didd filter and gasket on TH350 now have issues

[84 400]

Okay this past weekend i did tranny filter and gasket on my truck. Found what some said is clutch material in the bottom of the pan. I am guessing because it had been somewhat low on fluid. Fluid was clean. Put in 4 bottles of B and M had no gears at all. Then got second then got the others. But my tranny is acting really weird. while going around on a test run going around a corner it slipped. my trans has never slipped... ever. It goes into gear really easy now you can almost not feel it in reverse. I have heard trannys dieing when fluid is changed because the old fluid was allowing for more friction. The trans has 12k on a rebuild done long before I got the truck. So for the questions....

1. How much fluid does this thing take? my Haynes manual does not say.
2. Added 4 bottles of the B&M trick shift but being clear it is really hard to see on the dip stick.... my dad thinks it is still low?
3. The tranny leaked a little before i did the filter and gasket could it have been leaking from the converter? Also it did sit outside for the night before i could get the pan back on and we had rain.....

here are pictures of the pan




Thanks for the help
I am not a fan of auto trannies and do not know much about them at all.

[Longhorn Man]

sitting out in the rain shouldn't have done anything.
The clutch material in the pan is normal, but that is a bit on the heavy side... mine looked about the same, maybe a tad less after 13 months of driving. (big block to TH350, I'm beating it a bit harder than it was made for)
Your description does sound like it is too low on fluid level. I have no clue how much it should take on just a fluid and filter job, haven't done one in years... I had to replace the converter on mine, so I started from totally empty.
You need to try and get a good reading off the stick. Just becouse one tranny takes 4.5 quarts (pullin that number out of the air) doesn't mean yours will. There are too many variables to give a solid number like that.
While that trick shift is decent stuff, in reality you are throwing away your money. You have a BUNCH of 'normal' dextron in the converter diluting the B&M stuff.

[84 400]

Originally Posted by Longhorn Man

While that trick shift is decent stuff, in reality you are throwing away your money. You have a BUNCH of 'normal' dextron in the converter diluting the B&M stuff.

First off THANKS for the reply!

The trick shift was cheaper that was why i got it. They had it on sale and it was cheaper then dextron so I figured why not. I don't buy the whole "trick shift" nonsense just stating the brand I used. I wish it was red tho so I could see it on the stick. We thought 4 bottles should have filled it after a filter and gasket job but it still seems low. Again tho it is clear and hard to read on the stick. even before when my trans was low it did not slip like that. I am guessing the burnt clutch material is from a few brake stand (i know I know) i did in high school. She could break em loose and spin n down the street with no brakes at all but the smoke was fun. Still I only had about 3 good ones on it (like my tires). Any way to color the fluid so I can see it on the stick? My father is planning on using the truck to pick me and my crap up from school in 3 weeks and I will not be home between now and then.

Any input would be great and very helpful

[COBALT]

For a TH400 - The way I've always done it:

1. Put a quart in the torque converter before you put it on the transmission and into the vehicle.
2. Put X number of quarts in until you reach the "full" on the dipstick cold. Start the vehicle and let it run for a couple of minutes (not hot but not cold). Then shift through all the gears and check the fluid. It will be super low.
3. Add 1/2 quart at a time while shifting back and forth from P to L2. As you add fluid shifting will get stronger and stronger.
4. Stop when the fluid when the system is warm and at "full" (there's only a 1/2 quart difference between "add" and "full").

I vaguely remember the number being high: around 7-9 quarts. With a deep pan it can be as many as 13. For the TH350 it will be a bit lower, but if you follow the process above you'll be fine.

I've done this a few times with good results every time. I had a transmission shipped down to a local shop for rebuild, and swapped it into my truck about two years ago and did this, but I could only get the fluid to reach the "add" mark before it started burping Royal Purple all over the clean aluminum case and the shop floor. It's been that way ever since. The thing shifts like a dream (2600 rpm torque converter with shift kit), but I can never add any more fluid than that. Nobody can explain it - I think my dipstick is too short.

