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TH400 has no gears

nad

nad

1/2 ton status
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So I traded my K5 a couple weeks ago for this 2WD C30, and I haven't had much time to drive it. Had new exhaust put on it the other day, and when I went to drive it home from the shop, all gears acted like Neutral, then finally Reverse worked, then they were all engaging.

After I parked it in my driveway, now I can't get it to engage in any gear. I checked the linkage, and it's moving all the way down to the transmission. I checked the fluid and it wasn't even showing on the dipstick, so I put about 1 1/2 quarts in it to get it near the FULL line. Still won't engage in any gears.

Also, when I bought this truck, the kid told me the speedometer wouldn't work because he straddled a tire on the highway and ripped the cable, but the cable is completely intact all the way from the transmission to the firewall, so I dunno if this could have something to do with it, and he was just masking the problem from me?

Anybody have any ideas or suggestions?:dunno:
 
was it driving ok prior to the exhuast work?

Check the vacume modulator tube, how does the fluid color look?

If its a C30 the pan should come off easily, try dropping that to see what it looks like in there. Cahnge the fluid and filter. Maybe some valves sticking in the valvebody.
 
Well I drove it maybe twice, about 1/2 mile both times, before having the exhaust work done. And it shifted great gears 1-4, didn't slip or anything.

Where is the vacuum modulator tube? And would this actually keep it from going into gear at all? Everything else I've read about that seems like it just keeps the transmission from kicking up/down through gears.
 
Are you sure you have a th400, theres only 3 forward gears? I wouldn't be concerned with the vacuum tube, if it was off it should just cause the transmission to shift late. I would run the engine long enough to warm up the transmission and check the fluid level again. It could be that the torque converter isn't full.
 
Zimmer jumped ahead on you a little. Those transmissions with the vacuum modulator are bad about having the modulator go bad and letting the engine suck the fluid out.

You pull the tube off and check for fluid. Should not have any.

Is the truck sitting level? You need to get it level and make sure it has enough fluid in it.
It may have been so low the pump was sucking air.

Make sure it is at least on the stick sitting level, and crank it and let it run a few minutes in park.
Then check the fluid level again.
If it still has some on the stick, see if it will shift now. If its gone, and there is no huge puddle and you do not see clouds of smoke out the exhaust, then add some more.
The pump and torque converter may have been empty.
 
Well I started the truck this afternoon and it IS level, and I checked the fluid after it warmed up and didn't show but just a DAB on the end of the dipstick. So I had to add like a quart and a half to get it even close to the full line. I did all of this while the truck was running at normal operating temps.

Also, in Park or Neutral, it makes a weird squealing sound, but if I shift it into any other position the sound goes away. No strange clouds out the exhaust, it's cold out so it's hard to tell what's smoke and what's just condensation.

After adding all that, I still couldn't get it to move, I let it run for another 20 minutes or so, and tried again, with no progress.

And yes I'm sure it's a TH400, I'm sorry I meant 3 gears, keep forgetting this isn't a 4 speed like most other auto transmissions.
 
nad said:
Well I started the truck this afternoon and it IS level, and I checked the fluid after it warmed up and didn't show but just a DAB on the end of the dipstick. So I had to add like a quart and a half to get it even close to the full line. I did all of this while the truck was running at normal operating temps.

Also, in Park or Neutral, it makes a weird squealing sound, but if I shift it into any other position the sound goes away. No strange clouds out the exhaust, it's cold out so it's hard to tell what's smoke and what's just condensation.

After adding all that, I still couldn't get it to move, I let it run for another 20 minutes or so, and tried again, with no progress.

And yes I'm sure it's a TH400, I'm sorry I meant 3 gears, keep forgetting this isn't a 4 speed like most other auto transmissions.
Click to expand...

You might pull the pan and make sure the filter and pick-up didn't fall off. Its only going to cost the price of fluid and filter.
 
Well, that does not sound good. I have just about exhausted my ideas, although something about that noise rings a bell way back in my mind from a long time ago.

Maybe it will come to me later.

Someone else with newer knowledge than me should jump in soon.

I assume that it will not roll if pushed while in park.
Just thinking of a stripped output shaft.....
 
Nope, it won't roll in P, R, D, 2, 1. Tried pushing it. Of course it weights like 9000lbs so I dunno if it's just me being a weak bitch or the fact that it's stuck. I can rock it back and forth in any gear, but still won't move.

It's not really a squeal, more like a whine. I guess I can try to pull the pan if I have time. Just not sure I wanna deal with the huge mess it will make. What do I need to look for once I have the pan dropped?
 
Fordum said:
Well, that does not sound good. I have just about exhausted my ideas, although something about that noise rings a bell way back in my mind from a long time ago.

Maybe it will come to me later.

Someone else with newer knowledge than me should jump in soon.

I assume that it will not roll if pushed while in park.
Just thinking of a stripped output shaft.....
Click to expand...

What about the seal between the transmission and t-case? I know in later models if the rear seal goes bad the fluid will dump into the transfer case. Its been awhile since I've dealt with a th400 on a 205 that I can't remember.
 
jwilson76 said:
What about the seal between the transmission and t-case? I know in later models if the rear seal goes bad the fluid will dump into the transfer case. Its been awhile since I've dealt with a th400 on a 205 that I can't remember.
Click to expand...

Good thought process, but this a C30, and is 2WD. No transfer case in the mix to worry about.
 
nad said:
Nope, it won't roll in P, R, D, 2, 1. Tried pushing it. Of course it weights like 9000lbs so I dunno if it's just me being a weak bitch or the fact that it's stuck. I can rock it back and forth in any gear, but still won't move.

It's not really a squeal, more like a whine. I guess I can try to pull the pan if I have time. Just not sure I wanna deal with the huge mess it will make. What do I need to look for once I have the pan dropped?
Click to expand...

If it won't roll out of park then its probably suck in gear(park). Unhook the linkage and move the select lever, then try to roll it.
 
jwilson76 said:
If it won't roll out of park then its probably suck in gear(park). Unhook the linkage and move the select lever, then try to roll it.
Click to expand...


I had a buddy watch the linkage as I shifted, and the linkage is moving the shift lever on the tranny just fine. Doesn't seem to be the issue.
 
jwilson76 said:
Sorry, its been a long day and I'm jumping between different threads.:dunno:
Click to expand...


Don't feel bad, I started to ask if the transfer case was in gear but caught myself just in time.:doah:
 
nad said:
Nope, it won't roll in P, R, D, 2, 1. Tried pushing it. Of course it weights like 9000lbs so I dunno if it's just me being a weak bitch or the fact that it's stuck. I can rock it back and forth in any gear, but still won't move.

It's not really a squeal, more like a whine. I guess I can try to pull the pan if I have time. Just not sure I wanna deal with the huge mess it will make. What do I need to look for once I have the pan dropped?[/quote]

As far as the pick-up goes, the filter should be attached to the valve body by the pick-up tube. If you drop the pan and the pick-up/filter is laying in the pan and not attached, the pump can't pull up enough fluid. If the pick-up/filter is off it will be obvious when you pull the pan.

By putting the truck in any gear other than park it should still roll. If your positive that the selector shaft is moving, not just the lever that the linkage is hooked to, I'm about out of ideas. Without being there and seeing/hearing for myself its tuff to say for sure.
Click to expand...
 
Well the actual piece on the transmission is moving along with the linkage lever. Whether or not the linkage is moving inside the tranny is beyond me. What's the easiest way to pull the pan, can I drain some fluid out first, or do I just have to let it all dump on me when I pull the pan?
 
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