Lost 3rd gear?

[TechnoWeenie]

Need help. Won't shift out of first. In parking lot.

So, I parked my truck for 2 days, got back in it, and as I'm driving I noticed that it will shift from first to second but then it will stay in second until about 35 mph...

Eventually it shifts. But it seems like the third gear is completely missing it's like it's 1245.

What could have changed overnight to make that happen?

Edit: updated to 'help' thread due to being stuck.

 

[TechnoWeenie]

Update: less than 30 miles later...won't shift out of first, just flares.

Fluid has about 4k miles on it. Proper level, and doesn't smell burned.

 

[73m819]

Drain the fluid, see what comes out, drop the pan and see what has been deposited.

 

[TechnoWeenie]

I'll see what I can do about getting a catch pan that holds 5 gallons. I don't think Safeway would appreciate me dumping fluid in their parking lot.

 

[162tcat]

Pickup loose so it's not getting fluid?


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[162tcat]

Where in WA are you located? I may be able to assist if you need a tow


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[simp5782]

Do you have reverse? If you have limited to no power when you put it in gear I would pull your modulator cable off at the pump and pull on it. Maybe the cable broke as well. This would cause no pressure that the transmission needs to move. One of my customers took the liberty to replacing his " not moving" transmission and it ended up being the modulator cable after it didnt move with the new transmission.

Also try putting the transfer case into low range. It doesnt take much pressure to move the truck then. I blew a transmission while on the road. just quit pulling all together. Put it in low range and i was able to shift 1 thru 5 no problem. it slipped a little but would pull and was able to get it 5 miles down the interstate.

 

[TechnoWeenie]

I appreciate your guidance.

I was able to pull the pan.

There is, what I would describe as a normal amount of gray ooze. That has been present in every transmission I have ever dropped the pan on. There's a little bit more that I'm used to seeing, but I'm also used to dealing with passenger vehicle transmissions that are pushing a 4000 pound vehicle in only hold 6 quarts, not a truck pushing 40,000 lb, and holding 17 quarts.

There was a ever so tiny pile of about 10 tiny black flakes. Smaller than an eraser head. If I had to guess, I'd say that they had been there for a while.

I'm waiting on a call back from a local Allison Guru. I also have a couple people that are local that have tow capabilities that are willing to help out.

I will pull the modulator next. Thank you for the assistance.

 

[TechnoWeenie]

I have first and reverse.

 

[TechnoWeenie]

Looking from the pan to where the modulator is Mountain, there is a piece of metal coming from the modulator that looks shiny as ****. In my experience, shiny metal in an environment like that, means that something is rubbing against it.

 

[TechnoWeenie]

Having talked to the Allison guy. It seems that the modulator is fine. The next step is the governor assembly. However, I can't tell what's normal and what's not with the governor assembly. It seems to be Mighty floppy.

 

[TechnoWeenie]

This material was stuck in the filter. 3/8 drive 1/2" socket for size reference.

 

[TechnoWeenie]

Pickup loose so it's not getting fluid?


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I put a new filter in. Old pickup tube did not have an oring on it. TM shows it's supposed to be there.

I'm waiting for a ride to get fluid and another external filter.

 

[TechnoWeenie]

So, I replaced both the internal and external filter. I drained a hair under 5 gallons, and replaced it with Dexron 3. Got it to temp. Shifts into reverse and first just fine, but I was not having issues with that before. Did not have a chance to road-test it just yet but will give an update when I do

 

[TechnoWeenie]

Still exhibiting the same characteristics of not wanting to up shift from 1 to 2. However, on a nice downhill slope, I switched it from first gear to 5, and once he got past 2nd gear, it engage 3rd 4th and 5th and downshifted, with a distinct absence of second gear. So, if this transmission uses a clutch for each gear, which I think it does but I could be wrong, then I'm pretty sure the second gear clutch is completely shot.

 

[simp5782]

Did you try low range? It let's it build up pressure faster and will allow better gear shifts

 

[TechnoWeenie]

Did you try low range? It let's it build up pressure faster and will allow better gear shifts

Won't shift out of high.

I remember I had a **** of a time getting into low last time I tried...

I can hear a faint click where the solenoid is but not the usual 'thunk' that you'd expect