I just had a surprise leak on my TH 400 on the 1989 project truck I bought. It was coming through the pinhole in the yoke. I found out by pulling the driveshaft and cleaning it up. Someone had put silicone inside where the splines are. I'm guessing my fix will be a new o-ring inside the tail housing-cup. I still have to remove the housing, but thanks to your video I know what to look for. Thank you!
Just found your channel a week ago and it has turned out to be one of the best sources of TH400 info I have seen! Thanks for sharing your knowledge and experience. I have a 1970 Impala with it's original TH400; it uses the regular short tailhousing and output shaft.
Got an old long shaft Pontiac turbo 400 in a mid 80s Buick regal. Been a great transmission... But just started dripping fluid at the tail shaft mount. Was just watching this to see how difficult this was going to be to fix with the transmission in the car. But what's life without a little adventure.
Appreciate the tips and tricks man I got a couple Frankenstein's I'm about to put together in the yard and definitely needed this information keep it coming
My favorite tool is a stiff putty knife 1 inch sharpened like a razor and very square I use it for everything just about I loved watching you cuz it's mine too
Shawn I run across one of those 400s the other day that took the different rear seal. It was a first for me and the old man I work with. He has built transmissions since the late 70s early 80s.
Those cadillac tailhousings are different: smaller diameter seal & bushing - they use a thin wall 3R yoke. Probably not worth pushing past 450hp if I had to take a wild guess.
I am working on a 47 Buick with a 455 buick and a 68 Cadillac TH 400 with a V.P. convertor, short output shaft. I feel that the driveshaft is too long, almost 6 feet. I named the car Death Wish 7. Car looks good outside and inside but when you look under the skirt, not so much. Real hatchet job. My job is to make the car safe to drive. I do enjoy your channel.
Probably have it fixed by time i get a reply, but my truck started vibrating driving down the road checked and a lot of wobble at yoke was checking youtube for rear bearing replacement found this video and now thinking bushing us out. What you think
I guess I missed where you got your bushing driver but you seem to approve of it and I need one. Would you share where you purchased and what one it is? Great video I did not want the heavy driveshaft in my truck and this is a great way to fix that fixed yolk issue. Thank you
I have extension housing burned into my brain. When I went to technical school back in 1979, the instructor insisted that it be called the extension housing. If you called it by any other name , he wouldn't answer you.
Did the 400 come in 66 Chevy trucks. Or is it something someone put in my truck lol. Not sure cause it has an Olds 350 Engine as well. Trying to order the right rear output shaft seal for trans errr
I purchased a TH400 short shaft transmission to put in a truck I am building from scratch but notice that the yolk bolt and washer are missing. Can you help me with the size of bolt and washer?
I need help. I have that long tailed 400 and trying to put it in a 1985 Grand Prix GBody. The 400 i took out has no drive gears and only reverse works. Tips and recommendations are welcome, jerks are not.
So when I put the ('73 Catalina) TH375 in my '70 Lemans I just used what I'm pretty sure is the original '70 TH350 yoke (no hole in it). Is that a problem?
So if i want to remove the parking brake on My TH400 I'd have to put a bored slip yoke and short tail shaft housing? can i use the short tail housing that it has? Also why should we grind the output shaft is that only If we want stronger parts? I think ill have to go with the offshore stuff 😂
@@Joeylucio22 You can replace the tailhousing with a normal short 2wd one. I remove the o ring groove to allow the slip yoke to slide further. A counterbored yoke will also work without grinding.
Hi, I’m trying to a replacement vss for a th400. We recently replaced the th350 to a th400. The issue is that our car has mechanical speedometer and this transmission came with an electronic vss. I bought a Dakota digital electronic to mechanical speedometer converter. The converter unit is stating that it cannot find a speed signal. I looked up how to test a vss and the vss in the transmission now failed that test so I’ve determined that the vss is not working. Would you have or know anyone that might have a spare vss laying around? I’m from Hawaii and I checked a few places and nobody has one.
@@mountainsgarage we are changing the rear end and rear axle gearing so I thought that this unit would solve having to buy new drive gears for the mechanical speedometer
I just had a surprise leak on my TH 400 on the 1989 project truck I bought. It was coming through the pinhole in the yoke. I found out by pulling the driveshaft and cleaning it up. Someone had put silicone inside where the splines are. I'm guessing my fix will be a new o-ring inside the tail housing-cup. I still have to remove the housing, but thanks to your video I know what to look for. Thank you!
Just found your channel a week ago and it has turned out to be one of the best sources of TH400 info I have seen! Thanks for sharing your knowledge and experience. I have a 1970 Impala with it's original TH400; it uses the regular short tailhousing and output shaft.
Excellent!
this is exact problem I'm having right now, your video make perfect sense I appreciate the great info.
Got an old long shaft Pontiac turbo 400 in a mid 80s Buick regal. Been a great transmission... But just started dripping fluid at the tail shaft mount. Was just watching this to see how difficult this was going to be to fix with the transmission in the car. But what's life without a little adventure.
