Packed snow preventing me from shifting Allison?

[c5dura]

Yesterday I drove about 10 miles through virgin snow that was about 8-10 inches deep. Temps were hovering around 30F.

When I got out on the main road, I followed traffic moving very slowly down a steep grade, so I tried to shift the Allison down into 1 or 2, but I wasn't able to get it down past 3rd. It felt like there was some sort of mushy resistance.

This morning, after backing up the truck, I was barely able to get the Allison into drive, as I was once more feeling that mushy resistance. Temps were right around 26F.

I got snow packed all up underneath the truck, so my thinking is that is the cause of the problem. Has anyone else experienced this and short of waiting for everything to melt, is there anything I can do about it?

[RVC]

Had a similar problem, could not get trans. into lower gear after driving through some drifts. Took a screw driver slid underneath and started chipping. Just be careful when you start getting close to the shift cable and the NSBU switch. That or find a heated shop and let it thaw out for 24 hours.

[DmaxMaverick]

This happens, more often with the older design NSBU. Which one do you have? The older one is black, newer is tan.

A quick solution is to use a hair dryer or heat gun to thaw out the nsbu and linkage. Be careful if you use a heat gun, it can/will melt plastic and rubber parts. If you have the older NSBU, upgrading to the newer one will help to prevent this in the future. There have been some complaints of the newer one having a problem in extreme situations, but much less often.

[c5dura]

Thanks. So the area around the NSBU switch is the culprit. I do have the newer NSBU switch. The old one died @20k and was replaced under warranty (the gear indicator stopped working one morning).

Temps are in the mid 30's today, so hopefully the problem will solve itself. It not, I'll likely hose the whole truck down and park it in my heated shop overnight. I try to keep the shop nice and clean, so I don't want to park the 8200# monster in there without getting rid of what seems like several hundred pounds worth of snow and sludge first!

Here's a shop shot from last week when I replaced the engine in the wife's Grand Vitara (engine seized up at 80k due to a spun rod bearing). Thanks Jiffy Lube! No vehicle of mine is ever going back to that place!

[MIKE MOG]

HEY C5DURA,
WHAT DID YOU USE TO INSULATE THAT BARN? LOOKS GOOD, I COULD USE SOME OF THAT IN MY BARN.
MIKE

[madmatt]

nice garage! yes I've seen the snow around the shift selector shaft problem as well although around here it's more common to get the farm trucks come in w/ mud packed in there. for the snow, a heavy shot of brake cleaner will quickly melt it away. for the mud there is no sure cure but covering the problem area in a thick coat of spray lube helps for a while.

[c5dura]

Mike, I just used regular R-11 in the walls and R-19 in the ceiling. I got a 48x30x12 (4-bay) kit from Miracle Truss. Once you erect the steel frame, you add 2x6s for ceiling trusses and 2x4s for the walls. Here is another shot:

[Mike K.]

I think a run-in with some packed snow caused my Allison to leak... I didn't realize the snow caused this at the time, though.

The whole thing started with me towing a loaded two-place covered snowmobile trailer up an icy and snow-packed mountain pass. I was going no more than 20 mph coming around a large corner which then turned into several hundred feet of straight road. I still had the truck in 2WD...

Once I made it around the corner, I accidently gave it a little too much throttle, and the back end started to fish-tail. 'No problem', I thought, just let off the gas, and it will straigten back out. I was going uphill, after all...

Unfortunately, letting off the gas really had no effect, as the momentum of the trailer caused the truck to spin 180 degrees, and firmly plant itself in the piled up snow on the opposite side of the road. The next vehicle coming down the road happened to be an 18 wheeler, who's driver was cool enough to stop and offer to pull me out. That loaded 18 wheeler pulled my truck and trailer out of that 2-3 feet of packed snow like it was a toy!

I was pleased to see there was very little damage to my truck--only a small dent where the trailer hit it lightly during the spin out. But several days after I returned home, I noticed the transmission was leaking. At the time, I didn't put 2+2 together, and didn't think the leak was related to the little incident.

I took the truck to the dealer, and they first replaced the sealing washer where the gear selecter rod enters the transmission, near the NSBU switch. They gave the truck back to me, but after a few days, I noticed it was still leaking.

This time, the dealer took the transmission apart, and found that the rod was slightly bent. I bet the packed snow caused this...

The dealer replaced the rod, the NSBU switch (which was the old black one previously), and the sealing washer--all under warranty!

And that's the story of the ONLY TIME my 2001 Duramax has been to the dealer for a repair.

[Turbo Al]

DmaxMaverick;
Just crawled out from under the nieghbour's 05 yesterday and the NSBU switch was "BLACK" so I wonder if Chevy is STILL putting them in (defective ones) or there has been another change in colour. I put a tan one in my truck last Oct.
Last year I was up North for a week and the Allision was just covered in frozen mud and snow but I didn't have any problems with it on that trip. I think some kind of splash guard is needed for it.
Al

[c5dura]

Hmm, seems to me that gm should have added a cover or shield over the NSBU switch and linkage to prevent this type of problem in the first place.

I've had older 4x4 Chevy's and Ford's and played around with them plenty in deep snow and busting through drifts, etc, and never had a situation where I wasn't able to freely shift between gears.

Guess these $40k+ toys just aren't meant to be played hard in snow or mud?

[oyazi]

Left the snow country 40yrs ago. BUT ~ recall my 57 Buick would get sno packed around the linkage. It didn't hurt anything ~ until that eve/nite and froze solid ~ then, couldn't back out of the parking stall ~ after that time, I would back into the parking place so I could wiggle it enuff to slip it into drive so I could go home.

[MIKE MOG]

HI C5DURA. LOOKS LIKE A NICE SHOP. I HAVE A 24 BY 40 POLL BARN WITH A 13 FOOT HIGH CEILING. I GOT A HEATER LIKE YOURS FROM MY NEIGHBOR FOR FREE. I HUNG TO GET IT OUT OF THE WAY FOR NOW BUT WANT TO RUN A GAS LINE IN THE SPRING. THANKS FOR THE INFO ON THE INSULATION. IM GOING TO DO THE SAME THING. ALSO WANT TO PUT A LIFT IN. I HAVE A 2003 D/A, 4 DOOR WITH AN 8 FOOT BED ALSO A 1970 CUTLASS I WANT TO GET UP IN THE AIR AND BACK THE TRUCK UNDER IT. HAVE A 30 FOOT CAMPER INSIDE ALSO. COULD USE A LITTLE MORE ROOM TO WORK ON STUFF. ANYWAY, THANKS,
MIKE

[royalglen]

Shop is nice but that`s a good looking DOG!!!I bet you don`t have a thieft problem--Like you say though who would steel a GRAND VITARA with no engine!!!

[TSimpler]

Why is my dog (Nitro) in your picture. And you need to feed him, he looks a little small.

Trent

[c5dura]

Shepard's name is Rufus. He's 2 years old and change and weighs in at 80# give or take. He's got a sister that is around 65# or so. How much does Nitro weigh, and how old is he?

Here's another shot of him in the snow from the other day:



Mike, I strung some utility wire across the ceiling insulation as it tended to drop down in places as the staples let go over time. Haven't had any problems with it sagging since.

My truck is fine now btw, just took a couple of days with temps above freezing for the snow to clear.

[ 03-03-2005, 04:19 AM: Message edited by: c5dura ]

[TSimpler]

He is 3 and about 120+ lbs and is a small horse.

The good news is he is very freindly and never cares what the kids do to him. They can wake him from a dead sleep by pulling him into another room by his tail.

Trent