Community Forums

cgreer00 · 06-05-2018, 10:54 AM

Hey everyone,
I am at the beginning of a 6 week road trip and have a preventive question. We had a wheel seal go bad and leak fluid so we had it repaired. At the end of the repair the ABS light was on when I did the test drive. I brought it back in twice and the mechanic adjusted the sensor each time. The last time he adjusted it the light went off and stayed off during my 10 minute test drive. I am thinking it is good, but I want a backup plan just in case.

From my research I have learned that if the ABS light is on and the system is malfunctioning, it will send a signal to the Allison and the torque converter won't lock up. This could cause transmission damage if driven for a long time this way. I also saw a post that said if this happens, just pull the ABS fuse until you can get it fixed.

So I wanted to confirm that this will indeed work, and also confirm that the ABS fuse is a 60 amp fuse that is typically located in the fuse box on the passenger side behind the front wheel (in the storage area). Can anyone comment?

I don't want our trip to be ruined because we have to take the motorhome to a repair facility and have them troubleshoot a problem, I would rather turn ABS off and deal with it when we finish our travels.

Thank you!

CJ7365 · 06-05-2018, 11:10 AM

Quote:

Originally Posted by cgreer00

Hey everyone,
I am at the beginning of a 6 week road trip and have a preventive question. We had a wheel seal go bad and leak fluid so we had it repaired. At the end of the repair the ABS light was on when I did the test drive. I brought it back in twice and the mechanic adjusted the sensor each time. The last time he adjusted it the light went off and stayed off during my 10 minute test drive. I am thinking it is good, but I want a backup plan just in case.

From my research I have learned that if the ABS light is on and the system is malfunctioning, it will send a signal to the Allison and the torque converter won't lock up. This could cause transmission damage if driven for a long time this way. I also saw a post that said if this happens, just pull the ABS fuse until you can get it fixed.

So I wanted to confirm that this will indeed work, and also confirm that the ABS fuse is a 60 amp fuse that is typically located in the fuse box on the passenger side behind the front wheel (in the storage area). Can anyone comment?

I don't want our trip to be ruined because we have to take the motorhome to a repair facility and have them troubleshoot a problem, I would rather turn ABS off and deal with it when we finish our travels.

Thank you!

LOL, damage to the trans, based on a abs fault

Can you please explain, "your research", because this is the first time I have heard this, and frankly don't believe it.

Pretty frustrating when people cannot back up what they post, either from a web site or PDF.

cgreer00 · 06-05-2018, 11:51 AM

Quote:

Originally Posted by CJ7365

LOL, damage to the trans, based on a abs fault

Can you please explain, "your research", because this is the first time I have heard this, and frankly don't believe it.

Pretty frustrating when people cannot back up what they post, either from a web site or PDF.

http://www.irv2.com/forums/f22/abs-l...ge-119017.html

https://www.expeditersonline.com/for...on-tips.66456/

If you have know for sure that no damage would be caused, I would be interested to hear it. To the rest of the forum: I would love to hear any well-informed and respectful opinions on this. Thank you.

Forkyfork · 06-05-2018, 12:13 PM

I had the ABS light come on. It was related to a locked rear caliper. When your caliper drags it can heat all the components including your transmission potentially causing it to over heat.

I would check with our resident Allison fluids expert and may be able to shed some light on the concern.

Not saying it isn't possible. Im just wondering that since that post was from the heyday of the brake recalls that maybe it was more related to heat generated from caliper lockup than anything else.

cgreer00 · 06-05-2018, 12:20 PM

Yes but the other link I posted is from a trucking guy on a completely different forum who said the same thing: that Allisons won't lock up the torque converter if the ABS light is on.

CJ7365 · 06-05-2018, 01:01 PM

Quote:

Originally Posted by cgreer00

Yes but the other link I posted is from a trucking guy on a completely different forum who said the same thing: that Allisons won't lock up the torque converter if the ABS light is on.

Well you said trucker and maybe there is something there when dealing with 18wheelers, but then again they don't have the allison 1000.

When I meant research I meant from a pdf file, copy of a maint page. Not some guy from the internet.

CampDaven · 06-05-2018, 02:54 PM

I won’t badger or criticize. I believe you!
And you have my very best wishes!
Just trying to help.

https://www.expeditersonline.com/for...on-tips.66456/
An excerpt:
3) ABS CODES. If you have an ABS light burning, or you have opted to ignore it for too long the ABS module will tell the transmission control module to get your attention by not allowing your torque converter to lock up. This affects your shift patterns, causes the transmission to run hot, as well as drivability issues.

edgray · 06-05-2018, 02:54 PM

Quote:

Originally Posted by cgreer00

http://www.irv2.com/forums/f22/abs-l...ge-119017.html

https://www.expeditersonline.com/for...on-tips.66456/

If you have know for sure that no damage would be caused, I would be interested to hear it. To the rest of the forum: I would love to hear any well-informed and respectful opinions on this. Thank you.

