Allison Transmission Failure

Topic: Allison Transmission Failure (Read 2249 times) previous topic - next topic

Allison Transmission Failure

May 21, 2017, 03:19:03 pm

In conversations about motorhomes, I've had people express concern over the cost of operating and repairing a diesel motorhome. Mostly concerned about the transmission and engine. I would sometimes respond that the two things we might worry about the most are actually the two things that might be least likely to fail. So with that said...
A few months back I took a short trip to McKinney, TX to have MCD shades installed. The trip was uneventful on the way there but when I left I noticed two things about transmission performance. It seemed to downshift harshly and as I drove the temperature continued to slowly climb. When it reached about 230 deg. I would stop and let it cool. I made it back to Rayford and decided to call Beau Reece to check out. He found no codes in the transmission log but found the transmission fluid level was high (about 4 inches above full line on dipstick). He thought that could attribute to shifting differently and temp increase and recommended having the fluid level lowered. My thinking was I had not added fluid while at MCD and it was fine before. So...off to MOT for other scheduled work and get their opinion on the matter. By the time I reached MOT, the trans temp was 248 deg. Keith and I drove the coach and trans would heat as expected. Returned and lowered the fluid level to correct level and also used compressed air to blow off radiator fins. All this seemed to help some but on return trip to Rayford the temp would still increase, but only to 220 degrees or so. I had a trip scheduled to OTM on the 11th of this month to have a new seat installed and thought I would give them a try with the trans. They referred me to ATS Transmission in Arlington, TX so I drove to Arlington and had them look at it. They could not find any codes in the Allison at first but did find something that lead them to believe a sensor on the Cummins was not functioning properly. They could not read the Cummins codes and recommended I take it to a Cummins shop that could read the codes. So back to NAC and Bernd Ramspect's shop. Bernd determined that the issue was not a Cummins sensor and believed that the transmission temperature inside the trans was the problem. They dropped the pan to check / change the sensor and found metal (brass) particles in the fluid.

. Bernd shopped many sources and we decided on a factory rebuilt unit from Stuart Stevenson in Longview, TX. So the trans is ordered and expected to arrive the 31st of this month and Bernd says he can have me on the road in a couple days after it arrives. Upon removal of the tag wheel, a frozen slide pin in brake was found so having all checked and r/r as needed.
So here I sit at my daughters house, waiting for next week with an itch I cannot scratch. I was scheduled to leave on the 22nd to join Scott & Carrol for a month of touring southern Utah together but will join them when coach is back together.
My late wife Donna always said to look for the good in things that happen, so:
I'm grateful that I wasn't stranded at the top of a mountain pass with no shoulder to pull onto.
I'm grateful that I can get the coach repaired at a repair facility that I have confidence in.
I may be grateful that now that I'm broke, I can't overspend for a while.
I'm grateful that I got to meet "Saddlesore". Really enjoyed meeting you and our lunch together!
And so it is; the yin and the yang...
I don't know if this post will benefit anyone else but me, but I've heard it said many times on this forum to "do what makes you happy" and sharing my misery makes me feel better!
Thanks for listening.

Re: Allison Transmission Failure

Reply #1 – May 21, 2017, 03:25:08 pm

And you are at your daughter's house!

Re: Allison Transmission Failure

Reply #2 – May 21, 2017, 03:34:42 pm

Sorry to hear of the demise of your transmission. I suppose even the most rugged of things with the lowest of failure rates can indeed fail. I have also heard that these Allisons are very tough as they do Yeoman's duty in garbage trucks & city buses.

Might I (we) be so bold as to ask how much bank account damage is done by buying a re-maned Allison?

Re: Allison Transmission Failure

Reply #3 – May 21, 2017, 03:41:12 pm

Quote from: Bill B – May 21, 2017, 03:19:03 pm

A few months back I took a short trip to McKinney, TX to have MCD shades installed. The trip was uneventful on the way there but when I left I noticed two things about transmission performance. It seemed to downshift harshly and as I drove the temperature continued to slowly climb. When it reached about 230 deg. I would stop and let it cool. I made it back to Rayford and decided to call Beau Reece to check out. He found no codes in the transmission log but found the transmission fluid level was high (about 4 inches above full line on dipstick). He thought that could attribute to shifting differently and temp increase and recommended having the fluid level lowered. My thinking was I had not added fluid while at MCD and it was fine before.

Bill,

Going back to the original symptoms - how long *had* it been since anyone might have altered the transmission fluid level? Are you able to confirm there isn't a coolant leak into the transmission fluid?

