Chev PU transmission question

[Scott 730]

01 Chev 1/2 ton PU with auto transmission. Is there any way to slightly change the point at which it shifts out of OD? Kind of frustrating to be nearly to the crest of a hill and have it downshift. Darn newer trucks just aren't setup to lug and pull like the old ones.
 

[IAtractorKid]

Are you using the tow haul mode and what gear ratio do you have? Most likely you have 3.73s; changing to 4.10s would help you out but be sure you change front and rear. They have to match or you will burn up your transfer case assuming its 4wd. You other option would be programming. Custom tuning will give you the most gains but there are also a few pretty good hand help tuners. I have heard good things about Black Bear Performance. Diablo Sport tuners are also supposed to be top of the line and I know you can increase tranny line pressure and change shift points with them.

Sit down for a few hours and use google. It is your friend and there are tons of forums and discussions on these topics.
 

[mkirsch]

Let up on the gas pedal just a little just before the truck would shift out of OD. That tells the computer it's OK to go a little slower, and it won't shift.

The gas pedal is a "speed pedal" nowadays. The computer thinks that if you have it pressed a certain amount, that you want to go a certain speed, and will shift down to maintain that speed.

The gadget to program shift points is not cheap. For what it costs you can learn to put up with an occasional downshift.

Really, downshifting doesn't hurt anything. It doesn't use any more gas than lugging the engine down, in fact it uses less. It also puts less stress on both engine and transmission. The OD in those 4L60E transmissions is known to be weak.
 

[farmer boy]

Let off the throttle if you don"t want it to shift. They can be changed but it"s going to cost you a bit. Is it coming out of OD or is the TCC unlocking? If it"s the unlocking you want to be careful about how long it stays unlocked in OD. If it"s actually shifting into 3rd(D) then the TCC has already been unlocked for 1/2 the hill and you"ll really be building heat which is the #1 killer of the already weak OD gear. If you"re going to be doing alot of towing, it"s a good idea to install a heat gauge and an extra cooler if you haven"t already. Another good idea is to shift into 3rd at the bottom of the hill and get the TCC locked up for the hill.
 

[cd1]

Let me guess, 5.3 motor right, they don't have any low end grunt and that is the way they are.
 

[Scott 730]

[Brian Jasper co. Ia]

It's not overdrive thats weak, it's the forward sprag and the stator support/converter hub bushing. To get overdrive in a 4L60E you have a forward clutch on, the 3-4 clutch on, and the 2-4 band on. Only difference between 4th and 2nd is no 3-4 clutch.
 

[cd1]

You should not be towing with that truck in OD unless it can really pull the gear easily. The OD clutches are just not that big in the trans.
 

[VicS]

I have a friend with a little chevy with a 5.3 who
pulls a 16 ft stock trailer with up to 5 big quarter
horses squeezed in tight! He thinks 70000 miles is
time for a new trans. The rest of us have 3/4 ton
trucks and have no problems. Also the little Chevy
wages its tail going down a steep hill. He is fine
with this because it gets 20 mpg driving it to work.
And he does this a lot more than he pulls his
trailer loaded. To each his own.
 

[charles todd]

Drop it in 3rd, tow/haul button in. I have been on interstate going up hills in 2nd at +4000 rpm. The 5.3 can take it. 165k on the clock, one fuel pump. up to 18k loads. Gas on it, its not a 350.

CT
 

[mkirsch]

179,600 and counting on the original 4L60E here.

Thought the transmission was shot at 176,000 but it turned out to be the tail housing bushing and the U-joints.