What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Transmission problem

scooter122983

scooter122983

1/2 ton status
Joined
Oct 4, 2006
Posts
297
Reaction score
1
Location
Fond du Lac, WI
While on my way home for lunch today I noticed a thick smoke coming from my 78 k10 th350. I managed to limp it home (only 3/4 mile) once I got home there was a large amount of fluid coming from my dust shield. I have the tranny and t-case ready for removal, but I don't know what signs I should look for. Is it the Converter or the tranny. Any input is appreciated and will be considered.
 
Are you sure that the fluid was transmission fluid? Could it be engine oil?

The torque converter seal could have failed. There are oil galley plugs on the back of the engine block that could have blew out. ( not likely )

If the fluid that was leaking is red, I would look over any other potential leaks that would be from outside of the case of the transmission. Look over the cooler lines to be sure they didn't break or crack.
 
I would have to say that it was severly overheated for whatever reason. gonna need a rebuild at some point if not now. TH350 stuff is nice and cheap so you should be able to have something pretty stout without spending an assload of cash.

could be a front pump seal spraying on the exhaust though too. hard to say.
 
The fluid was definately tranny fluid, and I also checked the lines and their is no leaks from the lines. The smoke is from fluid on the exhaust. One other question is would it be more cost effective to rebuild the tranny or to replace it with a rebuilt one?
 
The least expensive route would be to repair what you have if it was working well before the leak. When you pull the trans check the converter hub to be sure the pump bushing has not eaten into it. Check the front seal and look at the pump bushing behind it to be sure it is still in place. While the trans is out, look at the dowel pins on the block and check the case at the dowel pin locations to be sure the dowels are penetrating and that the case is not worn in these areas. Also check the converter pilot where it seats in the crank to be sure it does not have excessive wear. Just some things to check.
 
How much am i looking at to have it rebuilt? Or how much to rebuild it. Should I upgrade, or stay stock? Finally will I need any special tools and can a simpleton like myself do it without making it worse.
 
Having the transmission and converter rebuilt will usually cost between 7-900 dollars depending on damage and modification options. Of course, you can build it for less money yourself, but a professional shop will be able to spot hard parts wear and damage that an untrained eye can miss. Special tools will be spring compressors for the clutch packs and a lip seal spoon, plus a pump alignment band and any bushing installation tools you may need to replace worn bushings. In all honesty, we see very few 350's that aren't in need of a lot of parts replacement and all bushing replacement. The extra money you spend on a good professional job with a warranty may be piece of mind enough for you to weigh against the DIY approach. Choose your rebuilder carefully, there are still some out there that can't fix a sandwich, let alone a transmission, the cleanliness of the facility and warranty should be a clue.
 
Based on how much a rebuild would cost to have done I think im going to tackle this myself.
Use a quality parts kit and take my time. Would autozone or oriellys have the specialty tools that i will need to get this done?
 
i did my th400 without any "specialty tools"
all i really used was a huge dia. hose clamp for the front pump alignment, and some heavy gauge wire to pull the drums out. i also used a 12 point 3/8ths thinwall socket.
 
Im sure they would have the snapring pliers you need. Lip seal spoons are getting a little more difficult to find IMO. The spring compressor for the rear most spring plate for the case piston also would not be easy to track down. You need to find you a quality parts supplier that carries tools, as well as if this is your first trans re-build a ATSG or rebuild book for your trans would be well worth the money.
 
Lip seal spoons are getting a little more difficult to find IMO. The spring compressor for the rear most spring plate for the case piston also would not be easy to track down. You need to find you a quality parts supplier that carries tools, as well as if this is your first trans re-build a ATSG or rebuild book for your trans would be well worth the money.
Click to expand...
spring compressor for the case piston is easy to make ....heck I made one with a piece of flat bar,,threaded rod and a big PVC pipe cap....Google it...should be some ideas out there...

lip seals tools ?? feeler gauges work fine with a little care..

Get a trans rebuild book....study it,, and dive in...most of the rebuild will become clear once you have the parts in your hands.....

heck, the first one I ever did, I bought the rebuild kit from B/M and the manual came with it....I still have the manual,,,,too bad the kits today do not come with them....:dunno:

bottom of this link has an exploded view...http://th350.com/
 
Look around for a nice "ma and pa" kind of transmission shop. If you get stuck on a certain step, you may be able to pay them to press a seal, align a pump, etc. Such shops may also have some rebuilt assemblies and other random parts they can sell you if you need them. For a lot of the special tools, it can be hard to know whether you can get by without them until you get to that step. Sometimes you can fabricate a compressor tool or whatever out of common stuff. It just takes a lot longer. Some of the special tools are strictly to save time - which is important for professionals.

Be sure to replace the torque converter - a rebuild is fine.

When I did my first one I figured that the worst case scenario was to give up, throw it all in a box and take the mess to the transmission shop. Pulling it out and putting it back in the vehicle is half of the labor cost anyway.

You'll need to prepare a suitable shop space. I recommend plenty of table/bench/shelf space to lay out all of the parts in order. If you lay them on newspaper, you can write down the names or numbers of the parts. Also, if you have ever considered buying a parts washer, now would be the time. Or buy a case of brakecleen.
 
Aren't we getting ahead of ourselves? Are you sure this tranny is broken? Maybe it was just overfilled or maybe it just needs a new front seal or something.
 
its gets intimidating right about... here.
DSCN0999.jpg
 
Judging from the color of fluid coming from the dust cover i think a rebuild would be the correct course of action. Not the red color that it should be. It was a bloody redish brown. I do have a parts washer at work that it will use for cleaning the parts, and I also have alot of table space for parts too.
 
it gets intimidating right about... here.
Click to expand...


yeah, but yours is a 400........didn't we would notice did ya...:haha:

heck, 350's and 400's are a piece of cake after you do them a few times...:waytogo:

DSCN0999.jpg
 
Pump Bushing Write Up?

I'm about to buy a used 700r4 and the guy selling it said he's pretty sure the front seal and pump bushing need replacing. Does anyone know of a write-up anywhere that can show me how to do this myself? I have NO money! Thanks!
 
I'd pass on that tranny and put your cash towards a working used one--most likely you'll have to replace the pump if the bushing has come loose in it,I haven't seen too many of those installed and have good luck with it,they always leak or the bushing comes loose again,the housing it is a press fit in gets damaged and replacing the pump is the only true "fix"..also if its got troubles there,chances are the rest of it has suffered some damage too,and you might as well have the whole tranny gutted and inspected and replace any worn parts...A "good used" one would be a cheaper way out..
 
Well let me ask you this then. The transmission in my truck was rebuilt shortly before my drive-shaft came loose and jammed- cracking my transmission's case. That's why I'm replacing the tranny. What if I took the used one I may buy, and replaced the pump in it with the pump from my original tranny? The guy will sell me the transmission for $100. It's working, but leaking pretty bad.
 
You must log in or register to reply here.

Latest Posts

Top Bottom