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XCLR8N · 05-29-2016, 07:23 AM

My 1st post here...

I'm hoping I can get some info or advice as to what (if anything) is wrong with my Allison 1000 transmission. I find it hard to believe that this slow shifting thing is not wearing something out.
When I'm going uphill and the tranny downshifts it revs up to a certain rpm and then takes a full second to drop down about 400 rpm (I'm assuming to the convertor lockup). Also when accelerating in second gear the rpm will suddenly drop about 200 rpm halfway through the gear. Any ideas... I doubt this is normal. The tranny oil is bright red (no black), up to the full mark and doesn't smell burnt.
Thanks in advance,
Steve

Skip426 · 05-29-2016, 10:39 PM

First question would be ;
Do you have any records of tune up work , fuel filter change.?
Any engine repairs?
Reasons for the questions , the Allison ECM shift program , shares info from the engine ECM, and poor engine performance , or a bad TPS ( Throttle Positioning Sensor ) can cause all sorts of shifting issues; and the RPM drop in second gear.
If for example the , shift program expects to see a certain RPM at a certain reading from the TPS and the RPM is different from the program then the shifts will be erratic.

Arch Hoagland · 05-29-2016, 11:22 PM

That year came with Dexron iii and the fluid needs to be changed every two years or 24,000 miles.

The spin on filter should be changed after the first 5,000 miles and then as needed. I always change it when I replace the fluid.

I recently changed mine to Transynd at 75,000 miles as I was tired of changing it. I do all my own transmission fluid and oil changes.

Another reason I switched to Transynd was a harsh downshift when stopping at a light, etc. The Transyned cured that problem.

So how many miles are on yours and has the fluid ever been changed on a regular basis?

XCLR8N · 05-30-2016, 09:11 PM

So many knowledgeable people here. Thank you

The unit only has 20000 miles on it. As for service records I didn't get any except for the brake calipers being replaced due to the recall. I believe I'm going to have to assume nothing much has been done to the tranny as far as service goes. I'm sure the tranny fluid is Dexron seeing as it is bright red. As for the engine... the oil was changed when we bought it from the dealer but I doubt they did anything else.
I like to do my own maintenance but the ECM reprogramming is over my head. Do you think it would be wise to change to TranSyn before I take it to the Allison shop or should I let them reprogram it and change the fluid.
The engine seems to run fine, not starving for fuel or stuttering. I'm going to do an oil and filter change, install a new fuel filter and hope I can get the spark plugs out (i would bet they are the original ones.
Thanks again,
Steve

Arch Hoagland · 05-30-2016, 10:31 PM

The transmission fluid is easy to change. The transmission pan has a drain plug so it's just like changing your engine oil. You do NOT remove the pan.

There is a red/orange small spin on transmission fluid filter near the oil filter that should be changed too.

It has a round magnet in the center and that should be cleaned and moved to the new filter.

You'll need to change the fluid twice to get a complete change. Do NOT do a transmission power flush. Allison is very specific about that.

Drain the original fluid into a bucket that has quart measurements on the side. Then refill with that exact amount of Transynd. Mine will usually drain about 11 quarts.

Run it until it is hot and check the level, adding more if necessary. Then drive the RV at least 25 miles or several days. I went on a 2,000 mile trip between my Transynd drains.

Drain it again, measuring it and then fill with Transynd and check the levels. From there you can go a long time, occasionally sending a sample to have it tested.

I suggest doing it yourself...I don't trust anybody when it comes to changing my fluids.

It won't be cheap...about $400 for the fluid and one filter, but it will be right. The filter is about $35 from Allison. I buy from my local Allison transmission dealer in Fresno California.

Skip426 · 05-30-2016, 10:36 PM

Trans service and check the Allison ECM for necessary up-dates is a good idea.
I don't know if Jacobson's still has any service bays for MHs; they were the Workhorse shop. I remember from being in Don Folk's that a coach just wouldn't fit , too bad I used to commute to work with their transmission mechanic.
If a trans service doesn't get the desired results, or the tune up , then don't rule out the TPS , because the CEL isn't coming on . Think of a TPS as a volume knob on an old radio , as you try to adjust the volume , you get scratchy sound, because the engine ECM still sees a signal ; even though it's a poor one ; the CEL won't be turned on, and the erratic signal can play havoc with the programming. The TPS can be tested with a high end OBD II shop tool that takes a snapshot of it's performance while the issues are happening.

XCLR8N · 06-01-2016, 07:03 AM

Thanks everyone,

Skip, do you know anything about Cullens Diesel in Penticton? They are the authorized Workhorse shop close to me.
What I'm planning on doing is do the tune up and then take the MH to Cullens and have them change the fluid to Transyn and run the diagnostic on it, that should update the ECM and would show if there's a problem with the TPS. After the tranny is working correctly I will do the second fluid and filter change.
Skip, where did you live in Kelowna, we used to live on Horak Rd. in Lower Mission. Now we're in Tallus Ridge in Westbank.