The reason I ask is that I recall this "very rare" situation coming up before... Different year, but I wonder if you fundamentally have the same problem, given the initial symptoms were shifting issues, heating issues, and several inches higher fluid level:

A very rare transmission story

Re: Allison Transmission Failure

Reply #4 – May 21, 2017, 04:23:43 pm

Michelle, I do see similarities in the two failures. I have always thought my retarder was slow to engage but have never had anything to compare to. I guess I will know about that when new trans is installed and I get a chance to drive it. As far as the trans fluid level...The transmission was serviced at FOT about 18 months ago. I should say that the shift pad monitor showed trans fluid level ok.
I should also note that when the pan was taken out, Bernd said he was certain that the trans had been worked on, and possibly by someone unfamiliar with the Allison transmission. Inside the pan is a metal bracket that holds a wire harness in place and that bracket was broken. Apparently, when the pan is lowered, it should be partially lowered and the harness disconnected before fully lowering and removing the pan. And the bracket was left broken and not repaired. Bernd also mentioned something about the gasket. I was not sure what he was talking about but it was one of the two things he saw that made him think the trans had been worked on before. I hope I'm relaying what Bernd actually said accurately. I should also note that although I have many service records from when the coach was originally sold, there is no record of transmission repair or conversion to Transynd fluid. Bernd had conversation with Allison and the folks he spoke with said this failure (with info they were provided) was extremely rare.

Bigdog, the Allison remanufactured transmission with a 3 year warranty was just shy of 11k. Don't know about labor yet. Set of new Michelins and two new slide bladders were just months prior to this. I've always tried to be prepared for the unexpected and grateful I could handle this still puts a big hole in the budget. But I'm expecting to get many more years of great service from my "home" on wheels.

Dave, Bernd would have certainly allowed me to stay with the coach. And I was until new trans was ordered and the waiting had started. Kinda boring to stay in coach for a week and I have a small business in Spring, TX that I needed to tend to before leaving on trip out west. And my daughters house is a sweet place to stay! Kids are in school so nice and quiet, pool and hot tub are at my disposal, bike and walking trails are just out the door and the foods good. I plan on returning to Bernd's shop on the 30th to be there for the install and checkout.

Re: Allison Transmission Failure

Reply #5 – May 21, 2017, 05:08:21 pm

Quote from: Bill B – May 21, 2017, 04:23:43 pm

I should also note that although I have many service records from when the coach was originally sold, there is no record of transmission repair or conversion to Transynd fluid.

Bill - as an '03 U320, I'm pretty sure your coach would have been built with Transynd.

Re: Allison Transmission Failure

Reply #6 – May 21, 2017, 05:09:46 pm

USED 2004 ALLISON 4000MH , S/N 6610131882 from 04 AMERICAN EAGLE ISM 500...

Little cheaper, low miles .. option

Re: Allison Transmission Failure

Reply #7 – May 21, 2017, 05:19:08 pm

HD4000 Rebuilt Allison Transmission, Global Industrial Automatics | eBay

Another option.

Re: Allison Transmission Failure

Reply #8 – May 21, 2017, 05:36:25 pm

Bill, did anyone actually say what happened to the transmission? Why did it fail?

Re: Allison Transmission Failure

Reply #9 – May 21, 2017, 06:04:39 pm

Michelle, I assumed it had been changed over as there is a paper tag on the dipstick handle that is faded and worn but says that fluid has been changed to Transynd. Tag is faded so can't read date and some other info.

David, thanks for the info. Many things were considered in selecting Stewart & Stevenson. Bernd checked into many sources including eBay and other suppliers. The first choice was a re-builder in Houston that Bernd has absolute confidence in but his delivery date was way down the road. Reputation, availability, price, warranty were all major considerations. Bernd has confidence in a factory re-manufactured transmission and I have confidence in Bernd.

Richard, no way to know. Only have the operational symptoms and the presence of metal in the fluid. I would like to know but don't know if Allison will diagnose and let us know. I will ask Bernd about that as he talked to the Allison folks.

Re: Allison Transmission Failure

Reply #10 – May 21, 2017, 06:11:27 pm

What did the shift pad show for fluid level?

This is an EASY check:

1. Drive coach to warm up transmission.
2. Stop on level ground. Leave engine running, transmission in neutral.
3. Push the up and down arrow on the Allison shift pad at the same time.
4. Let it do a count down and then tell you oil level. THIS IS MORE ACCURATE (ACCORDING TO ALLISON) THAN THE DIPSTICK.
Reading on the shift pad will show: O L (for oil level) and then plus or minus and a number of quarts.

BTW, if you read correct level and then either higher or lower in the future, IMMEDIATELY DETERMINE WHAT HAPPENED.

Re: Allison Transmission Failure

Reply #11 – May 21, 2017, 07:08:38 pm

Fluid level was checked with shift pad upon my return from MCD when problem first started. It checked ok. After MOT removed a little over a gallon of fluid, it still checked ok. Prior to removing the transmission pan, the shift pad reading checked ok and the dipstick level was on the full mark.
So Brett, maybe possible that fluid level ok on dipstick when serviced and then read high due to unknown issue/problem?

