Jump to content

My 8L90E is FINALLY fixed!


Dunc

Recommended Posts

Background:

I have a '15 6.2 Seirra with the 8L90E. It has never functioned like a transmission should. I had the delayed engagement shifting from P to D, R to D, etc. Also had a insanely harsh clunk that felt like you hit a giant pothole everytime it downshifted from 8 to 7. Also did it everytime shifting from 2 to 1 once you got to 5mph on deceleration. I tried the disabling grade braking thing and have watched the other transmission threads hoping I would eventually find something that worked.

 

A few months ago at just under 40k miles I took it to the dealership because I just couldn't deal with it anymore. They said that the clutch packs were out of spec and the replaced the whole transmission. Only problem is that didn't fix anything and made the problems even more noticable. I went back several more times with the same complaints which were met with the canned, "that's how they are designed to work and everything is normal."

 

It was the most embarassing car to drive, I hated getting into the truck everyday, and I truly felt swindled out of my money. The whole "operating as designed" really pissed me off the most because it was a bullshit excuse and I knew something wasn't right. I delt with it for about another 10k miles and I took it back yet again for probably the 5th or 6th time back on 12/29. I figured they'd either fix it or tell me everything is still normal and I'd have to go pay for a custom tune trying to fix it myself.

 

This time the service advisor said, "hmm something is definitely not right there is a clunk." I mean I was happy that they finally agreed with me that it wasn't right but I couldn't help but think "no kidding I've been trying to tell you guys that." I didn't want to get my hopes up and figured nothing would actually change. The next day they called and told me it was fixed...again I was skeptical.

 

When I got there they gave me the details on what they did. I was skeptical because I had already tried the same procedure the TSB outlined. I get in the car to drive away and I could notice a HUGE difference immediately. Absolutely zero clunk putting it into gear from park. Absolutely zero clunk when going from 8 to 7 and also 2 to 1 at that 5mph mark. I know it sounds stupid to be so happy to have a transmission work as it should have from day one, but after dealing with it for so long and having no recourse I couldn't be happier. It shifts smooth everywhere and functions as I would expect....FINALLY! I need some more time to give judgement but I am pretty sure it also fixed the issue that the "disabling grade braking" thread addressed. Hopefully it stays this way, but after several trips I am beginning to be hopeful that it won't relearn any bad habits.

 

What was done:

TSB# 14-07-30-001F. Here is a link to an online version Click here. If needed I will scan my copy from the dealer and post it.

 

I did the same procedure myself but obviously I must have done something differently. So if you have delayed engagement and/or super harsh clunking on shifting then have your dealer perform this procedure. It's night and day a different transmission now. So much better and functions like you'd expect a transmission to function. The 8-7 shifts are now so smooth I have look at the RPMs to know it shifted. It only took 5-6+ trips to the dealer but 50k miles later I finally love this 8-speed trans and the truck.

 

I know this post was long, but wanted others out there to know that there is hope and the 8-speed can in-fact function correctly.

Link to comment
Share on other sites

Now all there is to do is sell my Integra, buy the CNC I've been looking at, and then start to turbo the truck now that it's functioning. It's a great start to 2017!

Link to comment
Share on other sites

That is one of the funniest things I have read on this forum when you said "embarrassing to drive, I hated getting into the truck everyday, and I truly felt swindled out of my money." Thanks for the laugh, certainly brightens up having to return to work tomorrow reading something like that...

 

Tyler

Link to comment
Share on other sites

I have a 2017 Silverado with the 5.3L 8spd trans and its clunking also. It's has pretty bad low speed downshift and upshift clunks sometimes. It's going back to the dealer pretty soon for the fast learn procedure, hopefully it makes this trans shift a lot smoother . At this point all this truck is a $60k piece of garbage.

Link to comment
Share on other sites

Your truck is new and under warranty. If it has an issue you should take it back and get it repaired. These trucks are designed to run smoothly.

It has been back two times already. This is going to be the third time it's been back, pretty frustrating that i have to mention tsb's to them for them to even do anything to the truck .
Link to comment
Share on other sites

That is one of the funniest things I have read on this forum when you said "embarrassing to drive, I hated getting into the truck everyday, and I truly felt swindled out of my money." Thanks for the laugh, certainly brightens up having to return to work tomorrow reading something like that...

 

Tyler

It was a literal rolling billboard for why not to be buy a Sierra. Every person who got in the car and felt the jolt for the first time was like "wtf was that?" Which was followed by "you're kidding right" when I told them that I was told it was normal. Funny to you or not though that is the truth of how I felt.

Link to comment
Share on other sites

It was a literal rolling billboard for why not to be buy a Sierra. Every person who got in the car and felt the jolt for the first time was like "wtf was that?" Which was followed by "you're kidding right" when I told them that I was told it was normal. Funny to you or not though that is the truth of how I felt.

I can't imagine riding in someone's newer vehicle and thinking a malfunction is a reflection on the brand. My thought would be "wtf was that?" followed by "you're kidding,right? - is this vehicle not under warranty? - why don't you get it fixed?" I appreciate you may be experiencing difficulties with your dealership and your problem may turn people away from the dealership.

Link to comment
Share on other sites

Mine was done recently as well, but have held off posting while evaluating the results.

I had a 15 8 speed before this one, and have similar story of previous relearns and previous similar tsb jobs.

 

This time it seems to be right.

Link to comment
Share on other sites

For what it's worth my 5.3 8 speed was fine from the beginning then around 3000 miles it started getting really bad with the clunking, gear hunting etc, more often than not. From the many things I've read on this forum I was dreading a trip to the dealer so I was waiting till I was in the mood but in the interim but the dam thing healed itself over a period of about a 1000 miles and it's been fine ever since. In my mind it was really strange for something that out of whack to self correct.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Forum Statistics

    245.8k
    Total Topics
    2.6m
    Total Posts
  • Member Statistics

    333,235
    Total Members
    8,960
    Most Online
    fasal a
    Newest Member
    fasal a
    Joined
  • Who's Online   2 Members, 0 Anonymous, 566 Guests (See full list)



×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.