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Old 07-05-2006, 09:35 AM
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GM turbo400/475 trans

What is the difference between the 400 and 475 transmission, 475 seems to be HD, maybe or for towing is gearing different or what.

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Old 07-05-2006, 09:52 AM
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Quote:
Originally Posted by coyote74
What is the difference between the 400 and 475 transmission, 475 seems to be HD, maybe or for towing is gearing different or what.

======== the primary difference is the planetary units have straight cut gears in the t-475 unit. Tranny case is a bit beefier in the bell area

The straight cut gears reduces the side loads generated in the gear train of the tranny under a heavy load like a large motorhome.

The straight cut gears have a bit louder whine too


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Old 07-05-2006, 09:57 AM
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GM turbo400/475 trans

Thanks for the quick reply,
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Old 07-09-2006, 03:36 PM
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its the heaviest 3 speed transmission yes

i have one in my back entry way from an 87, its called the 3L80HD

HD is cast on the bellhousing pretty big

and its a real odd length and is 27 spline output though



good luck
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Old 07-09-2006, 05:45 PM
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turbo 400/475

thanks, I have one in a Motorhome, we use for towing and its scorched so I ordered a jasper, and they thought it was a 400. After running vin they decided its the 475. wanted to make sure.
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Old 07-09-2006, 06:49 PM
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the t-475 or 3l80hd .... which ever you choose to call it,

has a 32 spline out put shaft. it is not an odd length. it was used as a short tail housing unit or it had a motorhome tail housing on the short output shaft where a large parking brake assembly bolted on.

bell housings with HD cast into them does not always indicate a t-475 tranny.

the t-375 tranny had a longer output shaft and a longer tail housing. the splines on the output were 27
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Old 07-10-2006, 02:16 PM
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crosley, thanks again for your knowledge and reply.
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Old 07-14-2007, 05:22 PM
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Crosley ok then i need help

because my LJA tagged 400 trans out of the 87 R-10 pickup is 3" longer than a 9" tail th350
and is 27 spline output
but GM parts dept told me that the tag code is 3L80HD

wiki pedia says it was introduced into passenger trucks, that would be 10 to 30 series



so can you answer this ?

this trans was a new thing for 87
we recently found anothr one under an 88 pickup, identical splines and length and everything, we put it in place of the dead 9" th350 with a 3" shorter driveshaft that i had laying around, works great



so.,.,


http://en.wikipedia.org/wiki/Turbo-Hydramatic

http://louddomain.com/wiki/Turbo-Hyd...L80_.2F_3L80HD



th400 with 27 spline

'87 and up

they exist, gm made them.,

i have had two of them now

in 2wd 10 series trucks

so..


what do you think ?

ppl are claiming these are not 27 spline,

but they are



Quote:
Originally Posted by Crosley
the t-475 or 3l80hd .... which ever you choose to call it,

has a 32 spline out put shaft. it is not an odd length. it was used as a short tail housing unit or it had a motorhome tail housing on the short output shaft where a large parking brake assembly bolted on.

bell housings with HD cast into them does not always indicate a t-475 tranny.

the t-375 tranny had a longer output shaft and a longer tail housing. the splines on the output were 27



thanks

Last edited by fast68; 07-14-2007 at 05:29 PM.
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Old 07-14-2007, 05:32 PM
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A 27 splined out put shaft on a t-400 trans is a t-375 unit.

Often the tail housing has '375' cast into the bottom side of it
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Old 12-21-2007, 11:33 PM
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not in 87 and up

these are new units, 3L80HD

new for 87 and up

you arent up to date on your tranny models


this is not the old school 375

there is no 375 cast under the tail on a 3L80HD

because they are not the 375

it is a new 400 variant new for 87 and up HD version in light duty trucks


http://en.wikipedia.org/wiki/Turbo-Hydramatic

Th475 / 3l80hd

you old schoolers have alot to learn about later model trannies

hmm

thanks!
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Old 12-22-2007, 06:55 AM
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475 vs 3L80

Jasper installed a TH475 because of it bening in a motorhome, 14500 lbs. They would not honor a 36,000/3 yr warranty with any other application. So its in and working with 3000 k on it now and working fine. Thanks for the reply.
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Old 12-22-2007, 07:10 AM
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Quote:
Originally Posted by fast68
not in 87 and up

these are new units, 3L80HD

new for 87 and up

you arent up to date on your tranny models


this is not the old school 375

there is no 375 cast under the tail on a 3L80HD

because they are not the 375

it is a new 400 variant new for 87 and up HD version in light duty trucks


http://en.wikipedia.org/wiki/Turbo-Hydramatic

Th475 / 3l80hd

you old schoolers have alot to learn about later model trannies

hmm

thanks!

I am amazed at ill-informed information you often post.

GM has renamed it's trans line through out the years.

