Automatic Grade Brake on Allison 1000...

[Capt Joe]

I have a 2004 Winnebago on a 2003 Workhorse W20 chassis with an 8.1/Allison (5 speed). It does not have the Automatic Grade Brake...only a switch to turn the overdrive one or off.

Have been doing some reading about the AGB and was wondering if it was possible to add this feature to my Allison transmission? Anybody done this or know if it can be done?

In my 'research', I have been reading the Allison website as well as talked with the folks at Winnebago, Workhorse, Allison and the local Allison dealer/service center...and have not gotten a good answer yet. The top mechanic at the local shop was real nice but was not even aware of the AGB feature.:? He offered, if I will just bring our coach by the shop, to hook up his computer to it and read out the control module info to see it there was just a 'switch' to activate it. Also said he would contact Allison to see if there was a program flash to change the parameters to add it. Right now that looks like my best bet to continue my research.

BTW, I understand that the AGB was/is an option on WH chassis. Anybody know anything about that and what the approx cost was to chose the AGB? The Allison site said it was a software function without any mechanical hookups necessary.

Thanks for reading all of this. Any and all info would be greatly appreciated,

[DriVer]

Quote:

Originally posted by Capt Joe: Any and all info would be greatly appreciated,

Capt Joe, In the spirit of "any info" may I offer that what you are looking to accomplish I believe would be to install a Transmission Grade Brake or "TGB".

I am not at all sure it can be retrofitted. Please do keep in touch.

[Capt Joe]

Driver,
Thanks so very much for your 'Any and all info'. It should be very helpful.
Any idea as to where one might obtain this 'TGB' you refer to??? To include compatibility and installation instructions? Or might it be best to just jack up my current coach and run a new drive train under it...
I honestly don't know if it would even be worth paying very much to do a retrofit as I feel I can get pretty much the same results by using the shift lever....although the guy I talked to at Allison today said the Grade Brake did have some lock-up features you didn't get with manually selecting a lower gear with the shift lever.
Thanks again for your reply...

[FLYTYER]

Is the TGB the same as the Transmission Engine Brake? If so, it appears that it can be an add-on.

Look HERE

[Max Hubrich]

FLYTYER,

Thanks for the link-- Very interesting.

I couldn't get the link to come up through AOL, which I use all the time. I went to irv2 through Internet Explorer and it came right in. I only mention this because other AOL users might have similiar problems--- I've learned to do this over the years.

Please keep us posted Capt Joe.

[Capt Joe]

FLYTYER,

Thanks for finding that document. That looks like just what I'm looking for. I've printed it out and will take it to the local Florida Detroit Diesel-Allison shop and see what we can come up with.

The info I have been working off of called it an Automatic Grade Brake but most of that info refers to the feature with the Allison 1000 mated to a Duramax. Maybe they call it a Transmission Engine Brake in the heavier chassis.

Thanks Again,

[Clay L]

Back in 2005 when I talked to Allison customer service they said retrofit was not possible, however looking at the info on the site referenced by FLYTYER it sure looks like an add-on kit is available now.
Please let us know what you find out.

[oemtech]

If you look at the PDF it indicates an "Exhaust Brake" switch... indicating "Diesel" not gas powered vehicles.

[FLYTYER]

The Allison PDF really shows a exhaust brake for the 1000 series and an engine brake for the 2000/3000 series.

Take it to an Allison shop and get the real answer.

[Capt Joe]

Dale,
I did see the reference to exhaust brakes on the Allison PDF and was wondering if it would be applicable to the 8.1 gasser too.

The PDF also refers to single and multilevel compression brakes and I'm wondering if that might not be related to compression braking as you have with the 8.1 gas engine.

Glad you have tuned into this thread and would certainly appreciate any other imput you may have.

Have you, in your years of experience, worked with the Grade Brake on the Allison 1000? I plan to get by the local Allison service center in the next few days to show him what I've come up with and see if he can shed any additional light. I'm not sure it would be worth paying very much money to retrofit (if possible) my existing MH with the Grade Brake but if it could be done fairly reasonably I would probably do it to get the convenience of it and the converter lock features.

Thanks Again,

[Capt Joe]

FLYTYER,

You may be exactly right. I do plan, hopefully tomorrow, to take it by the Allison shop to get it checked out and will post my findings.

It does, on the PDF, show the exhaust/engine brakes as you said on the 1000/2000 and the 3000/4000 product families. It does seem odd, tho, that they are indicating the exhaust brake application on the smaller transmissions and the engine braking on the larger 3000 and 4000 ones. But, there are sure a lot of things I don't really understand or have knowledge of about these brakes, etc.

Maybe their experts and specialists can explain it in such a way that I can understand.

I have had one of the dreaded W20/22 brake failures on my coach and would like to try and reduce the wear and tear on my service brakes if possible.

[Richard 34A]

I have the Grade Brake and use it, but based on what it might cost to have it installed, is it really that much different than manually downshifting the transmission? Most likely, you don't start down the grade in high-geaar (5th) anyway and after tapping the brakes (which is the process to have the Grade Brake downshift) you could manually go to third, or from third to second on a steep grade. The Grade Brake is a great feature but manually downshifting already is available 'for no additional charge'.

[CoastieSCPO]

Recently, when we had the Allison 1000 replaced, I asked the Detroit Diesel Allison dealer if it came with a tranny grade brake. He told me that it was not possible to add one to this particular transmission. It is my understanding however, that the push button grade brake just does automatically what a person does manually with the shift lever.

[millsrv]

Hi, I agree with Richard 34A. I also have the grade brake on my W24 Chassis Allison 2100 and although it works fine so does manually down shifting. Keep in mind that the grade braking feature will not allow engine overspeed, you will need to watch the engine RPM when manually down shifting. In additon the transmission torque converter will make alot of heat on down grades (out of lock-up). A transmission temp. gauge is a very good addition.