Here is my "respectful opinion" :

Post # 7 in the iRV2 thread you linked seems to include the reference page from the Allison manual. I have not verified that quote is correct because I no longer have my Allison 1000 (W22). HOWEVER, I do know that the ECM and TCM on a Workhorse chassis communicate with each other, so it is entirely possible that the ABS fault could send a signal to the TCM to prevent TC lockup, which I understand is desirable because lockup reduces friction and associated heat generation. That said, I do not know that simply driving without the TC being "locked up" can cause the tranny to be destroyed (fried). I'm sure the lack of TC lockup can cause the TFT to increase, and that can cause expansion of the fluid which can result in fluid going out the vent. IF enough fluid was expelled to create a serious shortage, I would think the Allison is smart enough to go into limp mode before it destroyed itself, but I'm not an Allison engineer and really don't know if that can happen on a MH1000.

Because "most" of the ABS warnings are triggered by wiring damage and/or melted or out of place sensors, all of which are relatively cheap to fix, I would suggest getting the ABS fault fixed rather than driving great distances and risking even the potential for tranny damage. Plus, ya never know when a condition may present itself where you may actually need a properly functioning ABS.

Motor7 · 06-05-2018, 06:43 PM

I would PM Tom Johnson....a retired Allison tranny engineer and ask him and no other:

http://www.irv2.com/forums/f125/form...-89293-44.html

I'm with the others here...I do not think that an ABS light will in turn damage an Ally 1000....or any other Ally tranny.

And like Ed said....find out why the ABS sensor is telling you THERE IS A PROBLEM. Mine came on, went off, then came on again just before the caliper seized and cost me thousands of dollars in repairs. I shoulda "listened" to the ABS light.

cgreer00 · 06-05-2018, 07:15 PM

Thanks for the responses. Again, the light only came on after some work was done on my front left wheel...he had to remove the wheel and the brake calipers to do the repair. It is such a coincidence that I have to think the sensor got bumped out of place, but I am asking this question in here since we are about to be on the road for 6 weeks and I want to have a plan if indeed the ABS light comes back on.

Daveinet · 06-05-2018, 07:33 PM

It really depends on what RPM the engine runs at. Under normal conditions, the engine turns too slow to prevent TC stall at cruising speed. My advise would be if it ever happens, just flip the OD switch. Yes, your mileage will suck, but you won't overheat the trans. As long as the engine is turning above 2500 RPM, you would likely be OK.

You can watch your RPMs as you lean into the throttle If the RPM seems to change with small throttle changes, then you are below stall speed, and are being hard on the trans.

cgreer00 · 06-06-2018, 08:01 PM

Thanks for the advice everyone. I called Allison and talked to a mechanic. He said that it shouldn't cause any immediate damage but to take it in to an Allison shop the next chance you get to pull the codes and see what's going on. That is what we will do if it pops up again while we are on our trip.

Forkyfork · 06-07-2018, 07:33 AM

Quote:

Originally Posted by cgreer00

Thanks for the advice everyone. I called Allison and talked to a mechanic. He said that it shouldn't cause any immediate damage but to take it in to an Allison shop the next chance you get to pull the codes and see what's going on. That is what we will do if it pops up again while we are on our trip.

If you aren't using I TPMS I would start using one. Two of us posted the warning shot to a caliper lockup was an ABS light. On mine removing the sensors and cleaning cleared the error. Then the caliper locked up in the next 100 miles.

If you haven't been bleeding the brakes yearly and changing the fluid every 2-3 years you need to keep an eye out for calipers sticking or dragging after hard braking. Three forum members had locked calipers around the same time. I was one of them. Motor7 tire caught on fire from his locked caliper.

I started using a TPMS after replacing the locked caliper and it alerted me to a slightly dragging caliper on the front wheel. That could have been catastrophic had the tire blew from excessive heat.

The ABS sensors are available. If you are concerned they appear to be a simple change out. I would carry one.

raggedyedge · 09-09-2019, 05:54 AM

Do not just pull the ABS fuse. Allison transmission may be expecting data.

From TruckTransDiag.com rep:
"No abs signal will mess up the trans, its looking for it, The only way to disable it would be to bring to someone who has reprogram capabilities and have them shut off the ABS in the tcm. But im betting most wont due to liability. an Allison dealer is capable....It may shut off lock up as well and cause overheating and destroy the trans."