Technical th 400 transmission wont go in gear

Make sure your flex plate isn't installed backwards.

 

I'm 99 percent sure my flex plate is on the correct way but I will double check tomorrow. And my trans is fairly clean I cleaned it before I dropped the engine in I think ill build a quick stand to hold it on its end. Ill just pull the pump and take it to the parts store with me and see if they can match it. I assume my converter should be ok to use?

 

Use a strong magnet to clean out the hob on the converter. You will have to pull the filter out first. I would look for an independent tranny shop to see if they can hook you up with a pump, gaskets and seals.

 

I'm gonna drive to the trans shop in the next town and see if they can get me the parts tomorrow. If they won't does anyone know if shops like napa or advanced auto will be able to get them I've looked online but I can't seem to find anything

 

Most transmission shops will do you an exchange on the converter, beat up or not. At the worse you pay a core charge. Since its been sitting and there are other issues you should replace it.

Bob

 

Yuck !
Get a new/rebuilt converter.
I have a great converter shop local and they rebuild them very reasonably. I've been a gear head forever and had no idea they were there for almost as long.
You might have one too.

 

To remove the front pump take all of the bolts out of it and look for two holes that have threading in them. Thread two short 3/8 coarse thread bolts in and use a rolling head bar to gently pry it loose. As others have mentioned I would not use that convertor again unless I had it flushed. Most tranny shops should be able to do it but a rebuilt convertor might be cheaper.

 

I took the front pump out yesterday luckily I just happened to have a crappy slide hammer my buddy gave me that had the same threads as the front pump so I just uses that with light hits side to side and it pulled right out. Inside the pump I found the gear the drive tangs broke off was broke in half and it hauled the shaft up pretty bad. Don't think it's rebulidable. I drove to a tranny shop I bought some hard to find gaskets from before and there shop is no longer there so today I asked around some more and searched a few guys collections to no avail. I did find one on craigslist for 100 bucks so I'm gonna pick that up I think because just the pump and converters I've found used are at least 50 a piece plus my tranny had some rust on the inside drum part. But I figure if If the craigslist one I'm gonna get turns out no good at least ill have enough parts to rebuild one or have it rebuilt.

 

Well I ended up buying a rebuilt pump off eBay for cheap and put it all together it goes in every gear now and seems to be working but another issue came about. I noticed when I bolted it all together again this time that the space between the flex plate and converter "feet"? Where it bolts to the flexplate was a 1/2 inch. Seems like that's pretty far to pull it out of the pump or is that OK? The drive slots in the converter were only 5/8 deep if I remember correctly i put a couple washers on it to test it out and its working but I don't think I want to drive it like that. I noticed the newer SBC flywheels that are balanced have bumps where the converter bolts to them but the two flex plates I have are flat could this be the issue or should I just pull the washers and be fine without? Don't want to tear nothing up again

 

You can leave the washers in as long as there is some space between the washers and the converter.

 

1/2" is about right for the distance you need to pull the converter forward to meet the flex plate.

 

If that's the case the torque converter will only be engaged an 1/8 inch into the pump is that really enough to drive the pump safely? Or am I missing something.

 

Guess it's ok to just run it with washers?

 

Yes its fine I have done it before never a problem as long as you have some clearance between converter and your washers.

 

Ok cool I'm hoping to get my gas pedal installed and take it for a test drive tomorrow. Didn't want the converter to fly out from under it. I think ill take one of the three washers out though and only run two on each

 

You should be good just use a washer at least as large as the pad on the converter.

 

Why has no one addressed the modulator. If the hose to full vacuum is not hooked up, it won't shift. if the modulator is bad, it won't shift.

 

The gap between the converter and flex plate should be 3/16 to 1/8, any more and shims must be used. Use drill bits as a 'feeler gauge'. 1/2" is too much 'pull-out', you'll risk tearing up the drive tangs on the pump gears, again. Also, make sure the converter pilot and crank pilot hole are clean and mate properly, is the trans is flush to the block? (top to bottom, side to side).
The majority of TH400s use a large flat 'rippled' filter, with either a Dacron (fabric) element or a mesh screen, (the latter is popular in high-flow, high performance situations) either will suit your application, but I prefer the mesh screen, a pan magnet and regular servicing. It sounds like you have a factory deep pan, the filter is supposed to to 'float' between the spacer tube and the head of the long shouldered bolt, no need for washers , springs or other concoctions to 'tighten-up' the filter.

 

Trans is flush to block and I cleaned everything before installing. It has a newer trans filter in it but I'm going to change it again after I put a few miles on it I don't know if the modulator is good or not yet but I have it hooked up and the car has all the gears when in the air I'm not sure if it will shift on its own yet. I used drill bits as someone suggested before and 1/2 would just fit so I used three washers but I'm hoping I can pull at least one out. I just dont want to ruin my new trans pump now that everything seems to be working