Retarder Temperature Rising, but retarder set to Off

Topic: Retarder Temperature Rising, but retarder set to Off (Read 4110 times) previous topic - next topic

Re: Retarder Temperature Rising, but retarder set to Off

Reply #50 – July 26, 2017, 04:10:58 pm

I can't see the trans being warmed up in five min on a feeeway let alone the retarder actually being hot in five min.

Re: Retarder Temperature Rising, but retarder set to Off

Reply #51 – July 26, 2017, 04:13:42 pm

Exactly what the tech said when he watched it go up. He is currently in the library researching this. Never heard of it before. I first showed him the VMSPC and then we hooked up his laptop. Both recorded the high temps

Re: Retarder Temperature Rising, but retarder set to Off

Reply #52 – July 26, 2017, 04:36:14 pm

Ed,

Again, two separate questions for the tech:

1. What is the cause and remedy for your high temperatures?
2. Is there a way to disable the retarded to allow "limp in"?

Re: Retarder Temperature Rising, but retarder set to Off

Reply #53 – July 26, 2017, 05:33:06 pm

What code did the tech find.
To my way of thinking, the oil in the transmission, is the same oil in the retarder, what is the dash gauge reading.

Re: Retarder Temperature Rising, but retarder set to Off

Reply #54 – July 26, 2017, 05:45:13 pm

Quote from: wolfe10 – July 26, 2017, 04:36:14 pm

Ed,

Again, two separate questions for the tech:

1. What is the cause and remedy for your high temperatures?
2. Is there a way to disable the retarded to allow "limp in"?

No answer yet, today was just two road tests, a phone call to an Allison guru and speculation. The tech did confirm the high temps with his equipment so it is not the VMSPC software. We got the coach back to sleep in tonight and back in the shop tomorrow at 08:00L. He is going to get into the transmission. He will need all day and we may have to get a pet friendly room for the night.

I did ask him if the retarder could be disabled and he replied that it could be done electrically, but we did not get into the nitty gritty. He also mentioned they (Allison) no longer used the accumulator tank.

Re: Retarder Temperature Rising, but retarder set to Off

Reply #55 – July 26, 2017, 06:07:48 pm

He did not find codes, Bill. I know it is all the same tranny fluid. At times, there was a difference of some fifty degrees between retarder temps and tranny temps. This was probably due to the temps being recorded from different locations. Here is this quote from Barry and Cindy a little earlier in this thread.
"On our coach dash tranny gauge was controlled by a temp sender screwed into a 1/8" threaded hole in one of the large coolant elbows on bottom-front of tranny. OEM choice was to measure tranny fluid temps returning from tranny cooler."

Re: Retarder Temperature Rising, but retarder set to Off

Reply #56 – July 27, 2017, 12:16:52 pm

Ok, something caused the "Retarder Valve" to stick. If you have the schematic for the retarder it is part 54 on the schematic.

Quote from: wolfe10 – July 26, 2017, 04:36:14 pm

Ed,

Again, two separate questions for the tech:

1. What is the cause and remedy for your high temperatures?
2. Is there a way to disable the retarded to allow "limp in"?

To answer Brett's question #2
Yes, by disabling the retarder solenoid. (pretty much the same thing as turning off the switch)
However in my case this would not have helped as the retarder valve was already STUCK.
The tech is not sure what cause the valve to stick. More digging.

They are working on numbers now. Two possible scenarios.

Re: Retarder Temperature Rising, but retarder set to Off

Reply #57 – July 27, 2017, 12:26:13 pm

Ed,

Yes, thanks for the information. Understand the issue could be either electric or mechanical.

So, a mechanical fix (whether removing the solenoid, pulling its plunger, etc (that is what we need to know) would be the bomb-proof answer to the "how do I limp home" question.

Inquiring minds want to know.

Re: Retarder Temperature Rising, but retarder set to Off

Reply #58 – July 27, 2017, 12:48:33 pm

Quote from: wolfe10 – July 27, 2017, 12:26:13 pm

Ed,

Yes, thanks for the information. Understand the issue could be either electric or mechanical.

So, a mechanical fix (whether removing the solenoid, pulling its plunger, etc (that is what we need to know) would be the bomb-proof answer to the "how do I limp home" question.

Inquiring minds want to know.

