All,
I was driving my 1994 Grandvilla U280 in Houston Sunday. I stopped to rest, and when I got back in the vehicle to leave, the transmission would not go into gear. I tried for over an hour.
Symptoms: Pressing the "D" or "R" buttons would just produce a flashing "D" or "R", and a long steady beep from the transmission controller. I tried many combinations of things. RPMs were at 600, suggesting that wasn't the reason it wouldn't engage (over rev wasn't a problem). I tried the boost to increase voltage - that also wasn't successful. The house and chassis batteries, though, were fully charged before I left, and are all less than one year old, so I have confidence in them. I tried with the generator running. Same result.
Research suggests is could be many different things including the ECU. Weather was warm that day, and I haven't been anywhere cold, so I doubt using a hair dryer on it would make too much difference but I could try.
I had to have the vehicle towed back to my home in south Houston. Fortunately, I'm covered for that on my insurance.
In order to tow it, however, the tow truck driver had to pull the axle from the driver's side rear wheels. After doing some research, this appears to be normal (who knew? - I had to look it up). However, he says one of the wheel lugs (on the vehicle, not the lug nut) is moderately damaged. They could get the lug nut off, but says it probably needs to be re-threaded.
Lots of questions now:
1) The vehicle is parked in front of my home in Houston. I guess the first thing I need to do if find someone who can look at the Allison transmission. It is an MD3060 mated to a mechanical Cummins 8.3. Any suggestions in the Houston area?
2) I have the axle - very oily! I'll need someone to re-install it after the transmission is repaired, and will also need someone to look at that thread on the wheel lug. Also, any suggestions in the Houston area?
As always - thanks to everyone on this board for their help!
Mark
#2. Did the tow truck driver pull the driver's side axle?
Both axles should have been removed. How far was the tow? Hopefully the spyder gears turned enough to not damage the transmission.
The tow truck driver pulled one axle only - driver's side. He did not pull both axles. The tow was about 45 miles. Any possibility this could have damaged my transmission?
Thanks
Mark
Mark, I have sent you a PM.
For repair of your ECU/shift pad: Transmission Instruments (http://www.transmissioninstruments.com/)
That is all John does for a living. In the DFW area.
Don't know. Don't know anything except that the lug nuts on the drivers side have left hand threads.
And unless you have a posi rear end, one axle is enough for a short slow tow.
It's usually just the spider gears in the rear end that will be damaged. The reason they sell two hub plates only in pairs is that you need to remove both axles. The spider gears don't have roller bearings but bronze bearings and are only designed to move when you go around a corner so they are not lubricated properly when spun without the ring gear turning. Drag racers spinning the right rear tire can damage them. The problem is that the damage done may not be apparent for quite a while. So, long after the tow truck driver is gone. Just imagine how many revolutions they have made in 45 miles.
After a little argument with another forum member, I called the Spicer headquarters and talked to one of their engineers. He said both axles MUST be pulled, not one. Here is the address for the caps and gaskets. You will notice that they are only sold in pairs. Price List (http://www.axlecap.net/price-list.html) Cheap insurance against damage plus they keep the oil from making a mess.
Pierce
Craneman added a bit to my spider gear explanation. Depending on the resistance of the spider gears, the driveshaft may still spin and could damage the transmission output bearing because of lack of lubrication. Had not though of that.
Hats off to Chuck.
Pierce
All - thank you very much for the insight. I an Allison repair tech coming to the house on Thursday to have a look. He asked me over the phone to do some simple diagnostics on the shifter, and it came back with no error codes. He says that tells him a great deal about where to start looking (not at the shifter), and instead, spoke about a few other things it could be. He said the MD3060 is his favorite transmission because it is easy to diagnose and fix. I'm looking forward to the conversation with him and will ask him about the spider gear, second axle, and whether I might need to replace the spider gear now that it was towed. I'll also ask about the potential for any other damage. Once I have more insight, I'll report back what he found.
The adventure continues!
Mark
Assume he asked you to check for diagnostic codes using the shift pad. Were you able to perform that function, given the issues you are experiencing? Were there any-- if so what?
Yes - he asked me to push the "up" and "down" arrows simultaneously, and then read the resulting code back to him. The code was "d 1", which he says means there are no errors. That is how he concluded the problem was probably somewhere else.
Since I've not read yet about how the diagnostics for the shifter works, I can only take him at his word, but now I'm really curious about what diagnostic codes can be represented this way and what they all mean. It sounds like something I should print out and have handy in the coach for future reference.
