Alison transmission

gmc

Reitired - California-Central Chapter Leaders
I have a friend with that used to run a transmission shop. Said he never had an allison trans. come in to be fixed. said he had a lot of ford tansmissions though. Myself I drive an 06 duramax with an allison and I love it.
 

rumaco

US Army Retired (CW4)
To GMC, if it makes you feel like you made the right choice..........more power to you, BUT there are so many Allison transmissions repaired it would scare you. Most are internal splines!
 

Birchwood

Well-known member
If you can afford this vehicle you can't go wrong.Seems many that purchase others makes of tow vehicles do so because of lower cost .
 

Lynn1130

Well-known member
We have a Saturday morning auto repair show on one of the local radio stations. The two guys that do this show have a rather large auto repair business. A few Saturdays back someone called in asking about the Duramax and also had a question about the reliability of the Allison. One of the two made a comment to the effect that he could not comment about the Allison because while they have other transmissions come in for repair they have never had an Allison come in for repair. I am sure they sometimes break especially if you run a tuner and crank it up to high horse power but over all, it a strong running transmission.

The previous comment may be true but it is backed by what fact and statistics? "BUT there are so many Allison transmissions repaired it would scare you. Most are internal splines!"
 

scottyb

Well-known member
One of the two made a comment to the effect that he could not comment about the Allison because while they have other transmissions come in for repair they have never had an Allison come in for repair.

I got the same reply from the owner of a small tranny shop. He previously worked for a GM dealer. He said he has never had to re-build an Allison from a pickup, other than change a few solenoids. He has had to re-build some that were being used in medium sized trucks and school busses, but never in a pickup.
 

porthole

Retired
I have to agree. I am finding Fords to be a couple thou higher than the GM's, right now. I haven't priced Dodge.

Price hierarchy when I was shopping, Dodge, Chev, GMC, Ford, in that order with a couple thousand between each.

... by no means any better then the competitors. One thing that makes this transmission survive so well is because a V8 diesel is driving it. V8 diesels don't make good low end power. As the DMax makes its power higher in the rpms. Put a Alison behind a Cummins and you will see its weak points, it will not enjoy the low end power from that cummins. They don't build enough line pressure at low rpms to cope with the torque.

I believe the advantage the Allison has above the others is that solid base it had before mating up behind any LD truck. Chrysler 727 comes to mind there.
Over 10 years in production now, tweaked along the way, with the influx of cash from GM has made for a reliable, stout trans. I have seen no proof that it would not stand up to the Cummins. The Allison (in different varieties) is in many different platforms with a variety of engine combos on the road.
The weak point in the GM-Allison combo is the cold line pressure going out to the cooler and the cheesy fluid lines GM uses.

They are all awesome transmissions while running stock power.

Ford certainly seems to have hit it right with the 2011+ 6 speed. There are very few trans failure stories out on the Ford forums.

I had to put a new front seal in my 2005 approx 2 years ago. It went out because I had sand from the Oklahoma Pan-Handle in the bell housing. I could not find a transmission shop nor the local chevy houses that had had one out. The closest to me was Chevy dealer in Tulsa and they wanted $1200.00 plus parts. I put it in my shop and did it myself. The local GM dealer did print me out all the tech data and instructions. I hired a helper and we pulled it, replaced the seal ($9.00) and put it back in approx 10-12 hours. I do have a 450lb tranny jack and that is an absolute must. It is a beast.

Sand in the bell housing caused a front seal failure? Not saying that is a not possible, but ............ I have replaced a lot of front seals and rebuilt hundreds of transmissions in my past career. I would have to think that if it was possible for sand to get up that far and damage the front seal that you would also need a torque converter.
Front seals just go bad. Sometines nicked when installed but sealed OK for thousands of miles, sometimes they will fail due to other failures in the trans. Years ago the front seals came with only one spring on the lip seal. Upgrades were two springs. Overall front seal failures have dropped dramatically over the years.

Nobody else has a tranny to compare to the Allison !

2011+ Ford
 

mattpopp

Trouble Maker
I believe the advantage the Allison has above the others is that solid base it had before mating up behind any LD truck. Chrysler 727 comes to mind there.
Over 10 years in production now, tweaked along the way, with the influx of cash from GM has made for a reliable, stout trans. I have seen no proof that it would not stand up to the Cummins. The Allison (in different varieties) is in many different platforms with a variety of engine combos on the road.
The weak point in the GM-Allison combo is the cold line pressure going out to the cooler and the cheesy fluid lines GM uses.


Ford certainly seems to have hit it right with the 2011+ 6 speed. There are very few trans failure stories out on the Ford forums.

2011+ Ford

Ford has had a great trans for many years now. There was growing pains with the current 6spd but it seems they are working them out. Which if you follow CompD or Powerstroke.org it is quit clear.

68RFE has been in design for a long time. The 45RFE and 545RFE is the little brother to the 68. As the 45RFE came out in 99. The 68 is just an exploded version of those two. With one major difference, there is no 2nd gear prime for downshifting. So the 68 is by no means a ground up design. They took basically 9 - 10 years of proven transmission and made it bigger. To this day the 68 has proven to be an extremely reliable transmission with the stock power from the engine.