Shifting in reverse is an experience let me tell ya. As for "seeing" the fluid? Wipe it, stick it back in all the way, pull it out, and feel it with your fingers moving from top to bottom.

That clutch material looks pretty average. How many miles on the transmission? If it's behind a BB then I agree with Andy. If you start finding solid hunks of clutch material - that's when it gets fun.

New fluid in a used transmission can "scrub" it a bit and shorten the life, but it's not that dramatic. I did that on the first transmission I had in the truck (front seal went bye-bye), and it lasted another 2 years before it started to kinda slip, so I swapped it for a fresh one.

[SBTork]

if all you did was change the filter and add fluid, even if the fluid that you added was clear, all of it should be red because the rest of the trans has a few more quarts in it. If I were you, I would just re-drain and get some regular parts store dex3. My '86 has a drain plug on the pan of my th350, so you may have it that easy, but a new pan gasket would be cheap too. It would be better of you had a solid idea of what is in ther to begin with as far as fluid level.

[84 400]

okay to answer some questions

The trans has about 12,000 on it since rebuild. Had a 383 at first and now is behind a 400 small block. No i do not have a drain plug.. wish i did. My pan is dented up pretty good.... Why? I have no idea but i do know the this trans is original to the truck. I thought they might mix a bit too but for some reason it is only clear. I am starting to wonder if my leak was from the TC . Hope not tho. I wish i could be home and able to sort this out in 5 min. but I am up here at school. I will pass the info on so hopefully the truck can be back on the road soon. Sitting = Issues.


Thanks for all the input

[70rs/ss]

I have never seen clear trans fluid? I am wondering how that is possible, every type and brand I have seen is red (except the royal purple I bought, but purple is their trademark) is it possible it wasn't trans fluid? Deffinately low a filter change should be 6-8 quarts, but definately use the dipstick to gauge it. Fill it, then start the truck and work through the grears, slowly, then check it with the truck running in park and warmed up.

[COBALT]

I think what he means is that the fluid is so clean it can be hard to see on the end of the stick. Royal purple is like that. I have to turn it and get a reflection from the light sometimes to see how far up the stick it goes, or feel it with my fingers. The tiny trace of red isn't enough. Once you get enough volume to the fluid it's red.

Is that what you meant?

[70rs/ss]

Originally Posted by 84 400

I thought they might mix a bit too but for some reason it is only clear.

He's saying clear, not sure if he means like PS fluid clear or just faint red? That's why I asked if he was for sure it was trans fluid??

[84 400]

http://www.bmracing.com/index.php?id...ubcat=&pid=378

That is the stuff and it is clear. No red at all to it. looks more like gun oil then tranny fluid. I wish was red because then i could see it on the stick better. t has got to be low I am gonna see if my father can find time to mess with it this weekend (up at school). I had never seen clear before eather. Form the outside lookin in the side of the bottle i thought it was blue.

This is what i get for buying the cheaper stuff i guess.......
Thanks again

[c502]

I would drain it all again, including the torque converter if you could. Since you are dropping the pan, add a B&M drain plug kit (easy and cheap!), but add normal dex 3 fluid. The B&M is Type F fluid, not so swell for the T350/400 unless modified to use it.

[70rs/ss]

I see that is the best fluid they make, so you stole it, but you need to add more. Any red left in the torq converter is enough to color the fluid. I am thinking it is so low there isn't any fluid on the dipstick maybe? Just add one quart at a time then cycle through the gears then check it again (all while running parked on flat surface)

[Longhorn Man]

I don't recomend the drain plug kits... I've seen many installed over the years, and done a couple myself. They will leak eventually. Many leak right off the bat, but I've never seen one stay dry for a real long time.

[COBALT]

Just get a replacement pan (milled aluminum is better) with a plug already in it. Then use a gasket and an RTV meant for aluminum at high temperatures as an adhesive, and put it on both the gasket, and the mating surfaces on the transmission and the pan. Use a thread sealant for the drain plug (because it's not like your oil pan - you won't be draining it very often), and let the thread sealant set up for a while before you put the pan on.