Mark
Defendertx,
What was the air pressure readings when you experienced the flashing R & D ?
Have you tried to move the coach since it was towed home?
If so, same result?
Yes, an Allison diagnostic code of d-1 followed by a - - DOES mean there are no diagnostic codes stored in the Allison ECU. Were there codes it would show d-1 followed by two digit codes.
EVERYONE with the Allison electronic transmission needs to know how to check for codes. Not a bad idea to do it a couple of times a year.
From the driver's seat:
Ignition ON engine OFF
Push up and down arrows at the same time. On older units that will bring up d-1 and the first of any stored codes. On newer units that will bring up OL (oil level). Merely push the up and down arrows again at the same time to get to d-1.
If there is a d-1, copy down the numbers to look up in your Allison owners manual or on their on-line site. Then push the mode button to scroll to d-2. repeat until you get d- "whatever" and - -.
When you are finished, just turn off the ignition. You are finished and the ECU is back to its normal operation (yes, assuming there is not some failure keeping it from working).
Allison codes: Allison Transmission 3000/4000 series fault code list | Truckmanualshub.com (https://truckmanualshub.com/allison-transmission-3000-4000-series-fault-code-list/)
P
I've gone through this problem for over two years in a Dynasty, some time it would work some times it wouldn't. Allison tech said
it's a safety lookout, RPM to high or too low, jacks down or anything the manufacture added. There is a wire that goes from the
positive post on the chassis battery that goes to the EUC that I would check. I don't think that is your problem but it's worth a check.
Actually, there are TWO positive wires to the ECU-- one for stored memory and the other for ECU operation/driving that is hot when the ignition is on. Certainly on our 1993 there were two separate fuses in the "under driver's side corner of the lift up dash" labeled as such.
Justin and Cathy,
When the problem with the transmission occurred, air pressure was at 110 lbs - which is nominal for my coach.
Thanks
Mark
Ran into the same thing, maddening problem. Finally found an old trekmate security system.....which was tied into the transmission interlock. Removing it solved.
Anyone know what set I would need to order for my coach? Is it the lug nuts that need to be counted? I have ten lug nuts so would the MR10D be the correct one and does the gaskets come with them?
Thanks
Ron
I think that is the one but give them a call. No, order the gaskets separately. 410-784-7029 (NEW PHONE NUMBER)
Pierce
Reply #15 should be the one you want
Axle Caps (split from Going down highway and white smoke coming out) (https://www.foreforums.com/index.php?topic=20620.0)
Woke up too early this morning. Count the number of axle nuts and measure across like Craneman's link did.
The post Craneman links to is a coach that used a model MR8D-1 with 8 axle nuts but if you have 10 axle (not lug nuts) nuts, you may take the model MR10D. Call them.
The big chrome cover has to come off to remove the axles. This means removing 5 of the lug nuts (on our 10 lug rear axle) to get the cover out of the way. A torque multiplier may dent the chrome cover so you might try and see how it fits before you actually have to remove it. Tow truck driver will probably have a socket with air gun so not a problem. If you don't have the cover on, you can pull the axles in a couple of minutes with an electric impact on the small nuts. Coach should be level or oil will come out on the low side.
Pierce
Changed the rear axle to covers over the hubs center only. Not attached to the lug nuts
Smart! Still have a memory of where you purchased it? I did see this video and with a stainless cover, it looks like an instant on and off. Is this like yours? AMERICAN CHROME 16903 rear stainless steel axle hub cap 7.25" (lot of 2) | eBay (https://www.ebay.com/itm/AMERICAN-CHROME-16903-rear-stainless-steel-axle-hub-cap-7-25-lot-of-2/161769120229?epid=22003417376&hash=item25aa30e1e5:g:AK4AAOSw9N1VrTAo:sc:USPSPriority!95949!US!-1)
Or: 8" Diameter Rear "Dome" Hubcap - Stainless Steel Rear Hubcaps - Rear Hubcaps... (https://truxaccessories.com/universal-accessories/wheel-accessories/hubcaps/rear-hubcaps/stainless-steel-rear-hubcaps/rear-pointed-hubcap-8-diameter)
Video of how they attach:
https://www.youtube.com/watch?v=3j6sMp4DGfQ
Update!
I had an Allison transmission technician look at my RV today. He connected a computer to the diagnostic port on my RV (very interesting, by the way!), and looked at many different parameters of my transmission. The good news, my transmission is squeaky clean - from the diagnostic codes to the clutch packs (five evidently - I didn't know that), and even the synthetic fluid is in great shape. Apparently, the problem is NOT the transmission.