Alison's don't fair well with a cummins. It's been tried by many with epic failures. The Torque Shift from 07-10 is a better choice for a 5.9 CTD if you desire a 6pd. As nobody is building a stand alone TCM for the 68 to adapt it. I believe it is safe to assume you don't follow the Diesel world in performance and racing. 10 sec Dmax's tend to run the Dodge 48re behind them as there is no faster shifting stronger transmission then one built right.

From my experience of high HP diesels, the alison is my last choice.

But for the RV guy. They will all do well. You can't go wrong with any of the transmissions. Though the updated AS68RC will probably be the king of the road come 2013.

If you want to know what the weak points are on the Alison. Well, first your on the wrong forum. Go to Dieselplace.com or competitiondiesel.com
 

Lynn1130

Well-known member
This has turned in to a Ford vs Chevy vs Dodge thread. Where you sit is where you stand. And they all have weak points as well as strong. You are correct, for pulling trailers stock anything works fine. That is basically what the transmissions are designed for. I check in to Dieselplace daily and what I see is that the problems begin when you put in a tuner, turn it up to 150 HP over stock and expect the transmission to hold up. Neither the transmission nor the engine were designed for that hence the "I broke my transmission" comments on any of the web sites, including Dieselplace.

The original question was does this transmission have any problems he should know about and the answer is no, if you use it for what it was intended and don't try sled pulls with stock equipment.
 

mattpopp

Trouble Maker
This has turned in to a Ford vs Chevy vs Dodge thread. Where you sit is where you stand. And they all have weak points as well as strong. You are correct, for pulling trailers stock anything works fine. That is basically what the transmissions are designed for. I check in to Dieselplace daily and what I see is that the problems begin when you put in a tuner, turn it up to 150 HP over stock and expect the transmission to hold up. Neither the transmission nor the engine were designed for that hence the "I broke my transmission" comments on any of the web sites, including Dieselplace.

The original question was does this transmission have any problems he should know about and the answer is no, if you use it for what it was intended and don't try sled pulls with stock equipment.

I can agree with that.

My issue with comments here is people answering the question with comments about other brands yet their experience with them ends after they heard something. I grew up a GM guy, owned Dodges the last 8 years and now I drive a Ford. Not a single bad thing I could say about any of them. I drove a 750hp Dodge as a DD and Tow rig for that last two years at that power and the only transmission issue I had was a input shaft that I twisted off. I am very aware of what these transmissions are capable of and what they aren't.

I just wanted t to clear the negative comments and misleading comments about what they don't know.

They are all great transmissions like I mentioned a few times. But the Allison 1000 is not the end all and seriously doubt it's the best between the three. There shouldn't be any reason why you can't get 200k or 300k out of one.
 

Sandpirate69

Well-known member
It's great to hear everyone's ideas on what they think about what's the best Truck or the Best Manufacturer. This Forum isn't about performance or all out HP. If that's what your looking for, there are numerous Diesel Performance Forums for all your taste-buds. Everything in life, including yourself, will last a long time if you take care of it. Go out there and beat yourself day in and day out and see how long you'll last. I too, belong to several Diesel Perf. Forums and I much prefer to read about RV upgrades & mods. We all know what forums are for, but I've had great help from the senior RV'ers here.
 

porthole

Retired
My question is the Allison automatic gearbox a good transmission.
Doe's it have any problems that I should be concerned about.
Linked up to the Duramax motor sounds like a great match.

1) Yes it is
2) Minor
3) It is

The original question was does this transmission have any problems he should know about and the answer is no, if you use it for what it was intended

In case it got lost in the Ford, GM, Dodge debate - one issue is the trans cooler lines. The lines use rubber hose with crimp bands to attach to the lines. The Allison runs line pressure through these lines when cold. On real cold days, especially those who may have remote start, the lines start leaking. I went through three sets of lines on my GMC before selling the truck. And the new owner replaced them again with aftermarket lines.

I added a deep oil pan-filter combo to mine, along with a shift kit. Switched to synthetic as well. Once I did that the only maintenance was changing the the remote filter twice a year.
The deep oil pan was not for the perceived additional cooling, but for an extra 4 quarts of fluid capacity and the addition of a mechanical temperature gauge. Also changed the rear axle cover for the same reasons.
 

scottyb

Well-known member
The lines use rubber hose with crimp bands to attach to the lines. The Allison runs line pressure through these lines when cold. On real cold days, especially those who may have remote start, the lines start leaking. I went through three sets of lines on my GMC before selling the truck. And the new owner replaced them again with aftermarket lines.

This must be a geographical issue, due to cold temperatures. I have 180K on mine and use the remote start every single day of the week. Not one drop of oil has leaked out of it. Not arguing your point about there being a problem, but I know quiet a few others here in central Texas that have high mileage, as well. My good friend has 200K on his. Mine is stock and I have done very little maintenance except change the oil and filter at 100K.
 
We live in Minnesota and purchased our truck (diesel, with an Allison transmission) new in spring '08. In Fall of '08 Chevrolet sent us a letter saying to bring the truck in to reprogram the computer to allow more transmission fluid to flow on startup/warmup in the extreme cold climates.

Al Lambrecht
'08 Chevy 3500 4-door dually
'12 Sundance 3200 RE
 
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