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 Trans shifter cable "freezing"?
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Derbybug
Senior Member

USA
59 Posts

Posted - 03/20/2013 :  05:36:39 AM  Show Profile  Reply with Quote
I am running into a problem with several of my ealry 2000's 3800 conventionals. The shifter for the trans will not move. Stuck in neutral and will not move! This morning it was 5 degrees out and the shifter would not move out of neutral. The shifter assembly AND the cable to the trans were both replaced within the last 2 weeks to cure this problem. It has been working fine since replacement until this morning. If I let the bus warm up for a while, it will shift with no problem. It seems like the shifter is frozen but that does not seem logical since there is no evidence of ice build up on the detent or around the cable or on the shifter itself. Any thoughts or ideas? Its driving me nuts

Fastback
Top Member

1500 Posts

Posted - 03/20/2013 :  06:49:58 AM  Show Profile  Reply with Quote
We only have this problem when water has made its way into the shift cable, it can happen to the parking brake cables also. Usually occurs the cold mornings after driving through snow drifts on an afternoon run.
There is/was a tool that you could connect to the top of the shift cable and force lube through till it came out the bottom, I think the lube contained glycol.

Why yes, the ORIGinal CHARGER is a Fastback

Edited by - Fastback on 03/20/2013 06:53:03 AM
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Derbybug
Senior Member

USA
59 Posts

Posted - 03/20/2013 :  09:49:59 AM  Show Profile  Reply with Quote
Do you happen to have a manufacturer name or a part number for the lube tool? We had some serious snow drifts here in south western MN for the last few days, but this is a new cable, so I discounted that as an option. I will look into it. It there a certain spot where water would enter the cable? If I let the bus run for a while, it shifts just fine, so it would appear that it is inside the cab since, outside the cab, everything is still cold.

Safety in all things, always!
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Fastback
Top Member

1500 Posts

Posted - 03/20/2013 :  10:48:17 AM  Show Profile  Reply with Quote
Unlikly moisture could work its way up very far, look for low spots in the cable or near the bottom end, may be just getting enough heat off tranny/engine to thaw.
Sorry can't locate mine and not sure it would work on current cables either. Maybe check with allison tranny dealer or Hoglund bus for solutions, you cant be the only one having the trouble.

Why yes, the ORIGinal CHARGER is a Fastback
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bwest
Administrator

United States
3820 Posts

Posted - 03/20/2013 :  11:16:09 AM  Show Profile  Reply with Quote
I had this problem on an early BB Vison. I replaced the cable, like you did, with limited success. What I finally did was make a shield out of a piece of galvanized metal (such as heating and air guys use) and that solved the problem. I think I'm keeping the water from getting in there in the first place. I'll see if I can post a picture if you're interested. (been a while since I've posted a pic so might take a while. lol)

Bryan
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IBTMech
Top Member

USA
973 Posts

Posted - 03/20/2013 :  3:07:12 PM  Show Profile  Visit IBTMech's Homepage  Reply with Quote
Almost all of our fleet (Public Works, Fire, Parks, Police and School) have automatic transmissions and the Public Works and Fire Dept have many more cable operated functions on top of that. Up here in Maine, frozen cables are a way of life. Even new ones. Humid in the summer, cold in the winter.

I like to spray Fluid Film around the cable ends where I can to help keep moisture out.

If it doesn't fit, FORCE it.
If it breaks, well, it needed replacing anyway.
Pullin' wrenches for 45 years.
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slippert
Top Member

USA
630 Posts

Posted - 03/20/2013 :  7:18:35 PM  Show Profile  Click to see slippert's MSN Messenger address  Reply with Quote
[quote]Originally posted by IBTMech

Almost all of our fleet (Public Works, Fire, Parks, Police and School) have automatic transmissions and the Public Works and Fire Dept have many more cable operated functions on top of that. Up here in Maine, frozen cables are a way of life. Even new ones. Humid in the summer, cold in the winter.

I like to spray Fluid Film around the cable ends where I can to help keep moisture out.


I just started using Fluid film spray, I am impressed with it!! Drivers aren't super liking the smell, but smell goes away in a couple of days...Does work really good and doesn't seem to wash away with water...
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dwight
Senior Member

USA
58 Posts

Posted - 03/21/2013 :  03:21:47 AM  Show Profile  Reply with Quote
John
I've run all Allison's since 1965. I bought the pump kit 30 years ago but I didn't have good luck with the glycol. (The cables became rusty inside and that compounded the problem.) We filled the pump with 10 weight oil and lube from the bottom. It is much easier than fighting the adjustment on the shift lever end and by using oil on a clean cable we didn't have to worry about forcing crud up into the cable and the oil very slowly seeps out the bottom pushing out any moisture. I've been retired for 15 years but I remember stocking the little bellow type rubber sleeve for the transmission end to keep moisture out. In several million miles I've never replaced a shift cable.

The shift & steering cables on my jet boat became very hard to move and I lubed them from the top end by using a small cartridge grease gun filled with 10 weight oil. I adapted a clear hose over the grease gun fitting and slid the hose up over the end of my cable the same way we did with the buses. I used small hose clamps to hold the hose ends tight until I finished lubing.
Let me know if you need a part # for the rubber bellow sleeve.
A fellow Minnesotan

20 SCHOOL BUS FLEET OWNER/OPERATOR (Retired)
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Derbybug
Senior Member

USA
59 Posts

Posted - 03/21/2013 :  04:40:27 AM  Show Profile  Reply with Quote
The new cable I installed has the supposedly "waterproof" boot on the tranny side of the cable to help keep water out of the lower end. Apparently it isn't working as it should.
Bryan, if you get a chance, post the pics so I can see what you are talking about. That may be the way to go.
On a side note, the driver for the bus that is having this problem came in this morning and told me that when she releases the park brake, the trans shifter works fine?!?!?!?!?!?! I couldn't help it but I started laughing. I asked her if she reset the park brake, does the trans freeze up again. She said she only did it once so she didn't know. I highly doubt it will but that it was extremely funny.

Safety in all things, always!
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jeepcjron
Advanced Member

USA
262 Posts

Posted - 03/26/2013 :  08:56:08 AM  Show Profile  Reply with Quote
we have found having the drivers run them through a full motion of d1 to reverse every day helps also.

its like a slinky! useless but fun to watch.
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