Allison 3060 over heating

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Allison 3060 over heating

September 16, 2023, 01:40:21 pm

I have a 1997 U295, after purchasing it two years ago I did a complete service on it myself. When flushing the coolant system I noticed a pin hole leak in the tranny cooler. I bought a new one from Ice Box Diesel. I sent a fluid sample to Blackstone and it came back no trace of glycol in sample.

We made a 1700 mile trip pulling a toad through the Smokies with no problems last summer. We used it close to home several times and this past June we headed over to NAC to meet up with some friends and get new shoes on the coach. I live about three hours from NAC and when we got to town my tranny light came on. In hindsight, I should have stayed and had it looked at but I didn't want to ruin our trip as we had four in convoy to Hot Springs. We made it about three hours before the light came on again. We pulled over at a truck stop for 15 minutes and continued on to HS fine.

After our stay we left for Broken Bow and had no problem. We left BB a few days later and had to stop 4 times on our way home, a 5 hour drive. What's strange is I can pull over a kill it for 5 minutes and then continue on for a good while before it heats back up.

I made a huge mistake by taking it to United Engines in Shreveport to have it fixed and after $3500 they couldn't figure out what was wrong so I'm at a loss as to what to do now.

Do any of you have a clue as to what could be going on? Or have you ever seen something similar?

As a side note, the retarder doesn't work but it hasn't worked since I've owned it.

Any help would greatly appreciated.

Thanks, Mike

Re: Allison 3060 over heating

Reply #1 – September 16, 2023, 02:16:19 pm

What is the trans temp gauge say when the heat light comes on?
What is engine temp at same time?
What is the grade of the road at that time?
What gear is trans in ?

Heat comes from friction or it is transfered to the trans

Re: Allison 3060 over heating

Reply #2 – September 16, 2023, 02:22:00 pm

If you have an infra red heat you see if the lines coming out of the trans actually hot. Maybe a gauge or sender

Re: Allison 3060 over heating

Reply #3 – September 16, 2023, 02:26:26 pm

Light comes on around 220. Engine temp runs at 180 and doesn't rise. It will do it on flat interstate running is sixth gear.

I've shot the sump with infrared gun and it shows 250

Re: Allison 3060 over heating

Reply #4 – September 16, 2023, 02:27:58 pm

Tech hooked lap top to tcm and it shows overheat on four occasions

Re: Allison 3060 over heating

Reply #5 – September 16, 2023, 02:40:00 pm

Think the first thing I would find out is whythe retarder does not work,are there lines disconnected
Or what,you would think the tech would have wondered also.When were the filters and fluid changed.

Re: Allison 3060 over heating

Reply #6 – September 16, 2023, 03:07:51 pm

I did a complete service on the coach, including the trans, new filters and Transyd 668.

The 163 wire is showing no voltage. The shop asked me if I wanted them to trace the wire down but when they told me how much time they had spent on it with no results, I decided to go get it, I had no confidence in their ability. It seems to me they wanted to swap parts until it was fixed. I wasn't going to pay for them to experiment.

Re: Allison 3060 over heating

Reply #7 – September 16, 2023, 03:10:06 pm

How do I trace down the cause for no voltage on 163? Is this the wire that connects to the accumulator?

Re: Allison 3060 over heating

Reply #8 – September 16, 2023, 03:17:22 pm

Quote from: Scubajeeper – September 16, 2023, 03:10:06 pm

How do I trace down the cause for no voltage on 163? Is this the wire that connects to the accumulator?

The schematic linked below is found in our excellent Forum Library/Schematics folder. If you rotate it 90 degrees to the right so it is in landscape orientation, then you'll find wire 163 at the top right hand corner.

Check wire 5 coming into the retarder switch. From the diagram (above) looks like it should be HOT with Ignition Switch turned on (RUN position).

