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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: GUITAR1989 on May 25, 2011, 01:44:57 am
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Hey guys I was driving with my brother and he allways shifts down when hes going down hill so he doesnt need to ride his brakes. I was driving in my truck and noticed when I shift down from 3rd to 2nd it doesnt hold me back at all and 1st makes me go wayyyy to slow. He has a manual Tacoma and my trucks got a TH375 auto. Should it be holding me back or is that normal for our trucks when going from 3rd to 2nd to not slow me down at all?
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Its because he has a manual. A manual is DIRECTLY connected to the engine via the clutch. Automatics use torque converters which are kind of a free float between the two. Thats why when you stop an automatic, it still idles because of the free floating between the torque converter and the transmission. But if you stop with a manual without pressing the clutch it will stall because it is directly connected. It binds the engine and stops it from turning so it stalls. If the tires were broken loose and the rpms were high, then it would run at a stop because theres no bind stopping the engine from turning. So, the torque converter takes a certain RPM in a certain direction to connect the engine and transmission. Hope that makes sense.
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I had a th350 that would drop if I down shifted from 3rd to 2nd. I love to downshift in Maryland well the eastern shore we don’t have hills so the only time I do is when someone rides my but lol it like slamming on the brakes with no brake lights they usually come really close, if it too close I give it a little gas to avoid the accident but I’m sure they have a wet seat
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I have downshifted my automatics for years. They do slow you down some. My 74 Malibu 454, with a built TH 350 would screech the tires when downshifted into first. my 95 Camaro with a stock trans and a V6 that I have now will chrip the tires as well when dropped into first while moving at lower speeds.
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it also depends on backpressure. i know even on my sm465 before i cut the pipes off would almost do a nose dive when i downshifted but once i gut the pipes off it has little to no effect
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You should absolutely have engine braking in 2nd gear with your TH375. Are you sure it's going into second?
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Yeah its shifting into 2nd. If I should be getting held back what could be the reason its not?
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idk i have a TH400 and it doesnt have the 1st or 2nd gear it just has the complete gears to change the ratio for like pulling a big load up a hill. it has L1 and L2 so i cant down shift
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Whats your rear end gear ratio? That has a say in the matter too.
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the gearing is 3.73 in the rear.
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idk i have a TH400 and it doesnt have the 1st or 2nd gear it just has the complete gears to change the ratio for like pulling a big load up a hill. it has L1 and L2 so i cant down shift
What? ???
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idk i have a TH400 and it doesnt have the 1st or 2nd gear it just has the complete gears to change the ratio for like pulling a big load up a hill. it has L1 and L2 so i cant down shift
What? ???
I was wondering the same thing lmao!
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idk i have a TH400 and it doesnt have the 1st or 2nd gear it just has the complete gears to change the ratio for like pulling a big load up a hill. it has L1 and L2 so i cant down shift
What? ???
This has got to be good. LOL
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the gearing is 3.73 in the rear.
3.73s are a higher gear then 4.11, so it will allow less engine breaking than an automatic with 4.11's. Unless its a STEEP hill, you may not notice any slowing. My truck slows down in high gear with the gas out.
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Dang :( Looks like my brakes are gonne be getting the wrath cause where I live Its hills everywhere...Big Hills
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Its all about backpressure and rpms.
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No Engine braking in second:
Front servo or accumulator oil rings may be leaking.
Front band may be broken or burned out.
Front band not engaged on anchor pin and/or servo pin.
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well in the owners manual i had for my truck it showed that i can only go 45 in L1 and L2 and i can shift into the L ranges above 50 it wont go in until i hit 45 so as not to ruin the tranny also a cool thing i learned of my FF rear axle idk what type it is its a 1ton axle but until i get over 15 mph its a full pos rear end then switchs to regular after i get to 15 and ive proven that it works. i know i must be blowing some peoples minds right now
idk i have a TH400 and it doesnt have the 1st or 2nd gear it just has the complete gears to change the ratio for like pulling a big load up a hill. it has L1 and L2 so i cant down shift
What? ???
This has got to be good. LOL
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That posi is called a gov locker. Ive got one in the rear of my 2 wheel drive, and it can hang with the jeeps offroad(mostly). Supposedly theyre known to grenade. And mine unlocks closer to 20, and it seems ad if it locks up when theres too much load on one tire, like a limited slip.
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Yeah its a gov-loc or know as the gov-bomb. They work but if you look at one closely you or atleast I couldn't understand how they would hold up. I blew one up in the rearend of my 03 yukon xl. I've always had issues with them unlocking and locking randomly too.
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No Engine braking in second:
Front servo or accumulator oil rings may be leaking.
Front band may be broken or burned out.
Front band not engaged on anchor pin and/or servo pin.
i was about to pull out hte ATSG..
whats with the back pressure/rpm stuff???????? i can get a downshift skid when i had a 350 and 400s...
floating?????????? itsd fluid coupling.. and yes you acn shut the engine off and it will windmill down the road if your at speed.