Transmission Problems On 4l60e Equipped GMC Truck

[compulynx]

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"One of the other problems that I found on the 4L60E transmission was overheating from towing. If you tow, you should definitely consider getting a Hayden(or comparable) transmission cooler. Your torque converter takes a huge amount of abuse when you're towing and also put out a large amount of heat. If you drive hard, this should be one of your first modifications to the truck. If you overheat a transmission bad enough, you most definitely will be rebuilding that transmission and torque converter. Expect a $1500 to 2000 bill. Possibly more if you drive it until it stops"

 

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Does this mean the factory installed coolers with the trailer package (Z82) are not good enough, or are you talking about trucks with no cooler at all.

 

C

Edited August 29, 2008 by compulynx

[bgrif005]

I was talking to my local tranny shop about tranny temps when towing, noting that mine climbs to about 195-205 degrees when going up hill, and then leveling out about 186 during steady towing, and he told me that was acceptable. I then asked about synthetic oil in the tranny and would it help. He told me that he has not been sold on the synthetic oil as he has not seen enough evidence where it should be switched from dino oil. He also recommended a oil change yearly in the tranny if towing on a regular basis. I think that when I do take it in, I will most likely switch to Mobil syn oil in there. Any thoughts?

 

you already have synthetic in your tranny.

[bowserb]

Mike welcome to the site, great to have someone on here with your knowledge and expertise.............

 

Now we need to work on finding that beer and wings guy for the site......

[Mike Diaz]

Wow, lots of replies, let me go through this post by post.

 

Good info. Does tromping the gas from a stop put as much stress on the reaction sun gear as shifting between reverse and drive while moving?

 

No, the reaction sun gear is only used in 2nd, 4th, and reverse, so the only time you'll be doing damage is during a 1-2 shift, a 3-4 shift, a 3-2 upshift, or shifting into reverse. I must add that the replacement sun gear is much stronger than the factory one, because it's a one piece design, not a welded on piece like they did from the factory.

 

Hell, I put mine in reverse doing 55 one time. It wasn't in there but a second and I'm still hoping I didn't screw something up. Has worked good sence then.

 

If you must know I was going for N and hit R.

 

 

Don

 

If you didn't break it right away, you should be ok.

 

i think from now on i am going to make sure i completely stop before going in and out of reverse

 

btw what was the charge if you took the transmission out yourself and put it back in?

 

and would you recommend a filter change even though the fluid looks good and has a good smell? on a truck with 128,000 miles

 

If you removed it, and brought the transmission in we typically charged around $1000 for a complete rebuild, and $400-500 for sun gear replacement.. If the fluid smells and looks good, it's a good idea to get it changed about every 15,000-20,000 miles,depending on how hard you drive the truck, towing, etc. If your fluid smells burnt, or is getting discolored, most likely you already have a problem and some sort of failure down the road is imminent.

 

I have a 2008 NBS does it come with 4L60E ??

 

Correct me if I'm wrong, but I think this is how it breaks down:

The 4.8L and 5.3L can come with either a 4L60E, or 4L70E (4L60-E (RPO M30, M32, M33) / 4L70-E (RPO M70)

The 6.0L comes with either a 6L80E or 6L90E (not sure what the difference is)

The diesel comes with the Allison 1000.

 

I was talking to my local tranny shop about tranny temps when towing, noting that mine climbs to about 195-205 degrees when going up hill, and then leveling out about 186 during steady towing, and he told me that was acceptable. I then asked about synthetic oil in the tranny and would it help. He told me that he has not been sold on the synthetic oil as he has not seen enough evidence where it should be switched from dino oil. He also recommended a oil change yearly in the tranny if towing on a regular basis. I think that when I do take it in, I will most likely switch to Mobil syn oil in there. Any thoughts?

 

I have had zero problems ever with Mobil synthetic oils, although I never used them in transmissions. We got our transmission fluid from a local company and never had a problem. I'm sure it was just generic Dino oil though. Occasionally we used a product called Lube Gard that increased the silicone content of the fluid. Lube Gard would also get rid of the occasional torque converter shudder as well.

 

Basically, as long as you're changing the fluid and filter on a regular basis, I wouldn't worry about switching over. It's more of a personal preference.

 

Mike, we really do appreciate the info and I am with you 100% on the heat and cooler. Did you use Hayden's stacked plate design coolers? This is what we attempt to sell and recommend from our stores. All info indicates they are much more efficient and flow better than the old style tube and fin coolers.

 

We originally started using the tube and fin design, but started to switch over to the stacked plate design "if" the customer would fork over the extra money for it.

 

what about if you put it in neutral till you stop then put it in drive?

 

That shouldn't do anything at all to hurt the transmission.

[Mike Diaz]

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Does this mean the factory installed coolers with the trailer package (Z82) are not good enough, or are you talking about trucks with no cooler at all.

 

C

 

I was referring to trucks with the cooler that runs through the radiator. An external cooler should be installed on any truck that does any kind of light or heavy towing or stop and go city driving.

