Hot Rods TH350 Trans Issue

Stock SBC 350 with stock TH350, over 160,000 miles on both.

In the past week as I've be driving the car will drive fine for 3-5 mins then for 30 secs or so it's like it has a hesitation and sort of like I'm accelerating then not then accelerating again giving a sort of jerky movement. Last week it blew the dipstick out of the trans about an inch and sprayed trans fluid all over the car (never happened before) so I am suspecting trans issue.

 

Is the vent open?

 

Yep! Check vent, is the fluid at the proper operating level. What is the state of the fluid, look clean, not burned, dark ?

 

How do I check the breather with trans in car. I did try to check it a few days ago. I can get my hand to it and I can spin the green bit in the pic below and it spins freely...which I am therefore ***uming means it is probably OK. It won't pull out as limited space between it and tunnel.

Fluid was a very dark crimson and thick when I drained it (now replaced with new fluid and filter)...issue remains

 

Might be that the transmission is worn out. They wear out the pump and various shafts and bushings. I've never taken one apart that didn't need a few things replaced.

But for fun, tell us how you check the fluid level....

 

Fluid level is checked at cold, looking to see it about 1/8th inch below "full" mark on dipstick. I run a stock pan and know dipstick is the correct one. Then I drive teh car for a god 10-15 mins and re check level. I try to keep it at the full mark, but it usually is a touch over

 

When you check the fluid, you've started up the engine and run the shifter through the gears? And check it with the engine running?

anyways, it should be down quite a ways from "full" when it's cold. Might have a bit too much fluid in it.

 

160,000 miiiiiles...

 

Will check again, I do drive it (through the gears) before checking it hot, but usually have engine stopped, so will check with engine running

 

Have to check with engine running!!

 

Dark crimson and thick trans fluid isn't good. You might get lucky and save it with 2 or more fluid changes. Drain the converter if yours has the facility to do it.

Chris

 

Thick!

 

Ah, liquid rebuild in a bottle.
Use that **** and you will be surely rebuilding the transmission sooner than later!
Thats just as bad as putting sawdust in a differential to quiet it down.

Bill

 

Is that stuff why Op’s fluid was thick when he drained it? That’s all I was making reference to.

 

Puking out of the overflow tube is caused by excessive heat or fluid level too high. Both of those can cause the dipstick to be pushed out as well. Fluid full level should be level with the pan gasket.

 

Drop the pan and filter, see how much **** is in the bottom of the pan. That will tell the story, time for a rebuild.

 

That thing has been on borrowed time for 60,000 miles. I see a transmission rebuild in your immediate future.

 

Thanks all, quick update. So it's never had anything added but ATF.
I always check fluid both cold and hot but never with engine running...changing that process immediately
I did do another check last night and although I put over 5 quarts in it, with engine running it barely showed any fluid on the dipstick, so I suspect I am under on fluid right now. going to buy more today, get it to right level then lets see if I still have issues.
Update to follow
Note - when I did the service I did let it drain over night so I suspect it did drain the converter, but I filled it back up thinking the converter still had fluid in it

 

The converter won't drain overnight. And it can only drain about half way at most.

Generally if you check fluid level with it not running, you'll have it a quart or two low on fluid.

Let us know if it works any different

 

Thanks all...all fixed. Yeah fluid level was too low when engine running. Added another quart of fluid and she runs smooth as silk now. I learned something I did not know, check fluid level with engine running. Thank you

 

Cool, now change the fluid again! And filter of course. As you now realise, a fluid change gets most, but not all, of the fluid out, so it's about working at dilution ratios of new to old. A sucession of changes obviously help getting most of the old stuff out. Your old, and now abused, trans might live a good bit longer!

The tone arm will now be removed from the broken record!!

Chris