TH400 slow to go into gear

[inkedmonkey]

I've been having an issue with the trans being slow to go into gear the first time. It shifts fine afterwards but the first time is painfully slow and you have to switch in between gears to get it to engage. I dropped the pan and changed the filter. Everything looks fine in there and fluid smells great. Is my pump getting weak or should I look elsewhere? I've heard about the pickup tube needing an additional o-ring to prevent sucking air. Also read about needing to check the valve body bolts to make sure they are tight. The rebuild kits are not really expensive for it and I'm sure I can do it, but I'd really like to not drop the trans.

The interesting thing is with it overfilled, it goes into gear just fine. Makes me think the filter is sucking air or something?

[wiley-moeracing]

sounds like your getting drain back from the convertor.

[inkedmonkey]

What would cause that? Do I just need to replace the convertor?

[wiley-moeracing]

no, there is a anti drainback valve in the trans/valve body. you may need to pull trans and rebuild pump and valve body or upgrade with shift improver kit to help. the cheapest is to put it neutral for faster refill of torque convertor.

[inkedmonkey]

So it only pumps in neutral and drive. I could drop the valve body with it still in the car but might go ahead and just drop the whole thing.

[inkedmonkey]

Went out this morning and it went right into gear. Last night it took 20 min to engage. Guess I need to drop it.

[fulsizjeep]

Wait a sec. The 727 doesn't pump fluid in park. T400 does pump in park.

[wiley-moeracing]

Yes but the anti drain back valve is likely broken inside, either way it will need to come apart to repair.

[inkedmonkey]

Thanks guys, kit is on the way. Yanking the trans later today.

[inkedmonkey]

Lets dig in



I had dropped the pan and changed the filter 150 miles ago. I'd say that it needs rebuilt.



And this brings up a question. Is the bearing in the adapter from trans to transfer case supposed to hang out like this? I can see that it rides in the transfer case, but it just seems wrong to me. My OCD wants to press it in the rest of the way.

[wiley-moeracing]

Just push the bearing in, its fine. Hopefully you got the full kit with steels, clutches and bushings.

[inkedmonkey]

I did, master kit from Rockauto includes everything for $150. Clutches, metals, seals, filter, gaskets, modulator valve, etc.

[rang-a-stang]

...And this brings up a question. Is the bearing in the adapter from trans to transfer case supposed to hang out like this? I can see that it rides in the transfer case, but it just seems wrong to me. My OCD wants to press it in the rest of the way...

Mine was able to be moved by hand. It is not pressed fit and can be removed, cleaned, and re-installed.

[inkedmonkey]

Confirmation that this thing needs some love.



Pump is a little worn.....



Found a cracked intermediate clutch plate.



And the biggest surprise!



How does that even happen? Oh well, luckily I had the guts to another 400 laying around. This looks a little better.



Amazingly all the other parts look undamaged. I have replacement parts on the way then I can slam it back together. In the end, glad I had to take it apart. It needed it.

[rang-a-stang]

Eeewwwwwww!!!!! (Spoken like a 14 year old girl)

It is going to be amazingly better!!