Re: Allison Transmission Failure

Reply #12 – May 21, 2017, 08:32:55 pm

I had a small issue with the dipstick tube being loose when I bought our coach. Because the dipstick tube was actually coming out of the tranny, the readings were inconsistent with a leak from time to time. I discovered the gasket was not sealed right going in the tranny and replaced with a new one. No leaks and reads out like it should all for about 4 bucks! Thats a bummer hearing about your tranny, however, the post is funny!

Re: Allison Transmission Failure

Reply #13 – May 21, 2017, 09:02:18 pm

So let me understand the situation fully here. You have an issue with high transmission temperature on your instrumentation and some harsher than normal shifting. But otherwise, the RV drove and no other symptoms.

The transmission pan was removed, and some metal wear particles were noted in it. And from these particles, it is determined that the entire transmission is condemned and must be replaced for $11,000+?

When pans are removed on automatic transmission, wear particles are usually found. There are wear items inside an automatic transmission.

Were the temperature readings verified with other devices?

Again, the transmission operated correctly with no codes, other than the higher temp?

A slightly elevated fluid level is also blamed as a primary cause??? You think every allison 4000 out there is perfectly filled to the correct level?

Seems to me that lately, this shop in NacWorld loves to just replace entire components after condemning them instead of alternative repairs. However, do what makes you feel good.

Re: Allison Transmission Failure

Reply #14 – May 21, 2017, 09:20:02 pm

I'd strongly consider what Krush wrote. The thing I'm not understanding, though, is that if the trans if overfillled, what is it overfilled with? I would strongly suspect coolant, possibly from a failed transmission cooler. Has an analysis been done on fluid? Simple and cheap to do.

I'd sure drain it and fill with new fluid, doesn't have to be transynd, could be conventional, and try it again before condemning it.

Strongly suggest getting a written labor quote in advance of replacement.

Re: Allison Transmission Failure

Reply #15 – May 21, 2017, 09:42:12 pm

its hard to really say much without seeing the stuff in the pan however enough brass in the pan be able to see it and identify is bad. I am not an Allison expert but I have torn one apart and the only brass parts I remember are seeing are bushings. I would check to cooler as well. If they remove the cooler to access the trans have it pressure tested on the coolant side while on the bench. If they leave to cooler in the chassis pressure test the cooling system before hooking up the trans lines. If I saw a bunch of brass at minimum I would recommend a full teardown but would expect to find a lot of wear on shafts and possibly the case as well as related damage to assemblies misaligning. Add to that a new convertor and flushing everything you are pretty much at a full rebuild.

Re: Allison Transmission Failure

Reply #16 – May 21, 2017, 09:47:06 pm

Quote from: Chuck Pearson – May 21, 2017, 09:20:02 pm

I'd strongly consider what Krush wrote. The thing I'm not understanding, though, is that if the trans if overfillled, what is it overfilled with? I would strongly suspect coolant, possibly from a failed transmission cooler.

When my transmission cooler failed there was no fluid in the transmission, the transmission fluid was pumped into the cooling system. Transmission fluid pressure overcomes the engine coolant pressure.

Roland

Re: Allison Transmission Failure

Reply #17 – May 21, 2017, 10:08:53 pm

Wow 11k + install is a chunk O' change. Just my opinion unless I where in a big hurry I would let an Allison shop do a year down and repair. Got to be way less than 11k +.

Re: Allison Transmission Failure

Reply #18 – May 21, 2017, 10:11:03 pm

transmission fluid will move to the cooling system when running. when shut off the cooling system holds pressure longer and the coolant can then enter the transmission system and initially it will collect in the low point of the trans system.

Re: Allison Transmission Failure

Reply #19 – May 21, 2017, 10:20:17 pm

My local cummins dealer only swaps out remanufactured Allison's.

Re: Allison Transmission Failure

Reply #20 – May 22, 2017, 12:32:15 am

Quote from: Caflashbob – May 21, 2017, 10:20:17 pm

My local cummins dealer only swaps out remanufactured Allison's.

Sad to say, just goober mechanics being employed to be swappers, cause techs cost too much, and can't match the revenue generated by the swappers.

Re: Allison Transmission Failure

Reply #21 – May 22, 2017, 01:15:40 am

Allison shops may rebuild. They are around the country, like Cummins shops.

Re: Allison Transmission Failure

Reply #22 – May 22, 2017, 02:20:21 am

Yup, the good, the bad and ugly. What ever shop, you get suck with. Prevention is priceless

Re: Allison Transmission Failure

Reply #23 – May 22, 2017, 05:21:04 am

Have old Berned check the filters for metal,if they are clean then the particles of brass may have been in the pan for years.

Re: Allison Transmission Failure

Reply #24 – May 22, 2017, 05:22:29 am

It was nice to meet you at OTM Bill. Do consider the Allison shops. At the price quoted NOT including labor you are in their range. But you have a nationwide network for initial warranty.

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