In the process of doing the diagnostic, one of the pieces of information he was able to see was the Throttle Position Sensor (TPS). Evidently, it was reading "50%", even though the engine was idling at 600 rpm. He said that was very likely the culprit. So, he removed it, and said the cable wasn't sliding easily in and out of the sensor, which is evidently a simple mechanical variable resistor. So, the diagnosis is to simply replace it.
In the process of watching him and asking him questions, I learned quite a bit about the engine and transmission. It isn't such a mystery to me anymore how it all works. Another thing I learned about is that rectangular diagnostic under the dashboard. He says it is sort of like an "ODB-1" or "Pre-ODB" connector. I want to learn more about this because from what I saw, it appears it can provide quite a bit of important information. Anyone know about that port and the kinds of data I can get from it? I'd really like a connector linked to a laptop of tablet so I could read that information.
I suspect he will be back with the part early next week and then the saga will continue. Expect another update from me after that.
Thanks everyone for your help!
Mark
Mark,
You probably have a mechanical Cummins 8.3, correct? The OBD connector is either flat in one row over the other or a round connector. A Pro-Link 9000 will connect to your computer on your transmission. The Pro-Link reader is usually available on ebay for not that much $$ but the Allison cartridge that slides in the back is a bit more rare and expensive. The Ford/Chev cartridges are only worth $5 or $10 where the cartridge for Detroit Diesel DDEC I, II, III or IV and are at least $75 to $200. Cummins are even more. Ask the shop about the Pro-Link 9000.
Here is what the Pro-Link looks like. They have been out of production for quite a while but work well. Cartridges were made for Allison, Meritor brakes, MBZ, Mac, Volvo, CAT, etc. https://aepsurplus.com/custom/auctionArchiveDetail.cfm?aID=1198
Here is the cartridge Allison World Transmission owners are looking for. Cheap at $200. NEXIQ MPSI Pro-Link ALLISON WORLD TRANSMISSION Diagnostic Cartridge 201009 |... (https://www.ebay.com/itm/NEXIQ-MPSI-Pro-Link-ALLISON-WORLD-TRANSMISSION-Diagnostic-Cartridge-201009/333160397402?hash=item4d91e83a5a:g:g3gAAOSwdzRamvkU)
Here are the Allison fault codes: Allison Transmission 3000/4000 series fault code list - Truck manual, wiring... (https://www.pdfmanual4trucks.com/allison-transmission/allison-transmission-3000-4000-series-fault-code-list/) The Pro-Link 9000 does more than read the codes and can change certain operating peramaters but since I don't have the cartridge, I can't tell which ones. Your shop knows.
Pro-Link 9000 Allison cartridge user manual: Nexiq Pro-Link Allison Transmission Cartridge User Manual Prolink | eBay (https://www.ebay.ca/itm/Nexiq-Pro-Link-Allison-Transmission-Cartridge-User-Manual-Prolink/333143262989?_trkparms=aid%3D1110001%26algo%3DSPLICE.SIM%26ao%3D1%26asc%3D20160323102634%26meid%3Dafd4c3816a8b4c08aea1be7dd5baf552%26pid%3D100623%26rk%3D1%26rkt%3D5%26sd%3D333143262998%26itm%3D333143262989%26pmt%3D0%26noa%3D1%26pg%3D2047675&_trksid=p2047675.c100623.m-1)
Pierce
Kev,
While the truck driver is correct that uncoupling the driveshaft will eliminate the possibility of transmission damage, it has it's own set of problems. First, it may be difficult to get under the coach to unbolt the shaft. If it is done, it's easy to lose a fastener between this operation and putting it back together days or weeks later in the shop. Yes, needle bearing may fall out and may be hard to find in the dark and did the driver index the driveshaft so when it is bolted back together, it will operate without any vibration? Not all shops will torque the shaft correctly.
So, with all these possibilities, it's so much easier to spend the $39 for the poly caps for the hubs and pull BOTH axles. No chance of a mistake and faster too.
Pierce
Agreed, twice had tow, once when first bought FT with bad fuel lines, and once w/Monaco. Each time, driver had to use mallet to remove u-joint, damaging the u-joint. Doing install both times, tech recommended replacing u-joint, which I did.
Please post link to $39 poly caps. I want to carry a pair.
