Kain
3/4 ton status
driving home from farmers market getting on freeway it bounced off rev limiter. when i let off it drove like normal. Is there any chance its not blown? Is it the valve body? Any thing i should look for?
CK5
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Help Transmision gurus I lost 1st gear in d
- Thread starter Kain
- Start date
Kain
3/4 ton status
It looks a. Little over full just barely but it's just a hair, it's not black doesn't smell bad or burnt. Going to check again and make sure it's level make sure vacuum modulator is connected.
Next on bucket list is figure out how to rebuild an auto trans
Next on bucket list is figure out how to rebuild an auto trans
Which trans is it ?..TH350 or TH400?..
If its over filled it may foam up the fluid and let air get in the system,and make it lose pressure to the clutches temporarily..
Modulator probably wouldn't affect first gear,mainly it would just delay the upshifts and go in gear harder if its lacking vacuum--it does control the line pressure some though,if the modulator valve sticks it might affect the pressure to the clutches..
Greg is the man when it comes to automatics,I only know what I've experienced on my own vehicles or read in service manuals--I have diagnostic charts and automatic tranny rebuilding books if you want me to look up your symptoms..
If its over filled it may foam up the fluid and let air get in the system,and make it lose pressure to the clutches temporarily..
Modulator probably wouldn't affect first gear,mainly it would just delay the upshifts and go in gear harder if its lacking vacuum--it does control the line pressure some though,if the modulator valve sticks it might affect the pressure to the clutches..
Greg is the man when it comes to automatics,I only know what I've experienced on my own vehicles or read in service manuals--I have diagnostic charts and automatic tranny rebuilding books if you want me to look up your symptoms..
That's what mine did when the vacuum line slipped off.
Turbo 400.
It ran fine in 1st but would'nt shift until rpms pegged.
Then it was a hard shift.
1st gear was fine.
Kain
3/4 ton status
It's a 350
Kain
3/4 ton status
sad part i got a turbo 400 on the shelf but it wont work with my set up
3500 stall 10 tci converter tci master rebuild kit major shift kit.
and i have had a 400 filter fall lose inside the pan and no drive but not on 350
3500 stall 10 tci converter tci master rebuild kit major shift kit.
and i have had a 400 filter fall lose inside the pan and no drive but not on 350
Kain
3/4 ton status
if manually shift in first it works just not in drive
Kain
3/4 ton status
would the governor gear be bad and cause this?
Yes, a bad governor gear or sticking governor valve could cause this. I'm not 100% clear on your description, but it sounds like the symptom went away (at least temporarily). So pull the governor, inspect the teeth and roll pin and make sure the valve inside moves up and down with the weights. If you don't find anything, check the modulator to be sure there is no fluid in the line and you can't draw air through it. It's also possible the valve behind the modulator is hung up. You could also pull on the kickdown cable to verify there is smooth tension from inside the transmission. If that cable was bad it could hang up, causing the tranny to act like you have it floored all the time. That's all the easy stuff and hopefully it's one of these since all of your speeds still work.
The govenor gear was stripped on my G-10 van's TH350 (with a lock up converter) when I bought it with a "blown transmission"--it would only go in first gear and reverse,it refused to upshift out of first,only a few times when I tried shifting from low to second manually did it try to go in second,but it dropped back in low instantly..
Putting a used govenor out of a salvage yard transmission fixed it!..
All the things Blue85 just listed can cause it to act weird,the kick down cable especially,if it got stuck in the "passing gear" position..
My book only lists a few symptoms like "no drive in any gear",there is nothing listed about "slips in low gear",only other gears and upshift issues.
Improper fluid level and the modulator valve are listed as possible causes,and a faulty rear servo,one symptom under "no drive" also lists a faulty 1 way roller clutch--if you can get first gear by manually shifting to low though,I would think its valve body related--perhaps a gasket between the valve body & the case blew out and it letting pressure bleed off,or go into another passage it shouldn't..
Other things listed are low oil pressure,faulty forward clutches,and manual linkage adjustment being "off"...
I had a car with a Powerglide that started "slipping" in low on take offs,it was like it went in neutral by itself,them slammed into gear after the engine raced up...it turned out the drivers side engine mount had separated,and when I'd take off from a stop,the engine would lift up enough to pull the transmission shift linkage out of drive into neutral ,then I'd let off the gas and it would slam back in low..new motor mount fixed it..
Automatics are great when they are working right..but after seeing whats inside one in my overhaul manuals,I am not brave enough to try messing with one..dozens of springs,clutch plates,seals,etc--mess one thing up and it'll either never work again ,or never work "right"--I just get a good used one I know works and swap it..
Putting a used govenor out of a salvage yard transmission fixed it!..
All the things Blue85 just listed can cause it to act weird,the kick down cable especially,if it got stuck in the "passing gear" position..
My book only lists a few symptoms like "no drive in any gear",there is nothing listed about "slips in low gear",only other gears and upshift issues.
Improper fluid level and the modulator valve are listed as possible causes,and a faulty rear servo,one symptom under "no drive" also lists a faulty 1 way roller clutch--if you can get first gear by manually shifting to low though,I would think its valve body related--perhaps a gasket between the valve body & the case blew out and it letting pressure bleed off,or go into another passage it shouldn't..
Other things listed are low oil pressure,faulty forward clutches,and manual linkage adjustment being "off"...
I had a car with a Powerglide that started "slipping" in low on take offs,it was like it went in neutral by itself,them slammed into gear after the engine raced up...it turned out the drivers side engine mount had separated,and when I'd take off from a stop,the engine would lift up enough to pull the transmission shift linkage out of drive into neutral ,then I'd let off the gas and it would slam back in low..new motor mount fixed it..