The tech said I do not have a "plunger", I have a valve spool, Part 54 on the schematic. I asked about pulling the valve spool. He said no, I would have a large internal leak. Are we talking about the same part, Brett? It's all Greek to me. I can't find a schematic for the retarder on line (though Allison will sell me one). The tech had his schematic open and I peeked.

Ed

Re: Retarder Temperature Rising, but retarder set to Off

Reply #59 – July 27, 2017, 01:03:18 pm

Ed,

I have no first hand knowledge of the valve/solenoid. Just trying to see if we can get "how do I get home/to the nearest repair facility" for those with retarders.

That is the reason for my questions. I just ASSUME that there is an open and a closed position that controls retarder function, and speculate that in one position, there will be zero retarder function.

Re: Retarder Temperature Rising, but retarder set to Off

Reply #60 – July 27, 2017, 04:05:46 pm

Ed,

We are on the road and are late to chime in. I don't have a print handy to reference your numbers.
Is the valve you are talking about mounted on the accumulator tank end?
Does it look something like this? (there is several versions) Allison retarder air valve
If this isn't what you are talking about just disregard the following.
If so the way you disable it so you can get on down the road is:
1. Pull the little electrical connection after you have turned off the retarder switch. It is just a push/pull no/off.
2. Drain air from air system dry tanks
3. Remove the air line that feeds this valve and plug the air line. This requires an air line plug.
4. Unscrew the valve from the accumulator tank to release the trapped air. Be careful with your eyes.
5. Either completely remove the valve and plug the hole with a 1/4" npt plug or after the air has escaped just screw valve back up to keep trash out of the accumulator tank.
6. Make sure that the retarder switch is in the off position for the second time.
7. Wash hands and head on down the road. Just remember that you only have service brakes.

Pamela & Mike

Re: Retarder Temperature Rising, but retarder set to Off

Reply #61 – July 27, 2017, 04:20:52 pm

Ed,

If Mike's excellent write-up is the answer (a temporary fix approved by Allison), let's post that as a separate thread!

You might copy his post or just forward it to the shop and/or the guy at Allison the tech is working with for their feedback.

Re: Retarder Temperature Rising, but retarder set to Off

Reply #62 – July 31, 2017, 08:27:57 pm

Quote from: Pierce & Gaylie Stewart – July 18, 2017, 06:16:17 pm

Anyone call an Allison shop yet for advice?

Pierce

I'm in an Allison shop. Just nothing to report.
Before I forget, I'd like to thank you Pierce for all the info you have provided to me in this thread.

Today, Monday.... In the shop at 08:00L .... No parts... Out the shop ..... back in tomorrow at 08:00

It's been a long weekend, at least Lee Brice was playing at Big Sky Brewery Thursday night.

My tech at I State Truck was off on Friday, so we had to wait until today to get back in the shop. They ordered parts but are still waiting the "overnight shipment" The last thing to report was the retarder valve was stuck. He put it back together so we would have the coach to sleep in for the weekend.

Ed

Re: Retarder Temperature Rising, but retarder set to Off

Reply #63 – July 31, 2017, 09:01:37 pm

We are on the road and are late to chime in. I don't have a print handy to reference your numbers.
Is the valve you are talking about mounted on the accumulator tank end?
Does it look something like this? (there is several versions) Allison retarder air valve
If this isn't what you are talking about just disregard the following.

Pamela & Mike

I grabbed the attached photo from an on line auction site. This is referred to as a "retarder valve" on the schematic.
So to answer your question, No.
But thank you for replying. It is an excellent write up.

I do have this nagging question in the back of my head. No one has looked at the accumulator tank or air valve. Doesn't this force the transmission fluid in to the retarder? If it was malfunctioning could the fluid get stuck in the retarder and heat up?

Just to clarify NO feeling of transmission retarding when I release the throttle or press the brake pedal. The retard switch is in the Off position.

Ed

Re: Retarder Temperature Rising, but retarder set to Off

Reply #64 – August 01, 2017, 07:42:57 am

Quote from: Lance Camper – July 31, 2017, 09:01:37 pm

I do have this nagging question in the back of my head. No one has looked at the accumulator tank or air valve.
Doesn't this force the transmission fluid in to the retarder?
If it was malfunctioning could the fluid get stuck in the retarder and heat up?

