4t?? informative

Lesabre T-type or other H-body related topics.

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steveX

4t?? informative

Post by steveX » Wed May 18, 2005 5:13 am

A little history on the 4T60 used in FWD GM vehicles.
Best viewed fixed font.
The THM440-T4 was introduced in 1984 on the new GM
full sized luxury vehicles (Oldsmobile Regency 98, Buick
Park Avenue, Cadillac Sedan Deville - remember the logo
on the trunk lid "4-Speed Automatic"). This transmission
was basically the THM125-C with an overdrive added on.
The original 440 was not very reliable. Many changes
were made the first 3 years. Areas that suffered many
failures were torque converters (clutch rivets), 2nd
clutch housings, 4th clutch area, final drive.
When the Cadillac Allante was introduced, the 440
would not handle the torque of the V-8, so a special
version known as the F-7 was developed. It included
special sprockets, heavy duty final drive, special
fourth clutch, etc. A rare but solid transmission if
you can find one.
By 1988 the quality was better, but to make the
440 (now called the 4T60) a world class transmission,
electronic controls were added. The new transmission was
coded F-31 and became known as the 4T60-E. The 4T60-E was
phased in from 1988 to 1990. You can tell by looking at
the bottom oil pan - it will be stamped with "4T60-E".
This transmission has much better reliability. By the
1991 model year, all FWD Overdrive transmissions were
the 4T60-E model.
As a side note, with the introduction of the
Northstar V-8s, a new low volume transmission was
developed for these applications. It is known as the
4T80-E. Very durable but very expensive, about 80%
higher in cost than the 4T60-E. Also 60 pounds
heavier.
With the introduction of the Supercharged 3800,
a few modifications to the 4T60-E were made. The
biggest change is the final drive unit, which is of
heavy duty design. The transmission still can't
handle the full torque of engines such as the SC 3800
and the DOHC 3.4L V-6s at redline during shifts. GM
utilizes Engine Torque Management to maintain
reliability. This consists of controlling engine rpm
and engine torque (through timing and fuel) during
shifts. That is why the SC 3800 and DOHC 3.4L do
not shift at redline at WOT.
For the 1997 model year, GM introduce the 4T65-E.
This transmission is a heavily reworked 4T60-E design
which includes such features as a 258mm torque converter
instead of 245mm, twin chains and special sprockets for
noise, Electronic Line Pressure (ELP) for ECM control
of pump pressure to better regulate shift quality,
revised fourth clutch, revised second clutch housing,
and many other improvements to reliability. The first
applications to receive the 4T65-E will be the
SC 3800 V-6 and the DOHC 3.4L V-6 to minimize the need
for torque management. The phase in will be three
years and will be complete by model year 1999.
The biggest cause of failure of the original
4T60 (440) is heat. [snip of restricted info] Through
control of shift points and torque converter lockup,
tranmission temperature can be controlled. There is
a temperature sensor in the transmission for the ECM
to monitor. This shows the STRONG recommendation
to add and external air/oil transmission cooler
for 4T60 (440) equipped vehicles.
The following is a list of GM FWD transmissions
and their applications:

Model Years Current Application
--------------- ------------ ---------------------
THM125-C (3T40) 1979-2002 J (possibly to 2002)
4T40-E 1995-future J,N,P-90
THM-440T4 (4T60) 1984-1990 None
4T60-E 1988-1999 All except J,N,P-90
4T65-E 1997-future SC 3800, DOHC 3.4L
4T80-E 1992-2002 Northstar

Steve Ochs aka N8TYS- Mfg. Engineer - GM Powertrain - Parma Plant
Transmission Division (4T60/65-E) -
The statements and opinions expressed here are NOT an official
statement of General Motors or the GM Powertrain Division

Pontiac Automatic Transmissions
This table is provided for entertainment only. No warranty is expressed or implied as to its accuracy. Typographical errors are possible. Please send any corrections or additions to Rich. Many thanks to Ken Carothers for posting the original ratios table, and James Butler for posting the 4T65-E history, in the "Poncho" mailing list.


Model 1st 2nd 3rd 4th Reverse

Rear Wheel Drive
TH-180C (3L30) 2.400 1.479 1.000 2.000
TH-200-4R 2.741 1.568 1.000 0.674 2.067
TH-350 2.52 1.52 1.00 ?
TH-400 (3L80) 2.482 1.482 1.000 2.077
TH-700-R4 (4L60) 3.059 1.625 1.000 0.696 2.294
4L30-E 2.400 1.479 1.000 0.723 2.000
4L30-E Optional 2.860 1.620 1.000 0.723 2.000
4L60-E 3.059 1.625 1.000 0.696 2.294
4L80-E 2.482 1.482 1.000 0.750 2.077

Front Wheel Drive
TH-125C (3T40) 2.840 1.600 1.000 2.067
4T40-E ? ? ? ? ?
TH-440-T4 (4T60) 2.921 1.568 1.000 0.705 2.385
4T60-E 2.921 1.568 1.000 0.705 2.385
4T65-E 2.921 1.568 1.000 0.705 2.385
4T80-E 2.960 1.626 1.000 0.681 2.130



Here is the rough lineage of the 4T65-E:
Designed Yr.- Production Yr.- Model

1974 - 1978 - THM-125 (3T40) - Some bushings & bearings carried from
THM-200, some basic designs of splines & shafts from THM-200 and THM-350

1980 - 1983 - THM-440T4 (4T60) - Four speed version of THM-125. Some parts
identical or very similar. Somewhat stronger than THM-125.

