Re: Transmission Kaplooie

Na ur ok but its rebuild time I know it suck but now u can build it back stronger go to a 65e and never look back

 

Re: Transmission Kaplooie

The truck only has 2.9k miles (yes, only 2900 miles) on it with nothing strenuous, man that's early & covered by warranty. Now a dumb question, would the dealer 'upgrade' the transmission & still apply coverage?

 

Re: Transmission Kaplooie




I apologize for the concerns you are having with your vehicle. What I would like to do is look into this further for you. Would please PM with me first and last name, address, VIN and current dealer you are working with.

Thank you,

Tina
GM Customer Service

 

Re: Transmission Kaplooie

I apologize for the concerns you are having with your vehicle. What I would like to do is look into this further for you. Would please PM with me first and last name, address, VIN and current dealer you are working with.

PM sent, thanks for responding.

Nothing you did should have caused your trans to die. and yes it sounds like
the sun gear. GM had lots of prob with them cracking, they were not heat treated right.
I had the trans go in my S-10 with low mi. the sun gear destroyed the case also.
it took all the teeth right off the case where it locks into it. the dealer put a new trans in
under warranty. mine could not be repaired.

Thanks for that input -- it caught me completely off-guard especially since I had driven it the last 1.5-2 weeks without incident.

 

Re: Transmission Kaplooie

Nothing you did should have caused your trans to die. and yes it sounds like
the sun gear. GM had lots of prob with them cracking, they were not heat treated right.
I had the trans go in my S-10 with low mi. the sun gear destroyed the case also.
it took all the teeth right off the case where it locks into it. the dealer put a new trans in
under warranty. mine could not be repaired.

 

Re: Transmission Kaplooie

Warranty time. It seriously has to be hit or miss on these things. But I also didn't realize that your tranny only has 2900 miles on it. Not a good time to pop the servos in. You are still in break-in mode. Same reason why they say don't tow for the first 5k miles.

 

Re: Transmission Kaplooie

Yea, I see your point with the break-in time. But since I don't use my truck as a DD (I'm a cycling fool, work is a few miles away), it takes longer for me to break it in (the truck has had a lot of idle time though, for that reason). While I have been towing, I've been at maximum 2-2.25klbs -- heavy towing won't be for another few months (by which time I should be at 5k mi).

However, given that the servos are a low frequency, low displacement, hydraulically-actuated part, I don't think that they need a long break in period.

I'll keep everyone updated.

EDIT: So now a good debate question? The classic 4L60E improvements are the servos & boost valve, which essentially increase line pressure allowing for smoother shifts. With adaptive shifting (assuming it's not disabled), the pump should be working at a reduced flow rate because it wants to reduce line pressure to match the shift tables. What effect does the reduced flow have on the transmission pump (assuming again, you keep the adaptive learning)? I do drilling engineering and deal with hydraulic calculations all day and on a drilling rig, the more you can reduce the load on the pump, the longer it lasts. I would assume this is applicable in this case, but are there specific flow rates that the trans pump works better at? By reducing the flow with servos & boost valve, does that reduce wear & tear on the pump, or is it actually dropping off efficiency or below design considerations?

 

Re: Transmission Kaplooie

Yes...however what you have to remember is that by increasing the line pressure you are now forcing the gears together harder and faster, instead of a smooth transition. Because of this you are going to get more metal shavings into the system at an accelerated rate, instead of the gears slowly wearing into each other. I would also warn you, especially since I've got a lot of time hauling heavy loads with the truck at this point, you may not want the servos in place for the heavier trailering. One thing that I have noticed is that after towing, the next few days the truck shifts extremely hard and fast. Pretty much the adaptive system has learned to apply higher pressures between shifts because of the load. In your case, how will this jive with what the servos are already doing?

 

Re: Transmission Kaplooie

Yes...however what you have to remember is that by increasing the line pressure you are now forcing the gears together harder and faster, instead of a smooth transition. Because of this you are going to get more metal shavings into the system at an accelerated rate, instead of the gears slowly wearing into each other. I would also warn you, especially since I've got a lot of time hauling heavy loads with the truck at this point, you may not want the servos in place for the heavier trailering. One thing that I have noticed is that after towing, the next few days the truck shifts extremely hard and fast. Pretty much the adaptive system has learned to apply higher pressures between shifts because of the load. In your case, how will this jive with what the servos are already doing?