Look at axlecap.net
Ken
Axle Caps (Meritor/Rockwell 8-Bolt) (https://newtowtrucks.com/i-10397-axle-caps-meritor-rockwell-8-bolt.html)
Probably a good idea to buy the gaskets too. $12 for quite a few at: Gaskets for 10 pc.Motorcoach Set (http://axlecap.net/store/p51/Gaskets_for_10_pc.Motorcoach_Set.html)
P
for those interested.............. the caps listed in Craneman's link are 8 bolt pattern and the gaskets listed in Pierce"s link are 10 bolt.
Just didn't want someone to order both thinking they were the same bolt pattern.
Craneman per the link you attached in reply # 31 I would assume your 99 U320 is the 8 bolt pattern?? I want to order some for my 99 U320 but without looking at the unit I am unsure if it is the 8 or 10 pattern.
I think this is a set of gaskets for the 10 piece cap set, not ten lugs. In other words, there are 20 gaskets for the 10 different pairs of caps. I was exchanging emails with Craneman today and he thinks each set of two caps comes with gaskets. Makes sense and I will call the company tomorrow. The pictures are good but the wording leaves a little to be desired.
P
Maybe so............ I just noticed the gaskets had 10 holes and the caps had 8, two different bolt configurations.
Chuck,
Your coach will be an 8 bolt. You will need the MR8D-1 for the 5/8" studs that your axle has.
Price List (http://www.axlecap.net/price-list.html)
Mike
OK, problem solved. I called Wayne Olson at Froxlor Server Management Panel (http://www.axlecaps.net) and asked him about the covers. Chuck was correct in that all cover pairs come with gaskets. Extra gaskets are about a buck. He suggested that once the caps are received, the gaskets could be siliconed to the back on the cap so it would be ready for use and not have to look for the gasket when the occasion arises. He also said that most Foretravels will take the MR8D-1 cover.
Contact:
Wayne Olson
Olson & Company
23664 KEEN RD
CHANCE, MD 21821
PH: 410-784-7029
info@axlecap.net
Pierce
So I've got 10 lugs holding wheel on and only 8 holding the axle in place?
Yes. Most of us do.
I made my own out of cutting boards, then made the gaskets out of the correct material and siliconed them in place. Total cost about $4
JohnH
The axle is not carying the weight, the wheel bearings are.
You have 10 lug nuts holding the wheel onto a "hub" with two big bearings carrying all the weight and shock Gs from potholes, etc. plus lateral force. The axle just sits there with the much smaller studs/nuts having to carry the twisting force from acceleration, etc. It's almost along for the ride.
So what is the misconception? Good question. In most cars and half ton pickup, the axle carries the weight of the car and if it breaks out at the end, the tire/wheel/end of the axle all flop down on the street and the vehicle may crash. They are not so easy to change as the bearings are just pressed on in some cars, others have a snap ring holding the bearing in place. If a car is overloaded, the axle may slide out and hit the fender well. The reason for the snap ring. Full floating rear axles have two bearings that I mentioned above, a big plus.
The 3/4 ton trucks (even Austin Healy Sprites) have the "full floating" hubs. On anything over a half mile track, stock cars have to have full floating hubs so if the axle breaks, the car just stops but nothing falls off. My race car had semi-floating rear axle, a little lighter and less unsprung weight so a few hundreds of a second faster per lap but I could not race on the big tracks like Riverside, Ontario. The brother car to mine did have the full floating rear end so could race anywhere.
Here is a good video showing the difference between semi-floating and full floating rear axles:
https://www.youtube.com/watch?v=VFu-6tckyc8
Pierce
In an emergency, cardboard could be used to cover the axle open end after removing BOTH axles. Something is needed to keep rear axle gear oil from leaking out.
But we carry Axle Caps.
All - an update:
Though a forum member, I was able to contact a transmission technician who came to my home to look at and repair the problem. As I mentioned earlier, it appears to be the TPS (Throttle Position Sensor). After that component was replaced and calibrated, everything seems to be working fine. For anyone interested in knowing more about who I used for this service, please reach out to me directly. I was very pleased with the service from this individual. They even spotted something else on my engine that, while not urgent, probably needs to be addressed. They appear to be very knowledgeable and easy to work with, and I found the cost reasonable given the fact that I didn't have to tow the vehicle anywhere.
Next step is to take the RV into Houston to have to axles removed, re-seated with new gaskets, and some minor engine work done.
A big thanks to everyone on this forum who educated me through this process. I'm especially grateful Rudy for generously giving his time to help me.
Mark