TH350 mysterious shifting/not going into gear/freespin issue

[sommsdrumz]

i have a TH350 in my 67' 4x4 and i got a problem you guys might be able to help me with.. i did a fluid and filter change due to a leaky pan gasket, fluid was a little dirty nothing to be alarmed with, i get it back together, fluid levels checked, go for a test drive, it drives 100 yards and then freespins. doesn't do anything in any gear, turn it off let it sit for a min, goes back to normal operation, then, it does it again, no power... this keeps going on and is undriveable...

me and my buddy took a look at the trans lines to the cooler and the return was cold the other was warm, we took the trans lines off and made a short loop back to itself, no results.. i have a felling its some sort of a clog, but i have no idea where to start, short of tearing the trans down and all that, in which case i'd get a 400..

so any tips would be greatly appreciated.. great board!


thanks!

Joe

[sommsdrumz]

i have a TH350 in my 67' 4x4 and i got a problem you guys might be able to help me with.. i did a fluid and filter change due to a leaky pan gasket, fluid was a little dirty nothing to be alarmed with, i get it back together, fluid levels checked, go for a test drive, it drives 100 yards and then freespins. doesn't do anything in any gear, turn it off let it sit for a min, goes back to normal operation, then, it does it again, no power... this keeps going on and is undriveable...

i checked the fluid level after shifting through each gear, while it was on, etc...

me and my buddy took a look at the trans lines to the cooler and the return was cold the other was warm, we took the trans lines off and made a short loop back to itself, no results.. i have a felling its some sort of a clog, but i have no idea where to start, short of tearing the trans down and all that, in which case i'd get a 400..

so any tips would be greatly appreciated.. great board!


thanks!

Joe

[too much stuff]

Are you sure the fluid level is proper after warm up and being run through the gears?

[sommsdrumz]

definetly.

[Longhorn Man]

Not knowing your mechanical level are you checking the tranny fluid with the engine running after going through all the gears, or with the engine off?

[67CHIP72]

Is it possible the transfer case is slippin out?

[sommsdrumz]

longhorn: engine on, going through each gear, waiting, etc..


this hasnt been a one shot deal, its pretty consistent, it works when its cold, but as soon as it warms up, it acts like its in neutral, then, from time to time, fairly consistently, when you shut it off and wait a few mins, it will work again, but it works the longest from a cold start. the fluid in the t-case is fresh and new, it has been rebuilt less than 2k miles ago..

[Longhorn Man]

ok, I didn't want to sound like I was insulting you (sounds like you weren't) but i see sooooo many people not doing it right.
this IS an odd one... no clue though.

[sommsdrumz]

hey no problem, getting everyone on the same age is paramount. and yes, its very strange, and reaaaal annoying, when it works, it locks in and its as strong as it was before this happened, but when it doesn't, its a very good neutral..

[Green Machine]

The filter that was in there, was it the screen type or the "filter" type filter, kind of a paper type of filter ? And what type was the replacement ? The "filter" type could plug fairly fast if there was some trash in the oil. Do you notice any pump whine when this happens ? That would be a sign of a plugged filter, or it sucking air somewhere.

[too much stuff]

Did this happen before the fluid change? Is it the correct dipstick? It sure sounds like a low fluid problem to me.

[sommsdrumz]

screen type filter replaced by screen type filter, no whine that i know of, although when we replaced the filter (which had been replaced about 2k miles before) we noticed there was a tear in the screen about 1/2 inch long.

[sommsdrumz]

this never happened before the fluid change, and we replaced the dipstick made for the th350 old one was broken.

[Green Machine]

Maybe add 1 more quart just to make sure it isn't low ?

[Green Machine]

When did you replace the dipstick ? And I just noticed you are posting here as well as in engine and drivetrain - double posting is frowned upon !!!

[sommsdrumz]

when we replaced the fluid we replaced the dipstick, sorry about the double post, didn't know which one was best.

[Longhorn Man]

do you have the old broken dipstick?
How many pints went into it after the filter chainge?
I agree it sounds like the pan is getting sucked dry

[sommsdrumz]

i threw away the old dipstick, we put in some 4-5-6 quarts

[WorkinLonghorn]

Drop the pan and check ALL of the tubes.They wiggle loose.They are just easy press fits I think (It's been a LONG time).
Warning; DO NOT continue running this trans in this condition or it will be totally trashed if it isn't already.
Check that the pick-up and everything else is real tight.

[LONGHAIR]

Please post your question in only one place. Everyone has to agree to the same rules when they enroll, but most apparently skip over them. They are a sticky at the top of most pages.

Copied directly from the rules....

XIV. Multiple Posting - It is simply not acceptable to post your question more than once, or to post it in more than one forum. Choose the forum that your question or post best fits in, and place it there and only there. If, after posting, you feel it should be in another forum, private message the forum Moderator and ask if they would move it for you.

Merged

[sommsdrumz]

thanks longhair, i appologize, again, for my double post.

[89 crew]

Drop the pan and check the seal on the filter. If there is no seal, or it is cut, it can cause a problem.

[sandking]

I agree on the low fluid level. Add another quart to see if it improves. Did you drain the converter? If so, it will take a few quarts in addition to the rest of the tranny. If you can access the port that the dipstick uses, you can check the level there. Dont quote me, but I think the fluid should be at the top of that hole once the dipstick tube is removed from the tranny.

[jbarron]

Make sure your vacuum line is hooked up to the modulator. If it is not pulling vacuum it will take off and then loose power and not shift into upper gears. Other than that I would suspect fuild level

[Longhorn Man]

a bad modulator would prevent it from shifting, but would not keep it from moving