The auto transmission is a full time mesh system. All gears are always meshed together. Clutch packs and bands are what engage and disengage.

 

Re: Transmission Kaplooie

Good points, especially with the shift firmness, that will definitely affect breaking in the transmission--thanks for bringing that up, I was thinking about the servos only. But...

...since I already knew that adaptive shifting would negate the effects of the servos over time, I installed them with the intention of reducing the pump output, thereby reducing pump wear (I installed them not for just for firmer shifts, which would save the clutch packs but not the gears). For some background, my sister had a 4L60E whose pump went out at ~40k miles -- she babied that car, dealer maintenance on schedule, etc. and my parents had a 4L60E go out on one of their vehicles with less than 60k miles. However, the 4L60Es in their other cars have worked great, so I'm not in the mindset of 4L60s suck. Instead, you can say that I am being overly cautious towards specific aspects of the transmission from personal experience (since I believe the transmission to be the weakest part of my new truck, specifically since it has the V8).

But as you pointed out the adaptive shifting takes effect really fast. When I put the servos in, I did a bunch of city driving with a lot of shifting at stop lights running errands the next couple days. I immediately noticed a difference after installation in shift firmness and babied the shifts (but I'm not a WOT kind of driver either) -- by the end of the 2nd day I could tell the shifts were getting softer (returning to OEM firmness). So that just confirms how fast it responds.

But since I didn't disable adaptive shifting, the transmission will adjust the pump output (pump pressure) to keep the shifts within the PCM tables. It's my opinion that regardless of which servos you have in there, the adaptive shifting will adjust pump output to retain the proper shift times. Since the servos would be in there before/after transitioning from not-towing to towing, the PCM has already corrected all the shifts for the servos and now will correct for load only--i.e. the net effect is an overall reduced pump rate before/during/after towing.

Now in a perfect world, I would install the servos & boost valve which allow for reduced pump output. I would then tune the adaptive shifting to tighter time windows which allows for slightly firmer shifts but still lets the vehicle correct for load. To maintain the shorter shift times, the line pressure (pump output) would have to increase... but since we already installed the servos & boost valve, we are increasing from a reduced output (the pump will be running closer to a fully-stock 4L60E).

Man that was long-winded, but I wanted to explain my rational (or some might call irrational) approach to the servos.

 

Re: Transmission Kaplooie

Hole Poke time again..... Do you really want reduced pump flow while under load though? The slower the pump flows, the less fluid that makes it to the transmission cooler. That means your going to overall run hotter...which is counter to making the transmission last longer. That's why higher RPMs equal cooler tranny, and lower equals hotter tranny. Part of the advantage of towing in 3rd gear. More than anything heat is this tranny's worst nightmare.

 

Re: Transmission Kaplooie

Here is an awesome documents about the 4l60e.
4L60E

 

Re: Transmission Kaplooie

Wow, that's a sweet link. Thanks!

Interesting -- pump speed is controlled by engine speed. Pressure regulator valve determines final line pressure... Man this is a wealth of knowledge.

 

Re: Transmission Kaplooie

Wow, that's a sweet link. Thanks!

Interesting -- pump speed is controlled by engine speed. Pressure regulator valve determines final line pressure... Man this is a wealth of knowledge.

I figured you would like that. I went through that thing front to back when I was debating about putting servos in while towing. After fully understanding the whys of putting them in vs the trade-offs I decided that it was not really worth it. 90% of the population....yup. Light towing..sure. Heavy towing. Nope. Also the corvette servo swap became real popular with older revisions of the 4l60e.... GM has definitely fixed a lot of the issue with them, not to mention the programming has changed a lot as well. Now go and throw in advanced fluids as well and things change.

 

Re: Transmission Kaplooie



Sorry ya had trouble outta the trans...Good luck on the next one !!

 

Re: Transmission Kaplooie

Update: Dealer has to pull the transmission to diagnose. Looks like I'll have to wait until next week to find out more.

 

Re: Transmission Kaplooie

Well got a call back. Transmission is junked, bunch of metal shavings with some metal even embedded in the valve body.

