Allison transmission sprung a leak. Anyone else?

I just got back from the stealership from having an official quote done.

GAK!!!!! :E:E $2002.00 plus tax to do the tranny and torque converter seals. Another $596. to replace 2 of the 3 cooling lines that are leaking.

They got in there with some fancy tool and determined that both the pump and converter are leaking. And maybe the housing bolts on the converter. Can't see that one but....

Yunno, I can buy a lot of oil for $2600. plus tax.

I'm going to keep a close eye on it and if I only have to add a quart every couple thousand miles, it ain't getting fixed!

The tranny functions flawlessly.

I'm no car expert and I've never owned an Allison tranny. However, if it was me I would keep watching the fluid level, I would keep some extra fluid handy to top off, and I would buy a shallow pan to catch the dripping when I parked, if there was a lot of it. And I would keep driving.

+1 on the full tranny rebuild, but I see this as at least 20,000 miles out, maybe much much more. When I buy a car it's because I love it, and I hang on to them for a lot more miles than the OP has. The idea of selling a car after you've just covered expensive repairs is silly, IMO. The new tranny will take this rig to its Final Rest, many many miles from now.

You might want to watch it and see if it continues. Expansion / contraction of the seal can sometimes cause a temporary leak. While not a D/A, I had an Explorer that if the trans got a little too warm because of the poor cooling it had, like pulling a mountain or backing into a site) the seal would expand to the point it would leak. After sitting for a few hours it was fine, no more leaking. I was told I could get away with it happening a few times, but eventually it would not reseal and would need to be replaced. I was planning on adding additional cooling if we haden't outgrown it first.

I have the same 2007 classic dually with 160K on the clock.
Unfortunately my thoughts are the same as Burbman's. If the unit needs to come apart. It's time to consider rebuilding.
I had some overheating issues this past summer that were resolved, I was advised by the local Allison guru that if the tranny needs to come out it's time to rebuild plain and simple.
I feel like I dodged a bullet but now I know there are really no simple inexpensive fixes. Once the unit is removed and opened a rebuild is in order. I was quoted $3000-$3500 for a upgraded bullet proofed for towing rebuild.

Check in with the guys on Diesel Place Forum.
www.dieselplace.com/forum/
Check for "Pump Rub", a common problem.

Bob,

Better pick up a couple quarts of whatever fluid you need (I think the Ally takes a different fluid than the GM standard Dexron VI)so you can keep 'er topped off while you decide what to do.

Yes, cooling lines on the GM vehicles have been a problem just like the brake lines and fuel lines. For some unknown reason they put in a stainless exhaust system but used uncoated steel for the brake, fuel, and trans cooler lines.

I would look for a transmission shop that has experience with the Allison units, not necessarily a dealer. Unless your unit is really puking fluid, you should have some time to find the right place and get the job done right.

If they need to pull the trans to complete this repair, this may be a good time to look at a rebuild. 90% of the cost of a trans rebuild is the labor not the parts. If you're going to pay to have the trans removed, may as well change the other parts that are worn and likely to fail also. I wouldn't give up on the truck, nothing lasts forever, just needs a little TLC is all.

Bummer, but you do have a lot of miles on 'er.

I know people claim they get a quarter million miles and haven't done 'anything' to their trucks, but sadly, I think that's a vast minority. You can probably expect more problems in the future. Maybe time to sell it?

Search online, there have been a lot of cooling line failures on GM Allison.