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Topic: Allison Retarder (Read 618 times) previous topic - next topic

Allison Retarder

For the 1993 model year, was the trans retarder standard on the U240 Unihome with Caterpillar 3116 and Allison Transmission?
TIA

Re: Allison Retarder

Reply #1 –
I dont think there was a retarder or jake on 93 u240

Re: Allison Retarder

Reply #2 –
Thank you. I can't believe they didn't put the retarder in, as this is such a great help descending the steep grades out here in the West.

Re: Allison Retarder

Reply #3 –
Quote from: rinron –
I dont think there was a retarder or jake on 93 u240

No mention of either in the 1993 spec sheet or the options sheet

https://wiki.foreforums.com/_media/through_the_years:1993-u225-240-gv-specifications.pdf

Retarder is shown as standard in the 1995 U240

https://wiki.foreforums.com/_media/through_the_years:specs:1995-u240gv-specifications.pdf

1994 appeared to be a transition year, but I think that was only for the U280/U300.  No mention of jake or retarder for the U225/U240 (but we don't have a scan of the actual spec/options sheet for 1994)

1994 Foretravel Specifications

Re: Allison Retarder

Reply #4 –
Quote from: Michelle –
No mention of either in the 1993 spec sheet or the options sheet

https://wiki.foreforums.com/_media/through_the_years:1993-u225-240-gv-specifications.pdf

Retarder is shown as standard in the 1995 U240

https://wiki.foreforums.com/_media/through_the_years:specs:1995-u240gv-specifications.pdf


1994 appeared to be a transition year, but I think that was only for the U280/U300.  No mention of jake or retarder for the U225/U240 (but we don't have a scan of the actual spec/options sheet for 1994)

1994 Foretravel Specifications
Thank you. I was very much hoping that it would have the retarder.

Re: Allison Retarder

Reply #5 –
Our '93 U280 came from factory sans retarder, but the original owner (first of 5) installed an exhaust brake.  We have traveled from Texas to Oregon/California a number of times, and encountered some long/fairly steep downgrades on various mountain routes.  I found our exhaust brake provided a very noticeable and worthwhile speed control assist, resulting in little need for service brake application.

Link below to a brief description of my personal experience with the exhaust brake on our coach:

How important is the transmission retarder?

Edit:  The Super Duty D-Celerator exhaust brake on our coach is long out of production, hence the link in my post (linked above) is dead.

Just throwing out "exhaust brake" as a possible alternative to the missing retarder on older coaches.  Current product examples below:

C40119 - Pacbrake PRXB Exhaust Brake Caterpillar 3116 / 3126 4" Inline

Welcome | Bundy Motors

Re: Allison Retarder

Reply #6 –
Thank you very much. I just confirmed that the U240 I'm inspecting does not have the retarder, which I came to rely on with my U300. I will definitely read this material and look into acquiring the engine brake.

Re: Allison Retarder

Reply #7 –
The 240 we had was equipped with the exhaust brake. It worked verry well on all of our trips. One thing to note is if you go with the exhaust brake you will need to check the engine info to see if you will need to upgrade the valve springs.

Mike

Re: Allison Retarder

Reply #8 –
U240 with transmission retarder?  MAYBE.

Our 1993 U240 had an exhaust brake.  The PacBrake PRXB was the upgrade we did.

But, our close friend's 1994 U240 did have a transmission retarder.

No idea if his was a custom order or if standard at which chassis number the change was made.

We found the PRXB brake to be effective for mountain driving.

Re: Allison Retarder

Reply #9 –
Quote from: wolfe10 –
U240 with transmission retarder?  MAYBE.

Our 1993 U240 had an exhaust brake.  The PacBrake PRXB was the upgrade we did.

But, our close friend's 1994 U240 did have a transmission retarder.

No idea if his was a custom order or if standard at which chassis number the change was made.

We found the PRXB brake to be effective for mountain driving.

Thanks very much.


Since posting the question, I was back at the coach and verified that this one lacks the retarder. Chuck kindly sent me the link to various engine brakes including the PRXB, and I believe that is what I will go with. I'm still looking into potential engine issues, but I am literally surrounded by steep grades I have to negotiate on any trip out of the area, and had come to rely on the retarder on my DD/Allison configuration.

Re: Allison Retarder

Reply #10 –
Again, we found the PRXB to be adequate, and we did a lot of steep mountain driving, particularly in the mountains of Mexico.

Also, as suggested, limiting toad weight and have brake system on the toad.

BTW, per your Private Message, your 33" ride height at all wheel position is great.  It is actually the highest you want.  Subtracting the ride height shims RAISES ride height.  With 32-33" being spec, no worries.

Re: Allison Retarder

Reply #11 –
Quote from: RandallBrink –
Chuck kindly sent me the link to various engine brakes including the PRXB, and I believe that is what I will go with.
That link I posted to the PRXB was just an example.  Check for the best current price from all the online vendors before you order.

Re: Allison Retarder

Reply #12 –
Quote from: Chuck & Jeannie –
That link I posted to the PRXB was just an example.  Check for the best current price from all the online vendors before you order.

I will do that. Is that something I should be able to install or should I plan to have CAT do it?

Re: Allison Retarder

Reply #13 –
Quote from: RandallBrink –
Is that something I should be able to install or should I plan to have CAT do it?
Of course, I did not install my exhaust brake, but I've worked on it and am familiar with the basic components.  So take my comments for what they are worth...

The basic mechanical exhaust brake "valve" assembly is installed in the exhaust pipe just downstream of the turbo exhaust outlet.  This will require cutting a section out of the 4" exhaust pipe.  Not a simple task, but probably the easiest part of the installation.

The tricky part will be installing the electrical components and the air supply to the activation cylinder.  There will be several control devices (switches) that must be mounted in the driver area.  There will be a wiring harness that must run from the driver compartment back to the engine.  The air supply must be tapped off a nearby part of the coach air system and a pressure regulator added.  There is usually some electrical coordination required between the exhaust brake controller and the coach throttle and/or braking system.  The exhaust brake controller may also require an interface with the transmission .

In my opinion, if you can find a shop that is experienced doing the installation of the PRXB, then I would go with a professional installation.  This is not to say it can't be done by you, but I think it would be a pretty complicated DIY project.

Try going to the Pacbrake web page I linked earlier, and see if they have a online copy of the installation manual.  Might give you a better idea what's involved.

 

Re: Allison Retarder

Reply #14 –
Thanks very much—will definitely go with the prifrssional installation.