As expected I'll have to pay for replacement, they're citing the servos but don't have a root cause.

So what to do? Reman 4L60e or swap? I'd be out of a truck for a while and it'd cost more.

 

Re: Transmission Kaplooie

I'd be bitching to a rep. They can't confirm that's the cause so they should be replacing it with no questions asked.

 

Re: Transmission Kaplooie

Yes...but like I said earlier....they can't prove beyond a reasonable doubt that it's the servos, but they can make a pretty solid case to say it is. Servos cause additional line pressure. When gears are still getting seated, and they are getting slapped together that hard it's going to cause more metal in the fluid. My honest opinion would be that knowing you are towing with the truck heavily...go with an aftermarket tranny that is beefed up for towing. I would seriously look at doing the 4l65e conversion in the process. Get it so you can actually tow in OD. :lol: Sucks man...

 

Re: Transmission Kaplooie

So I made a visit to the dealer and I'm having them tear down the transmission... turns out they hadn't done that yet. Like I've stated earlier, I know you pay to play, but I would like to know the root cause of the failure (sun gear or 2-4 band I suspect); that way, if there was something in particular that I screwed up, I want to pass on that information to everyone on this board so they don't repeat my mistake.

It's frustrating because I've done this before and triple- & quadrupled-checked (should've quintupled checked) the assembly before putting it back in.

There was a good bit of metallic debris in the pan and the trans fluid had a lot of ground-up metal dust within... so it's toasted. I asked the service rep to look into putting in a 4L65 or 4L70, but he wasn't as versed on transmissions and was saying that the TM wouldn't allow that (difference between 4L60/65/70 is just internals, correct... no TM). Anyways, the new trans will come with a 36mo/50k mi warranty, so if I can get them to put a 4L65 or 70 in, I figure that's one up.

I've investigated the 6L80e swap and man it's pretty darn enticing but the cost is on the high side... do I want a second sled... or a cool ass swap?

I'll update more tomorrow hopefully.

 

Re: Transmission Kaplooie

Yup. The difference between a 4l60 and 4l65 is internals. Primarily the pinion gear,but a few other items as well. I'd avoid doing the 6l80 swap but that's just me.

 

Re: Transmission Kaplooie

Yup. The difference between a 4l60 and 4l65 is internals. Primarily the pinion gear,but a few other items as well. I'd avoid doing the 6l80 swap but that's just me.

You have been the voice of reason... I'm leaning that way too. I'm going to try to get the -70, if not the -65 (hardened input/output shafts on the -70)

 

Re: Transmission Kaplooie

I'm still curious if anything actually went per-say...or if it was literally death by metal shavings. It would be interesting to see what your gears actually look like at this point, as well as the clutch packs. Get them to let you take photos.

 

Re: Transmission Kaplooie

You should technically have a 4l65e already. . .

 

Re: Transmission Kaplooie

You should technically have a 4l65e already. . .

My transmission RPO is M30 (looked at my order paperwork since the truck is obviously not in front of me), isn't 4L65 M32? Or are you suggesting the improvements made to the -65 have trickled down to the -65?

In that case, can you list the differences between the -60 & -65 currently? (other than 5-pinion planetaries)

 

Re: Transmission Kaplooie

If ur going to do that do it right the first time and also get a trans cooler an external filter and a trans temp

 

Re: Transmission Kaplooie

If ur going to do that do it right the first time and also get a trans cooler an external filter and a trans temp

Already has a remote filter & trans cooler. I had the trans temp gauge in the test port & cable run up into the engine bay but hadn't gotten around to installing the actual gauge yet.

But I agree, it'll be done right and no servos this time!

 

Re: Transmission Kaplooie

That sucks dude. I wonder if (when my time comes) I could fit a -70 on mine.

 

Re: Transmission Kaplooie

08 and up trucks have a different trans. It should be close to being a 4l65e

 

Re: Transmission Kaplooie

My 08 had a 4L60e

 

Re: Transmission Kaplooie

The only recent difference that I can confirm is the inclusion of the ISS - input shaft speed sensor for the newest 4L60e. Regardless, getting the 5 pinion planetaries will be nicer as well as a strengthed sun shell -- I don't know if the 'HD' sunshell has made it down to the 4L60e.