GMC Sierra Transmission Leak Problem

[mwells4654]

I have a 2006 GMC Serria 5.3L SLE Crew Cab pickup with towing package. I have towed my Overlander and my pontoon boat over the last 3 years back and forth to the lake (20 miles each way) with no problems. A couple months ago I towed a short 5th wheel camper only a few miles and the front seal of the 4L60-E transmission started leaking. I took it to a transmission shop and paid my $250.00 (ouch) to have the front seal replaced and for the last two months everything has been great. Last weekend I moved the same trailer only a few yards and then my lady friend and myself went out to the lake to look around and while there I noticed the transmission leaking again. Now it looks like a $500.00 repair. Front seal and pump bushing.

My question - Is this normal for the 4L60E transmission to have this type of problem? I have been asking around and have been told the 4L60E transmission is for light duty towing only and if I am going to tow a 5th wheel or other campers I need the 4L65 or 4L80 transmission. Am I looking at purchasing a different pickup in my future for when I want to tow my Overlander cross country?

Sorry for being long winded. Thanks in advance for any and all input.

[withidl]

Although I have no specific knowledge about your transmission, basis my lubricant background I don't think that seal failure can be related to transmission loading because the seals don't carry any load. Seal failure would be basis improper seal installation, damaged seal before installation, sealed shaft machining (i.e. not smooth) or abraision from contaminates (dirt or wear metal). Check the transmission filter for wear metals or other contaminates as the seal failure is probably just a symptom.

[AL’ UM- MONEY]

This is what I know about GMC transmissions. I have a 2005 GMC with a towing package. I have never towed any thing with it. At 53000 miles it unraveled. When I purchased the truck I purchased extended warranty. Well of course GMC said out of miles and other warranty would not pay. That's worth another post. Any way it cost me dearly. Because I intend to pull my 31 foot and not comfortable with this,today I got my local dealer to quote a price on a Druamax but more an Allison. I should have been sitting down with the price but I still may swap trucks with them.

[LI Pets]

The allison is the ticket to ride!

[mwells4654]

Mine has 75000 miles on it and has never given me a bit of trouble. It has the 373 gears and the 5.3L motor. Pulls great, but if I am going to have on going trouble with it I might just trade it off and go with a 3/4 ton. Or, I might just start doing my towing with my old 84 GMC 3/4 ton. It is a gas hog but will tow anything. Thanks for the information.

[Jammer]

Originally Posted by mwells4654

Now it looks like a $500.00 repair. Front seal and pump bushing.

My question - Is this normal for the 4L60E transmission to have this type of problem? I have been asking around and have been told the 4L60E transmission is for light duty towing only and if I am going to tow a 5th wheel or other campers I need the 4L65 or 4L80 transmission. Am I looking at purchasing a different pickup in my future for when I want to tow my Overlander cross country?

No, not normal. The pickle you're in is that you can't fix the likely root causes without an overhaul and that's typically a $3500 repair soup to nuts. I'm not an expert but I'd guess that there is a problem with parts alignment or tolerances or lubrication that's leading to the repeat failures.

I doubt that it has much to do with the short heavy tows you've done. Coincidence maybe, or maybe you're watching more closely and see a leak that's been there for a while.

If you're thinking of replacing the truck anyway maybe it's best to just put in a new seal and sell it.

I have a 4L80e in my pickup and a 4L85e in my suburban. The 4L80e failed after 70,000 miles but the PO had been having his hourly help use it to plow parking lots and I suspect that it had a really hard life.

I would characterize the overall forum experience, with automatic transmissions and larger trailers like yours, like this: Many people find that, even with careful preventative maintenance, the transmission has to be replaced after 100,000 to 150,000 miles of towing. Even if the transmission is a 4L80e. Of course, there are all kinds of variables, like rear end ratio, and driving style, and combined vehicle weight, and how much driving is in the mountains. And to some degree I think it's a matter of luck.

Lots of people tow with a 4L60e but with a heavier rig like yours it's going to have a shorter life. It's a matter of tradeoffs, upgrading to a 3/4 ton chassis isn't cheap either.

I don't think the consumer Allison transmissions are bulletproof either but we'll know in time. There aren't enough older ones out there with 150,000 miles of towing on them to serve as the basis for an opinion. But then again for the cost of the powertrain upgrades maybe just putting the money in the bank to replace the 4L80e when it finally goes is better economically.

I'm probably not much help here but that's the way I see it I guess.

[CanoeStream]

I've got 90K miles on my '06 Duramax/Allison Sierra. It's coming out of the shop just now to the tune of $500 for a tranny cooler hose leak. They felt the 3 associated hoses had to be replaced and so most of my costs wer for parts. Picking it up today and am very curious if this was due to road hazards.

[ROBERT CROSS]

Bob, in the above post, has mentioned one of the most common leaks for all the GM tranny's. Especially in the sno-belt climates...corrosion.
As noted, best to replace all the lines at once. (my shoe-lace theory)

Bob

[mwells4654]

All of the trailers are well below the tow weight of the truck so that should not be the problem. Anyway, the truck is at the shop now. Starting price $400.00 and after doing some extensive reading it looks like the pump bushing/bearing is the problem. It will cause the seal to leak. I would have figured that a Trasmission shop would have known of the problem with the pump bushing and replaced it also. I would have understood that the cost for the repair would have been more than estimated but now I have to pay more for the repair because this guy is going to fix it right and not just patch it.

The repair guy is going to check it all out and give me a call on the cost. He said probably $500.00 to $600.00 total. That is fine as long as it fixes the problem.

[mwells4654]

Update on the leak. The transmission pump's front bushing/bearing was broken in half and had ripped the front seal. The mechanic replaced seal, bearing filter and fluid. Cost $550.00. I am very pleased so far. Will have to see in a couple months since that is how long it took to go out after last repair. I am getting legal advice to see if I should go after the transmission shop for some of my money back.

I was wrong, the truck has the 4L65e transmission instead of the 4L60e. Not found in many of the 1500 Serria 5.3L trucks. Normally found in the 6.0L due to the increased engine torque.

I should be ready to pull anything I need to. Have to get my Overlander finished. Not enough hours in a day.

[kingfisher24]

2004 GMC Sierra Denali AWD transfer case seal leaking?????

thanks

[mwells4654]

I checked the internet while I was trying to get mine fixed. There is all kinds of info. Here is a link you might try. Lots of TSBs for your truck

2004 GMC Truck Sierra Denali AWD Recalls and Technical Service Bulletins (TSB's) Provided by ALLDATAdiy.com