Built 4L60E Shift firmness clunk 1st-2nd
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Hi guys need a little help.
After I got my transmission built years ago with a 3600 yank convertor for some reason the 1st - 2nd shift depending upon how much throttle is given like 25-35% sounds like a squeak / clunk. If the throttle is under 25% it won't do that or if you're over 70% throttle. Doesn't happen in any other gear. Only the 1st - 2nd shift. Could it be too much shift pressure, because it is very aggressive. Though I've gotten rides in built 4L60E's with similar shift firmness that don't have this problem
Any ideas? This has been this way for years. I should have went back to my trans builder at the time, but it's too late now. I almost wonder if it could be a torque arm??
Anybodies help is greatly appreciated!
After I got my transmission built years ago with a 3600 yank convertor for some reason the 1st - 2nd shift depending upon how much throttle is given like 25-35% sounds like a squeak / clunk. If the throttle is under 25% it won't do that or if you're over 70% throttle. Doesn't happen in any other gear. Only the 1st - 2nd shift. Could it be too much shift pressure, because it is very aggressive. Though I've gotten rides in built 4L60E's with similar shift firmness that don't have this problem
Any ideas? This has been this way for years. I should have went back to my trans builder at the time, but it's too late now. I almost wonder if it could be a torque arm??
Anybodies help is greatly appreciated!
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This is common in a built 4l60e. You can try to have your shift points and transmission tuned on a dyno to see if it can be fixed but it does not really mean you have a problem. In most builds valve body mods are done to mechanically boost the pressure. You can have enough pressure for lots of power and full throttle shifts but it will just be slightly high on that partial throttle 1-2 shift. If it really bothers you put a factory valvebody in it, no shift kit, and they likely put the stiffer pump spring in for using the car above 6500 rpm so you can change that as well and you likely wont have the issue but it may not have the same potential and I would not let the transmission see much high rpm use.
http://www.sonnax.com/system/instruc...L60E-01-IN.pdf
The above link is a good idea of what most all 4l60e high performance builds include. Pretty much all the parts listed help shift firmness and keep fluid pressure up. If your shift kit did not include a PWM eliminator that can cause a harsh tcc engagement with a high stall converter. If you are feeling the fishbite converter lockup you will need to have your torque converter rebuilt and pwm eliminator installed on the valvebody.
http://www.sonnax.com/system/instruc...L60E-01-IN.pdf
The above link is a good idea of what most all 4l60e high performance builds include. Pretty much all the parts listed help shift firmness and keep fluid pressure up. If your shift kit did not include a PWM eliminator that can cause a harsh tcc engagement with a high stall converter. If you are feeling the fishbite converter lockup you will need to have your torque converter rebuilt and pwm eliminator installed on the valvebody.
Last edited by TurbopigB4C; 10-03-2013 at 02:47 PM.
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While everything TurbopigB4C said is correct, I think he missed that you are complaining about a "squeak/clunk", not about the shift firmness.
Looking at the torque arm is a good place to start. What type of mounts do you have on it? The stock rubber ones or urethane ones? I have read dozens of threads here about Urethane trans mounts squeaking/clunking and/or vibrating.
Other than than, I would drop the pan and remove the 1-2 accumulator (3 bolts) and examine the insides for a cracked piston or broken spring.
Looking at the torque arm is a good place to start. What type of mounts do you have on it? The stock rubber ones or urethane ones? I have read dozens of threads here about Urethane trans mounts squeaking/clunking and/or vibrating.
Other than than, I would drop the pan and remove the 1-2 accumulator (3 bolts) and examine the insides for a cracked piston or broken spring.
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While everything TurbopigB4C said is correct, I think he missed that you are complaining about a "squeak/clunk", not about the shift firmness.
Looking at the torque arm is a good place to start. What type of mounts do you have on it? The stock rubber ones or urethane ones? I have read dozens of threads here about Urethane trans mounts squeaking/clunking and/or vibrating.
Other than than, I would drop the pan and remove the 1-2 accumulator (3 bolts) and examine the insides for a cracked piston or broken spring.
Looking at the torque arm is a good place to start. What type of mounts do you have on it? The stock rubber ones or urethane ones? I have read dozens of threads here about Urethane trans mounts squeaking/clunking and/or vibrating.
Other than than, I would drop the pan and remove the 1-2 accumulator (3 bolts) and examine the insides for a cracked piston or broken spring.