1983? - 1986? - F-7 - Made exclusively for Cadillac Allante. Similar
design but many parts different to improve torque capacity. More
expensive.

1985 - 1988 - 4T60-E - (F-31) Electronic shift version of THM-440T4. Most
parts identical to THM-440T4.

1991? - 1993? - 4T60-E HD - Same as 4T60-E except with a few heavy duty
parts (mainly final drive gearset) for supercharged 3.8l V-6 application.

1992 - 1997 - 4T65-E - Very similar to 4T60-E with many common components,
but many major differences also.

custom88
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Post by custom88 » Wed May 18, 2005 5:41 pm

Good article but I do see a few flaws. One, the 4t60-E was not used until 1992, or maybe 1991, but I know that 92' was the first year it was widely used. The 440t4 from 88-90 was totally mechanical. Also, to add something, the 4t65-E also utilizes a torque converter who can partially lock for best fuel economy/performance. it isn't just lock/unlock. It can vary how much it is locked. the 4t60E does not do this. Oddly enough GM sees more 65E failures than 60E failures.
<b>2001 Oldsmobile Aurora 3.5 Twin Cam V6</b>

T
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Post by T » Wed May 18, 2005 5:55 pm

I caught that too, 91 was the first year, only available in some body styles(reatta, riv, PA, ect.)

Also the year is way off on the Allante, they shared a powertrain with the rest of the Cadillac line, except for the 93s which got a Northstar and the special 4T60E, the rest of the Northstars have the 4T80E.

-T

toasty
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Post by toasty » Thu May 19, 2005 12:08 am

wow... good info... now my memories of bad transmission in my dad'd 87 should not affect the t that i buy... YAY!

TuType
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Post by TuType » Fri May 20, 2005 4:59 am

Great info. On this subject of the trans. I have the 4t65e in my blt. L67 from 1997 Bonne SSEi & tranny from 2001 Regal GS. Is there a shift-kit from this trans, and if so, what are the benefits of a shift-kit. If a shift isn't a good idea, why not, and what enhancements can I/should I do?

Thanks in advance,

-TuType

ps, I see a bit of new members on the board....that's good to see.

GOD BLESS!!! :lol
1989 LeSabre T-Type
L67; 3.4" pulley; DHP 1.0 PCM
2.5 Exhaust w/Flowmaster 80 Series
Custom CAI
Paint (Twilight Blue) pics soon...

toasty
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Post by toasty » Fri May 20, 2005 5:13 am

TuType wrote:Great info. On this subject of the trans. I have the 4t65e in my blt. L67 from 1997 Bonne SSEi & tranny from 2001 Regal GS. Is there a shift-kit from this trans, and if so, what are the benefits of a shift-kit. If a shift isn't a good idea, why not, and what enhancements can I/should I do?

Thanks in advance,

-TuType

ps, I see a bit of new members on the board....that's good to see.

GOD BLESS!!! :lol

there probably is a kit for it, i would check out clubgp.com or zzperformance.com ... you will more than likely also need to have your pcm re-flashed with new info... may be ok to do so if you didnt have anything custom set up in yours now for the engine swap

T
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Post by T » Fri May 20, 2005 11:56 pm

There are two ways of shortening and firming the shifts on the 4T65e. A shift kit usually shims or replaces the springs allowing for a higher shift pressure. An aftermarket PCM can increase them to almost what a shift kit can do. I wouldn't do both.

-T

TuType
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Post by TuType » Sat May 21, 2005 1:41 am

Thanks guys for the info.

I did have the pcm re-flashed last year which resulted in firmer shifts. No real mods yet, but I will revisit the flashing aspect after some mods hopefully this year.

Thanks again,

-TuType
1989 LeSabre T-Type
L67; 3.4" pulley; DHP 1.0 PCM
2.5 Exhaust w/Flowmaster 80 Series
Custom CAI
Paint (Twilight Blue) pics soon...

Tbird
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Post by Tbird » Wed Jun 29, 2005 2:24 pm

Does that mean the transmission from the 1988 BLT (which has the 3800 Series 1) would fit in the 1987 BLT (which has the 3.8)?

Thanks!

luvgm
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Post by luvgm » Wed Jun 29, 2005 3:37 pm

Is there any way to change the gears in these transmissions to say 323s?
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prodigy_16
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Post by prodigy_16 » Wed Jun 29, 2005 4:52 pm

yes, buy and install the chosen gear ratio set.
FAST CARS ARE NOT CHEAP, CHEAP CARS ARE NOT FAST.

luvgm
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Post by luvgm » Wed Jun 29, 2005 6:33 pm

were would you get the gear sets? If these gears got changed to the lower gears it would make the car even more of a little rocket.
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1987 lesabre, 1988 lesabre, 1991 lesabre.1970 nova, 1989 k1500, 1982 280 zx 1994 GMC ext

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