 

Mike welcome to the site, great to have someone on here with your knowledge and expertise.............

 

Now we need to work on finding that beer and wings guy for the site......

 

Thanks! I can be the beer and Jack Daniels guy

[georgerosen06]

mike you being in the business and all whats your opinion on changing the fluid vs dropping the pan...not trying to start wars or anything over who thinks what but from doing work on all these transmissions what do you recommend?

[Mike Diaz]

mike you being in the business and all whats your opinion on changing the fluid vs dropping the pan...not trying to start wars or anything over who thinks what but from doing work on all these transmissions what do you recommend?

 

I always recommended dropping the pan first, replacing the filter and pan gasket, then flushing the transmission through the cooler lines at the radiator. We performed at least one of these services per day and never had one problem.

 

WHat is your opinion on the age old question:

 

Tow in D or 3?

 

After melting an early 4L60E in less then 10k miles while towing in OD, I started towing in 3. Noticed cooler temps & no failures in well over 200k miles. Improvements may have been made so what is you opininion on the current generation 4L60E trannys?

 

That's a good one. I would tow in 3 in the city. Most likely, you won't be hitting speeds over 45-50 mph, so there's no need to have 4th gear engage. If you're on the highway, I would just take it slowly and get the speed up enough for the torque converter to lock up.

 

Regardless, you should have an external cooler on that as well. How much weight are you towing?

[georgerosen06]

im at 53000 something miles and i havent changed any fluids or dropped the pan yet...what would you reccomend...figured why we got you here i might as well use ya

[VMax2007]

Correct me if I'm wrong, but I think this is how it breaks down:

The 4.8L and 5.3L can come with either a 4L60E, or 4L70E (4L60-E (RPO M30, M32, M33) / 4L70-E (RPO M70)

The 6.0L comes with either a 6L80E or 6L90E (not sure what the difference is)

The diesel comes with the Allison 1000.

 

Yes, you are wrong, so I will correct you. The 4.8 and 5.3's come with the 4L60E and are not available with the 4L70E. The 4L70E only comes with the L76 6.0 in the 1/2 tons. The 6.0's in the HD's come with the 6L80E/6L90E.

 

Oh, and you skipped my post about the 4L70E's????

[Mike Diaz]

im at 53000 something miles and i havent changed any fluids or dropped the pan yet...what would you reccomend...figured why we got you here i might as well use ya

 

I would go ahead and replace the filter and pan gasket, then have it flushed through the cooler lines. It's time to do it.

[Mike Diaz]

Correct me if I'm wrong, but I think this is how it breaks down:

The 4.8L and 5.3L can come with either a 4L60E, or 4L70E (4L60-E (RPO M30, M32, M33) / 4L70-E (RPO M70)

The 6.0L comes with either a 6L80E or 6L90E (not sure what the difference is)

The diesel comes with the Allison 1000.

 

Yes, you are wrong, so I will correct you. The 4.8 and 5.3's come with the 4L60E and are not available with the 4L70E. The 4L70E only comes with the L76 6.0 in the 1/2 tons. The 6.0's in the HD's come with the 6L80E/6L90E.

 

Oh, and you skipped my post about the 4L70E's????

 

 

 

Thanks for the correction, Alldata isn't always right.

 

I never had a 4L70E transmission in the shop, I don't know of any problems with it.

[georgerosen06]

thats what ive heard....why did i just quit my job for school....

[zxcv]

Welcome Mike !

 

Where ya been ???

We've been waitin' years for a trans guy.

 

Now we need a:

motor guy

A/C guy

'puter guy

steering wheel guy

front end guy

brakes guy

rear end guy

tires guy

electrical guy

truck wash guy

body guy

paint guy

fuel system guy

 

Who else do we not have?

 

 

 

 

uhhhhh a BEER GUY!!!

 

 

pizza and wings guy

 

 

I'll be the "awesome" guy.

 

 

 

 

Awesome topic man! It's really nice to have someone post valuable information for a change....unlike some other "6 wrench" members. Ahahah Just joking!

 

But seriously, good topic!

[Outbacker]

I was talking to my local tranny shop about tranny temps when towing, noting that mine climbs to about 195-205 degrees when going up hill, and then leveling out about 186 during steady towing, and he told me that was acceptable. I then asked about synthetic oil in the tranny and would it help. He told me that he has not been sold on the synthetic oil as he has not seen enough evidence where it should be switched from dino oil. He also recommended a oil change yearly in the tranny if towing on a regular basis. I think that when I do take it in, I will most likely switch to Mobil syn oil in there. Any thoughts?

 

you already have synthetic in your tranny.

 

I do? Sweet. Not to be rude, but how can I confirm that? How do I know for a fact that it is Syn oil in there (other then tasting it)?

 

And what style of tranny cooler would come in the GMT900?

 

Thanks.

Edited August 29, 2008 by Outbacker

[compulynx]

Ok, one more question.

 

In reference to the "Tow in 3 or D" question, you stated to run up speed enough for converter lockup. That I understand, but will the coverter lock up in 3 also, or only in D.

 

C