Yes, I know the schematic is for the 4000MH tranny, but the 163 wire origin should be the same for both models.

https://www.foreforums.com/index.php?action=media;sa=media;in=3282

Re: Allison 3060 over heating

Reply #9 – September 16, 2023, 04:42:01 pm

Thanks

Re: Allison 3060 over heating

Reply #10 – September 16, 2023, 05:27:46 pm

Have you personally checked the fluid level after the change?

Re: Allison 3060 over heating

Reply #11 – September 16, 2023, 05:56:07 pm

Fluid level shows Ok on Allison shift pad

Re: Allison 3060 over heating

Reply #12 – September 16, 2023, 07:11:11 pm

I'd give Keith Risch in NAC a shout. If anyone can track it down he can.

kwrisch40@yahoo.com

Re: Allison 3060 over heating

Reply #13 – September 16, 2023, 09:40:16 pm

I've talked with Keith about it, he happens to be a friend of my bud that went to Hot Springs with me. If I can't figure it out I'll definitely be taking it back to NAC. Thanks

Re: Allison 3060 over heating

Reply #14 – September 17, 2023, 08:05:23 am

Have you checked for DIAGNOSTIC CODES?

Something as simple as torque converter not locking up can cause overheating.

Re: Allison 3060 over heating

Reply #15 – September 17, 2023, 09:08:22 am

Can you shoot both ends of the trans cooler to see if you have a temp difference,if that sump is actually 250 the internal parts are a whole lot hotter.

Re: Allison 3060 over heating

Reply #16 – September 17, 2023, 09:22:36 am

The shop I took it to did a flow test and a temp check. The cooler drops temp 10 degrees and Allison said that was in spec. Also flow was in spec.

The only codes showing where high sump temp.

Re: Allison 3060 over heating

Reply #17 – September 17, 2023, 09:44:52 am

Quote from: Scubajeeper – September 17, 2023, 09:22:36 am

The cooler drops temp 10 degrees and Allison said that was in spec.

I have little knowledge of this subject, but from a purely amateur perspective, a measly 10 degree reduction in fluid temp seems hardly worth the trouble/expense of having a cooler.

Re: Allison 3060 over heating

Reply #18 – September 17, 2023, 10:01:10 am

If it,s in spec it,s in spec,from reading every post over and over it seems that for some reason
Under normal conditions the trans is getting muchhotter then normal,plus if the retarder was working it would be hotter,do you have the joystick or the rocker switch.

Re: Allison 3060 over heating

Reply #19 – September 17, 2023, 10:19:43 am

The IRV2 thread linked below may be of some interest for general comparison purpose. It seems 3060 trans temps are all over the chart, depending on vehicle cooler setup and where the fluid temp is actually measured.

3000 Allison Temperature - iRV2 Forums

Re: Allison 3060 over heating

Reply #20 – September 17, 2023, 01:52:51 pm

If this was on an M-11 I would say that the water pump bypass orifice has been left out of the system. When you did all the fluids did you replace the water pump also? Reason being you could have a bad/eroded impeller not delivering proper flow. That cooler should have a lot more differential between in and out.

Retarder problem, Have you checked the retarder relay (hid behind the kick panel in front of the passengers seat) and the retarder on/off switch (here is where the163 wire comes from)

Mike

Re: Allison 3060 over heating

Reply #21 – September 17, 2023, 06:30:27 pm

I'm with you, 10 degree drop doesn't seem to be enough but according to Allison, it is.

I have the rocker switch and a joy stick. The light comes on on the rocker when you back off the throttle when switch is on.

I pulled the relay and tested it and it's ok.

Re: Allison 3060 over heating

Reply #22 – September 17, 2023, 06:44:09 pm

Quote from: Chuck & Jeannie – September 17, 2023, 10:19:43 am

The IRV2 thread linked below may be of some interest for general comparison purpose. It seems 3060 trans temps are all over the chart, depending on vehicle cooler setup and where the fluid temp is actually measured.

3000 Allison Temperature - iRV2 Forums

I read that thread, the post about 200-230 being ok is disturbing, there's no way it can survive at those temps.