I put an aluminum pan on my transmission, and let both the gasket and the thread sealant set up for an entire day. I have zero leaks.

[COBALT]

Originally Posted by 84 400

http://www.bmracing.com/index.php?id...ubcat=&pid=378

That is the stuff and it is clear. No red at all to it. looks more like gun oil then tranny fluid. I wish was red because then i could see it on the stick better. t has got to be low I am gonna see if my father can find time to mess with it this weekend (up at school). I had never seen clear before eather. Form the outside lookin in the side of the bottle i thought it was blue.

This is what i get for buying the cheaper stuff i guess.......
Thanks again

Ah...I must have misunderstood. I've always been told it is not wise to mix fluids. Only go with a fluid like this if you have a fresh transmission. There's no real way to drain a used transmission unless you flush it, which of course is almost pointless. You might as well do a rebuild. It's almost impossible to drain the torque converter 100%, and the valve body will hold fluid as well, so unless you're planning on removing that...

[84 400]

Thanks for all the help. For now we will do something eather a drain/refill or just add more. I eventually plan on swapping in a Muncie m20 or m22. However there is no sense in destroying a good transmission. That said if i was planning on keeping this trans I would invest in a deep pan with a drain plug but after this change I will probably have swapped to a manual trans before the next fluid change is due. Thanks for all the tips and insight

[84 400]

UPDATE...
since my dad was home today he went and picked up some more fluid. At $2 a bottle I think the price is pretty fair. So he added more and says it still is at the "add 1 pint logo" even after adding 2 bottles and yes he did shift it through all the gears?

[COBALT]

Did he add while the truck was running and warmed up? The fluid has to be going somewhere. Is it:

a.) all over the transmission from the vent pipe
b.) all over the ground from the rear seal-to-slip yoke?

2 pints to a quart. You should have just added half a bottle.

[84 400]

yeah he did while running and cycled threw all the gears. Said it is now at the "add one pint line" I wonder how low it really was before? That could explain all the clutch material since I have not driven the truck in over 2 years it was hard to remember but it did leave a good size puddle after every former usage.

It is funny you mention the rear seal as I got one from NAPA thinking it was leaking. It is dry as a bone so that is all good. there was a good deal of fluid around the speedo cable that i noticed during the filter change. We tightened it up and left some large piece of cardboard under the truck and no leaks so far. IF it was really this low how did nit not slip or burn up?
this whole situation has got me confused to be honest....

Also no burping or overflow from the vent tube.

So so far it has taken 6 quarts and there is no way anything near that came out

[84 400]

Not to get off track but COBALT i also checked out your website. Nice looking truck you got there and I thought those Jack boxes where pretty neat.

[COBALT]

They came in handy this weekend when I needed to reseal my axle. I can use those to get my truck at least 24" into the air. Comes in handy with the transmission swap, but of course if I had a lift I would be in good shape.

That website is way out of date. I need to update it <blush>.

6 quarts isn't really a lot. You could probably stand another 2-3 quarts, but you really shouldn't see any fluid on the dipstick if it's that low.

[70rs/ss]

It could've been a drop from fluid in the tube after filling. I was thinking 8-10 quarts with a filter, but that is just a generalization depending on the pan depth, etc, etc. Pour a half to one quart at a time, cycle it through and then check the dipstick, if low add more. Once it reads on the dipstick it'll take one quart or less to fill it. Sounds as though it was pretty low to begin with, i have seen low fluid do wierd things, just fill it and drive it, if it is damaged you'll know soon enough.

[wedgemon]

An empty TH350 (and empty converter) will take near 11 quarts.

- Dave

[84 400]

Thanks you all for the input and help.

[Longhorn Man]

don't worry about mixing fluids. If it is OK for a GM tranny, then it is good for a GM tranny. Mixing mineral oils with synthetic (which is what you just did) does nothing wrong. The mineral oil is suplimented by it, while the flip side of that is you are not getting the full advantages of the synthetic oil, it's still better than straight mineral.