Trouble with 4L60E
Thread Starter
Teching In
Joined: Mar 2003
Posts: 19
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From: Longview, Texas
4L60E Problem Diagnosis Hi folks. I'm trying to get a feel for what might be wrong with my transmission before taking it into the shop. I have a '96 4 Door Tahoe with a Whipple Supercharger and 35" tires. I still have the factory 10 bolt rearend for now. The tires went on in the past week with a lift. I drive like a grandmother knowing that the 10 bolt and tranny can't hold up for long with the 100 pound wheel/tire combos.
Here's what I'm experiencing: During acceleration from a stop I experience no unusual behavior. After reaching cruising speed, if I'm nursing the gas at around 1600rpms to maintain speed while (usually) traveling up a minimal incline, the tranny starts to kick every once in awhile. It feels like a a hard shift, which I assume means it's slipping. What's going on here? What most likely is happening? How much does this type of repair cost? What type of enhancements should I ask them to make to prevent this from reoccuring?
Talk to me
Here's what I'm experiencing: During acceleration from a stop I experience no unusual behavior. After reaching cruising speed, if I'm nursing the gas at around 1600rpms to maintain speed while (usually) traveling up a minimal incline, the tranny starts to kick every once in awhile. It feels like a a hard shift, which I assume means it's slipping. What's going on here? What most likely is happening? How much does this type of repair cost? What type of enhancements should I ask them to make to prevent this from reoccuring?
Talk to me
Last edited by buffy; Sep 5, 2004 at 06:32 PM. Reason: Improve Description
I had a 96 Yukon, same thing basically. There were two TSB's related to tranny defects. One was a bad downshift solonoid. when mine would down shift it would feel like it went into neutral, then bang into gear. The other was a trans pcm issure. the TSB gave a part number for a repair kit that came with a grounding wire and instructions to move 3 pins to different locations in the pcm. I don't remember the part numbers. Might search alldata. As for a 10 bolt 
Mine had a factory 12 bolt. I'm not sure they ever came with 10's. Might want to count the bolts
Mine had a factory 12 bolt. I'm not sure they ever came with 10's. Might want to count the bolts Thread Starter
Teching In
Joined: Mar 2003
Posts: 19
Likes: 0
From: Longview, Texas
More information I'm not sure if it's even trying to down shift, it just kicks. Let's say I'm cruising and I barely ease into the gas (just more than idle) on a tiny incline. Over a period of 20 seconds I'l get something like 1-2-3-4-5-6-7-8-9-10-jerk-12-13-14-15-jerk-17-jerk-19-20.
Also, so that we're both doing some sharing, I'm pretty sure your Yukon came with a 10 bolt rearend (AAM 8.5" Semi-Floater). They quit putting 12 bolts into GMs in the early 80s. From the mid 80s on, 1/2 tons have come primarily with 10 bolt rearends. A couple of rigs like the old 454SS truck came with a 14 bolt SF (9.5" Semi-Floater). 3/4 tons come with either the 14 bolt SF or the 14 bolt FF (10.5" Full Floater). Most 1 tons will be found with a 14 bolt FF. In 2001, they added a larger 14 bolt FF to the line up (11.5" Full Floater) to go along with the other three basic axles. All of these axles are made by AAM, to my knowledge. Tahoes & Yukons (not XL 2500) all come with the 10 bolt rearend.
Also, so that we're both doing some sharing, I'm pretty sure your Yukon came with a 10 bolt rearend (AAM 8.5" Semi-Floater). They quit putting 12 bolts into GMs in the early 80s. From the mid 80s on, 1/2 tons have come primarily with 10 bolt rearends. A couple of rigs like the old 454SS truck came with a 14 bolt SF (9.5" Semi-Floater). 3/4 tons come with either the 14 bolt SF or the 14 bolt FF (10.5" Full Floater). Most 1 tons will be found with a 14 bolt FF. In 2001, they added a larger 14 bolt FF to the line up (11.5" Full Floater) to go along with the other three basic axles. All of these axles are made by AAM, to my knowledge. Tahoes & Yukons (not XL 2500) all come with the 10 bolt rearend.