Automatics are great when they are working right..but after seeing whats inside one in my overhaul manuals,I am not brave enough to try messing with one..dozens of springs,clutch plates,seals,etc--mess one thing up and it'll either never work again ,or never work "right"--I just get a good used one I know works and swap it..
Kain
3/4 ton status
ok i checked a few things before the wind started blowing 40 miles and hour
i pulled vacuum modulator line and it has fluid in it.
i have a b&m one in the tool box should i change it see if it works?
i pulled vacuum modulator line and it has fluid in it.
i have a b&m one in the tool box should i change it see if it works?
Substituting a "known good" one is probably the best thing to try first..
Modulators are fairly cheap--the TH350 & TH400 can use the same one..(they list 100 different ones in parts books,identified by colored stripes ,etc,but often transmission shops just use "universal" ones without any real issues)..
If that fails to change anything you'll probably need to investigate further--doing a pressure test in the vehicle is one thing that might help pinpoint whats causing the issue..
Modulators are fairly cheap--the TH350 & TH400 can use the same one..(they list 100 different ones in parts books,identified by colored stripes ,etc,but often transmission shops just use "universal" ones without any real issues)..
If that fails to change anything you'll probably need to investigate further--doing a pressure test in the vehicle is one thing that might help pinpoint whats causing the issue..
Kain
3/4 ton status
as soon as wind stops trying to blow me away ill get out there and change it
Thanks for the replies guys
Thanks for the replies guys
Kain
3/4 ton status
It is blown, not supposed to have little metal circles
Kain
3/4 ton status
My buddy Darren in Vegas says I blew the intermediate sprag why low made it move was the band kicked in and applied pressure
Kain
3/4 ton status
Kain
3/4 ton status
^this thing i think
Well,that sucks...I've taken pans off a quite a few TH400's and 350's and found "some" metallic bits of steel & brass and they still functioned fine after a fluid & filter change,but any sign of metal in the pan is never good..
The TH400 I had in my '69 GTO saw much abuse,I liked to do burnouts and in the rain on a wet road, you could do a one wheel peel for a mile if you kept your foot in it..many tires were spun till they popped on that car!..
One winter day we got 20" of snow and the car was in a field at my sisters house--I shoveled a path to it,and two paths to the rear wheels and tried backing it out thru the gate--ya,right..that car sucked bad in snow,it liked to slide sideways in drive or reverse, instead of move in either direction,even at idle with no throttle!..
I spread sand out on the paths and dumped some under the tires and kept rocking it back and forth--after about 20 minutes the transmission started sounding like a power steering pump that ran low on fluid..police siren type of noise..
..
I managed to finally get it out of the field--the trans whined in the morning like a siren even louder after a cold start..I noticed it no longer went into drive with a solid "thump" any more,it kind of "slid" in now..I feared it was done..
I took the car to a garage one of the customers of the parts store I worked at had--he would rent his lift out to me after 5 pm if it wasn't tied up,so I arranged to take my car there and dump the fluid and replace the filter in the trans,and man,I found about a pound of clutch material,looked like burnt coffee grounds,stuck to the bottom of the pan and the filter..it also .had some gold brass flecks in it too,and what appeared to be a chewed up ball from a bearing or a needle bearing..
I had little hope of it surviving,but went ahead and changed the filter and threw in 4 qts of dexron and to my surprise,the whine noise went away almost immediately after I started it up,and driving it around after revealed it seemed no worse for the wear,it would still chirp second gear and didn't slip at all,I could still bald one tire like it was on ice again..
I drove it another year before I sold it without any problems,and I often used to commute to work 150 miles a day for six of those months with it..I admit I always feared the trans would peuke and leave me stranded after that punishment,but it didn't..
Maybe you'll be as lucky ?...
If not, I'd plan on many other parts besides that sprag being wounded though,the shrapnel usually gets in places it shouldn't and wrecks other parts..
The TH400 I had in my '69 GTO saw much abuse,I liked to do burnouts and in the rain on a wet road, you could do a one wheel peel for a mile if you kept your foot in it..many tires were spun till they popped on that car!..
One winter day we got 20" of snow and the car was in a field at my sisters house--I shoveled a path to it,and two paths to the rear wheels and tried backing it out thru the gate--ya,right..that car sucked bad in snow,it liked to slide sideways in drive or reverse, instead of move in either direction,even at idle with no throttle!..
I spread sand out on the paths and dumped some under the tires and kept rocking it back and forth--after about 20 minutes the transmission started sounding like a power steering pump that ran low on fluid..police siren type of noise..
..I managed to finally get it out of the field--the trans whined in the morning like a siren even louder after a cold start..I noticed it no longer went into drive with a solid "thump" any more,it kind of "slid" in now..I feared it was done..
I took the car to a garage one of the customers of the parts store I worked at had--he would rent his lift out to me after 5 pm if it wasn't tied up,so I arranged to take my car there and dump the fluid and replace the filter in the trans,and man,I found about a pound of clutch material,looked like burnt coffee grounds,stuck to the bottom of the pan and the filter..it also .had some gold brass flecks in it too,and what appeared to be a chewed up ball from a bearing or a needle bearing..
I had little hope of it surviving,but went ahead and changed the filter and threw in 4 qts of dexron and to my surprise,the whine noise went away almost immediately after I started it up,and driving it around after revealed it seemed no worse for the wear,it would still chirp second gear and didn't slip at all,I could still bald one tire like it was on ice again..
I drove it another year before I sold it without any problems,and I often used to commute to work 150 miles a day for six of those months with it..I admit I always feared the trans would peuke and leave me stranded after that punishment,but it didn't..
Maybe you'll be as lucky ?...
If not, I'd plan on many other parts besides that sprag being wounded though,the shrapnel usually gets in places it shouldn't and wrecks other parts..
