Difference Between 4L60E From LT1 & LS1 F-Body??
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Difference Between 4L60E From LT1 & LS1 F-Body?? Is There A Difference Between LT1 & LS1 4L60E Transmissions? I Was Wondering If A 4L60E From An LT1 93-97 F-Body Would Bolt Up To An LS/LQ Motor And Work Just As Good As An LS1 98-02 F-Body?
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From: Westbank of N.O.
Difference in lt1 and ls1 4l60e...off the top of my head, The ls1 has a removable convertor housing with different height, has a different input shaft and stator support AND depending on the year of the lt1, it may not be PWM.
Companies do make convertor input sleeves and such to use a non-ls1 trans on the ls, but I would just locate the proper ls1 unit. Can it be made to work? Yes, but not the best option IMHO
Companies do make convertor input sleeves and such to use a non-ls1 trans on the ls, but I would just locate the proper ls1 unit. Can it be made to work? Yes, but not the best option IMHO
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Joined: Aug 2010
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From: Ann Arbor, MI
GM made many improvements in the 4L60E, especially after 2002, in order to handle the additional power of LS engines.
IMHO this is why 4L60E's have such a bad reputation - people take an old 1995 trans designed for 250 ft/lbs and hook it up to a 400 ft/lbs engine. The results are predictable. Also, such an old trans will have low line pressure, worn clutches and other wear which will lead to rapid failure behind an LS engine.
Finally, as JUNK points out, there are a large number of "small" but significant differences that will make it very difficult to use. And then it will fail.
The trans you want will have a removable bell housing with bolt hole at 12 O'Clock, which indicates it accommodates a 300mm converter. These started coming out in 1998 and were nearly universal by 1999.
Just my opinion.
IMHO this is why 4L60E's have such a bad reputation - people take an old 1995 trans designed for 250 ft/lbs and hook it up to a 400 ft/lbs engine. The results are predictable. Also, such an old trans will have low line pressure, worn clutches and other wear which will lead to rapid failure behind an LS engine.
Finally, as JUNK points out, there are a large number of "small" but significant differences that will make it very difficult to use. And then it will fail.
The trans you want will have a removable bell housing with bolt hole at 12 O'Clock, which indicates it accommodates a 300mm converter. These started coming out in 1998 and were nearly universal by 1999.
Just my opinion.
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Verdad Gallardo 1993 Fbodys had a removable chip PCM (PROM) which did not have any controls
over the transmission. The transmission was controlled by a vacuum modulator.
They were equipped with 4L60 transmissions.
94 and 95 Fbodys had OBD1 PCM's which electronically controlled the transmission
which was the 4L60E.
1996 and 1997 Fbodys had the OBD2 PCM's which also controlled the transmission
electronically which was the 4L60E.
NO 4L60 transmissions were used in any Fbody from the factory from 1994 on.
over the transmission. The transmission was controlled by a vacuum modulator.
They were equipped with 4L60 transmissions.
94 and 95 Fbodys had OBD1 PCM's which electronically controlled the transmission
which was the 4L60E.
1996 and 1997 Fbodys had the OBD2 PCM's which also controlled the transmission
electronically which was the 4L60E.
NO 4L60 transmissions were used in any Fbody from the factory from 1994 on.
GM made many improvements in the 4L60E, especially after 2002, in order to handle the additional power of LS engines.
IMHO this is why 4L60E's have such a bad reputation - people take an old 1995 trans designed for 250 ft/lbs and hook it up to a 400 ft/lbs engine. The results are predictable. Also, such an old trans will have low line pressure, worn clutches and other wear which will lead to rapid failure behind an LS engine.
Finally, as JUNK points out, there are a large number of "small" but significant differences that will make it very difficult to use. And then it will fail.
The trans you want will have a removable bell housing with bolt hole at 12 O'Clock, which indicates it accommodates a 300mm converter. These started coming out in 1998 and were nearly universal by 1999.
Just my opinion.
IMHO this is why 4L60E's have such a bad reputation - people take an old 1995 trans designed for 250 ft/lbs and hook it up to a 400 ft/lbs engine. The results are predictable. Also, such an old trans will have low line pressure, worn clutches and other wear which will lead to rapid failure behind an LS engine.
Finally, as JUNK points out, there are a large number of "small" but significant differences that will make it very difficult to use. And then it will fail.
The trans you want will have a removable bell housing with bolt hole at 12 O'Clock, which indicates it accommodates a 300mm converter. These started coming out in 1998 and were nearly universal by 1999.
Just my opinion.
LT1 motors are rated from 325-340 ft/lbs and run over 100k miles with ease. ****, I see 200k+ mile caprices and roadmasters all the time. Also, C5 Corvettes shared some components with the earlier style 4L60e's (mainly the torque converter), and you don't exactly see those riddled with problems commonly.
These trannys are really not as different (internally) as you're leading some to believe, especially on the durability aspect.
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
Designed for 250 ft lbs of torque? LT1 motors are rated from 325-340 ft/lbs and run over 100k miles with ease. ****, I see 200k+ mile caprices and roadmasters all the time.
Also, C5 Corvettes shared some components with the earlier style 4L60e's (mainly the torque converter), and you don't exactly see those riddled with problems commonly.
These trannys are really not as different (internally) as you're leading some to believe, especially on the durability aspect.
LT1 motors are rated from 325-340 ft/lbs and run over 100k miles with ease. ****, I see 200k+ mile caprices and roadmasters all the time. Also, C5 Corvettes shared some components with the earlier style 4L60e's (mainly the torque converter), and you don't exactly see those riddled with problems commonly.
These trannys are really not as different (internally) as you're leading some to believe, especially on the durability aspect.
As you stated, the stock factory built trans do last a long time, even on C5s. Seems that most complaints are about rebuilt transmissions, not the original factory one. I'm also trying to figure out why the 4L60E then has such a bad reputation. Are many of the rebuilds of poor quality, or is the addition of slicks and bolt-ons quickly overwhelming the trans.
Sorry, my reference to "250 ft/lbs" is misleading. The 4L60E shares many internals with the 700R4 and that was designed when engines only put out 250 ft/lbs.
You are also correct that the internals have not changed all that much, but GM did make important improvements to the known weak spots, including the sun shell, forward sprag and 3-4 clutch. (Very early units were only 5-friction and the latest 4L65E/4L70E are 7-friction.)
Again, I'm sorry if the skewed the facts a bit trying to make my point, which I honestly believe is useful to readers considering their options.
Ted.