Just to clarify NO feeling of transmission retarding when I release the throttle or press the brake pedal. The retard switch is in the Off position.

Ed,
The short answer,
1. Yes
2. Really not stuck but will cause the fluid temp to rise.
3. If the piston was stuck or air locked you should feel and have retardation.

As a side note that valve in the above picture looks like it is for a 3000 series. This comment is just from looks, so don't take it as gospel as parts for the 3000 and 4000 look a lot alike and some are the same. The reason for the comment is do you have a 3060R or the 3000R?

Pamela & Mike

Re: Retarder Temperature Rising, but retarder set to Off

Reply #65 – August 01, 2017, 12:14:30 pm

Quote from: Pamela & Mike – August 01, 2017, 07:42:57 am

As a side note that valve in the above picture looks like it is for a 3000 series. This comment is just from looks, so don't take it as gospel as parts for the 3000 and 4000 look a lot alike and some are the same. The reason for the comment is do you have a 3060R or the 3000R?

Pamela & Mike

Not my part, I grabbed the photo from an eBay auction. Closest I could find.
From the plate on the side of transmission, model MD3066.

Ed

Re: Retarder Temperature Rising, but retarder set to Off

Reply #66 – August 02, 2017, 04:28:06 pm

It is/was a broken snap ring. The valve that was stuck has another metal part on one end that was secured with a snap ring. The snap ring broke and scoured the metal on both the valve and the inside of the sleeve it slid in and out.

A new valve came with parts kit but since the sleeve is scratched the tech said it may or may not work if put back together.
So I can buy this part for two Coach Buck's or a remanufactured transmission with retarder for 4.8 CB's. I'd be saving additional labor and the parts for rebuilding the retarder.
I opted for a remanned transmission since cost is similar and better warranty on the remanned transmission.

A BROKEN SNAP RING !!!

Ed

Re: Retarder Temperature Rising, but retarder set to Off

Reply #67 – August 02, 2017, 08:56:09 pm

Quote from: Lance Camper – August 02, 2017, 04:28:06 pm

It is/was a broken snap ring. The valve that was stuck has another metal part on one end that was secured with a snap ring. The snap ring broke and scoured the metal on both the valve and the inside of the sleeve it slid in and out.

A new valve came with parts kit but since the sleeve is scratched the tech said it may or may not work if put back together.
So I can buy this part for two Coach Buck's or a remanufactured transmission with retarder for 4.8 CB's. I'd be saving additional labor and the parts for rebuilding the retarder.
I opted for a remanned transmission since cost is similar and better warranty on the remanned transmission.

A BROKEN SNAP RING !!!

Ed

I must have missed something here........ Two Coach Bucks! for a VALVE??

Re: Retarder Temperature Rising, but retarder set to Off

Reply #68 – August 14, 2017, 07:27:33 am

Ed,

Are you back on the road with the reman trans?

Re: Retarder Temperature Rising, but retarder set to Off

Reply #69 – August 16, 2017, 06:22:36 pm

Quote from: FourTravelers – August 02, 2017, 08:56:09 pm

I must have missed something here........ Two Coach Bucks! for a VALVE??

No, for a new retarder "housing" (as the Tech called it). The Valve slides in and out of this housing. The broken snap ring was causing all of the problems and it scratched, scored, and caused the valve to stick.

Re: Retarder Temperature Rising, but retarder set to Off

Reply #70 – August 16, 2017, 06:24:06 pm

Quote from: Mark Duckworth – August 14, 2017, 07:27:33 am

Ed,

Are you back on the road with the reman trans?

Finally today we are whole. Thank you for asking Mark.

Re: Retarder Temperature Rising, but retarder set to Off

Reply #71 – August 16, 2017, 07:30:52 pm

Thanks for the reply Ed, is troubling to think that a broken snap ring could result in damages that expensive. Just goes to show you that it doesn't take much to go wrong to put you on the side of the road.

Re: Retarder Temperature Rising, but retarder set to Off

Reply #72 – August 16, 2017, 08:18:52 pm

Ed -- Glad to hear it. About 30 days, I think? Oh well, I rather be stuck there than in Houston or LA (no offense, I've lived in both). I'd take Montana for a forced layover.

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