Appreciate the tips and tricks man I got a couple Frankenstein's I'm about to put together in the yard and definitely needed this information keep it coming
My favorite tool is a stiff putty knife 1 inch sharpened like a razor and very square I use it for everything just about I loved watching you cuz it's mine too
Man another video from Shawn I'll take it. Love the info sir. I would really like to meet you one day.
Yes! That would be nice!
These Videos are Awesome!!!
Shawn I run across one of those 400s the other day that took the different rear seal. It was a first for me and the old man I work with. He has built transmissions since the late 70s early 80s.
Cool!
Thanks Shawn!
Those cadillac tailhousings are different: smaller diameter seal & bushing - they use a thin wall 3R yoke. Probably not worth pushing past 450hp if I had to take a wild guess.
I am working on a 47 Buick with a 455 buick and a 68 Cadillac TH 400 with a V.P. convertor, short output shaft. I feel that the driveshaft is too long, almost 6 feet. I named the car Death Wish 7. Car looks good outside and inside but when you look under the skirt, not so much. Real hatchet job. My job is to make the car safe to drive. I do enjoy your channel.
Yeah the people watching transmission vids are probably not those Black lives matter types either. All the world is NOT lost. Good video
I am. Building auto slush boxes for 49 years.
Probably have it fixed by time i get a reply, but my truck started vibrating driving down the road checked and a lot of wobble at yoke was checking youtube for rear bearing replacement found this video and now thinking bushing us out. What you think
The worn bushing might be an effect of a driveline problem, frozen u joint or worn center support?
Hopefully it is obvious?
I guess I missed where you got your bushing driver but you seem to approve of it and I need one. Would you share where you purchased and what one it is?
Great video I did not want the heavy driveshaft in my truck and this is a great way to fix that fixed yolk issue. Thank you
I have extension housing burned into my brain. When I went to technical school back in 1979, the instructor insisted that it be called the extension housing. If you called it by any other name , he wouldn't answer you.
Funny!
I have a th350 but the drive shaft don’t feet is a c10 long bed year 84 can you give me a advice to now what I need to get so I can fix it
Did the 400 come in 66 Chevy trucks. Or is it something someone put in my truck lol. Not sure cause it has an Olds 350 Engine as well. Trying to order the right rear output shaft seal for trans errr
Looks like they came with them, but not with the Olds bellhousing.
@@mountainsgarage weird? This truck is such a Frankenstein. The chassis is GMC, Body is Chevy and it’s powered by Oldsmobile 😂
Great information video, what part number for the tail shaft seal did you use
The drive shaft I got I just to be in a 700R4
Yo
I purchased a TH400 short shaft transmission to put in a truck I am building from scratch but notice that the yolk bolt and washer are missing. Can you help me with the size of bolt and washer?
I need help. I have that long tailed 400 and trying to put it in a 1985 Grand Prix GBody. The 400 i took out has no drive gears and only reverse works. Tips and recommendations are welcome, jerks are not.
Take the tailhousing and output shaft out of the one you took out and put it in the long tail?
@mountainsgarage It cant be that simple... can it?
So when I put the ('73 Catalina) TH375 in my '70 Lemans I just used what I'm pretty sure is the original '70 TH350 yoke (no hole in it). Is that a problem?
So if i want to remove the parking brake on My TH400 I'd have to put a bored slip yoke and short tail shaft housing? can i use the short tail housing that it has? Also why should we grind the output shaft is that only If we want stronger parts? I think ill have to go with the offshore stuff 😂
@@Joeylucio22 You can replace the tailhousing with a normal short 2wd one.
I remove the o ring groove to allow the slip yoke to slide further. A counterbored yoke will also work without grinding.
@@mountainsgarage Awesome video very informative and knowledgeable, thank you for taking the time to respond
Why do you want to remove the old ring
I have a th400 with long tail extension. I a plan on putting in my 1980 Camaro. Do I have to convert it to a short tail for maximum performance?
If you go to the trouble of swapping, a long extension will be a odd ball combo. I throw them in the iron bin.
what bushing driver kit did you get?
I found a complete set (many sets) of the Kent Moore bushing service kit for the TH400. Same part numbers called out in the ATSG manual.
Hi, I’m trying to a replacement vss for a th400. We recently replaced the th350 to a th400. The issue is that our car has mechanical speedometer and this transmission came with an electronic vss. I bought a Dakota digital electronic to mechanical speedometer converter. The converter unit is stating that it cannot find a speed signal. I looked up how to test a vss and the vss in the transmission now failed that test so I’ve determined that the vss is not working. Would you have or know anyone that might have a spare vss laying around? I’m from Hawaii and I checked a few places and nobody has one.
They are hard to find. Why not install a mechanical speedo drive?
@@mountainsgarage we are changing the rear end and rear axle gearing so I thought that this unit would solve having to buy new drive gears for the mechanical speedometer
First