterparts have much tighter torque converters, and you can feel the shifts in those cars quite a bit more.

 

iv been having the same problems as you guys. have the random clucks off a dead stop and all this started after i removed the shift kit. waiting to reinstall it again and another thing i noticed is after i took it out i would be on the highway lets say going 70 on cruise and let off the gas when normally the RPMs would be around 2000- 2200 and just drop to around idle RPMs which is about 700 and now it would stay at the say up there and gradually drop with the speed..what do you guys think this could be..?

 

According to the last owner of my SS it mine was replaced at 45k. I am not approaching 89k. Hope it will hold.

 

My uncle runs a mechanic shop and hes rebuilt about a dozen GTP trans. He always installs a shift kit (trans go or zzp) in them during the rebuild and recommends a trans cooler as well. Ive owned my car since it was new 07 GXP with a trans cooler and shift kit installed a week after i bought it. running upwards of 99000 km on odometer and its still solid as the day i installed the cooler and shift kit.

 

I may be investing in a shift kit then.

 

have you tuned your car at all with all your mods?

 

Yep. HPT dyno tune.

 

k, just curious. sounds like you should be ok, but a shift kit and a retune should call it good. i need to wait for the shift kit until i can afford smaller wheels. 20'' wheels and shift kit wasnt recommended.