Replacing Transmission/Torque Converter

[Jon87V20]

So I finally pulled my transmission over the weekend. To my surprise the bell-housing had a giant crack going through it (see attached photo), and my torque converter seemed to be broken as well (tons of play in it). I was able to find another Turbo 400 and I bought a new torque converter as well. When I was removing the transfer case, I found that the large stabilizer bar that runs from the transfer case to the bell-housing, was only connected on the transfer case side. Someone had removed and/or lost the bolts on the engine side. Could this have been a contributing factor in the transmission case cracking?

Does anyone have any tips for re-installing these, or things to watch out for? It took me months to save up to start putting the truck back together and I want to take all the precautions not to mess anything up as I can't afford to replace these again. It's been suggested to me that I should be sure to flush the transmission cooler before re-connecting it. Is there a way to do this at home in the garage on the cheap? I'm going to replace the engine's rear main seal while I'm in there as it appears to be the cause of a messy leak down there.

Is there any special procedure to installing the torque converter? Do I need to fill it first? How much? Does it need to be seated a certain way to prevent damaging it? Just really nervous about doing something wrong. Also, to make matters worse, I had to cut the exhaust out to get the tranny out, as it was a solid chunk of rust so it's going to be extremely loud when I test it. I won't be able to hear any noises. I'll probably have to wait to fire it up until I have the new exhaust in place I suppose.

When I pulled the rear slip-yoke out of the transfer case, I noticed a bit of fluid on the shaft. Is this normal, or does this indicate that I may need to replace a seal there?

A bombardment of questions here, but I thank you in advance for any advice!

'87 Chevy Suburban V20 350ci TH400 NP208

-Jonathan

[Captkaos]

Are you talking about installing the braces?  If so the go on last.
On the converter I put a couple quarts (enough that it can tilt and not bathe me)  slide it in and with slight pressure turn it until it seats.

Chris Lucas
73-87chevytrucks.com
squarebody.biz

[Jon87V20]

Captain, I was talking about this stabilizer/brace that goes on the side of the t-case (see attached photo). Could not having this attached on both sides cause some kind of stress that could contribute to the transmission case cracking like that?

[VileZambonie]

Loose bellhousing bolts, bad mounts, excessive stress and the like can cause it. The support hooked up will certainly help prevent it from reoccurring but check  your mounts too. You should have 3 engagements of the torque converter, the pump gear, the stator and the turbine. Install it when you are ready to install the transmission as so that it is not hanging on the seal. Lube it with ATF and fill it as Captkaos suggested. When installed you should be able to easily rotate the TC before fastening it to the flexplate. Do no fully tighten all of the bolts until all 3 are in. Use a little thread locker and tighten them fully only after you've tightened all bellhousing bolts. As far as your exhaust goes, just slip on a connector and some exhaust clamps to get you up and running.

[Jon87V20]

Ok thanks. Also, what do you call the gasket between the transmission and t-case where they bolt together?

[hatzie]

The transfer case to bellhousing brace is a good preventative measure.  The intended function of that brace was to keep the bell from cracking.  I wouldn't run her for long without one.

The brace bolt-up is shown in the below illustration as well as the gaskets.  You can also see where they ran the transfer case vent to the rear of the engine...  I ran all my axle, trans, and xfer-case vents up there.
All you need is a longer bellhousing bolt or stud for the bar.  www.gmpartswiki.com/getpage?pageid=56919

The TH400 is RPO M40.

[VileZambonie]

Ok thanks. Also, what do you call the gasket between the transmission and t-case where they bolt together?

It's just called a gasket, no special name for it.

[fitz]

You can use this to clean the cooler & lines.

[Jon87V20]

You can use this to clean the cooler & lines.

Oh nice! I've never seen that before. That definitely makes things easier.


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[Jon87V20]

Ok thanks. Also, what do you call the gasket between the transmission and t-case where they bolt together?

It's just called a gasket, no special name for it.

If I have trouble tracking the gasket down at the store, is this something that I can RTV, or is that a bad idea?


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[Irish_Alley]

go oon ebay and search np208 gasket
http://www.ebay.com/sch/i.html?_odkw=th400+np208+gasket&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xnp208+gasket.TRS0&_nkw=np208+gasket&_sacat=0
me i would use rtv "right stuff"

[VileZambonie]

Anaerobic Sealer

[82silverado]

Anaerobic Sealer

Yup. I tell them that at work all the time. Nobody listens though.

[bd]

Loctite 518

[Jon87V20]

This looks right, correct?

If so do I want to use sealant in conjunction with this, or leave it dry?

http://www.oreillyauto.com/site/c/detail/PIO0/749090/03236.oap?year=1987&make=Chevrolet&model=V20%2BSuburban%2B4WD&vi=5013090&ck=Search_transmission+gasket_C0071_5013090_3825&keyword=transmission+gasket&pt=C0071&ppt=C0338#itemDetailTab_