DO you actually had any hands on experience with transmissions ? Or is this all internet education on transmissions you have?

Now........IF you actually read the wiki stuff you posted the link to... you would see NO Where is the 3L80HD listed as a 27 spline out put shaft since it is not.

I am not a huge fan of the wiki program - internet information .... since the wiki lists the 4L80E as new for 1992.... the trans was in 1991 vehicles too. I had my hands on a 4L80e in 1989.... but at the time I was friends with the engineer that managed the trans group at the GM proving grounds in Mesa AZ..

OK..... then IF the 3L80HD is a 27 spline out put shaft as you post.... what was the bolt on yoke t-400 trans labeled by GM? ... go find that info on the internet and report back when you can.

You list your age on HR as 29....If that is correct I've worked in the trans field longer than you are old and my youngest child just turned 34.

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Last edited by Crosley; 12-22-2007 at 07:18 AM. Reason: spelling stuff
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Old 09-09-2009, 08:01 PM
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ok mr ******* i see hw you want to be with me.

and im gnna be the same way back to you since you think you know what trans im talking about, but that i know that you DONT!

yes but im telling you for a fact that the 3L80HD '87-up are 27 spline output.

you better go do some damned research yourself! because you obviously dont know what trans i am talking about



it was a new model for '87-up


im not talking about the '86 older th400 trans 32 spline trannies

its not the same as the old '86 older th400
i have had several more since i posted this and the 2wd ones are always 27 spline output

yes i know th400 were and are 32 spline always

but these LJA tagged 3L80HD are 27 spline output

maybe you have not seen one yet

i can take pic of mine close up if you dont believe me

i dont know why you dont


just because youre older than me doesnt mean that you know what these 87-up LJA tagged 3L80HS trannie are

most ppl do not still yet


id like to show you and so you can learn about these 87-up ones, instead of completely discounting something that does indeed exist. and that i own one of and have had many of and have used and put into several different trucks now

3L80HD '87-up under the trucks 2wd are 27 spline output


also there is a 4x4 version of one under an '88 K1500 pickup out here right now

i dont know what spline they would be on the 4x4 version


i hate when people dont believe me about something that doesnt exist jhust because they've never seen or heard of it or because they think i dont know what im talking about,


surely i am not the only one here that owned an '87-up full size truck with a 3L80HD and/or that knows they are 27 spline output

just because the old th400 were always 32 spline does not mean the '87-up new version were not

i own one still and have run across many

yes i have owned tons of trucks and replaced billions of trannies i own a fully equipped shop with a lift and we replace trannies all the time.

i know what im talking about. i have owned and torn apart more vehicles than msot of you will ever touch

heres some albums of mine just to show you a few of what ive had and done over the years

im no noob,

ive been there and done it.

im not here to show off im here to learn you something that you think you know all about and that doesnt exist.


when it actually does

asome of the billion of vehicles i have had and yes i wrench on them all in some way or another

im tired of ppl trying to discount me as some internet noob who desnt know about vehicles or that hasnt owned any or wrenched on billions or know one model of trans from another.


here is the 3L80HD 2wd trans with 27 spline, tag code LJA that i still have.

it is stock and correct for 87-up c-10 pickup 2wd with 305 TBI

if yuou look up ther specs on the trans that came in these you will find it is a th400 body with 27 spline output

and it is 34.5" long overall







screw the wikipedia crap

get the info you need from a factual source


i thnk you are an ******* to discount me like you did above and to accuse me of not actually ever having done anything,. when the complete opposite is true

my entire life has been vehicles and most of them having been GM trucks.

as you could see in my photo albums here:

enjoy!:

http://smg.photobucket.com/albums/v2...spastvehicles/


http://www.flickr.com/photos/easterwabbit/


if you still want to be a dick and not believe me and finally learn about this model of trans that you obviously have no idea about then fine be that way.

but at least now i can feel better that i TRIED to teach a stubborn individual like yourself. just because youre older and think you know all the newer models of trannies that came out doesnt mean that you do know them.
if you do not give ppl to


who apparently has a bad trait of discounting ppl due to age and accusing me of not having experience with vehicles

which is soooooo far from reality and actuality

it just gets to me when i am right and know what im talking about and then someone wants to cut me down on the basis of age or asumption that i havent owned and wrenched on billions of chevies and get dirty gready every single day of my life!

Last edited by fast68; 09-09-2009 at 11:09 PM.
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Old 09-09-2009, 08:26 PM
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I am so happy you responded after 1.75 yrs.

keep up the good work

also.... using "masked profanity " as you did can result in a suspension from the forum. Just an FYI

If you edit out the "masked profanity" that would be a good thing.

And , yes I do dismiss you and your information
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Old 09-09-2009, 08:32 PM
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Looks like the (old) TH375A renamed 3L80.
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