slow shifting transmission u320

Topic: slow shifting transmission u320 (Read 787 times) previous topic - next topic

slow shifting transmission u320

April 17, 2019, 02:35:55 pm

I've notice over the past few colder months that my U320 will over rev a little between up shifts under normal acceleration. This goes away when the transmission gets up to temperature. Also, the downshift to 2nd is harsh sometimes when slowly coming to a stop (this has always been the case in the 3 years i have owned it). Fluid level is correct an fluid is clear and correct color. Time for a fluid change? Only about 10,000 mile since last fluid change.
What is involved changing the fluid? dump and refill, drive x amount of miles and repeat? these transmissions have a spin on filter?

Re: slow shifting transmission u320

Reply #1 – April 17, 2019, 02:42:11 pm

Try this:

transmission oil

Also, see "Transmissions" topic at beamalarm.com for helpful info:

Foretravel Motorhome technical help and information links

Re: slow shifting transmission u320

Reply #2 – April 17, 2019, 02:55:22 pm

Filters are internal, but easy to change. Get a filter kit for your particular Allison serial number (tag on driver's side of transmission).

Also, a pail (5 gallons) of Transynd. This is enough for the 3000 series. Ask Allison for the change volume for your 4000.

Any Allison dealer will have the filter kit (which has instructions) and Transynd.

An easy job to change fluid and filters with an inch-lb torque wrench the only "special" too needed.

If Transynd in there now, no need to change. If Dexron, I would upgrade to Transynd (Allison's synthetic fluid) ad the retarder classifies the transmission use as severe duty.

Re: slow shifting transmission u320

Reply #3 – April 17, 2019, 03:28:19 pm

Sounds like a trip to a FACTORY Allison dealer for some diagnostics. The transmission can be reset to the factory shift points if there are no other issues. No real need to change synthetic fluid and filters at 10K miles. The filters are not spin on they are accessed through the bottom of the transmission.

Re: slow shifting transmission u320

Reply #4 – April 17, 2019, 03:32:26 pm

so...has anyone experienced the symptoms I described? I'd like to hear your feedback and how it was resolved.

Re: slow shifting transmission u320

Reply #5 – April 17, 2019, 03:39:53 pm

The 3-4000 series transmissions have the ability to adjust them selves to your driving habits " adaptive learn strategy" some times resetting them can correct some of that, IF no other issues.
At this point anything is just a guess.

Re: slow shifting transmission u320

Reply #6 – April 17, 2019, 03:55:38 pm

Quote from: jelfert – April 17, 2019, 03:32:26 pm

so...has anyone experienced the symptoms I described? I'd like to hear your feedback and how it was resolved.

On automobiles those are the symptoms of "morning sickness" the piston seals get hard and fluid bypasses until the oil heats up and softens them. It is more of an age problem rather than miles. An Alison expert could tell you if this can happen to their transmissions.

Re: slow shifting transmission u320

Reply #7 – April 17, 2019, 04:39:57 pm

Allison Tech for 40 years - iRV2 Forums
This guy might help, you probably have to join the forum to post a question.

Re: slow shifting transmission u320

Reply #8 – April 17, 2019, 04:57:20 pm

Thanks

Re: slow shifting transmission u320

Reply #9 – April 17, 2019, 10:14:21 pm

Jody,Just changed my trans oil, had an analysis done and the report said low viscosity and recommended a change. If the bottom pan on transmission is about 3" deep it will take the tall filters but as Brett said the number will get you the right ones. The Allison tec told me mine would hold between 10 and 12 gallon. I put 10 gallon in and run it per tec instructions and key pad showed 4 Qt low so I added the 11th gallon ran it again and it still shows 1 QT low,
When dumping the filters one held about a gallon and the other about 1-1/2 gallon. Unless you have a pit to pull over or plan to block
(raise) your coach up you will need buckets that are about 10" tall to go under the tranny.
Also, the tech that I talked to ( been doing it for a lot of years) said let filters and drain plug drain for several hours and there would only be about 1 gallon of old oil left in transmission . He didn't recommend doing a double drain and refill
Chris

Re: slow shifting transmission u320

Reply #10 – April 18, 2019, 06:12:39 am

Thanks Chris! I'll definitely need to get some different pans to hold all that fluid. I'll be doing this on the ground. Good advice about letting it drain for several hours.

Re: slow shifting transmission u320

Reply #11 – April 22, 2019, 10:19:08 pm

Mine did this from 3rd to 4th when I bought it. Not often. Just once in a while. I replaced with transynd and it hasn't behaved in any unexpected way since.

Re: slow shifting transmission u320

Reply #12 – April 23, 2019, 11:15:47 am

I've noticed this occasionally. Turning the retarder off seems to cure it. Combination of downshift and retarder at an inopportune time I guess. Might try that.

Re: slow shifting transmission u320

Reply #13 – April 23, 2019, 11:51:59 am

Chris what kind of a container did you use to catch that much oil? If 2 1/2 gallons came outta the filters that still leaves 81/2 to come out the plug. I wanna do it but don't want an environmental event at my house, my DW says to just take it an have it done but that is just like going out and buying another pair of shoes for her and it takes an opportunity away from me to become closer with my coach. And I want to let it drain a while like you said to get as much out as possible because I don't know what is in it and I'm going back with transynd.

Re: slow shifting transmission u320

Reply #14 – April 23, 2019, 12:22:53 pm

My version of an oil drain pan. Made from old plastic 30 gallon drum. Used sabre saw to cut down and form handles. Worked great. I no longer have a FT and don't need it. If anyone wants it its theirs. Its in Conyers, GA, would be awkward to ship.

Re: slow shifting transmission u320

Reply #15 – April 23, 2019, 12:28:07 pm

I use these from Fry's

Fry's Electronics |

Re: slow shifting transmission u320

Reply #16 – April 23, 2019, 03:44:52 pm

You can "catch" the trans between gears sometimes. It can get "confused" as to what it's supposed to be doing for a few se ones. Shifts hard at that point.

Different if it does it every time.

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slow shifting transmission u320

April 17, 2019, 02:35:55 pm

Re: slow shifting transmission u320

Reply #1 – April 17, 2019, 02:42:11 pm

Re: slow shifting transmission u320

Reply #2 – April 17, 2019, 02:55:22 pm

Re: slow shifting transmission u320

Reply #3 – April 17, 2019, 03:28:19 pm

Re: slow shifting transmission u320

Reply #4 – April 17, 2019, 03:32:26 pm

Re: slow shifting transmission u320

Reply #5 – April 17, 2019, 03:39:53 pm

Re: slow shifting transmission u320

Reply #6 – April 17, 2019, 03:55:38 pm

Re: slow shifting transmission u320

Reply #7 – April 17, 2019, 04:39:57 pm

Re: slow shifting transmission u320

Reply #8 – April 17, 2019, 04:57:20 pm

Re: slow shifting transmission u320

Reply #9 – April 17, 2019, 10:14:21 pm

Re: slow shifting transmission u320

Reply #10 – April 18, 2019, 06:12:39 am

Re: slow shifting transmission u320

Reply #11 – April 22, 2019, 10:19:08 pm

Re: slow shifting transmission u320

Reply #12 – April 23, 2019, 11:15:47 am

Re: slow shifting transmission u320

Reply #13 – April 23, 2019, 11:51:59 am

Re: slow shifting transmission u320

Reply #14 – April 23, 2019, 12:22:53 pm

Re: slow shifting transmission u320

Reply #15 – April 23, 2019, 12:28:07 pm

Re: slow shifting transmission u320

Reply #16 – April 23, 2019, 03:44:52 pm

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