TH400 acting oddly

[Frankenchevy]

That looks like they’re flaking off from the inside of your pan.

Edit: disregard, at first glance I thought the flakey part of the pan was the inside of it. I now see you placed the metal flakes on the exterior of the pan for the photo.

 

[DoubleDingo]

They, as in steels? Define they please

 

[DoubleDingo]

This is the pan after being wiped down

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[HotRodPC]

Pop contacted me today, so I told him what the TH400 is doing. He said it's sticking inside because of varnish build-up. He said if it was pressure related there would be a lot of other issues. He said the creeping and other issues I described are caused by varnish build up making things hang-up inside the tranny. He also said to make sure the selector is dead-on, which I am sure it is because I followed the procedures that @chengny provided, although I will verify. So the rest of the week I'll be doing what he told me to do, along with the drain-fill and filter change, and making sure the selector is accurate. Will report back next week. He also agreed that because of this truck sitting most of its 76k mile life thus far hasn't helped at all. I told him if this doesn't fix it I will come up and we can check the pressures and such, but he was adamant that it was merely varnish build-up.

I started reading this thread one night and feel asleep reading it and never go back to it. It's so long now I've just skipped around. Just wanted to ask, have you tried a transmission conditioner in it yet? Being it's done so much sitting, that's the first thing I'd try and up to 2 bottles. No more than that. It could have some hardened seals from sitting, and temperature and conditions matter alot when seals or some seals are hardened and don't work just right. Also, the varnish mentioned is certainly possible. Trans conditioners do soften seals and help clean varnish. I added SeaFoam Trans Tune to a transmission recently that wasn't acting quite right. After about 10-15 miles and trans coming up to full temp I could gradually feel it getting better. By about 50 miles later there was quite a difference and it was working real well. About another 100 miles and 2 weeks later it kinda went backwards again not working near as good as it was, but it's still so much better than it was before and it seems to be holding up just fine in that same condition once it took a step back. This too was in a trans that sat for 6 or 7 years.

 

[HotRodPC]

How come that pan gives me the idea it had water in it? Or is it the angle of the shot? That looks like some water to me. Are those flakes chipped paint off the pan??? Is that pan painted inside?

 

[DoubleDingo]

Yes I've ran some conditioners and it's helped, but it didn't quite get it right. Better, but needing more correction if you will. Today I added some sea foam trans tune in with the new fluid. Noticed a difference for sure. Still may buy a rebuild kit and just make it a fresh unit.

 

[DoubleDingo]

It didn't look like water when I dropped it down and there wasn't anything that was mixed in. Could be condensation though. The flakes were thin pieces of metal, not paint. No paint in there, just bare metal.

 

[DoubleDingo]

In the pic of the filter, I wiped away a small area from the elongated opening. The filter and pan had that gray material covering them. And the filter didn't seem to have a filter element in it, but the new one does.

 

[DoubleDingo]

Is it worth getting a rebuild kit if the unit is operating like it's supposed to? It doesn't leak, it shifts normal for the most part. I hate buying stuff I don't need.

 

[HotRodPC]

You may not need it now, but you'll need it at some point. Might even be a a couple years away. No telling. I waited to buy my kit when I seen a sale they were having for 15% off and free shipping. It was under $100 IIRC and I also got new Kevlar bands and waffle clutches and a new filter. BTW, there are 2 types of filters, dacron and brass. The brass filters don't look like there is anything in them but it's a brass screen. The dacron is yellowish cloth like material. The brass is said actually be better and makes sense.

 

[DoubleDingo]

You may not need it now, but you'll need it at some point. Might even be a a couple years away. No telling. I waited to buy my kit when I seen a sale they were having for 15% off and free shipping. It was under $100 IIRC and I also got new Kevlar bands and waffle clutches and a new filter. BTW, there are 2 types of filters, dacron and brass. The brass filters don't look like there is anything in them but it's a brass screen. The dacron is yellowish cloth like material. The brass is said actually be better and makes sense.

Good to know I have time. If this thing didn't shift and operate like normal most of the time I'd just pull it and rebuild it. Did a quick search for kits and they seem to vary a lot in price. Oregon Performance Transmission has a complete kit that includes the Stock Stall TC for $469, and one without the TC for $159.

Drove it to the golf course yesterday, it is shifting better, yet the intermittent shudder shows up when it wants to but I can get it stop. Got another vacuum leak too. Heard it after test driving it Saturday night. And it is intermittent. Can hear a hiss, then it stops, then it'll hiss, stop... That leak causes the engine to stumble when the transmission upshifts. I couldn't pinpoint the source or location of the leak, but I'll find that sucker.

 

[HotRodPC]

Good to know I have time. If this thing didn't shift and operate like normal most of the time I'd just pull it and rebuild it. Did a quick search for kits and they seem to vary a lot in price. Oregon Performance Transmission has a complete kit that includes the Stock Stall TC for $469, and one without the TC for $159.

Drove it to the golf course yesterday, it is shifting better, yet the intermittent shudder shows up when it wants to but I can get it stop. Got another vacuum leak too. Heard it after test driving it Saturday night. And it is intermittent. Can hear a hiss, then it stops, then it'll hiss, stop... That leak causes the engine to stumble when the transmission upshifts. I couldn't pinpoint the source or location of the leak, but I'll find that sucker.

Looks like these guys are running the same deal as I got some time ago right now except FREE shippin is for $199 or more instead of $100. I see the banner rebuild kit with waffled clutches is $79 without steels. I normally don't buy steels because they are usually good and in the event they're not, I have tons of spare good used steels. I only replace steels if they're burnt or warped. Add bands, filter and bushing kit you can probably get over the minumum to get the 15% discount. In this case here myself since I know I'll use it build a transmission for someone else or have a kit for another of my vehicles, I'd buy another kit to get over the $199 to get the shipping. These guys have real nice kits. I've never gotten a kit with cheap **** in it from them and from FL to OKC, depending on what time of day and day I order, like a Monday or Tuesday morning, I have it on my porch within 2 days, sometimes 3 if I order late in the day.

http://www.transmissionpartsusa.com/

 

[DoubleDingo]

I didn't see a kit that included the converter. Isn't it recommended that the Torque Converter be replaced too so there isn't any bad fluid being sent through the fresh build? And the cooler lines flushed out too? Do you build-your-own kit perse using Transmission Parts USA? I don't have spare steels to choose from so I'd probably go with new ones.

This is the complete kit I was referring to from Oregon Performance Transmission, it appears to include everything, but I am not well versed on these transmissions like you are. What are your thoughts on this kit? https://www.oregonperformancetransmission.com/product/OPT-TH400-PKG.html

 

[HotRodPC]

I don't think they sell converters. I normally just get a converter locally because shipping usually kills a deal on a converter. That kit seems awful high too. You should be able to get a used remanned TC for about $100 and even a kit with steels should be under $150. Chances are, all of your steels are fine. Unless you burn up the trans or have a catastropic failure, your steels will be good. It's rare I need to get into my stash pile. I can ship you some in a flat rate envelope for I think it's $7 now.

 

[DoubleDingo]

I'll see what I can get locally since a reman converter is okay. I think the trans is okay to run as is, so the steels, if they typically stay good with normal use and no catastrophic failure, should be good too. I prefer rebuilding stuff to be as good as new again, but if saving money and still getting it to that point works, I like having the extra cash.